Patent Publication Number: US-2017362608-A1

Title: COMPOSITIONS AND METHODS FOR THE PRODUCTION OF scAAV

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Patent Application No. 62/091,062, entitled Compositions and Method for the Production of scAAV, filed Dec. 12, 2014, the contents of which are herein incorporated by reference in their entirety. 
    
    
     REFERENCE TO THE SEQUENCE LISTING 
     The present application is being filed along with a Sequence Listing in electronic format. The Sequence Listing file, entitled 1500PCTSEQLST.txt, was created on Dec. 10, 2015 and is 241,930 bytes in size. The information in electronic format of the Sequence Listing is incorporated herein by reference in its entirety. 
     FIELD OF THE INVENTION 
     The present invention relates to compositions and methods for the production of self-complementary genome-containing viral particles with improved transduction efficiencies and gene expression and therapeutic uses of these scAAV, 
     BACKGROUND OF THE INVENTION 
     Viruses of the Parvoviridae family are small non-enveloped icosahedral capsid viruses characterized by a single stranded DNA genome, Parvoviridae family viruses consist of two subfamilies: Parvoviridae, which infect vertebrates, and Densovirinae, which infect invertebrates. 
     Viruses of the Parvoviridae family are used as biological tools due to a relatively simple structure that may be easily manipulated with standard molecular biology techniques. The genome of the virus may be modified to contain a minimum of components for the assembly of a functional recombinant virus, or viral particle, which is loaded with, or engineered to deliver and/or express, a desired payload nucleic acid construct, e.g., a transgene, genome-editing sequence, miR, polypeptide-encoding polynucleotide, or a modulatory nucleic acid. 
     Preclinical studies have demonstrated the efficacy of recombinant adeno-associated virus (rAAV) as payload delivery viral particles, and recently rAAVs have been successfully used in clinical trials of gene therapy. Transduction efficiencies generally range from 25 to several hundred viral genome-containing particles (VGP) per transducing unit, depending on the cell type. However, the transduction efficiency of these viral genomes, in terms of the number of VGP required for transduction, is hindered by the need to convert the single-stranded DNA (ssDNA) genome into double-stranded DNA (dsDNA) prior to expression. 
     This rate-limiting step can be entirely circumvented through the use of scAAV, which package an inverted repeat genome that can fold into dsDNA without the requirement for DNA synthesis or base-pairing between multiple viral genomes. 
     Like all viral particle-based approaches to gene therapy, in addition to the production of large quantities of highly concentrated virus, another obstacle in translating therapies from pre-clinical trials into a human clinical application is the efficient transduction and delivery of the therapeutic payload nucleic acid construct. 
     In view of these issues there remains a need for alternative and improved methods of efficiently, safely, and economically producing viral particles with improved transduction efficiencies. The present invention provides compositions and methods for the production of self-complementary parvoviral genome-containing particles, e.g. scAAV particles, with improved transduction efficiencies and consequently more efficacious therapeutic outcomes. 
     SUMMARY OF THE INVENTION 
     The present disclosure provides compositions and methods for the production of viral particles with improved transduction efficiencies and increased gene expression useful as therapeutic modalities which employ viral delivery methods. Also provided are engineered nucleic acid and vector constructs for viral vector design and production which are useful components for viral particle production methods. Further provided are modified regulatory proteins engineered to improve viral particle transduction efficiencies and increase gene expression used alone or in conjunction with the engineered nucleic acid and vector constructs. The viral particles of the invention comprise one or more engineered polynucleotides or polypeptides as described herein. In addition, the present disclosure provides methods for producing viral particles which comprise one or more engineered polynucleotides or polypeptides, e.g., engineered genomes and/or engineered ITRs and/or engineered regulatory proteins and/or engineered payloads or any combination thereof. 
     The single-stranded nature of the parvoviral genome requires the use of cellular mechanisms to provide a complementary-strand for gene expression, the recruitment of which is considered to be a rate-limiting factor in the efficiency of transduction and gene expression in parvoviruses and parvoviral particles. This problem can be circumvented by packaging both strands as a single duplex DNA molecule. Parvoviral particles comprising such duplexed DNA have been shown to have increased transduction efficiency and a higher level of transgene expression than their single-stranded counterparts. 
     The present disclosure provides parvoviral particles having a duplexed genome resulting from the presence of a self-complementary viral genome sequence which may be packaged in a viral particle. The present disclosure thus provides a parvoviral particle comprising a parvovirus capsid and a parvoviral genome encoding a heterologous nucleotide sequence, e.g., a payload sequence, in which the parvoviral genome may be self-complementary, i.e., forms a dimeric inverted repeat via intra-strand base-pairing. In this manner, a double-stranded sequence may be formed by the base-pairing between complementary heterologous nucleotide sequences, thus producing the requisite structure for gene expression in a host cell without the need for host cell machinery to convert the viral genome into a double-stranded form. 
     Such a parvoviral genome may be formed by employing the use of one or more parvoviral genome sequences that are altered in a manner that results in the formation of a self-complementary viral genome during replication. 
     In one embodiment, the altered parvoviral genome sequence comprises at least one parvoviral inverted terminal repeat (ITR) sequence having an engineered. Rep binding sequence region (eRBSR). In this embodiment, the Rep binding sequence region may be altered such that binding with the Rep protein is decreased. The decrease in Rep binding affects the Rep nicking activity in a manner that promotes the formation of a self-complementary viral genome during replication. 
     In another embodiment, the altered parvoviral genome sequence comprises at least one parvoviral inverted terminal repeat sequence having a chimeric nicking stem loop, which abolishes Rep mediated nicking such that a self-complementary viral genome is formed during replication. 
     In another embodiment, the Rep protein, or polynucleotide sequence encoding the Rep protein, is engineered such that Rep protein binding to its cognate Rep binding sequence region is decreased in a manner that likewise promotes the formation of a self-complementary viral genome during replication. 
     In one embodiment, a parvoviral particle comprising a self-complementary viral genome is provided. The parvoviral particle may comprise a parvoviral capsid and a self-complementary parvoviral genome comprising: a first parvoviral inverted terminal repeat sequence, a first heterologous sequence, a parvoviral inverted terminal repeat nucleotide sequence comprising an engineered Rep binding sequence region, a second heterologous sequence, wherein the second heterologous sequence is complementary to the first heterologous sequence, and a second parvoviral inverted terminal repeat sequence. The viral genome may be capable of intra-strand base-pairing between the heterologous nucleotide sequences. 
     In another embodiment, the parvoviral particle comprises a parvoviral capsid and a self-complementary parvoviral genome comprising: a first parvoviral inverted terminal repeat sequence, a first heterologous sequence, a parvoviral inverted terminal repeat nucleotide sequence comprising a chimeric nicking stem loop, a second heterologous sequence, wherein the second heterologous sequence is complementary to the first heterologous sequence, and a second parvoviral inverted terminal repeat sequence. The viral genome may be capable of intra-strand base-pairing between the heterologous nucleotide sequences. 
     In another embodiment, the parvoviral particle comprises a parvoviral capsid and a self-complementary parvoviral genome comprising: a first parvoviral inverted terminal repeat sequence, a first heterologous sequence, a parvoviral inverted terminal repeat nucleotide sequence comprising an engineered Rep binding sequence region and a chimeric nicking stem loop, a second heterologous sequence, wherein the second heterologous sequence is complementary to the first heterologous sequence, and a second parvoviral inverted terminal repeat sequence. The viral genome may be capable of intra-strand base-pairing between the heterologous nucleotide sequences. 
     In any of the embodiments where the parvoviral particle comprises an engineered Rep binding sequence region and/or a chimeric nicking stern loop, production of the parvoviral particle can optionally further comprise a sequence encoding an engineered Rep protein which binds to the Rep binding sequence region and/or engineered Rep binding sequence region with decreased affinity. 
     The present disclosure additionally provides compositions and methods for improving the transduction efficiency and heterologous gene expression of viral particles having parvoviral polynucleotide sequences (e.g., a parvoviral genome encoding heterologous nucleotide sequence or a payload sequence or a fragment thereof) by altering one or more of several Rep binding activities to effect the production of viral particles having a self-complementary or duplexed genome. As a non-limiting example, the transduction efficiency and heterologous gene expression of viral particles having parvoviral polynucleotide sequences may be increased by altering the Rep binding sequence region and/or by altering the Rep nicking sequence found in parvoviral ITR sequences, and/or altering one or more Rep proteins. Thus, the present disclosure provides, among other things, a parvoviral polynucleotide, such as an adeno-associated viral (AAV) polynucleotide, comprising an engineered Rep binding sequence region and/or an altered Rep nicking sequence. In addition, the present disclosure provides an engineered Rep protein, and a polynucleotide sequence encoding the engineered Rep protein, which can be used independently in the production of a viral particle having a self-complementary or duplexed genome (i.e., with wild-type Rep binding sequence region and wild-type Rep nicking stem loop) or can be used in conjunction with an engineered Rep binding sequence region and/or an altered Rep nicking sequence in the production of a viral particle having a self-complementary or duplexed genome. 
     The present disclosure provides a polynucleotide (e.g., a parvoviral polynucleotide) comprising an engineered Rep binding sequence region (eRBSR). In one embodiment, the eRBSR comprises a sequence in which one or more of the nucleotides are altered or modified as compared to the native or reference Rep binding sequence region. In one embodiment, the eRBSR is altered as a result of one or more nucleotide insertions, deletions, substitutions, or any combination thereof as compared to the native Rep binding sequence region. In another embodiment, the eRBSR is altered by swapping the native Rep binding sequence region with the Rep binding sequence region of a different parvoviral serotype or species. In one embodiment, the entire Rep binding sequence region is swapped. In another embodiment, a portion or partial sequence of the Rep binding sequence region is swapped. In one embodiment, the engineered Rep binding sequence region can comprise a non-native Rep binding sequence region from an AAV viral genome, including, but not limited to, the Rep binding sequence regions of AAV1, AAV2, AAV3, AAV4, AAV5, AAV 5, AAV7, AAV8, AAV9, AAV10, AAV 11, AAV12, AAVrh8, AAVrh10, AAV-DJ, and AAV-DJ8. 
     In one embodiment, one or more of the nucleotides in the eRBSR are chemically modified as compared with the native Rep binding sequence region. In individual embodiments, the chemical modification(s) is on the nucleobase and/or the sugar and/or the phosphate backbone, or any combination thereof. In another embodiment, the eRBSR has one or more altered nucleotides and one or more chemically-modified nucleotides. In one embodiment, the Rep binding to the sequence is decreased. 
     Studies have shown that Rep protein recognizes and binds to a series of about four to five GCTC consensus motifs. Thus, decreased binding with Rep protein can be affected by altering the number and/or position of the GCTC motifs present in the Rep binding sequence region and/or by altering the sequence of the individual GCTC motif(s). Thus, in one embodiment, the eRBSR comprises one to three GCTC consensus motifs. In another embodiment, the eRBSR comprises about one to about five GCTC consensus motifs in which one or more nucleotides in at least one of the GCTC consensus motifs is altered or modified. 
     The present disclosure also provides polynucleotides comprising any of the eRBSRs described herein. In one embodiment, the polynucleotide comprises one or more parvoviral inverted terminal repeat (ITR) sequences wherein one of the ITR sequences comprises an eRBSR. In one embodiment, the polynucleotide comprising at least one parvoviral ITR sequence with an eRBSR is capable of forming a double-stranded Rep binding sequence region. In one embodiment, the engineered Rep binding sequence region is located between a 5′ parvoviral inverted terminal repeat sequence and a 3′ parvoviral inverted terminal repeat sequence. In another embodiment, the engineered Rep binding sequence region is located within a parvoviral inverted terminal repeat sequence. 
     In one embodiment, the polynucleotides described herein comprising the eRBSR can further comprise a heterologous or payload sequence, which can be, for example, a regulatory sequence, a sequence encoding a nucleic acid (e.g., such as a miR or an antisense sequence), or a sequence encoding a polypeptide (e.g., such as a transgene). In one embodiment, the heterologous sequence may be operatively linked to one or more regulatory sequence(s) that allows or controls expression of the heterologous sequence. In one embodiment, the polynucleotide comprises a first ITR sequence comprising an eRBSR and a second ITR sequence, wherein the heterologous sequence is flanked by the first and second ITR sequences, 
     In one embodiment, a parvoviral polynucleotide (e.g., a parvoviral genome) comprises in the 5′ to 3′ direction: (a) a 5′ parvoviral inverted terminal repeat sequence; (b) a first payload encoding region; (c) an engineered Rep binding sequence region; (d) a second payload encoding region; and (e) a 3′ parvoviral inverted terminal repeat sequence. In this embodiment, the first and second payload encoding regions are essentially self-complementary and may form a hairpin structure that comprises the parvoviral polynucleotide. 
     In one embodiment, the parvoviral ITR sequence(s) can be an adeno-associated virus (AAV) ITR or derived from an adeno-associated virus (AAV) ITR. AAV ITR sequences include, but are not limited to, any of those having an AAV1, AAV2, AAV3, AAV4, AAV5, AAV6, AAV7, AAV8, AAV9, AAV10, AAV11, AAV12, AAVrh8, AAVrh10, AAV-DJ, and AAV-DJ8 ITR sequence or a sequence derived therefrom. 
     Another way to promote the generation of self-complementary parvoviral genome sequences is to alter or modify the Rep nicking stem loop such that nicking by the Rep protein is decreased. This alteration or modification can promote the generation of self-complementaty parvoviral genome sequences. The present disclosure thus provides a polynucleotide comprising a chimeric nicking stem loop, in which the native nicking stem loop sequence of one parvoviral serotype or species is substituted or swapped with the nicking stem loop sequence of a different parvoviral serotype or species. In one embodiment, the entire nicking stem loop sequence is swapped. In another embodiment, a portion or partial sequence of the nicking stem loop sequence is swapped. In one embodiment, the chimeric nicking stem loop can comprise a non-native nicking stem loop from an AAV viral genome, including the Rep binding sequence region of AAV1, AAV2, AAV3, AAV4, AAV5, AAV6, AAV7, AAV8, AAV9, AAV 10, AAV11, AAV12, AAVrh8, AAVrh10, AAV-DJ, and AAV-DJ8. 
     The present disclosure also provides a polynucleotide comprising the chimeric nicking stem loop. The polynucleotide comprising the chimeric nicking stem loop can further comprise a heterologous or payload sequence, which can be, for example, a regulatory sequence, a sequence encoding a nucleic acid, or a sequence encoding a polypeptide. In one embodiment, the heterologous sequence is operatively linked to one or more regulatory sequence(s) that allows expression of the heterologous sequence. In one embodiment, the polynucleotide comprises a first ITR sequence comprising a chimeric nicking stem loop and a second ITR sequence, wherein the heterologous sequence is flanked by the first and second ITR sequences. 
     In one embodiment, the disclosure provides a parvoviral polynucleotide (e.g., a parvoviral genome) comprising in the 5′ to 3′ direction: (a) a 5′ parvoviral inverted terminal repeat sequence; (h) a first payload encoding region; (c) a chimeric nicking stem loop sequence; (d) a second payload encoding region; and (e) a 3′ parvoviral inverted terminal repeat sequence. In this embodiment, the first and second payload encoding regions are essentially self-complementary and may form a hairpin structure that comprises the parvoviral polynucleotide. 
     The present disclosure also provides a polypeptide comprising an engineered Rep protein and a polynucleotide encoding the polypeptide comprising the engineered Rep protein. The engineered Rep protein comprises at least one amino acid that may be altered or modified as compared to the corresponding wild-type Rep protein. In one embodiment, the engineered Rep protein comprises one or more amino acids involved with DNA binding that are altered or modified as compared to the corresponding wild-type Rep protein. The engineered Rep protein has decreased binding to its cognate Rep binding sequence region and, as a consequence, promotes the formation of a self-complementary viral genome during replication. 
     The engineered Rep binding sequence region, chimeric nicking stem loop, and engineered Rep protein are each altered and/or modified, and used individually or in combination, such that binding to and/or nicking of the parvoviral ITR sequence is decreased. Thus, the present disclosure provides a parvoviral polynucleotide (e.g., a parvoviral genome) comprising an engineered Rep binding sequence region in which the binding affinity between a Rep protein and the engineered Rep binding sequence region is decreased relative to a parvoviral polynucleotide (e.g., a parvoviral genome) comprising the native Rep binding sequence region. The present disclosure provides a parvoviral polynucleotide (e.g., a parvoviral genome) comprising an engineered Rep binding sequence region in which the binding affinity between an engineered Rep protein and the engineered Rep binding sequence region is decreased relative to a parvoviral polynucleotide (e.g., a parvoviral genome) comprising the native Rep binding sequence region. 
     The present disclosure also provides a parvoviral polynucleotide (e.g., a parvoviral genome) encoding an engineered Rep protein in which the binding affinity between the engineered Rep protein and a Rep binding sequence region is decreased relative to a parvoviral polynucleotide a parvoviral genome) encoding the native Rep protein. The present disclosure additionally provides a parvoviral polynucleotide (e.g., a parvoviral genome) encoding an engineered Rep protein in which the binding affinity between the engineered Rep protein and an engineered Rep binding sequence region is decreased relative to a parvoviral polynucleotide (e.g., a parvoviral genome) encoding the native Rep protein. 
     The present disclosure further provides a parvoviral polynucleotide (e.g., a parvoviral genome) comprising an engineered Rep binding sequence region and/or a chimeric nicking stern loop in which the nicking by a Rep protein is decreased relative to a parvoviral polynucleotide (e.g., a parvoviral genome) comprising the native Rep binding sequence region and/or native Rep nicking stem loop. The present disclosure also provides a parvoviral polynucleotide (e.g., a parvoviral genome) comprising an engineered. Rep binding sequence region and/or chimeric nicking stem loop in which the nicking by an engineered Rep protein is decreased relative to a parvoviral polynucleotide (e.g., a parvoviral genome) comprising the native Rep binding sequence region and/or native Rep nicking stern loop. 
     The present disclosure also provides a parvoviral polynucleotide (e.g., a parvoviral genome) encoding an engineered Rep protein in which the nicking of the native Rep nicking stem loop is decreased relative to a parvoviral polynucleotide (e.g., a parvoviral genome) encoding the native Rep protein. The present disclosure additionally provides a parvoviral polynucleotide (e.g., a parvoviral genome) encoding an engineered Rep protein in which the nicking of the chimeric nicking stem loop Rep is decreased relative to a parvoviral polynucleotide (e.g., a parvoviral genome) encoding the native Rep protein. 
     The present disclosure also provides a parvoviral polynucleotide (e.g., a parvoviral genome) comprising an engineered Rep binding sequence region and/or a chimeric nicking stem loop in which a self-complementary (SC) parvoviral polynucleotide (e.g., a parvoviral genome) is produced during genome replication. The present disclosure also provides a parvoviral polynucleotide (e.g., a parvoviral genome) encoding an engineered Rep protein in which a self-complementary (SC) parvoviral polynucleotide (e.g., a parvoviral genome) is produced during genome replication. 
     The present disclosure provides a method of delivering to a cell or tissues a parvoviral particle comprising a payload, which method comprises contacting the cell or tissue with the parvoviral particle. The method of delivering the parvoviral particle to a cell or tissue can be accomplished using in vitro, ex vivo, or in vivo methods. 
     The present disclosure additionally provides a method of delivering to a subject, including a mammalian subject, parvoviral particle described herein, which method comprises administering to the subject the parvoviral particle. 
     The present disclosure additionally provides a method for treating a disease, disorder and/or condition in a mammalian subject, including a human subject, comprising administering to the subject parvoviral payload particle described herein. In one embodiment, the disease, disorder and/or condition is a neurological disease, disorder and/or condition. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       The foregoing and other objects, features and advantages will be apparent from the following description of particular embodiments of the invention, as illustrated in the accompanying drawings. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of various embodiments of the invention. 
         FIG. 1  is a schematic showing the structure of the self-complementary parvoviral genome that is produced by a parvoviral payload construct comprising an engineered Rep binding sequence region (eRBSR). 
         FIG. 2  is a schematic showing the structure of the 3′ ITR from AAV2 (SEQ ID NO: 242). The strands of the double stranded Rep binding sequence region are underlined (SEQ II) NO: 1 and SEQ ID NO: 2), the terminal resolution site is bolded; and the nicking stein loop (SEQ ID NO: 199) is double-underlined. 
         FIG. 3  shows an alignment of 5′ and 3′ ITR sequences from selected AAV sequences aligned to AAV2 ITR sequence. Rep binding sequence regions are underlined and the nicking stem loop sequences are boxed. 
         FIG. 4  shows an alignment of 5′ and 3′ ITR sequences from selected AAV sequences aligned to AAV5 ITR sequence, Rep binding sequence regions are underlined and the nicking stem loop sequences are boxed. 
         FIG. 5  is a PRIOR ART schematic depicting an example of parvovirus (AAV) replication in which single-stranded genomes are derived and showing the various unprocessed replicative intermediates that produce self-complementary genomes. The figure is from N. L. Craig et al.  Mobile DNA II . ASM Press, Washington, D.C. 2002, the contents of which are herein incorporated by reference in their entirety. 
         FIG. 6A  is a schematic diagram of a polynucleotide having a swapped nicking stem loop payload construct (SEQ ID NO: 76).  FIG. 6B  is a schematic diagram comprising the AAV5 Rep nicking stem loop sequence (SEQ ID NO: 77) and the AAV2 Rep nicking stem loop sequence (SEQ ID NO: 312) inserted into an AAV2 3′ ITR sequence (SEQ ID NO: 78), 
         FIG. 7  is a schematic depicting a 3-dimensional model showing Rep protein binding to the Rep binding domain of the AAV5 ITR. Arrows indicate amino acid and nucleic acid residues involved in binding affinity. 
         FIG. 8  shows an alignment of selected AAV Rep protein sequences aligned to AAV5 Rep protein. Beta sheet 4 and Beta sheet 5 sequence regions are underlined; alpha helix C sequences are bold, residues involved in binding to the Rep binding sequence region are boxed. 
         FIG. 9  is a diagram depicting the steps involved in scAAV viral particle production. 
         FIG. 10  is a diagram depicting the steps involved in scAAV viral particle production divided by the stages of production. 
         FIG. 11A - FIG. 11F  are schematic diagrams of polynucleotides comprising an engineered Rep binding sequence region and in which the eRBSR sequences are underlined.  FIG. 11A  is a schematic diagram comprising an α-pal payload construct (SEQ II) NO: 67).  FIG. 11B  is a schematic diagram comprising α-pal sequence (SEQ ID NO: 68) inserted into the Rep binding sequence region of an AAV2. ITR sequence (SEQ ID NO: 69).  FIG. 11C  is a schematic diagram comprising the 5-5/EGR payload construct (SEQ ID NO: 70). FIG. I ID is a schematic diagram comprising 5-5/EGR sequence (SEQ ID NO: 71) inserted into the Rep binding sequence region of an AAV2. ITR sequence (SEQ ID NO: 72).  FIG. 11E  is a schematic diagram comprising the JcDNV NS1 payload construct (SEQ ID NO: 73).  FIG. 11F  is a schematic diagram comprising JcDNV NS1 sequence (SEQ ID NO: 74) inserted into the Rep binding sequence region of an AAV2 ITR sequence (SEQ ID NO: 75). 
     
    
    
     DETAILED DESCRIPTION 
     Like all parvoviruses, the adeno-associated (AAV) genome is packaged as a linear ssDNA molecule with palindromic inverted terminal repeat (ITR) sequences forming dsDNA hairpin structures at each end. The wild-type AAV2 genome encodes four replication proteins from a single Rep gene open reading frame, three capsid proteins from a single Cap gene open reading frame and a viral assembly protein (APP). The self-complementary ITR sequences serve as priming sites for host-cell DNA polymerase to begin synthesis of the second (complementary) strand and as replication origins during productive infection. Thus, the wild-type replication scheme of AAV requires de novo synthesis of the complementary DNA strand before subsequent steps of genome replication and genome transcription can begin. The second strand synthesis is considered to be one of several blocks to efficient infection. 
     Transduction of a target cell by wild-type AAV is dependent on a stepwise series of events including, but not limited to, cell surface binding, endocytic uptake, endosomal escape, nuclear entry, capsid uncoating, release of the ssDNA genome, second strand synthesis, transcription of the genome, and replication of the genome (Murlidharan et al. 2014, Frontiers in Molecular Neuroscience. 2014 Sep. 19; 7:76; the contents of which are herein incorporated by reference their entirety). In addition to the few gene products of the AAV genome, productive wild-type AAV infection is dependent on the presence of adenovirus co-infection which supplies helper genes E1a, E1b, E2a, E4, and VA. These helper genes provide transactivation activity, aid in transcription of the AAV genome, and facilitate AAV mRNA processing. 
     Replication of wild-type ssDNA AAV genomes begins at the 3′ end of the genome where the self-complementary portion of the ITR forms a double stranded region that acts as a primer for the initiation of DNA synthesis. Replication continues in the 5′ to 3′ direction until a double stranded hairpin structure has been formed with a loop at one end. Rep protein binds to the Rep binding sequence region near the end of the hairpin comprising the loop and nicks the DNA, allowing the resolution of the loop and formation of a linear double stranded DNA molecule. The complementary strands are then separated and the replication cycle continues on both resultant strands of ssDNA, 
     Self-complementary or scAAV is formed in the event that Rep protein does not nick the DNA. Replication of the genome may still proceed by an alternative pathway wherein the complementary strands of the hairpin are separated, forming a replication species that comprises an ITR on either end and an ITR region in the center of the ssDNA strand. An AAV genome comprising scAAV is efficiently packaged within a viral capsid and transduces target cells wherein the double stranded genome that is delivered does not require the rate limiting second strand synthesis step before expression of the payload. 
     Recombinant adeno-associated virus (rAAV) comprises the minimal number of components to produce a non-replicative virus designed to deliver a payload to a target cell. The genome of the rAAV is comprised of ITRs flanking a payload sequence that replaces the wild-type Rep and Cap genes. Genes provided in trans for AAV replication comprise Rep and Cap genes expressing the three capsid proteins VP1, VP2, and VP3 and the non-structural protein. Rep78. The ITR sequences are the only required cis acting element required for AAV replication. 
     I. SELF-COMPLEMENTARY ADENO-ASSOCIATED VIRUS (SCAAV) 
     The present disclosure provides compositions and methods for the production of viral particles (e.g., parvoviral particles) with improved transduction efficiencies and gene expression. 
     The single-stranded nature of the parvoviral genome requires the use of cellular mechanisms to provide a complementary strand for gene expression. Recruitment of cellular factors and second strand synthesis are considered to be the rate-limiting factors in the efficiency of transduction and gene expression in parvoviral particles. This problem can be circumvented by packaging both strands as a single duplex DNA molecule. 
     The scAAV duplex molecule of the invention is produced by engineering certain components of the AAV genome to promote the generation of scAAV during the replication process. In one non-limiting example of the invention, the payload construct polynucleotide sequences encoding an ITR are altered to comprise an engineered Rep binding sequence region (eRBSR) that promotes production of self-complementary genomes during genome replication ( FIG. 1 ). The final self-complementary ssDNA genome comprises in the 5′ to 3′ direction an ITR, a first complementary payload sequence, an ITR comprising an engineered Rep binding sequence region, a second complementary payload sequence, and an ITR. The ssDNA spontaneously folds to form a double stranded hairpin comprising an engineered Rep binding sequence region forming a closed loop at one end of the molecule, a double stranded DNA payload encoding region, and at least two ITR hairpins at the end of the molecule opposite the closed end. 
     The present disclosure provides viral particles, e.g., parvoviral particles, comprising a duplexed genome resulting from the presence of a self-complementary viral genomic sequence which is packaged in a single viral particle. In general, the parvovirus particle comprises a parvovirus capsid and a parvoviral genome encoding a heterologous nucleotide sequence, e.g. a payload sequence, in which the parvoviral genome is self-complementary. Such parvoviral particles are produced by employing the use of different parvoviral genome sequences that are altered in a manner that result in the formation of a self-complementary viral genome during replication. For example, a parvoviral particle comprising a parvoviral capsid and a duplexed genome can be produced using a parvoviral inverted terminal repeat nucleotide sequence comprising an engineered Rep binding sequence region which has decreased binding with its cognate Rep protein during viral replication. Similarly, a parvoviral particle comprising a parvoviral capsid and a duplexed genome can be produced using a parvoviral inverted terminal repeat nucleotide sequence comprising a chimeric nicking stem loop which has decreased nicking activity during viral replication. Parvoviral particles having a duplexed genome can also be produced using a sequence encoding an engineered Rep protein which binds to the Rep binding sequence region with decreased affinity. The parvoviral particles of the invention can further be produced using a combination of these nucleotide sequence components which can function individually or in combination to produce the parvoviral particles having duplexed genome. 
     Parvoviral ITRs are palindromic sequences, comprising complementary, symmetrically arranged sequences referred to as “A,” “B,” “C” and regions ( FIG. 2 ). The ITR functions as an origin of replication comprising recognition sites for replication proteins Rep 78 and Rep68. The “D” region of the ITR is an asymmetrical region of the ITR where DNA replication initiates and provides directionality to the nucleic acid replication step. 
     Rep78 and Rep68 function in two distinct roles as part of a replication mechanism that is characteristic of Rep proteins from parvoviruses. Rep78 and Rep68 comprise both exonuclease activity and DNA helicase activity. Rep exonuclease activity comprises the steps of binding to a specific site within the ITR and nicking the DNA phosphodiester backbone at a specific location. Either Rep78 and/or Rep68 bind to unique and known sites within the ‘A’ region of the ITR (FIG,2). The Rep binding sequence region comprises a sequence of repeated consensus ‘GCTC’ motifs located on the ‘A’ region of the ITR hairpin. The ‘A’ region of the AAV genome is a dsDNA region formed by base pairing of two complementary ssDNA sequence regions encoded in the ITR. The nicking stern loop region is comprised of a sequence that spans the border of the dsDNA ‘A’ and ssDNA ‘D’ regions that further comprises a specific nicking stem loop of the DNA backbone at the border of the ‘A’ and ‘D’ regions. In a second mode of activity, Rep78 or Rep68 exerts an ATP-dependent helicase activity for unwinding double-stranded DNA. Consequently, Rep78 and Rep68 act to break and unwind the hairpin structures on the end of the parvoviral genome, thereby providing access to replication machinery of the viral replication cell. 
     A single ITR may be engineered with Rep binding sites or sequence regions on both strands of the A regions and two symmetrical I) regions on each side of the ITR palindrome. Such an engineered construct on a double-stranded circular DNA template allows Rep78 or Rep68 initiated nucleic acid replication that proceeds in both directions. A single ITR is sufficient for AAV replication of a circular vector. 
     Although similar to other AAV serotypes in many respects, AAV5 differs from other human and simian AAV serotypes more than other known human and simian serotypes. For example, AAV5 Rep and ITR sequences are unable to efficiently cross-complement corresponding Rep and ITR sequences from AAV2 in mammalian cells. See, e.g., Chiorini et al., J. Virol., 73(5):4293-4298 (1999) and Chiorini et al., J. Virol., 73(2):1309-1.319 (1999) the contents of which are herein incorporated by reference in their entirety. This lack of functional homology in AAV5 Rep and ITR sequences may be due to the relatively significant differences in the nucleotide and amino acid sequences of AAV5 from the corresponding sequences of other AAV serotypes. See, e.g., Bantel-Schaal et al., J. Virol., 73(2):939-947 (1999) the contents of which are herein incorporated by reference in their entirety. 
     To identify the Rep binding sequence regions at the genomic sequence level, the genome sequences of several different AAV serotypes and species including AAV1, AAV2, AAV3, AAV4, AAV5, AAV7, AAV8, Bat AAV, Bovine AAV, Snake AAV, Avian AAV DA-1, and Avian AAV VR865 (SEQ ID NO: 280-291) were obtained from the NCBI Genome database. The 5′ and 3′ inverted terminal repeat sequences of selected genomes were aligned with the Clustal Omega multiple sequence alignment program using either AAV2 or AAV5 as the parent sequence, as shown in  FIG. 3  and FIG, 4, respectively. Additional Rep binding sequence regions found in the ITR sequences of other parvoviral serotypes and species, including AAV8 5′ ITR (SEQ ID NO: 253), AAV8 3′ ITR (SEQ ID NO: 254), Bat AAV 5′ ITR (SEQ ID NO: 261). Bat AAV 3′ ITR (SEQ ID NO: 262) are obtained in the same manner using this alignment program. 
     Based on the genomic sequence alignments, two groups of Rep binding sequence regions, “AAV2-like” and “AAV5-like,” were identified as regions of interest.  FIG. 3  shows the sequences having the AAV2-like Rep binding sequence region and  FIG. 4  shows the sequences having the AAV5-like Rep binding sequence region, in which the underlined regions represent the complementary Rep binding sequence in the 5′ and 3′ ITR regions. The Rep binding sequence regions share a consensus GCTC motif that is repeated four to five times. In total, the identified consensus Rep binding sequence regions are about 16-20 nucleotides in length. 
     In one embodiment, the altered parvoviral genome sequence comprises an engineered Rep binding sequence region. In this embodiment, the Rep binding sequence region is altered such that binding with its cognate Rep protein is decreased. Decreasing Rep binding to the Rep binding sequence region reduces the ability of the Rep protein exonuclease to successfully nick the DNA at the Rep nicking stem loop. Failure of the Rep protein to successfully nick DNA promotes an alternative pathway of genome replication and formation of a self-complementary viral genome during replication. 
     The affinity of Rep protein for a Rep binding sequence region is described as the affinity constant or K D . The kinetics of binding between a Rep protein and a polynucleotide comprising a Rep binding sequence region is a dynamic process defined by the rate of association (k a ) and the rate of dissociation (k d ). The affinity constant (K D ) is determined by the following formula: K D =k d /k a . At equilibrium, the rate of protein-DNA association is equal to the rate of dissociation wherein the measurement of reaction rate constants are used to define an equilibrium constant 1/K D . Due to the inverse nature of this constant, a smaller affinity constant represents a greater binding affinity. The affinity constant describing the binding of an engineered Rep binding sequence region and a Rep protein will be larger than the affinity constant describing the binding of a wild-type Rep binding sequence region and a Rep protein. 
     Replication of ssDNA AAV genomes begins at the 3′ end of the genome where the self-complementary portion of the ITR forms a double stranded region that acts as a primer for the initiation of DNA synthesis, Replication continues in the 5′ to 3′ direction until a double stranded hairpin structure called the replicative form monomer (RF M ) has been formed with a loop at one end ( FIG. 5 ). Rep protein binds to the Rep binding sequence region near the end of the hairpin comprising the loop, and nicks the DNA, allowing the polymerase to replicate the loop and form a linear double stranded DNA molecule. The complementary strands are then separated by Rep protein to allow reformation of the ITR complementary loop and the replication cycle continues on both resultant strands of ssDNA. 
     In the event that the RF M  species is not nicked by Rep protein, an alternative replication process is used. The 3′ end of the molecule reforms the ITR complementary loop and replication continues along the length of the molecule, forming the replicative form dimer duplex (RF D ). The RF D  species may be resolved by two different pathways. In the first pathway, productive nicking of the RF D  species on both strands results in two copies of the RF M  species. In the second pathway, the RF D  species reforms the ITR complementary loop allowing replication and formation of a 2× RF D  species. Productive nicking of the 2× RF D  species results in two copies of the RF D  species. 
     An AAV genome comprising one engineered Rep binding sequence region with decreased affinity for Rep protein and one wild-type Rep binding sequence region prevents productive nicking. A lack of binding to the engineered Rep binding sequence region reduces nicking and promotes replication of the RF M  species by the alternative pathway. In the resultant RF D  species, the position of the engineered Rep binding sequence region reduces Rep binding and promotes productive replicative cycling of the RF D  species. In the second cycle of RF D  species replication a wild-type Rep binding sequence region is positioned to promote nicking and results in two copies of the RF D  species. 
     Viral particles. e.g., AAV particles, produced from viral genomes comprising wild-type ITR regions are observed to contain both single stranded and self-complementary viral genomes. Self-complementary AAV genomes are derived from unprocessed replicative intermediates. The nucleic acid content of recombinant AAV analyzed by analytical ultracentrifugation has shown that although the Raleigh interference curves for DNA species with sedimentation coefficients of 84S and 106S indicate similar particle numbers, the 106S absorbance at 260 nm is 1.6 times greater than the 84S peak. The difference in absorbance peak area indicates greater nucleic acid content in the 106S peak. Thus, approximately half of the viral particles contain a self-complementary genome that is 1.6 times as large as the single stranded genome. 
     Intermediate replicative species are successfully packaged in virus particles. AAV viral particles produced in vitro are collected by ultracentrifugation and the DNA genomes isolated by standard molecular biology techniques known in the art. The genomes are separated by denaturing (alkaline) gel electrophoresis. Analysis of the DNA content banding pattern has shown multiple sizes of viral genomes including scAAV, scAAV intermediate species, ssAAV monomer, and an ssAAV repaired from scAAV. 
     In accordance with the present disclosure, a parvoviral particle comprising a duplexed genome is provided. In one embodiment, the parvoviral particle comprises a parvoviral capsid and a viral genome comprising: a first parvoviral inverted terminal repeat sequence, a first heterologous sequence, a parvoviral inverted terminal repeat nucleotide sequence comprising an engineered Rep binding sequence region, a second heterologous sequence, wherein the second heterologous sequence is complementary to the first heterologous sequence, and a second parvoviral inverted terminal repeat sequence. The viral genome is capable of intra-strand base-pairing between the heterologous nucleotide sequences upon release from the parvoviral capsid. The parvoviral particle can optionally further comprise a sequence encoding an engineered Rep protein which binds to the Rep binding sequence region and/or engineered Rep binding sequence region with decreased affinity, 
     In another embodiment, the parvoviral particle comprises a parvoviral capsid and a parvoviral genome comprising: a first parvoviral inverted terminal repeat sequence, a first heterologous sequence, a parvoviral inverted terminal repeat nucleotide sequence comprising a chimeric nicking stem loop, a second heterologous sequence, wherein the second heterologous sequence is complementary to the first heterologous sequence, and a second parvoviral inverted terminal repeat sequence. The parvoviral particle can further comprise a sequence encoding an engineered Rep protein which binds to the Rep binding sequence region and/or engineered Rep binding sequence region with decreased affinity. 
     The present disclosure additionally provides compositions and methods for improving the transduction efficiency and heterologous gene expression of viral particles having parvoviral polynucleotide sequences by altering one or more of several Rep binding activities to effect the production of viral particles having a self-complementary or duplexed genome, for example, by altering the Rep binding sequence region, and/or by altering one or more Rep proteins, and/or by altering the Rep nicking sequence found in parvoviral ITR sequences. Thus, the present disclosure provides, among other things, a parvoviral polynucleotide, such as an adeno-associated viral (AAV) polynucleotide, comprising an engineered Rep binding sequence region and/or an altered Rep nicking sequence. In addition, the present disclosure provides an engineered Rep protein, and a polynucleotide sequence encoding the engineered Rep protein, which can be used independently in the production of a viral particle having a self-complementary or duplexed genome (i.e., with wild-type Rep binding sequence region and wild-type Rep nicking stem loop) or can be used in conjunction with an engineered Rep binding sequence region and/or an altered Rep nicking sequence in the production of a viral particle having a self-complementary or duplexed genome. 
     II. ENGINEERED REP BINDING SEQUENCE REGION (ERBSR) AND POLYNUCLEOTIDES 
     One way to promote the generation of self-complementary parvoviral genome sequences is to alter or modify the Rep binding sequence region such that Rep binding is decreased, thus affecting the nicking activity of the Rep protein and consequently promoting the generation of self-complementary parvoviral genome sequences. Accordingly, the present disclosure provides a nucleic acid comprising an eRBSR in which one or more of the nucleotides in the engineered Rep binding sequence region are altered or modified as compared to the native or wild-type Rep binding sequence region. 
     As used herein, the term “altered nucleotide” or the term “altered” as it is used to describe a nucleotide, refers to a nucleotide that differs from the native nucleotide found at the same sequence position in a nucleic acid or polynucleotide sequence, including an eRBSR or polynucleotide comprising an eRBSR. The altered nucleotide can contain any naturally or non-naturally occurring nucleoside selected from adenosine, guanosine, uridine, cytidine, thymidine, as long as it differs from the native nucleoside. Any known method can be used to produce an eRBSR having one or more of the altered nucleotides. In one embodiment, the altered nucleotide is designed in silica and manufactured by methods standard in the art including solid phase synthesis. In one embodiment, the altered nucleotide is designed in silico and manufactured by the phosphoramidite method of solid state synthesis. 
     As used herein, there term “modified nucleotide” or the term “modified” as it is used to describe a nucleotide, refers to a nucleotide that has been chemically modified. The present disclosure provides for modified nucleosides and nucleotides. As described herein “nucleoside” is defined as a compound containing a sugar molecule (e.g., a pentose or ribose) or a derivative thereof in combination with an organic base (e.g., a purine or pyrimidine) or a derivative thereof (also referred to herein as “nucleobase”). As described herein, “nucleotide” is defined as a nucleoside including a phosphate group. The modified nucleotides may by synthesized by any useful method, as described herein (e.g., chemically, enzymatically, or recombinantly to include one or more modified or non-natural nucleosides). The chemical modification can be on the nucleobase, and/or the sugar, and/or on the backbone of the nucleotide. The chemical modification can be any chemical modification used to modify nucleic acid. 
     The modified nucleotides can be modified on the sugar of the nucleic acid. In some embodiments, chemical modifications include for example, the 2′ hydroxyl group (OH) can be modified or replaced with a number of different substituents. Exemplary substitutions at the 2′-position include, but are not limited to, H, halo, optionally substituted C1-6 alkyl; optionally substituted C1-6 alkoxy; optionally substituted C6-10 aryloxy; optionally substituted C3-8 cycloalkyl; optionally substituted C3-8 cycloalkoxy; optionally substituted C6-10 aryloxy; optionally substituted C6-10 aryl-C1-6 alkoxy, optionally substituted C1-12 (heterocyclyl)oxy, a sugar (e.g., ribose, pentose, or any described herein); a polyethyleneglycol (PEG), —O(CH2CH2O)nCH2CH2OR, where R is H or optionally substituted alkyl, and n is an integer from 0 to 20 (e.g., from 0 to 4, from 0 to 8. from 0 to 10, from 0 to 16, from 1 to 4, from 1 to 8, from 1 to 10, from 1 to 16, from 1 to 20, from 2 to 4, from 2 to 8, from 2 to 10, from 2 to 16, from 2 to 20, from 4 to 8, from 4 to 10, from 4 to 16, and from 4 to 20); “locked” nucleic acids (LNA) in which the 2′-hydroxyl is connected by a C1-6 alkylene or C1-6 heteroalkylene bridge to the 4′-carbon of the same ribose sugar, where exemplary bridges included methylene, propylene, ether, or amino bridges; aminoalkyl, aminoalkoxy, amino, and amino acid. 
     Further examples include replacement of the oxygen in ribose (e.g., with S, Se, or alkylene, such as methylene or ethylene); addition of a double bond (e.g., to replace ribose with cyclopentenyl or cyclohexenyl); ring contraction of ribose (e.g., to form a 4-membered ring of cyclobutane or oxetane); ring expansion of ribose (e.g. ;  to form a 6- or 7-membered ring having an additional carbon or heteroatom, such as for anhydrohexitol, altritok mannitol, cyclohexanyl, cyclohexenyl, and morpholino that also has a phosphoramidate backbone); multicyclic forms (e.g., tricyclo; and “unlocked” forms, such as glycol nucleic acid (GNA) (e.g., R-GNA or S-GNA, where ribose is replaced by glycol units attached to phosphodiester bonds), threose nucleic acid (TNA, where ribose is replace with α-L-threofuranosyl-(3′→2′)) , and peptide nucleic acid (PNA, where 2-amino-ethyl-glycine linkages replace the ribose and phosphodiester backbone) The sugar group can also contain one or more carbons that possess the opposite stereochemical configuration than that of the corresponding carbon in ribose. 
     The modified nucleotide base pairing encompasses not only the standard adenosine-thymine, adenosine-uracil, or guanosine-cytosine base pairs, but also base pairs formed between nucleotides and/or modified nucleotides comprising non-standard or modified bases, wherein the arrangement of hydrogen bond donors and hydrogen bond acceptors permits hydrogen bonding between a non-standard base and a standard base or between two complementary non-standard base structures. One example of such non-standard base pairing is the base pairing between the modified nucleotide inosine and adenine, cytosine or uracil. 
     The modified nucleotides can be modified on the nucleobase of the nucleic acid. Examples of nucleobases include, but are not limited to, adenine, guanine, cytosine, thymine, and uracil. 
     In some embodiments, the modified nucleobase is a modified uracil. Exemplary nucleobases and nucleosides having a modified uracil include pseudouridine (ψ), pyridin-4-one ribonucleoside, 5-aza-uridine, 6-aza-uridine, 2-thio-5-aza-uridine, 2-thio-uridine (s2U), 4-thio-uridine (s4U), 4-thio-pseudouridine, 2-thio-pseudouridine, 5-hydroxy-uridine (hoSU), 5-aminoallyl-uridine, 5-halo-uridine (e.g., 5-iodo-uridine or 5-bromo-uridine), 3-methyl-uridine (m3U), 5-methoxy-uridine (mo5U), uridine 5-oxyacetic acid (cmo5U), uridine 5-oxyacetic acid methyl ester (mcmo5U), 5-carboxymethyl-uridine (cm5U), 1-carboxymethyl-pseudouridine, 5-carboxyhydroxymethyl-uridine (chm5U), 5-carboxyhydroxymethyl-uridine methyl ester (mchm5U), 5-methoxycarbonylmethyl-uridine (mcm5U), 5-methoxycarbonylmethyl-2-thio-uridine (mcm5s2U), 5-aminomethyl-2-thio-uridine (nm5s2U), 5-methylaminomethyl-uridine (mnm5U), 5-methylaminomethyl-2-thio-uridine (mnm5s2U), 5-methylaminomethyl-2-seleno-uridine (mnm5se2U), 5-carbamoylmethyl-uridine (ncm5U), 5-carboxymethylaminomethyl-uridine (cmnm5U), 5-carboxymethylaminomethyl-2-thio-uridine (cmnm5s2U), 5-propynyl-uridine, 1-propynyl-pseudouridine, 5-taurinomethyl-uridine (τm5U), 1-taurinomethyl-pseudouridine, 5-taurinomethyl-2-thio-uridine(τm5s2U), 1-taurinomethyl-4-thio-pseudouridine, 5-methyl-uridine (m5U, i.e., having the nucleobase deoxythymine), 1-methylpseudouridine (m1ψ), 5-methyl-2-thio-uridine (m5s2U), 1-methyl-4-thio-pseudouridine (m1s4ψ), 4-thio-1-methyl-pseudouridine, 3-methyl-pseudouridine m3ψ), 2-thio-1-methyl-pseudouridine, 1-methyl-1-deaza-pseudouridine, 2-thio-1-methyl-1-deaza-pseudouridine, dihydrouridine (D), dihydropseudouridine, 5,6-dihydrouridine, 5-methyl-dihydrouridine (m5D), 2-thio-dihydrouridine, 2-thio-dihydropseudouridine, 2-methoxy-uridine, 2-methoxy-4-thio-uridine, 4-methoxy-pseudouridine, 4-methoxy-2-thio-pseudouridine, N1-methyl-pseudouridine (also known as 1-methylpseudouridine (m1ψ)), 3-(3-amino-3-carboxypropypuridine (acp3U), 1-methyl-3-(3-aniino-3-carboxypropyppseudouridine (acp3 ψ), 5-(isopentenylaminomethyl)uridine (inm5U), 5-(isopentenylaminomethyl)-2-thio-uridine (inm5s2U), α-thio-uridine, 2′-O-methyl-uridine (Um), 5,2′-O-dimethyl-uridine (m5Um), 2′-O-methyl-pseudouridine (ψm), 2-thio-2′-O-methyl-uridine (s2Um), 5-methoxycarbonylmethyl-2′-O-methyl-uridine (mcm5Um), 5-carbamoylmethyl-2′-O-methyl-uridine (ncm5Um), 5-carboxymethylaminomethyl-2′-O-methyl-uridine (cmnm5Um), 3,2′-O-dimethyl-uridine (m3Um), 5-(isopentenylaminomethyl)-2′-O-methyl-uridine (inm5Um), 1-thio-uridine, deoxythymidine, 2′-F-ara-uridine, 2′-F-uridine, 2′-OH-ara-uridine, 5-(2-carbomethoxyvinyl) uridine, and 5-[3-(1-E-propenylamino)uridine. 
     In some embodiments, the modified nucleobase is a modified cytosine. Exemplary nucleobases and nucleosides having a modified cytosine include 5-aza-cytidine, 6-aza-cytidine, pseudoisocytidine, 3-methyl-cytidine (m3C), N4-acetyl-cytidine (ac4C), 5-formyl-cytidine (f5C), N4-methyl-cytidine (m4C), 5-methyl-cytidine (m5C), 5-halo-cytidine (e.g., 5-iodo-cytidine). 5-hydroxymethyl-cytidine (hm5C), 1-methyl-pseudoisocytidine, pyrrolo-cytidine, pyrrolo-pseudoisocytidine, 2-thio-cytidine (s2C), 2-thio-5-methyl-cytidine, 4-thio-pseudoisocytidine, 4-thio-1-methyl-pseudoisocytidine, 4-thio-1-methyl-1-deaza-pseudoisocytidine, 1-methyl-1-deaza-pseudoisocytidine, zebularine, 5-aza-zebularine, 5-methyl-zebularine, 5-aza-2-thio-zebularine, 2-thio-zebularine, 2-methoxy-cytidine, 2-methoxy-5-methyl-cytidine, 4-methoxy-pseudoisocytidine, 4-methoxy-1-methyl-pseudoisocytidine, lysidine (k2C), α-thio-cytidine, 2′-O-methyl-cytidine Cm), 5,2′-O-dimethyl-cytidine (m5Cm), N4-acetyl-2′-O-methyl-cytidine ac4Cm), N4,2′-O-dimethyl-cytidine (m4Cm), 5-formyl-2′-O-methyl-cytidine (f5Cm), N4,N4,2′-O-trimethyl-cytidine (m42C), 1-thio-cytidine, 2’-F-ara-cytidine, 2′-F-cytidine, and 2′-OH-ara-cytidine. 
     In some embodiments, the modified nucleobase is a modified adenine. Exemplary nucleobases and nucleosides having a modified adenine include 2-amino-purine, 2,6-diaminopurine, 2-amino-6-halo-purine (e.g., 2-amino-6-chloro-purine), 6-halo-purine (e.g., 6-chloro-purine), 2-amino-6-methyl-purine, 8-azido-adenosine, 7-deaza-adenine, 7-deaza-8-aza-adenine, 7-deaza-2-amino-purine, 7-deaza-8-aza-2-amino-purine, 7-deaza-2,6-diaminopurine, 7-deaza-8-aza-2,6-diaminopurine, 1-methyl-adenosine (m1A), 2-methyl-adenine (m2A), N6-methyl-adenosine (m6A), 2-methylthio-N6-methyl-adenosine (ms2m6A), N6-isopentenyl-adenosine (i6A), 2-methylthio-N6-isopentenyl-adenosine (ms2i6A), N6-(cis-hydroxyisopentenyl)adenosine (io6A), 2-methylthio-N6-(cis-hydroxyisopentenyl)adenosine (ms2io6A), N6-glycinylcarbamoyi-adenosine (g6A), N6-threonylcarbamoyl-adenosine (t6A), N6-methyl-N6-threonylcarbamoyl-adenosine (m6t6A), 2-methylthio-N6-threonylcarbamoyl-adenosine (ms2g6A), N6,N6-dimethyl-adenosine (m62A), N6-hydroxynorvalylcarbamoyl-adenosine (hn6A), 2-methylthio-N6-hydroxynorvalylcarbamoyl-adenosine (ms2hn6A), N6-acetyl-adenosine (ac6A), 7-methyl-adenine, 2-methylthio-adenine, 2-methoxy-adenine, α-thio-adenosine, 2′-O-methyl-adenosine (Am), N6,2′-O-dimethyl-adenosine (m6Am), N6,N6,2′-O-trimethyl-adenosine (m62Am), 1,2′-O-dimethyl-adenosine (m1Am), 2′-O-ribosyladenosine (phosphate) (Ar(p)), 2-amino-N6-methyl-purine, 1-thio-adenosine, 8-azido-adenosine, 2c-F-ara-adenosine, 2′-F-adenosine, 2′-OH-ara-adenosine, and N6-(19-amino-pentaoxanonadecyl)-adenosine. 
     In some embodiments, the modified nucleobase is a modified guanine. Exemplary nucleobases and nucleosides having a modified guanine include inosine (I), 1-methyl-inosine (m1I), wyosine (imG), methylwyosine (mimG), 4-demethyl-wyosine (imG-14), isowyosine (imG2), wybutosine (yW), peroxywybutosine (o2yW), hydroxywybutosine (OHyW), undermodified hydroxywybutosine (OHyW*), 7-deaza-guanosine, queuosine (Q), epoxyqueuosine (oQ), galactosyl-queuosine (galQ), mannosyl-queuosine (manQ), 7-cyano-7-deaza-guanosine (preQ0), 7-aminomethyl-7-deaza-guanosine (preQ1), archaeosine (G+), 7-deaza-8-aza-guanosine, 6-thio-guanosine, 6-thio-7-deaza-guanosine, 6-thio-7-deaza-8-aza-guanosine, 7-methyl-guanosine (m7G), 6-thio-7-methyl-guanosine, 7-methyl-inosine, 6-methoxy-guanosine, 1-methyl-guanosine (m1G), N2-methyl-guanosine (m2G), N2,N2-dimethyl-guanosine (m22G), N2,7-dimethyl-guanosine (m2,7G), N2, N2,7-dimethyl-guanosine (2,2,7G), 8-oxo-guanosine, 7-methyl-8-oxo-guanosine, 1-methyl-6-thio-guanosine, N2-methyl-6-thio-guanosine, N2,N2-dimethyl-6-thio-guanosine, a-thio-guanosine, 2′-O-methyl-guanosine (Gm), N2-methyl-2′-O-methyl-guanosine (m2Gm), N2,N2-dimethyl-2′-O-methyl-guanosine (m22Gm), 1-methyl-2′-O-methyl-guanosine (m1Gm), N2,7-dimethyl-2′-O-methyl-guanosine (m2,7Gm), 2′-O-methyl-inosine (Im), 1,2′-O-dimethyl-inosine (m1Im), and 2′-O-ribosylguanosine (phosphate) (Gr(p)). 
     The nucleobase of the nucleotide can be independently selected from a purine, a pyrimidine, or a purine or pyrimidine analog. For example, the nucleobase can be independently selected from adenine, cytosine, guanine, uracil, or hypoxanthine. In another embodiment, the nucleobase can also include, for example, naturally-occurring and synthetic derivatives of a base, including pyrazolo[3,4-d]pyrimidines, 5-methylcytosine (5-me-C), 5-hydroxy methyl cytosine, xanthine, hypoxanthine, 2-aminoadenine, 6-methyl and other alkyl derivatives of adenine and guanine, 2-propyl and other alkyl derivatives of adenine and guanine, 2-thiouracil, 2-thiothymine and 2-thiocytosine, 5-propynyl uracil and cytosine, 6-azo uracil, cytosine and thymine, 5-uracil (pseudouracil), 4-thiouracil, 8-halo (e.g., 8-bromo), 8-amino, 8-thiol, 8-thioalkyl, 8-hydroxyl and other 8-substituted adenines and guanines, 5-halo particularly 5-bromo, 5-trifluoromethyl and other 5-substituted uracils and cytosines, 7-methylguanine and 7-methyladenine, 8-azaguanine and 8-azaadenine, deazaguanine, 7-deazaguanine, 3-deazaguanine, deazaadenine, 7-deazaadenine, 3-deazaadenine, pyrazolo[3,4-d]pyrimidine, imidazo[1,5-a]1,3,5 triazinones, 9-deazapurines, imidazo[4,5-dipyrazines, thiazolo[4,5-d]pyrimidines, pyrazin-2-ones, 1,2,4-triazine, pyridazine; and 1,3,5 triazine. When the nucleotides are depicted using the shorthand A, G, C, T or U, each letter refers to the representative base and/or derivatives thereof, e.g., A includes adenine or adenine analogs, e.g., 7-deaza adenine). 
     The modified nucleotides can be modified on the internucleoside linkage (e.g., phosphate backbone). Herein, in the context of the polynucleotide backbone, the phrases “phosphate” and “phosphodiester” are used interchangeably. Backbone phosphate groups can be modified by replacing one or more of the oxygen atoms with a different substituent. Further, the modified nucleosides and nucleotides can include the wholesale replacement of an unmodified phosphate moiety with another intemucleoside linkage as described herein. Examples of modified phosphate groups include, but are not limited to, phosphorothioate, phosphoroselenates, boranophosphates, boranophosphate esters, hydrogen phosphonates, phosphoramidates, phosphorodiamidates, alkyl or aryl phosphonates, and phosphotriesters. Phosphorodithioates have both non-linking oxygens replaced by sulfur. The phosphate linker can also be modified by the replacement of a linking oxygen with nitrogen (bridged phosphoramidates), sulfur (bridged phosphorothioates), and carbon (bridged methylene-phosphonates). 
     The (t-thio substituted phosphate moiety is provided to confer stability to RNA and DNA polymers through the unnatural phosphorothioate backbone linkages, Phosphorothioate DNA and RNA have increased nuclease resistance and subsequently a longer half-life in a cellular environment. 
     In specific embodiments, a modified nucleoside includes an alpha-thio-nucleoside (e.g., 5′-O-(1-thiophosphate)-adenosine, 5′-O-(1-thiophosphate)-cytidine (α-thio-cytidine), 5′-O-(1-thiophosphate)-guanosine, 5′-O-(1-thiophosphate)-uridine, or 5′-O-(1-thiophosphate)-pseudouridine). 
     in some embodiments, a combination of modifications to the sugar, the nucleobase, and/or the internucleoside linkage may be used. 
     Methods for chemically modifying nucleic acids are known in the all and include, for example, any available technique including, but not limited to, chemical synthesis, enzymatic synthesis, and enzymatic or chemical cleavage of a longer precursor. Methods of synthesizing nucleotides are known in the art (see, e.g., Gait, M. J. (ed.) Oligonucleotide synthesis: a practical approach, Oxford [Oxfordshire], Washington, D.C.: IRL. Press, 1984; and Herdewijn, P. (ed.) Oligonucleotide synthesis: methods and applications, Methods in Molecular Biology, v. 288 (Clifton, N.J.) Totowa, N.J.: Humana Press, 2005; both of which are incorporated herein by reference in their entirety). 
     In one embodiment, the engineered Rep binding sequence region or eRBSR has a single altered or modified nucleotide as compared to the native Rep binding sequence region. In another embodiment, the eRBSR has two or more altered or modified nucleotides as compared to the native Rep binding sequence region. In certain embodiments, the eRBSR has two to twelve altered or modified nucleotides, including, for example, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12 altered or modified nucleotides as compared to the native Rep binding sequence region. In one embodiment, all of the nucleotides of the eRBSR are altered, e.g., such as in a swapped sequence (discussed below), as long as the eRBSR retains some minimal binding with the Rep protein. 
     In another embodiment, the eRBSR has one or more nucleotide insertions, deletions, substitutions, or any combination thereof as compared to the corresponding native Rep binding sequence region. For example, the engineered Rep binding sequence region can comprise a sequence having one or more nucleotides that differ from the Rep binding sequence region of an adeno-associated virus (AAV), including the Rep binding sequence region of AAV1, AAV2, AAV3, AAV4, AAV5, AAV6, AAV7, AAV 8, AAV9, AAV10, AAV11, AAV12, AAV rh8, AAVrh10, AAV-DJ, and AAV-DJ8. 
     In another embodiment, the present disclosure provides a nucleic acid comprising an eRBSR in which the Rep binding sequence region is not native to the parvoviral genome. The eRBSR can comprise a Rep binding sequence region that is found in a different parvoviral serotype or species genome. In one embodiment, the eRBSR is a Rep binding sequence region from a parvoviral serotype or species that differs from the serotype or species of the native parvoviral ITR sequence. In one embodiment, the eRBSR is a Rep binding sequence region from a parvoviral serotype or species that differs from the serotype or species of the native Rep protein or sequence encoding the Rep protein. Thus, in certain embodiments, the eRBSR is created by swapping the native Rep binding sequence region with all or most of the Rep binding sequence region of a different serotype or species. In one embodiment, the entire Rep binding sequence region is swapped. In another embodiment, a portion or partial sequence of the Rep binding sequence region is swapped. In one embodiment, the engineered Rep binding sequence region can comprise a non-native or swapped Rep binding sequence region from an AAV viral particle, including the Rep binding sequence region of AAV1, AAV2, AAV3, AAV4, AANT5, AAV6, AAV7, AAV8, AAV9, AAV10, AAV11, AAV12, AAVrh8, AAVrh10, AAV-DJ, and AAV-DJ8. In one embodiment, the eRBSR for an AAV2 polynucleotide, genome, or viral particle (i.e., comprising an AAV2 ITR and/or AAV2 Rep protein coding sequence) is the Rep binding sequence region found in AAV-5 (Table 1; SEQ ID NO: 3, SEQ ID NO: 4). 
     In other embodiments, the engineered Rep binding sequence region can comprise a sequence having both alterations and chemical modifications. Thus, in one embodiment, the eRBSR comprises one or more nucleotides that are altered and one or more nucleotides that are chemically modified. Examples of suitable chemical modifications are provided above. 
     The engineered Rep binding sequence region must have minimal length sufficient to bind a Rep protein and is only constrained in its maximal length by the length of any ITR packaged in the viral particle. In one embodiment, the eRBSR can approximate the length of a typical parvoviral ITR sequence. In one embodiment, the eRBSR is from about four to about 145 nucleotides in length. In one embodiment, the engineered Rep binding sequence region is from four to 145 nucleotides in length. In another embodiment, the engineered Rep binding sequence region is from about four to about sixty-four nucleotides in length, including any length within that size range, for example 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 19, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, and 64 nucleotides in length. In other embodiments, the engineered Rep binding sequence region is from about four to about forty-eight, about four to about thirty-six, about four to about twenty-four, about four to about twenty, about four to about sixteen, and about four to about eight nucleotides in length. In another embodiment, the engineered Rep binding sequence region is from about eight to about twenty, about eight to about sixteen, and about eight to twelve nucleotides in length. In another embodiment, the engineered Rep binding sequence region is four, eight, twelve, sixteen, or twenty nucleotides in length. In one embodiment, the eRBSR is sixteen nucleotides in length. 
     In one embodiment, the eRBSR is a nucleic acid comprising one or more consensus motifs having the sequence GCTC. In one embodiment, the eRBSR comprises one to three GCTC consensus motifs. In one embodiment, the eRBSR comprises one GCTC consensus motif In one embodiment, the eRBSR comprises two GCTC consensus motifs. In one embodiment, the eRBSR comprises three GCTC consensus motifs. In any of these embodiments, the one to three GCTC consensus motifs can function as an eRBSR when the consensus motif(s) sequence is substituted for (swapped with) the native Rep binding sequence region. Thus, the eRBSR is created by swapping the native Rep binding sequence region with one, two, or three GCTC consensus motif(s). In one embodiment, the entire native Rep binding sequence region is swapped. In another embodiment, a portion or partial sequence of the native Rep binding sequence region is swapped. In any of these embodiments, the eRBSR is about 4-20 nucleotides in length. In one embodiment, the eRBSR has a length of about 4-20 nucleotides and comprises one GCTC motif. In another embodiment, the eRBSR has a length of 4-20 nucleotides and comprises one GCTC motif. In another embodiment, the eRBSR has a length of 4-16 nucleotides and comprises one GCTC motif. In any of these variations, the eRBSR can have a sequence selected from: [GCTC]-(N)x (SEQ ID NO: 292) or (N)x-[GCTC] (SEQ ID NO: 293), wherein x=0-16 and N is any naturally or non-naturally occurring nucleoside selected from adenosine, guanosine, uridine, cytidine, thymidine. In one variation, x=0-12. In another embodiment, the eRBSR has a length of about 8-2C) nucleotides and comprises two GCTC motifs. In another embodiment, the eRBSR has a length of 8-20 nucleotides and comprises two GCTC motifs. In another embodiment, the eRBSR has a length of 8-16 nucleotides and comprises two GCTC motifs. In any of these variations, the eRBSR can have a sequence selected from: (1)1GCTC12-(N)x (SEQ ID NO: 294) or (N)x-1GCTC12 (SEQ ID NO: 295), wherein x is 0-12 and N is any naturally or non-naturally occurring nucleoside selected from adenosine, guanosine, uridine, cytidine, thymidine; (2) [GCTC]N)x-[GCTC]-(N)y (SEQ ID NO: 296) or (N)x-[GCTC]-(N)y-[GCTC] (SEQ ID NO: 297), wherein x and y are independently 0-12, with the proviso that x+y&lt;12 and N is any naturally or non-naturally occurring nucleoside selected from adenosine, guanosine, uridine, cytidine, thymidine; and (3) (N)x-[GCTC12-(N)y (SEQ ID NO: 298) or [GCTC1-(N)x-[GCTC] (SEQ ID NO: 299), wherein x and y are independently 0-12, with the proviso that x+y&lt;12 and N is any naturally or non-naturally occurring nucleoside selected from adenosine, guanosine, uridine, cytidine, thymidine. In one variation, x=0-8 and y=0-8, with the proviso that x+y&lt;8. In another embodiment, the eRBSR has a length of 12-20 nucleotides and comprises three GCTC motifs. In one embodiment, the eRBSR has a length of 12-20 nucleotides and comprises three GCTC motifs. In another embodiment, the eRBSR has a length of 12-16 nucleotides and comprises three GCTC motifs. In any of these variations, the eRBSR can have a sequence selected from: (1) [GCTC]3-(N)x (SEQ ID NO: 300) or (N)x-[GCTC]3 (SEQ ID NO: 301), wherein x is 0-8 and N is any naturally or non-naturally occurring nucleoside selected from adenosine, guanosine, uridine, cytidine, thymidine; (2) [GCTC]-(N)x-[GCTC]2-(N)y (SEQ ID NO: 302) or (N)x-[GCTC]-(N)y-[GCTC]2 (SEQ ID NO: 303), wherein x and y are independently 0-8, with the proviso that x+y&lt;8 and N is any naturally or non-naturally occurring nucleoside selected from adenosine, guanosine, uridine, cytidine, thymidine; (3) [GCTC]2-(N)x-[GCTC]N)y (SEQ ID NO: 304) or Nx-[GCTC]2-Ny-[GCTC] (SEQ ID NO: 305), wherein x and y are independently 0-8, with the proviso that x+y&lt;8 and N is any naturally or non-naturally occurring nucleoside selected from adenosine, guanosine, uridine, cytidine, thymidine; (4) (N)x-[GCTC]3-(N)y (SEQ ID NO: 306) or [GCTC]-(N)x-[GCTC]-(N)y-[GCTC] (SEQ ID NO: 307), wherein x and y are independently 0-8, with the proviso that x+y&lt;8 and N is any naturally or non-naturally occurring nucleoside selected from adenosine, guanosine, uridine, cytidine, thymidine. In one variation, x and y are independently 0-4, with the proviso that x+y&lt;4. In any of these embodiments, the engineered Rep binding sequence region comprising one, two, or three GCTC consensus motifs can be swapped with a Rep binding sequence region from an AAV viral genome, including the Rep binding sequence region of AAV1, AAV2, AAV3, AAV4, AAV5, AAV6, AAV7, AAV8, AAV9, AAV10, AAV11, AAV12, AAVrh8, AAVrh10, AAV-DJ, and. AAV-DJ8. Also, in any of these embodiments, one or more of the nucleotides in at least one of the GCTC consensus motifs is altered or modified. 
     In one embodiment, the eRBSR is a nucleic acid comprising one or more consensus motifs having the sequence GCTC, in which one or more of the nucleotides in at least one of the GCTC consensus motifs is altered or modified. In one embodiment, one or more of the GCTC consensus motif(s) is altered or modified to a motif sequence selected from the group consisting of (1) NCTC, (2) GNTC, (3) GCNC, (4) GCTN, and (5) in the case of two or more altered or modified motif sequences, any combination of these altered or modified motifs, wherein N is either any naturally or non-naturally occurring nucleoside selected from adenosine, guanosine, uridine, cytidine, thymidine with the proviso that N differs from the consensus nucleotide in that position or N is a chemically modified nucleotide, in which the chemical modification(s) can be on the nucleobase, and/or on the sugar and/or on the backbone. In another embodiment, one or more of the GCTC consensus motif(s) is altered or modified to a motif sequence selected from the group consisting of (1) NNTC, (2) GNNC, (3) GCNN, (4) GNTN, (5) NCNC, (6) NC N, and (7) in the case of two or more altered or modified GCTC: motif sequences, any combination of these altered or modified motifs, wherein N is any naturally or non-naturally occurring nucleoside selected from adenosine, guanosine, uridine, cytidine, thymidine with the proviso that N differs from the consensus nucleotide in that position or N is a chemically modified nucleotide, in which the chemical modification(s) can be on the nucleobase, and/or on the sugar and/or on the backbone. The individual GCTC consensus motifs can be contiguous with one another or can be separated by intervening sequence, in certain of these embodiments having two or more GCTC consensus motifs, the consensus GCTC motifs are contiguous with one another. In other of these embodiments having one or more GCTC consensus motifs none of the consensus motifs are contiguous with one another. In other individual embodiments, two, three, four, five or more GCTC consensus motifs are contiguous with one another. 
     In one embodiment, the eRBSR is a nucleic acid comprising one or more consensus motifs having the sequence GCTC, in which one or more of the nucleotides in at least one Of the GCTC consensus motifs is altered or modified. In one embodiment, one or more of the GCTC consensus motif(s) is altered to a motif sequence selected from the group consisting of (1) NCTC, (2) GNTC, (3) GCNC, (4) GCTN, and (5) in the case of two or more altered motif sequences, any combination of these modified altered motifs, wherein N is any naturally or non-naturally occurring nucleoside selected from adenosine, guanosine, uridine, cytidine, thymidine. In one embodiment, one or more of the GCTC consensus motifs) contains at least one nucleotide which is chemically modified. The chemical modification(s) can be on the nucleobase, and/or on the sugar and/or on the backbone. The individual GCTC consensus motifs can be contiguous with one another or can be separated by intervening sequence. In certain of these embodiments having two or more GCTC consensus motifs, the consensus GCTC motifs are contiguous with one another. In other of these embodiments having one or more GCTC consensus motifs none of the consensus motifs are contiguous with one another. In other individual embodiments, two, three, four, five or more GCTC consensus motifs are contiguous with one another. 
     in one embodiment, the eRBSR has the formula (GCTC)x (SEQ ID NO: 308), where x=1-4, in which one or more of the nucleotides in at least one of the GCTC consensus motifs is altered or modified. In one embodiment, one nucleotide in at least one of the GCTC consensus motifs is altered or modified. In one variation of this embodiment, one nucleotide in one of the GCTC consensus motifs is altered or modified. In another variation, one nucleotide in two of the GCTC consensus motifs is altered or modified. In vet another variation, one nucleotide in three of the GCTC consensus motifs is altered or modified. In still another variation, one nucleotide in four of the GCTC consensus motifs is altered or modified. In one embodiment, two nucleotides in at least one of the GCTC consensus motifs is altered or modified. In variations of this embodiment, two nucleotides in one, two, three, or four of the GCTC consensus motifs are altered or modified. 
     In one embodiment, the eRBSR has the formula (GCTC) x -N y -(GCTC) z  (SEQ ID NO: 309), wherein N is any naturally or non-naturally occurring nucleoside selected from adenosine, guanosine, uridine, cytidine, thymidine; x and z are 0-2 with the proviso that when x=0, z=1 or 2. and when z=0. x=1 or 2; and y=0-8, in which one or more of the nucleotides in at least one of the GCTC consensus motifs is modified. In one embodiment, the eRBSR has the formula (GCTC)-N y (GCTC) z -N y -(GCTC) w  (SEQ ID NO: 310), wherein N is any naturally or non-naturally occurring nucleoside selected from adenosine, guanosine, uridine, cytidine, thymidine; w, x, and z are 0-2 with the proviso that when x=0, z=1 or 2 and w=I or 2, when z=0, x=1 or 2 and w=1 or 2; when w=0, x=1 or 2 and z=1 or 2, and y=0-8. In any of the embodiments described here, when y=4 the N′s can comprise a GCTC consensus motif in which at least one of the nucleotides in the consensus motif is altered or modified. In one variation of this embodiment, one of the nucleotides in the consensus motif is altered or modified. In another variation of this embodiment, two of the nucleotides in the consensus motif is altered or modified. Also, in any of the embodiments described here, when y=8 the N′s can comprise two GCTC consensus motif in which at least one of the nucleotides in at least one of the consensus motifs is altered or modified. In one variation of this embodiment, one of the nucleotides in one or both of the consensus motifs is altered or modified. In another variation of this embodiment, two of the nucleotides in one or both of the consensus motifs is altered or modified. 
     Table 1 provides Rep binding sequence regions found in various AAV serotypes and species which can function as an eRBSR (SEQ ID NOs: 1-20). 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 Native or Wild-Type Rep Binding Sequence Regions 
               
            
           
           
               
               
               
            
               
                   
                   
                 SEQ ID 
               
               
                 Rep-binding sequence 
                 Sequence 
                 NO 
               
               
                   
               
               
                 AAV2 5′ 
                 GCGCGCTCGCTCGCTC 
                  1 
               
               
                   
               
               
                 AAV2 3′ 
                 GAGCGAGCGAGCGCGC 
                  2 
               
               
                   
               
               
                 AAV5 5′ 
                 GCTCGCTCGCTGGCTC 
                  3 
               
               
                   
               
               
                 AAV5 3′ 
                 GAGCCAGCGAGCGAGC 
                  4 
               
               
                   
               
               
                 AAV1 5′ 
                 GCGCGCTCGCTCGCTC 
                  5 
               
               
                   
               
               
                 AAV1 3′ 
                 GAGCGAGCGAGCGCGC 
                  6 
               
               
                   
               
               
                 AAV3 5′ 
                 GCGCACTCGCTCGCTC 
                  7 
               
               
                   
               
               
                 AAV3 3′ 
                 GAGCGAGCGAGTGCGC 
                  8 
               
               
                   
               
               
                 AAV4 5′ 
                 GCGCGCTCGCTCACTC 
                  9 
               
               
                   
               
               
                 AAV4 3′ 
                 GAGTGAGCGAGCGCGC 
                 10 
               
               
                   
               
               
                 AAV7 5′ 
                 GCGCGCTCGCTCGCTC 
                 11 
               
               
                   
               
               
                 AAV7 3′ 
                 GAGCGAGCGAGCGCGC 
                 12 
               
               
                   
               
               
                 Avian AAV Strain DA1 5′ 
                 GCTCGCTCGCTC 
                 13 
               
               
                   
               
               
                 Avian AAV Strain DA1 3′ 
                 GAGCGAGCGAGC 
                 14 
               
               
                   
               
               
                 Avian AAV ATCC VR-865 5′ 
                 GCTCGCTCGCTC 
                 15 
               
               
                   
               
               
                 Avian AAV ATCC VR-865 3′ 
                 GAGCGAGCGAGC 
                 16 
               
               
                   
               
               
                 Bovine AAV5′ 
                 GCTCGTTCGCTGGCTC 
                 17 
               
               
                   
               
               
                 Bovine AAV3′ 
                 GAGCCAGCGAACGAGC 
                 18 
               
               
                   
               
               
                 Snake AAV5′ 
                 GCGCGCGCTC 
                 19 
               
               
                   
               
               
                 Snake AAV3′ 
                 GAGCGCGCGC 
                 20 
               
               
                   
               
            
           
         
       
     
     Table 2 provides engineered Rep binding sequence regions which can function as an eRBSR (SEQ ID NOs: 21-66). 
     
       
         
           
               
             
               
                 TABLE 2 
               
             
            
               
                   
               
               
                 Engineered Rep Binding Sequence Regions 
               
            
           
           
               
               
            
               
                 Sequence 
                 SEQ ID NO 
               
               
                   
               
               
                 GCTCNNNNNNNNNNNNNNNN 
                 21 
               
               
                   
               
               
                 GCTCNNNNNNNNNNNN 
                 22 
               
               
                   
               
               
                 GCTCNNNNNNNN 
                 23 
               
               
                   
               
               
                 GCTCNNNN 
                 24 
               
               
                   
               
               
                 NNNNNNNNNNNNNNNNGCTC 
                 25 
               
               
                   
               
               
                 NNNNNNNNNNNNGCTC 
                 26 
               
               
                   
               
               
                 NNNNNNNNGCTC 
                 27 
               
               
                   
               
               
                 NNNNGCTC 
                 28 
               
               
                   
               
               
                 GCTCNNNNNNNNNNNNGCTC 
                 29 
               
               
                   
               
               
                 GCTCNNNNNNNNGCTC 
                 30 
               
               
                   
               
               
                 GCTCNNNNGCTC 
                 31 
               
               
                   
               
               
                 GCTCGCTCNNNNNNNNNNNN 
                 32 
               
               
                   
               
               
                 GCTCGCTCNNNNNNNN 
                 33 
               
               
                   
               
               
                 GCTCGCTCNNNN 
                 34 
               
               
                   
               
               
                 GCTCGCTCGCTCNNNNNNNN 
                 35 
               
               
                   
               
               
                 GCTCGCTCGCTCNNNN 
                 36 
               
               
                   
               
               
                 NNNNNNNNNNNNGCTCGCTC 
                 37 
               
               
                   
               
               
                 NNNNNNNNGCTCGCTC 
                 38 
               
               
                   
               
               
                 NNNNGCTCGCTC 
                 39 
               
               
                   
               
               
                 NNNNNNNNGCTCGCTCGCTC 
                 40 
               
               
                   
               
               
                 NNNNGCTCGCTCGCTC 
                 41 
               
               
                   
               
               
                 GCTCGCTCNNNNNNNNGCTC 
                 42 
               
               
                   
               
               
                 GCTCGCTCNNNNGCTC 
                 43 
               
               
                   
               
               
                 GCTCNNNNNNNNGCTCGCTC 
                 44 
               
               
                   
               
               
                 GCTCNNNNGCTCGCTC 
                 45 
               
               
                   
               
               
                 NNNNGCTCGCTCGCTCNNNN 
                 46 
               
               
                   
               
               
                 NNNNNNNNGCTCGCTCNNNN 
                 47 
               
               
                   
               
               
                 NNNNGCTCGCTCNNNNNNNN 
                 48 
               
               
                   
               
               
                 NNNNGCTCGCTCNNNN 
                 49 
               
               
                   
               
               
                 NNNNNNNNNNNNGCTCNNNN 
                 50 
               
               
                   
               
               
                 NNNNNNNNGCTCNNNNNNNN 
                 51 
               
               
                   
               
               
                 NNNNNNNNGCTCNNNN 
                 52 
               
               
                   
               
               
                 NNNNGCTCNNNN 
                 53 
               
               
                   
               
               
                 NNNNGCTCNNNNNNNNNNNN 
                 54 
               
               
                   
               
               
                 NNNNGCTCNNNNNNNN 
                 55 
               
               
                   
               
               
                 GCTCNNNNGCTCNNNN 
                 56 
               
               
                   
               
               
                 GCTCNNNNNNNNGCTCNNNN 
                 57 
               
               
                   
               
               
                 GCTCNNNNGCTCNNNNNNNN 
                 58 
               
               
                   
               
               
                 NNNNGCTCNNNNGCTC 
                 59 
               
               
                   
               
               
                 NNNNGCTCNNNNNNNNGCTC 
                 60 
               
               
                   
               
               
                 NNNNNNNNGCTCNNNNGCTC 
                 61 
               
               
                   
               
               
                 GCTCGGGG 
                 62 
               
               
                   
               
               
                 GCTCGGGGG 
                 63 
               
               
                   
               
               
                 GCTCGGGGGG 
                 64 
               
               
                   
               
               
                 GCTCGGGGGGG 
                 65 
               
               
                   
               
               
                 GCTCGGGGGGGG 
                 66 
               
               
                   
               
            
           
         
       
     
     Table 3 provides oligonucleotide sequences that comprise Rep protein binding properties which may therefore function as an eRBSR (SEQ NOs: 79-197) (Chiorini et al. 1995 Journal of Virology 69(11) 7334-7338, the contents of which are incorporated herein by reference in their entirety). 
     
       
         
           
               
             
               
                 TABLE 3 
               
             
            
               
                   
               
               
                 Rep Binding Sequence Region Oligonucleotides 
               
            
           
           
               
               
            
               
                 Sequence 
                 SEQ ID NO 
               
               
                   
               
               
                 ATACGCCGCCTCGCGCTCAG 
                  79 
               
               
                   
               
               
                 ATCTGTCGCTCGTCCGGCTA 
                  80 
               
               
                   
               
               
                 TCCGCGCTGGCTCATCGTCC 
                  81 
               
               
                   
               
               
                 TCCGCGCTGGCTCATCGTCC 
                  82 
               
               
                   
               
               
                 TCCCCGCCCCCGCTCATTCT 
                  83 
               
               
                   
               
               
                 GTGCCCCCGCTCAGAGTCCA 
                  84 
               
               
                   
               
               
                 TTTACCGCCGCTCAGATAGA 
                  85 
               
               
                   
               
               
                 GACCCCCAGGCGCTCCTATG 
                  86 
               
               
                   
               
               
                 ATCTCGCTCATGCCCCTTAG 
                  87 
               
               
                   
               
               
                 TCCCCGGTCAGGGGCTCACT 
                  88 
               
               
                   
               
               
                 CCGCCGCTCTATCCACTGGT 
                  89 
               
               
                   
               
               
                 TTGCCTCGCTGCTACTGTTC 
                  90 
               
               
                   
               
               
                 CATATCTCCGCTTAGTTGCC 
                  91 
               
               
                   
               
               
                 TCGTTAAGAACCTTCCTCAT 
                  92 
               
               
                   
               
               
                 CCCCCGCATCCTCCGCCTTC 
                  93 
               
               
                   
               
               
                 CATATCTCCGCTTAGTTGCC 
                  94 
               
               
                   
               
               
                 CACAGTTCTCGCCTACCCGT 
                  95 
               
               
                   
               
               
                 CTCTCCTTCAGGGCCTCAGC 
                  96 
               
               
                   
               
               
                 GCTGCCCGCGTACTCACCCG 
                  97 
               
               
                   
               
               
                 GCTCGAAGGAAGCGGGGAAC 
                  98 
               
               
                   
               
               
                 GTCAGTTCGCTGGGTGATTC 
                  99 
               
               
                   
               
               
                 ATCGGACGGCTTCGTTGTGC 
                 100 
               
               
                   
               
               
                 TCGCTGACCAAGCCGCATGC 
                 101 
               
               
                   
               
               
                 CCAGTATTCTGCGCAGCTGG 
                 102 
               
               
                   
               
               
                 GGCGTCCCCTTTCCTTTTCG 
                 103 
               
               
                   
               
               
                 TAATCGTATGCATCGTCGTG 
                 104 
               
               
                   
               
               
                 TGAACGGTCGCGACGCAGCA 
                 105 
               
               
                   
               
               
                 ACGTTCAACCCGCCGCGTCG 
                 106 
               
               
                   
               
               
                 ATCGGACGGCTTCGTTGTGC 
                 107 
               
               
                   
               
               
                 CCATGTGTTGCGCCCGTCGC 
                 108 
               
               
                   
               
               
                 GGTCCCCCCATGCACTGCCC 
                 109 
               
               
                   
               
               
                 CCCGTATCCACGCCCCACGC 
                 110 
               
               
                   
               
               
                 TGCCCCACGCGCGCTCGTAC 
                 111 
               
               
                   
               
               
                 ATGCTTTCTCGCTCAGTCC 
                 112 
               
               
                   
               
               
                 ACACTTCTCACTCGCTGCCT 
                 113 
               
               
                   
               
               
                 CCTTCGCGCTCGTTCGAATA 
                 114 
               
               
                   
               
               
                 TGCTTTCTCGCTCAGTCC 
                 115 
               
               
                   
               
               
                 GCGATTGCCTCGGTGGCTCA 
                 116 
               
               
                   
               
               
                 CTTCACTTACTCGCGCACCC 
                 117 
               
               
                   
               
               
                 TGCCCTTGGCTTGCTCAGTG 
                 118 
               
               
                   
               
               
                 GTCTCGCTCGGTCAGCTACT 
                 119 
               
               
                   
               
               
                 ATCCGTTCACTCGTTCGCCT 
                 120 
               
               
                   
               
               
                 ACGCACTCACTCGCCGGCGC 
                 121 
               
               
                   
               
               
                 CTCTTGCTCGCTCAATTGCT 
                 122 
               
               
                   
               
               
                 GGGTGCTCGCCTGGGTTGCG 
                 123 
               
               
                   
               
               
                 CCAGTGCTCACTCAGCTCGC 
                 124 
               
               
                   
               
               
                 TCGGCGCTCGCTCGGTCCTC 
                 125 
               
               
                   
               
               
                 CGCGGGTTGTTTTCACTCAC 
                 126 
               
               
                   
               
               
                 TGTCATCTGCTCGCTCACTT 
                 127 
               
               
                   
               
               
                 AGATCCTTGTGGCTCACTCG 
                 128 
               
               
                   
               
               
                 ACTGGCTGGTTCGCTCAGAC 
                 129 
               
               
                   
               
               
                 CCACAGATGTAGCTCACTCA 
                 130 
               
               
                   
               
               
                 CTGGTATCGCTCACTTGACC 
                 131 
               
               
                   
               
               
                 TCGCGCTCGTTCGCCTCTGC 
                 132 
               
               
                   
               
               
                 AGATCCTTGTGGCTCACTCG 
                 133 
               
               
                   
               
               
                 CAATCAGTTAACCACTTCAA 
                 134 
               
               
                   
               
               
                 CTCGCTTGCAGTCACTCACT 
                 135 
               
               
                   
               
               
                 GAGTTTATCTCATGTTCTGC 
                 136 
               
               
                   
               
               
                 CAATTCAGCCAACCACTCAA 
                 137 
               
               
                   
               
               
                 GCTGACTCGTTGACTCATCT 
                 138 
               
               
                   
               
               
                 TCTCCGCTGGTTCACCGTAC 
                 139 
               
               
                   
               
               
                 TGTGCGGCCCACTGAGACGT 
                 140 
               
               
                   
               
               
                 CCACGTGCTCGCTCAACCTT 
                 141 
               
               
                   
               
               
                 TCCTACAGCTTGCTCACTCT 
                 142 
               
               
                   
               
               
                 CACAGTTACTGGCTCACTGA 
                 143 
               
               
                   
               
               
                 GGGGTTGGTTGGTTCACTCC 
                 144 
               
               
                   
               
               
                 GGGTGCTCGCCTGGGTTGCG 
                 145 
               
               
                   
               
               
                 GCCACTTAGCGTACTGGTTC 
                 146 
               
               
                   
               
               
                 CCCTGTTCGCTTGCTCGTTC 
                 147 
               
               
                   
               
               
                 TTAACATGGCGCGTTCACTG 
                 148 
               
               
                   
               
               
                 CCATCTTATTGGTTCACTGG 
                 149 
               
               
                   
               
               
                 CTCTTCCCGCGCACTGACTC 
                 150 
               
               
                   
               
               
                 CTAAGATGCCCCGCTCGCTC 
                 151 
               
               
                   
               
               
                 GTATGGCACTCGCTCGCTGG 
                 152 
               
               
                   
               
               
                 TGCATCTGCCCTTGCTCACT 
                 153 
               
               
                   
               
               
                 ACTCACTCACTGAGTTGTCC 
                 154 
               
               
                   
               
               
                 TTCGTTGGCTCACTCACCCC 
                 155 
               
               
                   
               
               
                 GTGCCCGTTTCTACTCACTG 
                 156 
               
               
                   
               
               
                 TGGTCGCTCGCCCCAGCCGC 
                 157 
               
               
                   
               
               
                 TTGCTTGCTCACTCCGCGCT 
                 158 
               
               
                   
               
               
                 CGCCAGCTCCCTCCTCATGC 
                 159 
               
               
                   
               
               
                 CCTCCACTCGCTGGGTGAGC 
                 160 
               
               
                   
               
               
                 TCGTCGCTCGCTCTGCATCC 
                 161 
               
               
                   
               
               
                 TACCGCGATCTCGCTCTCTG 
                 162 
               
               
                   
               
               
                 CCCACGCCCTCGCTCACTGC 
                 163 
               
               
                   
               
               
                 TCTCTGTCACTCGTCTCCGG 
                 164 
               
               
                   
               
               
                 CTCGTGCCCCGGTGCGCTCA 
                 165 
               
               
                   
               
               
                 CGTGTACTTCGTGCTCAGCC 
                 166 
               
               
                   
               
               
                 CCCGTGTAGGTGCGCTCGCT 
                 167 
               
               
                   
               
               
                 TCCACCCTACTCCGTCGGCC 
                 168 
               
               
                   
               
               
                 CTCACCGCACTCACTGGCCC 
                 169 
               
               
                   
               
               
                 GCCCCTCCTTTCGCTCGTTT 
                 170 
               
               
                   
               
               
                 CCTCTCCGCGTGCCCACTCG 
                 171 
               
               
                   
               
               
                 CCTTCTTTTCCGCTGGCTCA 
                 172 
               
               
                   
               
               
                 CTCGTGCCCCGGTGCGCTCA 
                 173 
               
               
                   
               
               
                 GGCGATTCACTCATCTGACC 
                 174 
               
               
                   
               
               
                 ACTGCCCGGCCGTTTCGCTC 
                 175 
               
               
                   
               
               
                 CCTCTCCGCGTGCCCACTCG 
                 176 
               
               
                   
               
               
                 GCTTGCTCGACCCAGCCACG 
                 177 
               
               
                   
               
               
                 CCTGGTTCGGTCCTTCTCCC 
                 178 
               
               
                   
               
               
                 ATCCTCCTATCTCACTCGCT 
                 179 
               
               
                   
               
               
                 CCCGGGTACTGACTCGCGCT 
                 180 
               
               
                   
               
               
                 TCCATGCCACTTGGTTCACT 
                 181 
               
               
                   
               
               
                 CTGCTATCGTTAACTCACCT 
                 182 
               
               
                   
               
               
                 TGCACTCATTCGACTGCCTC 
                 183 
               
               
                   
               
               
                 CGAGCGAGCTTAGTGAACGT 
                 184 
               
               
                   
               
               
                 AGCTGGTCGGTGTTCACTGC 
                 185 
               
               
                   
               
               
                 ATTCAGTCGCGGTTGCGCAC 
                 186 
               
               
                   
               
               
                 TCTCGCTGGTTCAGTCCTTC 
                 187 
               
               
                   
               
               
                 GCATTTCTGGGTAGCTCGCT 
                 188 
               
               
                   
               
               
                 TAGCTGAATCGCCAGGCTTG 
                 189 
               
               
                   
               
               
                 TGGCTCATTCATTGAGTCCA 
                 190 
               
               
                   
               
               
                 CATTGGCTGTTGCTGACT 
                 191 
               
               
                   
               
               
                 TCCATGCCACTTGGTTCACT 
                 192 
               
               
                   
               
               
                 GCCCCTCCTTTCGCTCGTTT 
                 193 
               
               
                   
               
               
                 CGGCCCCTTCCCACTGGCTC 
                 194 
               
               
                   
               
               
                 CGCCAGCTCCCTCCTCATGC 
                 195 
               
               
                   
               
               
                 GTCGCTCCCTCCTTACCGCG 
                 196 
               
               
                   
               
               
                 CCAGCGAACGCCCTCCCGCA 
                 197 
               
               
                   
               
            
           
         
       
     
     In some embodiments, the present disclosure provides an eRBSR comprising any of SEQ ID NOs: 1-20, 21-66, and/or 79-197. Any one of the Rep binding sequence regions listed in Table 1 can function as an eRBSR when substituted into a non-native ITR sequence in place of the native Rep binding sequence regions. In one embodiment, SEQ ID NOs: 3-4 (AAV-5) are inserted into an AAV1, AAV2, AAV3, AAV4, AAV6, AAV7, AAV8, AAV9, AAV10, AAV11, AAV12, AAVrh8, AAVrh10, AAV-DJ, and AAV-DJ8 in place of the native AAV5 Rep binding sequence regions. In other embodiments, SEQ ID NOs: 7-8 (AAV3) are inserted into an AAV1, AAV2, AAV4, AAV5, AAV6, AAV7, AAV8, AAV9, AAV10, AAV11, AAV12, AAVrh8, AAVrh10, AAV-DJ, and AAV-DJ8 in place of the native AAV3 Rep binding sequence regions. In other embodiments, SEQ ID NOs: 9-10 (AAV4) are inserted into an AAV 1. AAV2, AAV3, AAV5, AAV6, AAV7, AAV8, AAV9, AAV10, AAV11, AAV12, AAVrh8, AAVrh10, AAV-DJ, and AAV-DJ8 in place of the native AAV4 Rep binding sequence regions. In other embodiments, SEQ ID NOs: 1-2 (AAV2/ AAV1/ AAV7) are inserted into an AAV3, AAV4, AAV5, AAV6, AAV8, AAV9, AAV10, AAV11, AAV12, AAVrh8, AAVrh10, AAV-DJ, and AAV-DJ8 in place of the native AAV2 Rep binding sequence regions. In other embodiments, SEQ ID NOs: 17-18 (bovine) are inserted into an AAV1, AAV2, AAV3, AAV4, AAV5, AAV6, AAV7, AAV8, AAV9, AAV10, AAV11, AAV12, AAVrh8, AAVrh10, AAV-DJ, and AAV-DJ8 in place of the native Rep binding sequence regions. In other embodiments. SEQ ID NOs: 19-20 (snake) are inserted into an AAV1, AAV2, AAV3, AAV4, AAV5, AAV6, AAV7, AAV8, AAV9, AAV10, AAV11, AAV12, AAVrh8, AAVrh10, AAV-DJ, and AAV-DJ8 in place of the native Rep binding sequence regions. In other embodiments, SEQ ID NOs: 13-14 (avian) are inserted into an AAV1, AAV2, AAV3, AAV4, AAV5, AAV6, AAV7, AAV8, AAV9, AAV10, AAV11, AAV12, AAVrh8, AAVrh10, AAV-DJ, and AAV-DJ8 in place of the native Rep binding sequence regions. 
     In another embodiment, the present disclosure provides an engineered Rep binding sequence region in which one or more nucleotides in any of SEQ II) NOs: 1-20 listed in Table 1 is altered or modified as discussed elsewhere herein. For example, any of the Rep binding sequence regions listed in Table 1 (SEQ ID NOs: 1-20) can be altered by having one or more nucleotide insertions, deletions, substitutions, or any combination thereof as compared to the corresponding native Rep binding sequence region. 100110] In certain embodiments, the engineered Rep binding sequence region is selected from the sequences of SEQ ID NO: 68 (GCGCCGCATGCGGCTC) (αPal, SEQ ID NO: 71 (GAGCGGGGGCGCGCTC) (5-5/EGR) and SEQ ID NO: 74 (CCGACCACGACGACGG) (JcDNVNS1). 
     The eRBSRs provided here can be made by methods commonly known and practiced by those skilled in the art. For example, the eRBSRs provided here can be designed in silico and synthesized using molecular biology techniques well known to those of skill in the art. See, e.g., Sambrook et al, Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Press (Cold Spring Harbor, N.Y.). 
     In any of SEQ ID NOs: 1-291, one or more nucleotides can be altered or modified as provided in the present disclosure. 
     As discussed herein, the Rep binding sequence region of the parvoviral genome is altered and/or modified to decrease the binding of the Rep protein so as to promote the production of a parvovirus having a duplexed or self-complementary genome. Thus, the engineered Rep binding sequence regions (eRBSRs) provided herein comprise at least one nucleic acid sequence that has decreased binding with wild-type and/or engineered Rep protein. In one embodiment, the engineered Rep binding sequence region has decreased binding with a wild-type Rep protein as compared to the binding with the corresponding wild-type or native Rep binding sequence region. In another embodiment, the engineered Rep binding sequence region has decreased binding with an engineered Rep protein as compared to the binding with the corresponding wild-type or native Rep binding sequence region. In another embodiment, the engineered Rep binding sequence region has decreased binding with both wild-type and engineered Rep protein as compared to the respective binding with the corresponding wild-type or native Rep binding sequence region. In one embodiment, the binding affinity of an eRBSR with a wild-type and/or engineered Rep protein is decreased 1-10 fold relative to the binding affinity of the corresponding wild-type or native Rep binding sequence region with the same Rep protein. In one embodiment, the binding affinity is decreased by at least 2-fold. In another embodiment, the binding affinity is decreased by at least 5-fold. In a further embodiment, the binding affinity is decreased by at least 10-fold. In one embodiment, the wild-type Rep protein with which the eRBSR has decreased binding affinity is an AAV Rep protein. In another embodiment, the engineered Rep protein with which the eRBSR has decreased affinity is derived from an AAV Rep protein that has been altered or modified, e.g., having one or more altered or modified nucleotides. In certain embodiments, the wild-type AAV Rep protein is selected from Rep22, Rep68, Rep78, Rep4-0, and Rep52. In certain embodiments, the engineered AAV Rep protein is selected from a Rep 22, Rep68, Rep78, Rep40, and Rep52 that has one or more altered or modified nucleotides. 
     The binding affinity can be measured by several methods well-known in the art, including electro-mobility shift assay and surface plasmon resonance, as described in the Examples section. In one embodiment, the binding affinities of the following polypeptide-polynucleotide pairs are determined using an Octet surface plasmon resonance instrument (ForteBio, Menlo Park, Calif.): wild-type Rep protein and a wild-type Rep binding sequence region, an engineered Rep protein and a wild-type Rep binding sequence region, a wild-type Rep protein and an eRBSR, an engineered Rep protein and an eRBSR. The polynucleotide encoding either a wild-type Rep binding sequence region or an engineered Rep binding sequence region is immobilized on the biosensor layer. A solution is prepared comprising either wild-type Rep protein or engineered Rep protein that is then passed over the biosensor to determine the rate of association (K a ). A second solution devoid of wild-type or Rep protein is passed over the saturated biosensor layer to determine the rate of dissociation (K d ). 1001151 The present disclosure also provides polynucleotides comprising any of the engineered Rep binding sequence regions (eRBSRs) described herein. The polynucleotide can be any deoxyribonucleotide or ribonucleotide polymer or sequence of nucleotide bases, in linear or circular conformation, and in either single- or double-stranded form. The polynucleotide can include natural nucleotides, known maims of natural nucleotides, as well as nucleotides that are modified in the base, sugar, and/or phosphate moieties (e.g., the phosphorothioate backbone). Thus, the polynucleotide can be RNA, DNA or DNA-RNA hybrid sequences that are naturally occurring or non-naturally occurring nucleotides. 
     The polynucleotide comprising the eRBSR can further comprise one or more heterologous sequences. The heterologous sequence can be any sequence that is not native to the viral genome. Heterologous sequences include regulatory sequences, sequences encoding a nucleic acid, such as but not limited to an siRNA, dsRNA, miRNA, antisense, aptamer, and the like, genome editing sequences, sequence encoding a polypeptide (e.g., such as a transgene), functional domain sequences, marker, tag, stuffer sequences, linker sequences. In one embodiment, the heterologous sequence is operatively linked to one or more regulatory sequence(s) that allows expression of the heterologous sequence. 
     In one embodiment, the polynucleotide comprises one or more parvoviral inverted terminal repeat (ITR) sequences wherein one of the ITR sequences comprises an eRBSR. Typically, the FIR sequence comprising the eRBSR also contains a reverse complementary sequence of the eRBSR downstream of the eRBSR such that the eRBSR and the reverse complementary sequence are capable of intra-strand base-pairing. Thus, in one embodiment, the polynucleotide comprises a parvoviral ITR nucleotide sequence comprising an eRBSR wherein the parvoviral ITR nucleotide sequence is capable of forming a double-stranded engineered Rep binding sequence region. In one embodiment, the engineered Rep binding sequence region is located between a 5′ parvoviral inverted terminal repeat sequence and a 3′ parvoviral inverted terminal repeat sequence. In another embodiment, the engineered Rep binding sequence region is located within a parvoviral inverted terminal repeat sequence. 
     The parvoviral inverted terminal repeat sequences)can be a full-length ITR sequence, a partial ITR sequence, or an ITR with an additional sequence, for example, one or more regulatory sequences, one or more functional domain sequence(s) and/or one or more stuffer or linker sequences. The parvoviral inverted terminal repeat sequence(s) can comprise naturally-occurring or wild-type sequence(s) or variant sequence(s), including natural variants and artificial variants, as well as truncated and elongated ITR sequences. The parvoviral ITR sequence can alternatively be modified to include one or more insertions, deletions and/or substitutions. 
     In one embodiment, in a polynucleotide comprising an eRBSR which comprises an ITR sequence, the polynucleotide can further comprise a regulatory sequence or other heterologous sequence, such as a payload sequence. In one embodiment, the heterologous sequence is operatively linked to one or more regulatory sequence(s) that allows expression of the heterologous sequence. In one embodiment, the polynucleotide comprises a first ITR sequence comprising an eRBSR and a second ITR sequence, wherein the heterologous sequence is flanked by the first and second ITR sequences. In any of these embodiments, the ITR sequence can be an adeno-associated virus (AAV) ITR or derived from an adeno-associated virus (AAV) ITR. AAV ITR sequences include any of those having an AAV1, AAV2, AAV3, AAV4, AAV5, AAV6, AAV7, AAV8, AAV9, AAV10, AAV11, AAV12, AAVrh8, AAVrh10, AAV-DJ, and AAV-DJ8 ITR sequence or a sequence derived therefrom. 
     In one embodiment, the parvoviral polynucleotide comprises in the 5′ to 3′ direction: (a) a 5′ parvoviral inverted terminal repeat sequence; (b) a first payload encoding region; (c) an engineered Rep binding sequence region; (d) a second payload encoding region; and (e) a 3′ parvoviral inverted terminal repeat sequence. In this embodiment, the first and second payload encoding regions are essentially self-complementary and may form a hairpin structure that comprises the parvoviral polynucleotide. In one embodiment, the parvoviral polynucleotide (e.g., a parvoviral genome) is an AAV polynucleotide, genome or parvoviral particle. 
     The designations of 5′ and 3′ with respect to the ITR sequences are also referred to as “left” and “right” ITR. The 5′ and 3′ wild-type ITR sequences encoded by ssDNA and dsDNA are reverse complements of each other that encode identical secondary structures. The AAV2 ssDNA genome, for example, comprises a TT dimer Rep nicking site within the nicking stem loop sequence of one ITR and a complementary AA dimer within the nicking stem loop sequence of the second ITR. As discussed herein, Rep protein only nicks AAV2 ssDNA at the TT dimer Rep nicking site. As used herein, the term 3′ or “right” designates the ITR comprising the Rep nicking site. 
     In one embodiment, the transgene or payload sequence encodes human aromatic L-amino acid decarboxylase. In another embodiment, the transgene or payload sequence encodes human SOD1. In another embodiment, the transgene or payload sequence encodes human frataxin (FXN). 
     The present disclosure provides a polynucleotide comprising an eRBSR in which the binding affinity of a Rep protein (wild-type or engineered) to the eRBSR is decreased relative to the binding of a polynucleotide comprising a wild-type or native Rep binding sequence region. In one embodiment, the binding affinity is decreased 1-10 fold relative to a polynucleotide comprising a wild-type Rep binding sequence region. In one embodiment, the binding affinity is decreased at least 2-fold. In another embodiment, the binding affinity is decreased at least 5-fold. In a further embodiment, the binding affinity is decreased at least 10-fold. In one embodiment, the Rep protein is Rep68 or Rep78. In one embodiment, the wild-type AAV Rep protein is selected from Rep 22. Rep68, Rep78, Rep40, and Rep52. In another embodiment, the engineered AAV Rep protein is selected from a Rep 22. Rep68, Rep78, Rep40. and Rep52 that has one or more altered or modified nucleotides. 
     The present disclosure also provides a polynucleotide comprising an engineered Rep binding sequence region in which the nicking by a Rep protein (wild-type or engineered) decreased relative to the nicking of a polynucleotide comprising a wild-type Rep binding sequence region. In one embodiment, the nicking is decreased 1-10 fold relative to the nicking of a polynucleotide comprising a wild-type Rep binding sequence region. In one embodiment, the nicking is decreased by at least 2-fold. In another embodiment, the nicking is decreased by at least 5-fold. In a further embodiment, the nicking is decreased by at least 10-fold. In one embodiment, the Rep protein is Rep68 or Rep78. In one embodiment, the Rep protein is Rep68 or Rep78. in one embodiment, the wild-type AAV Rep protein is selected from Rep 22, Rep68, Rep78, Rep40, and Rep52. In another embodiment, the engineered AAV Rep protein is selected from a Rep 22, Rep68, Rep78, Rep40, and Rep52 that has one or more altered or modified nucleotides. 
     The present disclosure also provides polynucleotide comprising an engineered. Rep binding sequence region in which the presence of the engineered Rep binding sequence region results in an increase in the generation of self-complementary AAV genomes during viral genome replication. 
     In any of the above-described embodiments, the polynucleotide is an AAV polynucleotide or derived from an AAV polynucleotide. AAV polynucleotides include those of AAV1, AAV2, AAV3, AAV4, AAV 5, AAV6, AAV7, AAV8, AAV9, AAV10, AAV11, AAV12, AAVrh8, AAVrh10, AAV-DJ, and AAV-DJ8. 
     In one embodiment, the serotype which may be useful in the present invention may be AAV-DJ8. The amino acid sequence of AAV-DJ8 may comprise two or more mutations in order to remove the heparin binding domain (HBD). As a non-limiting example, the AAV-DJ sequence described as SEQ ID NO: 1 in U.S. Pat. No. 7,588,772, the contents of which are herein incorporated by reference in their entirety, may comprise two mutations: (1) R587Q where arginine (R; arg) at amino acid 587 is changed to glutamine (Q; gin) and (2) R590T where arginine (R; arg) at amino acid 590 is changed to threonine (T; thr). As another non-limiting example, the AAV-DJ sequence may comprise three mutations: (1) K406R where lysine (K; lys) at amino acid 406 is changed to arginine (R; arg), (2) R587Q where arginine (R; arg) at amino acid 587 is changed to glutamine (Q; gln) and (3) 85901 where arginine (R; arg) at amino acid 590 is changed to threonine (T; thr). 
     Swapped Nicking Stem Loop 
     Parvoviral ITR sequences comprise a short self-complementary region that forms a secondary structure loop required for nicking single stranded DNA during the course of replication as discussed previously: The nicking stem loop sequence varies between parvoviral serotypes and may be between about 20-25 nucleotides in length spanning the border between the A and D regions of the parvoviral genome. Complementary sequences of about 6-10 nucleotides form the stem of the secondary structure. The loop at the top of the stem is a non-complementary sequence of about 3-6 nucleotides that further comprises the terminal resolution site where the nicking of the phosphodiester backbone occurs. The terminal resolution site, or nicking site, of the AAV2 genome is a TT dimer that is located at the end of the ITR A region adjacent to the D region. This TT dimer is also present in the AAV1, AAV3, AAV4, and AAV7 genomes. An alternative nicking stem loop and nicking site is exemplified by AAV5, wherein the nicking site is a GT dimer. Nicking of the parvoviral genome only occurs at the nicking site, TT or GT, comprised within the nicking stem loop sequence that spans the A and D regions. Nicking of the parvoviral genome does not occur at the reverse complementary nicking site, AA or AC, comprised within a reverse complementary nicking stem loop sequence that spans the A and D regions. 
     Parvoviral serotypes with closely related genomes encode Rep proteins that are complementary. For example, An AAV2 Rep protein may productively promote replication of an AAV3 genome by binding to the AAV3 genome Rep binding sequence and cutting the nicking stein loop at the nicking site. However, some parvoviral serotypes encode Rep proteins that recognize heterologous Rep binding sequence regions, nicking stem loops, and nicking sites that are not cross-complementary. In one example, an AAV2 Rep protein may not nick the nicking stem loop of an AAV5 genome due to the lack of the TT dimer. 
     Accordingly, one way to promote the generation of self-complementary parvoviral genome sequences is to alter or modify the Rep nicking stem loop such that nicking by a heterologous Rep protein is abolished, consequently promoting the generation of self-complementary parvoviral genome sequences as discussed above in the previous section. The present disclosure thus provides a chimeric, altered, or modified Rep nicking stem loop sequence designed to decrease or abolish the nicking activity of the Rep protein. 
     Typically, the Rep nicking stem loop sequence of a parvoviral genome is from about 20 to about 2.5 nucleotides in length. The present disclosure accordingly provides a chimeric, altered, or modified Rep nicking stem loop sequence that is from about 20 to about 25 nucleotides in length. In one embodiment, the chimeric, altered, or modified Rep nicking sequence is from 20 to 25 nucleotides in length. 
     The present disclosure provides a nucleic acid comprising a Rep nicking stem loop in which one or more of the nucleotides in the nicking stem loop are altered or modified as compared to the native nicking stem loop. An “altered” nucleotide can be any nucleotide having a naturally or non-naturally occurring nucleoside selected from adenosine, guanosine, uridine, cytidine, thymidine, as long as it differs from the native nucleoside. Methods for producing nucleic acid sequences with altered nucleosides have been discussed herein in the previous section. A modified nucleotide refers to a nucleotide that has been chemically modified, in which the modification can be on the nucleobase, and/or the sugar, and/or on the backbone of the nucleotide. The chemical modification can be any chemical modification used to modify nucleic acids. Examples of suitable chemical modifications have been provided herein in the previous section, along with methods for chemically modifying a nucleic acid. 
     In one embodiment, the Rep nicking stem loop sequence has a single altered or modified nucleotide as compared to the native Rep nicking stem loop sequence. In another embodiment, the Rep nicking stem loop sequence has two or more altered or modified nucleotides as compared to the native Rep nicking stein loop sequence. In certain embodiments, the Rep nicking stem loop sequence has two to twenty five altered or modified nucleotides, including, for example, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25 altered or modified nucleotides as compared to the native Rep nicking stem loop sequence. In one embodiment, all of the nucleotides of the Rep nicking stem loop sequence are altered or modified. 
     In another embodiment, the Rep nicking sequence has one or more nucleotide insertions, deletions, substitutions, or any combination thereof as compared to the corresponding native Rep nicking sequence. In one embodiment, the Rep nicking sequence can comprise a sequence having one or more nucleotides that differ from the Rep nicking sequence of an adeno-associated virus (AAV), including the Rep nicking sequence of AAV 1, AAV2, AAV3, AAV4, AAV5, AAV6, AAV7, AAV8, AAV9, AAV10, AAV11, AAV12, AAVrh8, AAVrh10, AAV-DJ, and AAV-DJ8. 
     In other embodiments, the Rep nicking stem loop can comprise a sequence having both alterations and chemical modifications. Thus, in one embodiment, the Rep nicking stem loop comprises one or more nucleotides that are altered and one or more nucleotides that are chemically modified. 
     The present disclosure further provides a chimeric nicking stem loop, in which the Rep nicking stem loop is not native to the parvoviral genome. In one embodiment, the invention provides a chimeric nicking stem loop in which the chimeric nicking stem loop is from a parvoviral serotype or species that differs from the serotype or species of the native parvoviral ITR sequence. In one embodiment, the chimeric nicking stem loop is from a parvoviral serotype or species that differs from the serotype or species of the native Rep protein or sequence encoding the Rep protein. The chimeric nicking stem loop is created by substituting or swapping the native Rep nicking stem loop with the Rep nicking stem loop of a different serotype or species. In one embodiment, the entire Rep nicking stem loop is swapped. In another embodiment, a portion of the Rep nicking stem loop is swapped. In another embodiment, the Rep nicking stein loop comprises a non-native or swapped Rep nicking stein loop from an AAV viral genome, including but not limited to the Rep nicking stem loop of AAV1, AAV2, AAV3, AAV4, AAV5, AAV6, AAV7, AAV8, AAV9, AAV10, AAV11, AAV12, AAVrh8, AAVrh10, AAV-DJ, and AAV-DJ8. 
     The Rep nicking stein loops found in various AAV serotypes and species are shown in  FIG. 3  and  FIG. 4  and provided in Table 4. The genome sequences of several different AAV serotypes and species including AAV1, AAV2, AAV3, AAV4, AAV5, AAV7, AAV8, Bat AAV, Bovine AAV, Snake AAV, Avian AAV DA-1, and Avian AAV VR865 (SEQ ID NO: 280-291) were obtained from the NCBI Genome database. The 5′ and 3′ inverted terminal repeat sequences of selected genomes were aligned with the Clustal Omega multiple sequence alignment program using either AAV2 or AAV5 as the parent sequence, as shown in  FIG. 3  and  FIG. 4 , respectively. Additional Rep nicking stem loops found in the ITR sequences of other parvoviral serotypes and species, including AAV8 5′ ITR (SEQ ID NO: 253), AAV8 3′ ITR (SEQ ID NO: 254), Bat AAV 5′ ITR (SEQ ID NO: 261), Bat AAV 3′ ITR (SEQ ID NO: 262) are obtained in the same manner using this alignment program. 
     
       
         
           
               
             
               
                 TABLE 4 
               
             
            
               
                   
               
               
                 Native or Wild-Type Rep Nicking Stem Loop 
               
               
                 Sequences 
               
            
           
           
               
               
               
            
               
                   
                   
                 SEQ 
               
               
                 Name 
                 Sequence 
                 ID NO 
               
               
                   
               
               
                 AAV2 5′ 
                 AGAGGGAGTGGCCAACTCCATCA 
                 198 
               
               
                   
               
               
                 AAV2 3′ 
                 TGATGGAGTTGGCCACTCCCTCT 
                 199 
               
               
                   
               
               
                 AAV5 5′ 
                 GGGGGAGAGTGCCACACTCTCA 
                 200 
               
               
                   
               
               
                 AAV5 3′ 
                 TGAGAGTGTGGCACTCTCCCCC 
                 201 
               
               
                   
               
               
                 AAV1 5′ 
                 AGAGGGAGTGGGCAACTCCATCA 
                 202 
               
               
                   
               
               
                 AAV1 3′ 
                 TGATGGAGTTGCCCACTCCCTCT 
                 203 
               
               
                   
               
               
                 AAV3 5′ 
                 AGAGGGAGTGGCCAACTCCATCA 
                 204 
               
               
                   
               
               
                 AAV3 3′ 
                 TGATGGAGTTGGCCACTCCCTCT 
                 205 
               
               
                   
               
               
                 AAV4 5′ 
                 AGAGGGAGTGGCCAACTCCATCA 
                 206 
               
               
                   
               
               
                 AAV4 3′ 
                 TGATGGAGTTGGCCACATTAGCT 
                 207 
               
               
                   
               
               
                 AAV7 5′ 
                 AGAGGGAGTGGCCAACTCCATCA 
                 208 
               
               
                   
               
               
                 AAV7 3′ 
                 AATGGAGTTGGCCACTCCCTCT 
                 209 
               
               
                   
               
               
                 Avian AAV Strain 
                 ACTGGCCAGCACTCCGGTGA 
                 210 
               
               
                 DA1 5′ 
                   
                   
               
               
                   
               
               
                 Avian AAV Strain 
                 TCACCGGAGTGCTGGCCAGT 
                 211 
               
               
                 DA1 3′ 
                   
                   
               
               
                   
               
               
                 Avian AAV ATCC 
                 ACTGGCCAGCACTCCGGTGA 
                 212 
               
               
                 VR-865 5′ 
                   
                   
               
               
                   
               
               
                 Avian AAV ATCC 
                 TCACCGGAGTGCTGGCCAGT 
                 213 
               
               
                 VR-865 3′ 
                   
                   
               
               
                   
               
               
                 Bovine AAV 5′ 
                 GGGGGGGAGTGCCACACTCTCT 
                 214 
               
               
                   
               
               
                 Bovine AAV 3′ 
                 AGAGAGTGTGGCACTCCCCCCC 
                 215 
               
               
                   
               
               
                 Snake AAV 5′ 
                 TGGGGCGAGTGCCCTGCTC 
                 216 
               
               
                   
               
               
                 Snake AAV 3′ 
                 GAGCAGGGCACTCGCCCCA 
                 217 
               
               
                   
               
            
           
         
       
     
     Based on the sequence alignments, several different Rep nicking stern loops were identified (see boxed sequence in  FIG. 3  and  FIG. 4 ). The Rep nicking stem loops for AAV2, AAV I, AAV3, and AAV7 share the same nicking stem loop sequence: AGAGGGAGTGGCCAACTCCATCA (SEQ ID NO: 198) on the 5′ ITR and its reverse complement TGATGGAGTFGGCCACTCCCTCT (SEQ ID NO:199) on the 3′ITR. AAV-4 has the same nicking sequence on the 5′ ITR and a slightly different sequence on the 3′ ITR (TGATGGAGTTGGCCACATTAGCT; SEQ ID NO: 207). The Rep nicking stem loop for AAV5 is GGGGGAGAGTGCCACACTCTCA (SEQ IF) NO: 200) on the 5′ ITR and its reverse complement TGAGAGTGIGGCACTCTCCCCC (SEQ ID NO: 201) on the 3′ ITR. The Rep nicking stein loop for bovine AAV is GGGGGGGAGTGCCACACTCTCT (SEQ ID NO: 214) on the 5′ ITR and its reverse complement is AGAGAGTGTGGCACTCCCCCCC (SEQ ID NO: 215) on the 3′ ITR. The Rep nicking stem loop for snake AAV is TGGGGCGAGTGCCCTGCTC (SEQ ID NO: 216) on the 5′ ITR and its reverse complement is GAGCAGGGCACTCGCCCCA (SEQ ID NO: 217) on the 3′ ITR. The Rep nicking stem loop for avian AAV (AAVDA1 and VR865) is ACTGGCCAGCACTCCGGTGA (SEQ ID NO: 210) on the 5′ ITR and its reverse complement is TCACCGGAGTGCTGGCCAGT (SEQ ID NO: 211) on the 3′ ITR. In one embodiment, the Rep nicking stem loop comprises any of SEQ ID NOs: 21-66. In another embodiment, the Rep nicking stem loop comprises any of SEQ ID NOs: 198-217, in which one or more nucleotides are altered or modified. 
     The chimeric nicking stem loop is achieved by swapping the nicking stem loop sequence of one parvoviral serotype or species with the native nicking stem loop sequence of a different parvoviral serotype or species. In one embodiment, the nicking stem loop sequence of any of SEQ ID NOs: 198-217 (listed in above paragraph) is swapped with the native nicking stem loop sequence of a different parvoviral serotype or species. In one embodiment, the nicking stem loop for AAV2 (SEQ ID NO: 199) (which is the same nicking stem loop for AAV1, AAV3, and AAV7) is swapped into (replaces all or a portion of) the native nicking stem loop sequence in any of the following ITR sequences: AAV4, AAV5, AAV6, AAV8, AAV9, AAV10, AAV11, AAV12, AAVrh8, AAVrh10, AAV-DJ, and AAV-DJ8 ITR. In another embodiment, the nicking stem loop for AAV4 (SEQ ID NO: 207) is swapped into (replaces all or a portion of) the native nicking stein loop sequence in any of the following ITR sequences: AAV1, AAV2, AAV3, AAV5, AAV6, AAV7, AAV8, AAV9, AAV10, AAV11, AAV12, AAVrh8, AAVrh10, AAV-DJ, and AAV-DJ8 ITR. In another embodiment, the nicking stem loop for AAV5 (SEQ ID NO: 201) is swapped into (replaces all or a portion of) the native nicking stein loop sequence in any of the following ITR sequences: AAV1, AAV2, AAV3, AAV4, AAV6, AAV7, AAV8, AAV9, AAV10, AAV11, AAV12, AAVrh8, AAVrh10, AAV-DJ, and AAV-DJ8 HR. In an additional embodiment, the nicking stem loop for bovine AAV (SEQ ID NO: 215) is swapped into (replaces all or a portion of) the native nicking stem loop sequence in any of the following ITR sequences: AAV1, AAV2, AAV3, AAV4, AAV5, AAV6, AAV7, AAV8, AAV9, AAV10, AAV11, AAV12, AAVrh8, AAVrh10, AAV-DJ, and AAV-DJ8 ITR. In yet another embodiment, the nicking stem loop for snake AAV (SEQ ID NO: 217) is swapped into (replaces all or a portion of) the native nicking stem loop sequence in any of the following ITR sequences: AAV1, AAV2, AAV3, AAV4, AAV5, AAV6, AAV7, AAV8, AAV9, AAV10, AAV11, AAV12, AAVrh8, AAVrh10, AAV-DJ, and AAV-DJ8 ITR. In still another embodiment, the nicking stem loop for avian AAVDA1 or avian AAVVR865 (SEQ ID NO: 211) is swapped into (replaces all or a portion of) the native nicking stem loop sequence in any of the following ITR sequences: AAV1, AAV2, AAV3, AAV4, AAV5, AAV6, AAV7, AAV8, AAV9, AAV10, AAV11, AAV12, AAVrh8, AAVrh10, AAV-DJ, and AAV-DJ8 ITR. 
     In other embodiments, the polynucleotide comprising the chimeric nicking stein loop comprises any of SEQ ID NOs: 218-240. (Table 5). In one embodiment, the nicking stem loop for AAV2 is swapped with (replaces all of) the native nicking stem loop sequence of the AAV5 ITR sequence (SEQ ID NO: 218). In one embodiment, the nicking stem loop for AAV4 is swapped with (replaces all of) the native nicking stem loop sequence of the AAV5 ITR sequence (SEQ ID NO: 219). In one embodiment, the nicking stem loop for AAV2 is swapped with (replaces all of) the native nicking stem loop sequence of the AAV4 ITR sequence (SEQ ID NO: 220). In one embodiment, the nicking stem loop for AAV5 is swapped with (replaces all of) the native nicking stem loop sequence of the AAV2 ITR sequence (SEQ ID NO: 221). In one embodiment, the nicking stem loop for AAV5 is swapped with (replaces all of) the native nicking stem loop sequence of the AAV1 ITR sequence (SEQ ID NO: 222). In one embodiment, the nicking stem loop for AAV5 is swapped with (replaces all of) the native nicking stem loop sequence of the AAV3 ITR sequence (SEQ ID NO: 223). In one embodiment, the nicking stem loop for AAV5 is swapped with (replaces all of) the native nicking stem loop sequence of the AAV4 ITR sequence (SEQ ID NO: 224). In one embodiment, the nicking stem loop for AAV5 is swapped with (replaces all of) the native nicking stem loop sequence of the AAV7 ITR sequence (SEQ ID NO: 225). In one embodiment, the nicking stem loop for Bovine AAV is swapped with (replaces all of) the native nicking stem loop sequence of the AAV2 ITR sequence (SEQ ID NO: 226). In one embodiment, the nicking stem loop for Bovine AAV is swapped with (replaces all of) the native nicking stem loop sequence of the AAV1 ITR sequence (SEQ ID NO: 227). In one embodiment, the nicking stem loop for Bovine AAV is swapped with (replaces all of) the native nicking stem loop sequence of the AAV3 ITR sequence (SEQ ID NO: 228). In one embodiment, the nicking stem loop for Bovine AAV is swapped with (replaces all of) the native nicking stem loop sequence of the AAV4 ITR sequence (SEQ ID NO: 229). In one embodiment, the nicking stem loop for Bovine AAV is swapped with (replaces all of) the native nicking stem loop sequence of the AAV7 ITR sequence (SEQ ID NO: 230). In one embodiment, the nicking stem loop for Snake AAV is swapped with (replaces all of) the native nicking stem loop sequence of the AAV2 ITR sequence (SEQ ID NO: 231). In one embodiment, the nicking stein loop for Snake AAV is swapped with (replaces all of) the native nicking stem loop sequence of the AAV1 ITR sequence (SEQ ID NO: 232). In one embodiment, the nicking stem loop for Snake AAV is swapped with (replaces all of) the native nicking stem loop sequence of the AAV3 ITR sequence (SEQ ID NO: 233). In one embodiment, the nicking stem loop for Snake AAV is swapped with (replaces all of) the native nicking stem loop sequence of the AAV4 ITR sequence (SEQ NO: 234). In one embodiment, the nicking stem loop for Snake AAV is swapped with (replaces all of) the native nicking stem loop sequence of the AAV7 ITR sequence (SEQ ID NO: 235). In one embodiment, the nicking stem loop for Avian AAV is swapped with (replaces all of) the native nicking stem loop sequence of the AAV2 ITR sequence (SEQ NO: 236). In one embodiment, the nicking stem loop for Avian AAV is swapped with (replaces all of) the native nicking stem loop sequence of the AAV1 ITR sequence (SEQ ID NO: 237). In one embodiment, the nicking stem loop for Avian AAV is swapped with (replaces all of) the native nicking stem loop sequence of the _AAV3 ITR sequence (SEQ ID NO: 238). In one embodiment, the nicking stem loop for Avian AAV is swapped with (replaces all of) the native nicking stem loop sequence of the AAV4 ITR sequence (SEQ ID NO: 239). In one embodiment, the nicking stem loop for Avian AAV is swapped with (replaces all of the native nicking stem loop sequence of the AAV7 ITR sequence (SEQ ID NO: 240). 
     
       
         
           
               
             
               
                 TABLE 5 
               
             
            
               
                   
               
               
                 Chimeric Rep Stem Loop Sequences 
               
            
           
           
               
               
               
               
            
               
                   
                 Donor 
                   
                   
               
               
                 Acceptor 
                 Nicking Stem 
                   
                 SEQ ID 
               
               
                 ITR 
                 Loop 
                 Chimeric Sequence 
                 NO 
               
               
                   
               
               
                 AAV5 
                 AAV2 
                 TACAAAACCCCCTTGCT TGATGGAGTTGGCCACTCCCT   
                 218 
               
               
                   
                   
                   CT CTGTCGCGTTCGCTCGCTCGCTGGCTCGTTTGGGGGG 
                   
               
               
                   
                   
                 GCGACGGCCAGAGGGCCGTCGTCTGGCAGCTCTTTGAG 
                   
               
               
                   
                   
                 CTGCCACCCCCCCAAACGAGCCAGCGAGCGAGCGAAC 
                   
               
               
                   
                   
                 GCGACAGGGGGGAGAG 
                   
               
               
                   
               
               
                 AAV5 
                 AAV4 
                 TACAAAACCCCCTTGCT TGATGGAGTTGGCCACATTACT   
                 219 
               
               
                   
                   
                   CT CTGTCGCGTTCGCTCGCTCGCTGGCTCGTTTGGGGGG 
                   
               
               
                   
                   
                 GCGACGGCCAGAGGGCCGTCGTCTGGCAGCTCTTTGAG 
                   
               
               
                   
                   
                 CTGCCACCCCCCCAAACGAGCCAGCGAGCGAGCGAAC 
                   
               
               
                   
                   
                 GCGACAGGGGGGAGAG 
                   
               
               
                   
               
               
                 AAV4 
                 AAV2 
                 TGGCAAACCAGA TGATGGAGTTGGCCACTCCCTCT ATG 
                 220 
               
               
                   
                   
                 CGCGCTCGCTCACTCACTCGGCCCTGGAGACCAAAGGT 
                   
               
               
                   
                   
                 CTCCAGACTGCCGGCCTCTGGCCGGCAGGGCCGAGTGA 
                   
               
               
                   
                   
                 GTGAGCGAGCGCGCATAGAGGGAGTGGCCAA 
                   
               
               
                   
               
               
                 AAV2 
                 AAV5 
                 AGGAACCCCTAG TGAGAGTGTGGCACTCTCCCCC CTGC 
                 221 
               
               
                   
                   
                 GCGCTCGCTCGCTCACTGAGGCCGCCCGGGCAAAGCCC 
                   
               
               
                   
                   
                 GGGCGTCGGGCGACCTTTGGTCGCCCGGCCTCAGTGAG 
                   
               
               
                   
                   
                 CGAGCGAGCGCGCAGAGAGGGAGTGGCCAA 
                   
               
               
                   
               
               
                 AAV1 
                 AAV5 
                 TTACCCCTAG TGAGACTTGTGGCACTCTCCCCC CTGCGC 
                 222 
               
               
                   
                   
                 GCTCGCTCGCTCGGTGGGGCCGGCAGAGCAGAGCTCTG 
                   
               
               
                   
                   
                 CCGTCTGCGGACCTTTGGTCCGCAGGCCCCACCGAGCG 
                   
               
               
                   
                   
                 AGCGAGCGCGCAGAGAGGGAGTGGGCAA 
                   
               
               
                   
               
               
                 AAV3 
                 AAV5 
                 GCCATACCTCTAG TGAGAGTGTGCACTCTCCCCC ATG 
                 223 
               
               
                   
                   
                 CGCACTCGCTCGCTCGGTGGGGCCGGACGTGCAAAGCA 
                   
               
               
                   
                   
                 CGTCCGTCTGGCGACCTTTGGTCGCCAGGCCCCACCGA 
                   
               
               
                   
                   
                 GCGAGCGAGTGCGCATAGAGGGAGTGGCCAA 
                   
               
               
                   
               
               
                 AAV4 
                 AAV5 
                 TGGCAAACCAGA TGAGAGTGTGGCACTCTCCCCC ATGC 
                 224 
               
               
                   
                   
                 GCGCTCGCTCACTCACTCGGCCCTGGAGACCAAAGGTC 
                   
               
               
                   
                   
                 TCCAGACTGCCGGCCTCTGGCCGGCAGGGCCGAGTGAG 
                   
               
               
                   
                   
                 TGAGCGAGCGCGCATAGAGGGAGTGGCCAA 
                   
               
               
                   
               
               
                 AAV7 
                 AAV5 
                 CGCGGTACCCCTAG TGAGAGTGTGGCACTCTCCCCC AT 
                 225 
               
               
                   
                   
                 GCGCGCTCGCTCGCTCGGTGGGGCCGGCAGAGCAGAG 
                   
               
               
                   
                   
                 CTCTGCCGTCTGCGGACCTTTGGTCCGCAGGCCCCACC 
                   
               
               
                   
                   
                 GAGCGAGCGAGCGCGCATAGAGGGAGTGGCCAA 
                   
               
               
                   
               
               
                 AAV2 
                 Bovine 
                 AGGAACCCCTAG AGAGAGTGTGGCACTCCCCCCC CTGC 
                 226 
               
               
                   
                   
                 GCGCTCGCTCGCTCACTGAGGCCGCCCGGGCAAAGCCC 
                   
               
               
                   
                   
                 GGGCGTCGGGCGACCTTTGGTCGCCCGGCCTCAGTGAG 
                   
               
               
                   
                   
                 CGAGCGAGCGCGCAGAGAGGGAGTGGCCAA 
                   
               
               
                   
               
               
                 AAV1 
                 Bovine 
                 TTACCCCTAG AGAGAGTGTGGCACTCCCCCCC CTGCGC 
                 227 
               
               
                   
                   
                 GCTCGCTCGCTCGGTGGGGCCGGCAGAGCAGAGCTCTG 
                   
               
               
                   
                   
                 CCGTCTGCGGACCTTTGGTCCGCAGGCCCCACCGAGCG 
                   
               
               
                   
                   
                 AGCGAGCGCGCAGAGAGGGAGTGGGCAA 
                   
               
               
                   
               
               
                 AAV3 
                 Bovine 
                 GCCATACCTCTAG AGAGAGTGTGGCACTCCCCCCC ATG 
                 228 
               
               
                   
                   
                 CGCACTCGCTCGCTCGGTGGGGCCGGACGTGCAAAGCA 
                   
               
               
                   
                   
                 CGTCCGTCTGGCGACCTTTGGTCGCCAGGCCCCACCGA 
                   
               
               
                   
                   
                 GCGAGCGAGTGCGCATAGAGGGAGTGGCCAA 
                   
               
               
                   
               
               
                 AAV4 
                 Bovine 
                 TGGCAAACCAGA AGAGAGTGTGGCACTCCCCCCC ATGC 
                 229 
               
               
                   
                   
                 GCGCTCGCTCACTCACTCGGCCCTGGAGACCAAAGGTC 
                   
               
               
                   
                   
                 TCCAGACTGCCGGCCTCTGGCCGGCAGGGCCGAGTGAG 
                   
               
               
                   
                   
                 TGAGCGAGCGCGCATAGAGGGAGTGGCCAA 
                   
               
               
                   
               
               
                 AAV7 
                 Bovine 
                 CGCGGTACCCCTAG AGAGAGTGTGGCACTCCCCCCC AT 
                 230 
               
               
                   
                   
                 GCGCGCTCGCTCGCTCGGTGGGGCCGGCAGAGCAGAG 
                   
               
               
                   
                   
                 CTCTGCCGTCTGCGGACCTTTGGTCCGCAGGCCCCACC 
                   
               
               
                   
                   
                 GAGCGAGCGAGCGCGCATAGAGGGAGTGGCCAA 
                   
               
               
                   
               
               
                 AAV2 
                 Snake 
                 AGGAACCCCTAG GAGCAGGGCACTCGCCCCA CTGCGC 
                 231 
               
               
                   
                   
                 GCTCGCTCGCTCACTGAGGCCGCCCGGGCAAAGCCCGG 
                   
               
               
                   
                   
                 GCGTCGGGCGACCTTTGGTCGCCCGGCCTCAGTGAGCG 
                   
               
               
                   
                   
                 AGCGAGCGCGCAGAGAGGGAGTGGCCAA 
                   
               
               
                   
               
               
                 AAV1 
                 Snake 
                 TTACCCTTAG AGAGAGTCTGGCACTCCCCCCCC TGCGC 
                 232 
               
               
                   
                   
                 GCTCGCTCGCTCGGTGGGGCCGGCAGAGCAGAGCTCTG 
                   
               
               
                   
                   
                 CCGTCTGCGGACCTTTGGTCCGCAGGCCCCACCGAGCG 
                   
               
               
                   
                   
                 AGCGAGCGCGCAGAGAGGGAGTGGGCAA 
                   
               
               
                   
               
               
                 AAV3 
                 Snake 
                 GCCATACCTCTAG GAGCAGGGCACTCGCCCCA ATGCGC 
                 233 
               
               
                   
                   
                 ACTCGCTCGCTCGGTGGGGCCGGACGTGCAAAGCACGT 
                   
               
               
                   
                   
                 CCGTCTGGCGACCTTTGGTCGCCAGGCCCCACCGAGCG 
                   
               
               
                   
                   
                 AGCGAGTGCGCATAGAGGGAGTGGCCAA 
                   
               
               
                   
               
               
                 AAV4 
                 Snake 
                 TGGCAAACCAGA GAGCAGGGCACTCGCCCCA ATGCGC 
                 234 
               
               
                   
                   
                 GCTCGCTCACTCACTCGGCCCTGGAGACCAAAGGTCTC 
                   
               
               
                   
                   
                 CAGACTGCCGGCCTCTGGCCGGCAGGGCCGAGTGAGT 
                   
               
               
                   
                   
                 GAGCGAGCGCGCATAGAGGGAGTGGCCAA 
                   
               
               
                   
               
               
                 AAV7 
                 Snake 
                 CGCGGTACCCCTAG GAGCAGGGCACTCGCCCCA ATGCG 
                 235 
               
               
                   
                   
                 CGCTCGCTCGCTCGGTGGGGCCGGCAGAGCAGAGCTCT 
                   
               
               
                   
                   
                 GCCGTCTGCGGACCTTTGGTCCGCAGGCCCCACCGAGC 
                   
               
               
                   
                   
                 GAGCGAGCGCGCATAGAGGGAGTGGCCAA 
                   
               
               
                   
               
               
                 AAV2 
                 Avian 
                 AGGAACCCCTAG TCACCGGAGTGCTGGCCAGT CTGCGC 
                 236 
               
               
                   
                   
                 GCTCGCTCGCTCACTGAGGCCGCCCGGGCAAAGCCCGG 
                   
               
               
                   
                   
                 GCGTCGGGCGACCTTTGGTCGCCCGGCCTCAGTGAGCG 
                   
               
               
                   
                   
                 AGCGAGCGCGCAGAGAGGGAGTGGCCAA 
                   
               
               
                   
               
               
                 AAV1 
                 Avian 
                 TTACCCCTAG TCACCGGAGTGCTGGCCAGT CTGCGCGC 
                 237 
               
               
                   
                   
                 TCGCTCGCTCGGTGGGGCCGGCAGAGCAGAGCTCTGCC 
                   
               
               
                   
                   
                 GTCTGCGGACCTTTGGTCCGCAGGCCCCACCGAGCGAG 
                   
               
               
                   
                   
                 CGAGCGCGCAGAGAGGGAGTGGGCAA 
                   
               
               
                   
               
               
                 AAV3 
                 Avian 
                 GCCATACCTCTAG TCACCGGAGTGCTGGCCAGT ATGCG 
                 238 
               
               
                   
                   
                 CACTCGCTCGCTCGGTGGGGCCGGACGTGCAAAGCACG 
                   
               
               
                   
                   
                 TCCGTCTGGCGACCTTTGGTCGCCAGGCCCCACCGAGC 
                   
               
               
                   
                   
                 GAGCGAGTGCGCATAGAGGGAGTGGCCAA 
                   
               
               
                   
               
               
                 AAV4 
                 Avian 
                 TGGCAAACCAGA TCACCGGAGTGCTGGCCAGT ATGCGC 
                 239 
               
               
                   
                   
                 GCTCGCTCACTCACTCGGCCCTGGAGACCAAAGGTCTC 
                   
               
               
                   
                   
                 CAGACTGCCGGCCTCTGGCCGGCAGGGCCGAGTGAGT 
                   
               
               
                   
                   
                 GAGCGAGCGCGCATAGAGGGAGTGGCCAA 
                   
               
               
                   
               
               
                 AAV7 
                 Avian 
                 CGCGGTACCCCTAG TCACCGGAGTGCTGGCCAGT ATGC 
                 240 
               
               
                   
                   
                 GCGCTCGCTCGCTTCGGTGGGGCCGGCAGAGCAGAGCTC 
                   
               
               
                   
                   
                 TGCCGTCTGCGGACCTTTGGTCCGCAGGCCCCACCGAG 
                   
               
               
                   
                   
                 CGAGCGAGCGCGCATAGAGGGAGTGGCCAA 
               
               
                   
               
            
           
         
       
     
     IV. ENGINEERED REP PROTEIN AND POLYNUCLEOTIDES 
     The present disclosure also provides a polypeptide comprising an engineered Rep protein and a polynucleotide encoding the polypeptide comprising the engineered. Rep protein. The engineered Rep protein of the present disclosure comprises at least one amino acid that is altered or modified as compared to the corresponding wild-type Rep protein. In one embodiment, the engineered Rep protein comprises one or more amino acids involved with DNA binding that are altered or modified as compared to the corresponding wild-type Rep protein. The engineered Rep protein has decreased binding to its cognate Rep binding sequence region and, as a consequence, promotes the formation of a self-complementary viral genome during replication. 
     Rep protein is an essential viral protein that catalyzes several reactions during viral replication. The N-terminal domain of Rep protein, consisting of about the first 200 amino acids, has site-specific endonuclease and sequence-specific DNA binding activities. The C-terminal region of Rep protein has ATPase and 3′-5′ helicase activities. The Rep protein interacts with the viral ITRs, which serve as viral origins of replication, in the performance of these various functions. Within the ITRs are two sequences required for replication: a Rep binding sequence region consisting of several direct repeats of a 5’-GCTC-3′ motif and a terminal resolution site, or nicking site. Viral replication requires Rep binding at the Rep binding sequence region and subsequent cleavage of the ssDNA at the nicking site to generate the 3′-OH group which allows conversion of the viral ends into linear duplex DNA. An additional Rep binding sequence comprising a CTTTG motif, located in the loop region between the B and B′ sequences of the ITR hairpin, aids in determining the directionality of parvoviral genome replication. The endonuclease domain of the Rep protein recognizes the nicking site substrate in the context of an ssDNA stem loop secondary structure generated by the Rep helicase activity. 
     The Rep protein is altered so as to decrease its binding with its cognate Rep binding sequence region by altering or modifying amino acid residues involved in DNA binding. Previous studies analyzing the crystal structure of AAV5 Rep protein bound to the AAV5 Rep binding sequence region indicate which residues play a role in DNA binding. (Hickman et al 2004 The Nuclease Domain of Adeno-Associated Virus Rep Coordinates Replication Initiation Using Two Distinct DNA Recognition Interfaces, Molecular Cell 13:403-414, the contents of which are referenced herein in their entirety). The N-terminal domain of Rep protein has determinants for ITR binding and has been shown to specifically bind ITR sequences (Owens 1993, Yoon, 2001, Hickman). In the Hickman studies, a crystal structure of an AAV5 N-terminal Rep protein fragment (AA 1-197) bound to a 26 by double-stranded sequence containing the AAV5 Rep binding sequence region was analyzed. Three-dimensional modeling showed that the stable protein-DNA complex contained five Rep protein monomers bound independently to one molecule of the AAV5 Rep binding sequence region, which adopted an overall f3-DNA structure. Further examination of the crystal structure showed that the five monomers bind to the Rep binding sequence region and spiral around the DNA axis, off-set from one another by four base pairs. The studies further revealed that the structural elements of the Rep protein integral to recognition and binding of the repeated GCTC consensus motif in the Rep binding sequence region are the surface loop sequence between the β4 and β5 strands (referred to as the j34/05 loop: residues 135-144) and the a-helix C sequence (residues 101-118), which are located along one edge of the central 13 sheet. 
       FIG. 7  is a schematic depicting a three-dimensional model showing Rep protein binding to the Rep binding domain of the AAV5 ITR. As shown in  FIG. 7 , several amino acid residues in the β4/β5 loop (amino acid residues K135, K137, and N142) and in the α-helix C (S101, G105, 5109, and Q110) contact the phosphodiester backbone in the major groove structure of the Rep binding sequence region.  FIG. 7  also shows the amino acid residues in the α-helix C (R106, K137, and K138) and an amino acid residue in the β4/β5 loop (K137) that contact one or more nucleosides in the Rep binding sequence region. Amino acid residue K137 contacts both the phosphodiester backbone and one or more nucleosides in the Rep binding sequence region. The identified amino acid residues contribute to Rep protein binding to its cognate Rep binding sequence region, with those residues contacting the phosphodiester backbone contributing to stabilization of the protein-DNA interaction and those residues contacting one or more nucleosides contributing to the specificity of the interaction. 
     An alignment of the polynucleotide sequences encoding Rep protein from different AAV serotypes (AAV5, AAV2Rep68, AAV2Rep78, AAV2Rep40, AAV2Rep52, AAV1, AAV3, AAV4, AAV7, and AAV8) and AAV species (Avian AAVDA-1, Avian AAVVR865, Bat, and Bovine), shown in  FIG. 8 , shows that the identified amino acids discussed above are conserved across AAV serotypes and AAV species. An analysis of the correlation between structural features of the Rep binding sequence region in the ITR and the degree of conservation of the Rep protein sequence was performed in silica The combination of sequence and structural analysis of Rep proteins confirms that the identified conserved residues of the α-helix C and β-sheet 4/β-sheet 5 loop are involved in DNA binding and are the appropriate target residues for alteration and/or modification. Table 6 provides a list of target residues within structural elements of the Rep protein that contact the phosphodiester backbone contributing to stabilized protein-DNA interaction as shown in  FIG. 7 . Table 7 provides a list of target residues in the Rep protein that contact nucleosides of either DNA strand (the complementary strand is noted with a ‘) contributing to specific protein-DNA interaction as shown in  FIG. 7 . The residue numbering used here and in Tables 4 and 5 are that of AAV5. Corresponding residues in other AAV serotypes and species can be obtained using the sequence alignment shown in  FIG. 8 . Of the ten residues that form direct side chain interactions with the Rep binding sequence region, seven are strictly conserved among serotypes AAV2-6. There are three consecutive amino acids in the β4/β5 loop that are highly conserved- Gly-139, Gly-140, and Ala-141 (in AAV5), which correlate to three sequential Glycines in AAV2-6. Other conserved residues in the β4/β5 loop are Asp-142, Lys-135, and Lys-137. Conserved residues in the α-helix C are Ser101, Met-102, Gly105, Arg-106, Ser-109, Gln-110, Lys137, and Lys138. Arg-106 and Lys-137 provide important base contacts and Lys-135 forms a salt bridge to the phosphate backbone. 
     
       
         
           
               
             
               
                 TABLE 6 
               
             
            
               
                   
               
               
                 Residues Contacting the Phosphodiester Backbone Contributing 
               
               
                 to Stabilized Protein-DNA Interaction 
               
            
           
           
               
               
               
            
               
                   
                 Residue 
                 Structural Element 
               
               
                   
                   
               
               
                   
                 S101 
                 A helix C 
               
               
                   
                 G105 
                 A helix C 
               
               
                   
                 S109 
                 A helix C 
               
               
                   
                 Q110 
                 A helix C 
               
               
                   
                 K135 
                 β4/β5 loop 
               
               
                   
                 K137 
                 β4/β5 loop 
               
               
                   
                 N142 
                 β4/β5 loop 
               
               
                   
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 7 
               
             
            
               
                   
               
               
                 Residues Contacting Nucleosides Contributing 
               
               
                 to Specific Protein-DNA Interaction 
               
            
           
           
               
               
               
            
               
                   
                 Residue 
                 Nucleoside 
               
               
                   
                   
               
               
                   
                 R106 
                 T14, C15 
               
               
                   
                 K137 
                 G18′, C9, G8 
               
               
                   
                 K138 
                 G8 
               
               
                   
                 G139 
                 A17′ 
               
               
                   
                   
               
            
           
         
       
     
     The engineered Rep protein of the present disclosure comprises one or more amino acids that are altered or modified as compared to the corresponding wild-type Rep protein, in which modification(s) and/or alteration(s) results in decreased binding to the Rep binding sequence region. The engineered Rep protein can be derived from an AAV Rep protein. In one embodiment, the engineered Rep protein is derived from an AAV Rep protein selected from an AAV1, AAV2, AAV3, AAV4, AAV5, AAV7, AAV8, Avian AAVDA-1, Avian AAV VR865, Bat, Snake, and Bovine AAV Rep protein (SEQ :ID NO: 265-279). In one embodiment, the engineered Rep protein is derived from an AAV Rep protein selected from art AAV6, AANT9, AAV10, AAV12, AAVrh8, AAVrh10, and AAV-DJ Rep protein. In one embodiment, the AAV Rep protein from which the engineered Rep protein is derived is selected from AAV2 Rep68, AAV2 Rep78, AAV2 Rep40, AAV2 Rep52, AAV1 Rep, AAV3 Rep, AAV4 Rep, AAV7 Rep, AAV 8 Rep, Avian Rep, Bat Rep, or Bovine Rep. In some embodiments, the AAV Rep protein from which the engineered Rep protein is derived is Rep protein 68 or Rep protein 78. AAV Rep78 proteins are described in International Patent Publication No. WO2001032711, WO2007130519, and WO2007148971, the contents of which are herein incorporated by reference in their entirety. 
     The engineered Rep protein can be derived from a naturally-occurring parvoviral Rep protein or a naturally-occurring variant parvoviral Rep protein. Alternatively, the Rep protein can be derived from a non-naturally Rep protein, including, for example, a synthetic or artificial Rep protein. The Rep protein can be altered by insertions, deletions, and/or substitutions of amino acid residues. In one embodiment, the engineered Rep protein has at least 85% sequence identity with any of the AAV Rep proteins disclosed herewith. In another embodiment, the engineered Rep protein has at least 900o sequence identity with any of the AAV Rep proteins disclosed herewith, including 90% 91%, 92%, 93%, 94%, 95%, 96%, 97% 98%, and 99% identity with the AAV Rep proteins. 
     In one embodiment, the one or more altered or modified amino acid residues in the engineered Rep protein is an amino acid residue that in its wild-type form (i.e., unaltered or unmodified form) contacts a Rep binding sequence region. In one ethbodiment, one of the altered or modified amino acid residues in the engineered Rep protein is an amino acid residue that in its wild-type (unaltered or unmodified) form contacts a Rep binding sequence region. In another embodiment two of the altered or modified amino acid residues are amino acid residues that in their wild-type form contact a Rep binding sequence region. In another embodiment, three of the altered or modified amino acid residues are amino acid residues that in their wild-type form contact a Rep binding sequence region. In another embodiment, four of the modified amino acid residues are amino acid residues that in their wild-type form contact a Rep binding sequence region. In another embodiment, about 10% to about 50% of the amino acid residues that in their wild-type form (unaltered or unmodified form) contact a Rep binding sequence region are altered or modified in the engineered Rep protein. In one embodiment, at least 10% of the amino acid residues that in their wild-type form contact a Rep binding sequence region are altered or modified. In one embodiment, at least 20%, 30%, 40% or 50% of the amino acid residues that in their wild-type form contact a Rep binding sequence region are altered or modified. 
     In one embodiment, the one or more altered or modified amino acid residue(s) of the engineered Rep protein is an amino acid residue(s) that in its wild-type form (e.e., unaltered or unmodified) contacts the phosphodiester backbone of a nucleotide sequence comprising the Rep binding sequence region. In another embodiment, the one or more altered or modified amino acid residue(s) of the engineered Rep protein is an amino acid residue(s) that in its wild-type form contacts at least one nucleoside of a nucleotide sequence comprising a Rep binding sequence region. In another embodiment, the one or more altered or modified amino acid residue(s) of the engineered Rep protein is an amino acid residue(s) that in its wild-type form contacts the phosphodiester backbone and at least one nucleoside of a nucleotide sequence comprising a Rep binding sequence region. In one embodiment, the one or more altered or modified amino acid residue(s) of the engineered Rep protein is an amino acid residue that in its wild-type form stabilizes the binding of Rep protein to a Rep binding sequence region. In one embodiment, the one or more altered or modified amino acid residue(s) in the engineered. Rep protein is an amino acid residue(s) that in its wild-type form is located in the α-helix C of the Rep protein. In one variation of this embodiment, the altered or modified amino acid residue(s) further contacts the phosphodiester backbone and/or at least one nucleoside of a nucleotide sequence comprising a Rep binding sequence region. In another embodiment, the one or more altered or modified amino acid residue(s) in the engineered Rep protein is an amino acid residue(s) that in its wild-type form is located in the β4/β5 loop of the Rep protein. In one variation of this embodiment, the altered or modified amino acid residue(s) further contacts the phosphodiester backbone and/or at least one nucleoside of a nucleotide sequence comprising a Rep binding sequence region. In another embodiment, the one or more altered or modified amino acid residue(s) is selected from the amino acid residue that is or corresponds with: (1) Serine-101; (2) Glycine-105; (3) Arginine-I06; (4) Serine-109; (5) Glutamine-110; (6) Lysine-135; (7) Lysine-137; (8) Lysine-138; (9) Glycine-139; and (10) Asparagine-142. In another embodiment, the one or more altered or modified amino acid residue(s) is selected from the amino acid residue that is or corresponds with: (1) Glycine-140; (2) Alanine-141; and (3) Met-102. 
     In one embodiment, the one or more altered or modified amino acid residue(s) of the engineered Rep protein is modified by conservative substitution with a different amino acid having similar biochemical properties as the wild-type residue. For example, acidic amino acid residues, e.g., Aspartic acid and Glutamic acid can be substituted with one another. Basic amino acids, such as Lysine, Arginine, and Histidine, can be substituted with one another. Hydrophobic aliphatic amino acids, such as Valine, Isoleucine, Leucine, and Alanine, can be substituted with one another. Hydrophobic aromatic amino acids, such as Phenylalanine, Tyrosine, and Tryptophan, can be substituted with one another. Neutral polar amino acids, such as Asparagine, Cysteine, Glutamine, Methionine, Serine, and Threonine, can be substituted with one another, Hydrophilic amino acids, such as Alanine, Proline, Glycine, Glutamic acid, Aspartic acid, Glutamine, Asparagine, Serine, and Threonine, can be substituted with one another. These are non-limiting examples of conservative amino acid substitution and are not meant to exclude other combinations of amino acid substitutions. 
     In one embodiment, the engineered Rep protein comprises one or more alterations in amino acid residue(s) corresponding to the following amino acid residues in wild-type AAVS Rep protein sequence selected from: (1) amino acid corresponding to Glycine-139 substituted with a Proline, Alanine, or Serine residue; (2) amino acid corresponding to Glycine-140 substituted with a Proline, Alanine, or Serine residue; (3) amino acid corresponding to Alanine-141 substituted with a Serine, Glycine, Threonine, Cysteine, or Valine residue; (4) amino acid corresponding to Lysine-138 substituted with a Arginine, Glutamine, Glutamic acid, Asparagine, or Serine residue; (5) amino acid corresponding to Methionine-102 substituted with a Leucine, Isoleucine, Glutamine, Valine, or Phenylalanine residue; (6) amino acid corresponding to Serine-109 substituted with a Threonine, Alanine, Asparagine, Aspartic acid, Glutamine, Glutamic acid, Glycine, Lysine, or Threonine residue; (7) amino acid corresponding to Glutamine-110 substituted with an Arginine, Asparagine, Aspartic acid, Histidine, Lysine, or Serine residue; (8) amino acid corresponding with Asparagine-142 substituted with an Aspartic acid, Serine, Glutamine, or Glutamic acid residue; (9) amino acid corresponding to Lysine-137 substituted with a Arginine, Glutamine, Glutamic acid, Asparagine, or Serine residue; (10) amino acid corresponding to Lysine-135 substituted with a Arginine, Glutamine, Glutamic acid, Asparagine, or Serine residue; (11) amino acid corresponding to Ser-101 substituted with a Threonine, Alanine, Asparagine, Aspartic acid, Glutamine, Glutamic acid, Glycine, Lysine, or Threonine residue; (12) amino acid corresponding to Glycine-105 substituted with a Proline, Alanine, or Serine residue; (13) amino acid corresponding to Arginine 106 substituted with a Lysine or Histidine residue; and (14) any combination of these alterations. In one embodiment, the engineered Rep protein comprises one or more alterations in amino acid residue(s) corresponding to the following amino acid residues in wild-type AAV5 Rep protein sequence selected from: (1) amino acid corresponding to Lycine-135 substituted with Glycine; (2)) amino acid corresponding to Lycine-135 substituted with Threonine. (3) amino acid corresponding to Asparagine 142 substituted with Glycine, (4) amino acid corresponding to Asparagine 142 substituted with Threonine, (5) amino acid corresponding to Lycine-135 substituted with Glycine and amino acid corresponding to Asparagine 142 substituted with Glycine; (6) amino acid corresponding to Lycine-I35 substituted with Glycine and amino acid corresponding to Asparagine 142 substituted with Threonine; (7) amino acid corresponding to Lycine-135 substituted with Threonine and amino acid corresponding to Asparagine 142 substituted with Glycine; and (8) amino acid corresponding to Lycine-135 substituted with Threonine and amino acid corresponding to Asparagine 142. substituted with Threonine. The amino acid residue position numbering in the listed substitutions corresponds with the position numbering found in the wild-type AAV5 Rep protein (SEQ ID NO: 269). Corresponding amino acid residues at these positions for other AAV serotypes and species of Rep proteins can be found in the sequence alignments provided in  FIG. 8 . Corresponding amino acid residues at these positions for additional parvoviral serotypes and species of Rep proteins can be determined by sequence alignment analysis using the methods described herein or otherwise known in the art. 
     In any of the above-described embodiments, the altered or modified amino acid residue(s) of the engineered Rep protein has decreased contact with a wild-type Rep binding sequence region relative to the amount of contact a wild-type Rep protein has with the wild-type Rep binding sequence region. In another embodiment, the modified amino acid residue(s) of the engineered Rep protein has decreased contact with an engineered Rep binding sequence region relative to the amount of contact a wild-type Rep protein has with the engineered Rep binding sequence region. In another embodiment, the modified amino acid residue(s) of the engineered Rep protein has decreased contact with an engineered Rep binding sequence region relative to the amount of contact it has with a wild-type Rep binding sequence region. In any of these embodiments, the engineered Rep binding sequence region can be an engineered Rep binding sequence region provided in the present disclosure. 
     In another embodiment, the one or more altered or modified amino acid residue(s) of the engineered Rep protein is modified by non-conservative substitution with a different amino acid residue. 
     In any of these embodiments in which the altered or modified amino acid residue of the engineered Rep protein is an amino acid residue that in its wild-type form contacts a Rep binding sequence region, the Rep binding sequence region can be a wild-type Rep binding sequence region or an engineered Rep binding sequence region. Thus, in one embodiment in which the altered or modified amino acid residue of the engineered Rep protein is an amino acid residue that in its wild-type form contacts a Rep binding sequence region, the Rep binding sequence region is a wild-type Rep binding sequence region. The wild-type Rep binding sequence region can be an AAV Rep binding sequence region. In certain specific embodiments, the AAV is selected from any of the AAV serotypes and species provided herein. In one embodiment wherein the altered or modified amino acid residue of the engineered Rep protein is an amino acid residue that in its wild-type form contacts a Rep binding sequence region, the Rep binding sequence region is selected from any of SEQ ID NOs: 1-20, 21-66, and/or 79-197. Also, in any of these embodiments in which the altered or modified amino acid residue of the engineered Rep protein is an amino acid residue that in its wild-type form contacts a Rep binding sequence region, the Rep binding sequence region can be an engineered Rep binding sequence region. The engineered Rep binding sequence region can be derived from art AAV Rep binding sequence region. In certain specific embodiments, the AAV is selected from any of the AAV serotypes and species provided herein. In another embodiment wherein the altered or modified amino acid residue of the engineered Rep protein is an amino acid residue that in its wild-type form contacts an engineered. Rep binding sequence region, the engineered Rep binding sequence region is selected from any of the engineered Rep binding sequence regions provided in the present disclosure. In some embodiments the engineered Rep binding sequence region is selected from any of SEQ ID NOs: 1-20, 21-66, and/or 79-197. 
     In one embodiment, the modified amino acid residue of the engineered Rep protein is modified by chemical, enzymatic, or other post-translational modification. 
     The engineered Rep protein has decreased binding affinity with a Rep binding sequence region as a result of the one or more alterations and/or modifications. In one embodiment, the engineered Rep protein has decreased binding affinity with a wild-type Rep binding sequence region relative to the binding affinity of a wild-type Rep protein with the wild-type Rep binding sequence region as a result of the one or more alterations and/or modifications. In another embodiment, the engineered Rep protein has decreased binding affinity with an engineered Rep binding sequence region relative to the binding affinity of a wild-type Rep protein with the engineered Rep binding sequence region. In another embodiment, the engineered Rep protein has decreased binding affinity with an engineered Rep binding sequence region relative to the binding affinity it has with a wild-type Rep binding sequence region. In any of these embodiments, the binding affinity is decreased about 2-fold to about 20-fold. In another embodiment, the binding affinity is decreased at least 2-fold, at least 5-fold, at least 10-fold, or at least 20-fold. In any of these embodiments, the Rep binding sequence region is a wild-type Rep binding sequence region, for example, an AAV Rep binding sequence region, such as an AAV Rep binding sequence region selected from any of the AAV serotypes and species provided herein. In any of these embodiments, the Rep binding sequence region is an engineered Rep binding sequence region, for example, an engineered Rep binding sequence region derived from aft AAV Rep binding sequence region, such as AAV Rep binding sequence region selected from any of the AAV serotypes and species provided herein. 
     V. PAYLOAD: TRANSGENES, POLYPEPTIDE-ENCODING POLYNUCLEOTIDES AND/OR MODULATORY NUCLEIC ACIDS 
     The payload construct vector of the present invention comprises a nucleic acid sequence encoding at least one “payload molecule.” As used herein, a “payload molecule” refers to a transgene, a polynucleotide encoding a polypeptide or a modulatory nucleic acid. The payload molecule may comprise any nucleic acid encoded in the viral genome produced in accordance with the present invention for expression in a target cell transduced or contacted with the viral particle. 
     According to the present invention, the payload construct vector encodes a “payload construct.” As used herein, a “payload construct” is a polynucleotide sequence encoding at least a payload molecule and sufficient ITR sequence to allow for expression of the payload molecule in a cell transduced with the viral particle. 
     The payload molecule may comprise a polypeptide, an RNA molecule, or any other gene product that is desired for expression in the target cell. The payload construct may comprise a combination of coding and non-coding nucleic acid sequences. 
     In one embodiment, the payload construct vector comprises more than one nucleic acid sequences encoding more than one payload molecule of interest. In such an embodiment, a payload construct vector encoding more than one payload molecule may be replicated and packaged into a viral particle. A target cell transduced with a viral particle comprising more than one payload molecule may express each of the payload molecules in a single cell. 
     In some embodiments, the payload construct vector sequence may encode a coding or non-coding RNA. 
     Where the payload construct vector sequence encodes a polypeptide, the polypeptide may be a peptide or protein. A protein encoded by the payload construct vector sequence may comprise a secreted protein, an intracellular protein, an extracellular protein, and/or a membrane protein. The encoded proteins may be structural or functional. Proteins encoded by the payload construct vector or payload construct include, but are not limited to, mammalian proteins. The viral vectors encoding polypeptides (e.g., mRNA) of the invention may be used in the fields of human disease, antibodies, viruses, veterinary applications and a variety of in vivo and in vitro settings. 
     In some embodiments, the viral particles are useful in the field of medicine for the treatment, palliation or amelioration of conditions or diseases such as, but not limited to, blood, cardiovascular, CNS, dermatology, endocrinology, genetic, genitourinary, gastrointestinal, musculoskeletal, oncology, and immunology, respiratory, sensory and anti-infective, 
     In some embodiments, viral particles in accordance with the present invention may be used for the treatment of disorders, and/or conditions, including but not limited to one or more of the following: autoimmune disorders (e.g. diabetes, lupus, multiple sclerosis, psoriasis, rheumatoid arthritis); inflammatory disorders (e.g. arthritis, pelvic inflammatory disease); neurological disorders (e.g. Alzheimer&#39;s disease, Huntington&#39;s disease; autism; Parkinson&#39;s disease); cardiovascular disorders (e.g. atherosclerosis, hypercholesterolemia, thrombosis, clotting disorders, angiogenic disorders such as macular degeneration); proliferative disorders (e.g. cancer, benign neoplasms); respiratory disorders (e.g. chronic obstructive pulmonary disease); digestive disorders (e.g. inflammatory bowel disease, ulcers); musculoskeletal disorders (e.g. fibromyalgia, arthritis); endocrine, metabolic, and nutritional disorders (e.g. diabetes, osteoporosis); urological disorders (e.g. renal disease); psychological disorders (e.g. depression, schizophrenia); skin disorders (e.g. wounds, eczema); blood and lymphatic disorders (e.g. anemia, hemophilia); etc. 
     In some embodiments, the payload construct encodes a messenger RNA (mRNA). As used herein, the term “messenger RNA” (mRNA) refers to any polynucleotide which encodes a polypeptide of interest and which is capable of being translated to produce the encoded polypeptide of interest in vitro, in vivo, in situ or ex vivo. 
     Traditionally, the basic components of an mRNA molecule include at least a coding region, a 5′UTR, a 3′UTR, a 5′ cap and a poly-A tail. According to the present invention, payload constructs encoding mRNA may comprise a coding region only. They may also comprise a coding region and at least one UTR. They may also comprise a coding region, 3′UTR and a poly-A tail. 
     In one embodiment the polypeptide encoded by the payload construct is between 50-5000 amino acids in length. In some embodiments the protein encoded is between 50-2000 amino acids in length. In some embodiments the protein encoded is between 50-1500 amino acids in length. In some embodiments the protein encoded is between 50-1000 amino acids in length. In some embodiments the protein encoded is between 50-800 amino acids in length. In some embodiments the protein encoded is between 50-600 amino acids in length. In some embodiments the protein encoded is between 50-400 amino acids in length. In some embodiments the protein encoded is between 50-200 amino acids in length. In some embodiments the protein encoded is between 50-100 amino acids in length. 
     In some embodiments the peptide encoded by the payload construct is between 4-50 amino acids in length. In one embodiment, the shortest length of a region of the payload molecule of the present invention encoding a peptide can be the length that is sufficient to encode for a tetrapeptide, a pentapeptide, a hexapeptide, a heptapeptide, an octapeptide, a. nonapeptide, or a decapeptide. In another embodiment, the length may be sufficient to encode a peptide of 2-30 amino acids, e.g. 5-30, 10-30, 2-25, 5-25, 10-25, or 10-20 amino acids. The length may be sufficient to encode for a peptide of at least 11, 12, 13, 14, 15, 17, 20, 25 or 30 amino acids, or a peptide that is no longer than 50 amino acids, e.g. no longer than 35, 30, 25, 20, 17, 15, 14, 13, 12, 11 or 10 amino acids. 
     An RNA encoded by the payload construct may comprise an mRNA, tRNA, rRNA, tmRNA, miRNA, RNAi, siRNA, piRNA, shRNA antisense RNA, double stranded RNA, snRNA, snoRNA, and long non-coding RNA (lncRNA). Examples of such lncRNA molecules and RNAi constructs designed to target such lncRNA any of which may be encoded in the payload constructs are taught in International Publication, WO2012/018881 A2, the contents of which are incorporated herein by reference in their entirety. 
     In one embodiment, the payload construct encodes a microRNA or miRNA as the payload molecule. These payload molecules are also referred to as modulatory nucleic acid payloads. 
     microRNAs (or miRNA) are 19-25 nucleotide long noncoding RNAs that bind to the 3′UTR of nucleic acid molecules and down-regulate gene expression either by reducing nucleic acid molecule stability or by inhibiting translation. The payload constructs of the invention may comprise one or more microRNA target sequences, microRNA sequences ;  or microRNA seeds. Such sequences may correspond to any known microRNA such as those taught in US Publication US200510261218 and US Publication US2005/0059005, the contents of which are incorporated herein by reference in their entirety. 
     A microRNA sequence comprises a  - seed” region, i.e., a sequence in the region of positions 2-8 of the mature microRNA, which has perfect Watson-Crick complementarily to the miRNA target sequence. A microRNA seed may comprise positions 2-8 or 2-7 of the mature microRNA. In some embodiments, a microRNA seed may comprise 7 nucleotides (e.g., nucleotides 2-8 of the mature microRNA), wherein the seed-complementary site in the corresponding miRNA target is flanked by an adenine (A) opposed to microRNA position 1. In some embodiments, a microRNA seed may comprise 6 nucleotides (e.g., nucleotides 2-7 of the mature microRNA), wherein the seed-complementary site in the corresponding miRNA target is flanked by an adenine (A) opposed to microRNA position 1. See for example, Grimson A, Farh K K, Johnston W K, Garrett-Engele P. Lim L P, Bartel D P; Mol Cell. 2007 Jul. 6; 27(1):91-105; each of which is herein incorporated by reference in their entirety. The bases of the microRNA seed have complete complementarily with the target sequence: 
     A payload molecule may comprise polypeptides that serve as marker proteins to assess cell transformation and expression, fusion proteins, polypeptides having a desired biological activity, gene products that can complement a genetic defect, RNA molecules, transcription factors, and other gene products that are of interest in regulation and/or expression. A payload molecule may comprise nucleotide sequences that provide a desired effect or regulatory function (e.g., transposons, transcription factors). A payload molecule may comprise, but is not limited to: hormone receptors (e.g., mineral corticosteroid, glucocorticoid, and thyroid hormone receptors); intramembrane proteins (e.g., TM-1 and TM-7); intracellular receptors (e.g., orphans, retinoids, vitamin D3 and vitamin A receptors); signaling molecules (e.g., kinases, transcription factors, or molecules such signal transducers and activators of transcription receptors of the cytokine superfamily (e.g, erythropoietin, growth hormone:, interferons, and interleukins, and colony-stimulating factors; G-protein coupled receptors, e.g., hormones, calcitonin, epinephrine, gastrin, and paracrine or autocrine mediators, such as somatostatin or prostaglandins); neurotransmitter receptors (norepinephrine, dopamine, serotonin or acetylcholine); pathogenic antigens, which can be of viral, bacterial, allergenic, or cancerous origin; and tyrosine kinase receptors (such as insulin growth factor, and nerve growth factor). 
     A payload molecule may comprise a gene therapy product. A gene therapy product may comprise a polypeptide, an RNA molecule, or other gene product that, when expressed in a target cell, provides a desired therapeutic effect. In some embodiments, a gene therapy product may comprise a substitute for a non-functional gene that is absent or mutated. In sonic embodiments, a gene therapy product may comprise a method for elimination of a gene that is over-active or dysregulated. Goldsmith et al., WO 90/07936, the contents of which are incorporated herein by reference in their entirety. 
     A payload construct vector encoding a payload molecule may comprise a selectable marker. A selectable marker may comprise a gene sequence or a protein encoded by that gene sequence expressed in a host cell that allows for the identification, selection, and/or purification of the host cell from a population of cells that may or may not express the selectable marker. In one embodiment the selectable marker provides resistance to survive a selection process that would otherwise kill the host cell, such as treatment with an antibiotic. In some embodiments an antibiotic selectable marker may comprise one or more antibiotic resistance factors, including but not limited to neomycin resistance (e.g., neo), hygromycin resistance, kanamycin resistance, and/or puromycin resistance. 
     In some embodiments a selectable marker may comprise a cell-surface marker, such as any protein expressed on the surface of the cell including, but not limited to receptors, CD markers, lectins, integrins, or truncated versions thereof. In sonic embodiments, cells that comprise a cell-surface marker may be selected using an antibody targeted to the cell-surface marker. In some embodiments an antibody targeted to the cell-surface marker may be directly conjugated with a selection agent including, but not limited to a fluorophore, sepharose, or magnetic bead. In some embodiments an antibody targeted to the cell-surface marker may be detected using a secondary labeled antibody or substrate which binds to the antibody targeted to the cell-surface marker. In sonic embodiments, a selectable marker may comprise negative selection by using an enzyme, including but not limited to Herpes simplex virus thymidine kinase (HSVIX) that converts a pro-toxin (ganciclovir) into a toxin or bacterial Cytosine Deaminase (CD) which converts the pro-toxin 5′-fluorocytosine (5′-FC) into the toxin 5′-fluorouracil (5′-FU). In some embodiments, any nucleic acid sequence encoding a polypeptide can be used as a selectable marker comprising recognition by a specific antibody. 
     In some embodiments, a payload construct vector encoding a payload molecule may comprise a selectable marker including, but not limited to, β-lactamase, luciferase, β-galactosidase, or any other reporter gene as that term is understood in the art, including cell-surface markers, such as CD4 or the truncated nerve growth factor (NGFR) (for GFP, see WO 96/23810; Heim et al.,  Current Biology  2:178-182 (1996); Heim et al.,  Proc. Natl. Acad. Sci. USA  (1995); or Heim et al.,  Science  373:663-664 (1995); for β-lactamase, see WO 96/30540). In some embodiments, a nucleic acid encoding a selectable marker may comprise a fluorescent protein. A fluorescent protein as herein described may comprise any fluorescent marker including but not limited to green, yellow, and/or red fluorescent protein (GFP, YFP, and RFP). 
     In accordance with the invention, a payload molecule comprising a nucleic acid for expression in a target cell will be incorporated into the viral particle produced in the viral replication cell if the payload molecule is located between two ITR sequences, or is located on either side of an asymmetrical ITR engineered with two D regions. 
     A payload construct vector sequence encoding one or more payload molecules for expression in a target cell may comprise one or more nucleotide sequences operably linked to at least one target cell-compatible promoter. A person skilled in the art may recognize that a target cell may require a specific promoter including but not limited to a promoter that is species specific, inducible, tissue-specific, or cell cycle-specific Parr et al.,  Nat Med. 3:1145-9 (1997). 
     VI. VIRAL PRODUCTION 
     The present disclosure provides a method for increasing the generation of self-complementary (SC) AAV during AAV genome replication in a viral replication cell comprising contacting the viral replication cell or tissue with an AAV polynucleotide or AAV genome or AAV particle comprising a chimeric Rep binding sequence region, or contacting the cell or tissue with a vector comprising the AAV polynucleotide or AAV genome, or contacting the cell or tissue with any of the described compositions, including pharmaceutical compositions. 
     The present disclosure provides a method for producing an AAV particle having enhanced (increased, improved) transduction efficiency comprising the steps of I) co-transfecting competent bacterial cells with a bacmid vector and either a viral construct vector or payload construct vector, 2) isolating the resultant viral construct expression vector and payload construct expression vector and separately transfecting viral replication cells, 3) isolating and purifying resultant payload and viral construct particles comprising viral construct expression vector or payload construct expression vector, 4) co-infecting a viral replication cell with both the payload and viral construct particles comprising viral construct expression vector or payload construct expression vector, 5) harvesting and purifying the viral particle comprising a self-complementary parvoviral genome ( FIG. 9  and  FIG. 10 ). 
     Vectors 
     The invention also provides nucleic acids encoding the mutated or modified virus capsids and capsid proteins of the invention. Further provided are vectors comprising the nucleic acids, and cells (in vivo or in culture) comprising the nucleic acids and/or vectors of the invention. Suitable vectors include without limitation viral vectors (e.g., adenovirus, AAV, herpesvirus, vaccinia, poxviruses, baculoviruses, and the like), plasmids, phage, YACs, BACs, and the like as are well known in the art. Such nucleic acids, vectors and cells can be used, for example, as reagents (e.g., helper packaging constructs or packaging cells) for the production of modified virus capsids or virus vectors as described herein. 
     The molecules of the invention which contain AAV sequences include any genetic element (vector) which may be delivered to a host cell, e.g., naked DNA, a plasmid, phage, transposon, cosmid, episome, a protein in a non-viral delivery vehicle (e.g., a lipid-based carrier), virus, etc., which transfers the sequences carried thereon. The selected vector may be delivered by any suitable method, including transfection, electroporation, liposome delivery, membrane fusion techniques, high velocity DNA-coated pellets, viral infection and protoplast fusion. The methods used to construct any embodiment of this invention are known to those with skill in nucleic acid manipulation and include genetic engineering, recombinant engineering, and synthetic techniques. See, e.g., Sambrook et al, Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Press, Cold Spring Harbor, N.Y. 
     The transgene can be carried on any suitable vector, e.g., a plasmid, which is delivered to a host cell. The plasmids useful in this invention may be engineered such that they are suitable for replication and, optionally, integration in prokaryotic cells, mammalian cells, or both. These plasmids contain sequences permitting replication of the transgene in eukaryotes and/or prokaryotes and selection markers for these systems. Selectable markers or reporter genes may include sequences encoding geneticin, hygromnicin or purimycin resistance, among others. The plasmids may also contain certain selectable reporters or marker genes that can be used to signal the presence of the vector in bacterial cells, such as ampicillin resistance. Other components of the plasmid may include an origin of replication and an amplicon, such as the amplicon system employing the Epstein Barr virus nuclear antigen. This amplicon system, or other similar amplicon components permit high copy episomal replication in the cells. Preferably, the molecule carrying the transgene is transfected into the cell, where it may exist transiently. Alternatively, the transgene may be stably integrated into the genome of the host cell, either chromosomally or as an episome. In certain embodiments, the transgene may be present in multiple copies, optionally in head-to-head, head-to-tail, or tail-to-tail concatamers. Suitable transfection techniques are known and may readily be utilized to deliver the transgene to the host 
     cell. Cells 
     The present disclosure provides a cell comprising an engineered Rep protein or an AAV polynucleotide, AAV genome, or AAV comprising an engineered Rep protein, a cell comprising a viral vector comprising the AAV polynucleotide or AAV genome, and a cell comprising a composition comprising the AAV polynucleotide or AAV genome or the AAV or a composition comprising the viral vector. 
     Viral production of the invention disclosed herein describes processes and methods for producing viral vector that contacts a target cell to deliver a payload construct, e.g. a recombinant viral construct, which comprises a nucleotide encoding a payload molecule. 
     In one embodiment, the viral vector of the invention may be produced in a viral replication cell that comprises an insect cell. 
     Growing conditions for insect cells in culture, and production of heterologous products in insect cells in culture are well-known in the art, see U.S. Pat. No. 6,204,059, the contents of which are herein incorporated by reference in their entirety. 
     Any insect cell which allows for replication of parvovirus and which can be maintained in culture can be used in accordance with the present invention. Cell lines may be used from  Spodoptera frugiperda , including, but not limited to the Sf9 or Sf21 cell lines,  drosophila  cell lines, or mosquito cell lines, such as,  Aedes albopictus  derived cell lines. Use of insect cells for expression of heterologous proteins is well documented, as are methods of introducing nucleic acids, such as vectors, e.g., insect-cell compatible vectors, into such cells and methods of maintaining such cells in culture. See ;  for example, METHODS IN MOLECULAR BIOLOGY ;  ed. Richard, Humana Press, NJ (1995); O&#39;Reilly et al., BACULOVIRUS EXPRESSION VECTORS, A LABORATORY MANUAL, Oxford Univ. Press (1994); Samulski et al.,  J. Vir. 63:3822-8 (1989); Kajigaya et al.,  Proc. Nat&#39;l Acad. Sci. USA  88: 4646-50 (1991); Ruffing et al.,  J. Vir.  66:6922-30 (1992); Kinibauer et al.,  Vir. 219:37-44 (1996); Zhao et al.,  Vir. 272:382-93 (2000); and Samulski et al., U.S. Pat. No. 6,204,059, the contents of each of which are herein incorporated by reference in their entirety. 
     The viral replication cell may be selected from any biological organism, including prokaryotic (e.g., bacterial) cells, and eukaryotic cells, including, insect cells ;  yeast cells and mammalian cells. Viral replication cells may comprise mammalian cells such as A549, WEH1, 3T3, 10T1/2, BHK, MDCK, COS 1, COS 7, BSC 1, BSC 40, BMT 10, VERO. W138, HeLa, 293, Saos, C2C12, L cells, HT1080, HepG2 and primary fibroblast, hepatocyte and myoblast cells derived from mammals. Viral replication cells of the invention comprise cells derived from mammalian species including, but not limited to, human, monkey, mouse, rat, rabbit, and hamster or cell types, including but not limited to fibroblast, hepatocyte, tumor cell, cell line transformed cell, etc. 
     Small Scale Production of the Self-Complementary Viral Particle 
     Viral production of the invention disclosed herein describes processes and methods for producing viral vector that contacts a target cell to deliver a payload construct, e.g. a recombinant viral construct, which comprises a nucleotide encoding a payload molecule. 
     In one embodiment, the viral vector of the invention may be produced in a viral replication cell that comprises a mammalian cell, 
     Viral replication cells commonly used for production of recombinant AAV viral vector include, but are not limited to 293 cells, COS cells, Heta cells, KB cells, and other mammalian cell lines as described in U.S. Pat. Nos. 6,156,303, 5,387,484, 5,741,683, 5,691,176, and 5,688,676; U.S. patent application 2002/0081721, and International Patent Applications WO 00/47757, WO 00/24916, and WO 96/17947, the contents of each of which are herein incorporated by reference in their entireties. 
     In one embodiment, viral vector produced in mammalian-cells wherein all three VP proteins are expressed at a stoichiometry approaching 1:1:10 (VP1:VP2:VP3), The regulatory mechanisms that allow this controlled level of expression include the production of two mRNAs, one for VP1, and the other for VP2 and VP3, produced by differential splicing. 
     In another embodiment, viral vector is produced in mammalian cells using a triple transfection method wherein a payload construct, parvoviral Rep, and Cap and helper virus are comprised within three different constructs. The triple transfection method of the three components of AAV viral vector production may be utilized to produce small lots of virus for assays including transduction efficiency, target tissue (tropism) evaluation, and stability. 
     Large Scale Production of the Self Complementary Viral Particle Baculovirus 
     Self-complementary viral particle production of the invention disclosed herein describes processes and methods for producing scAAV that contacts a target cell to deliver a payload construct which comprises a nucleotide encoding a payload molecule. 
     In one embodiment, the process comprises production of viral particles in a baculoviral system using a viral construct vector and a payload construct vector as depicted in  FIG. 9  and  FIG. 10 . Briefly, the viral construct vector and the payload construct vector of the invention are each incorporated by a transposon donor/acceptor system into a bacmid, also known as a baculovirus plasmid, by standard molecular biology techniques known and performed by a person skilled in the art. Transfection of separate viral replication cell populations produces two baculoviruses, one that comprises the viral construct expression vector, and another that comprises the payload construct expression vector. The two baculoviruses depicted in  FIG. 9  and  FIG. 10  may be used to infect a single viral replication cell population for production of scAAV. 
     Baculovirus expression vectors for producing viral particles in insect cells, including but not limited to Spodoptera frugiperda (SP)) cells, provide high titers of viral particle product. Recombinant baculovirus encoding the viral construct expression vector and payload construct expression vector initiates a productive infection of viral replicating cells. Infectious baculovirus particles released from the primary infection secondarily infect additional cells in the culture, exponentially infecting the entire cell culture population in a number of infection cycles that is a function of the initial multiplicity of infection, see Urabe, M. et al. J Virol. 2006 February; 80(4):1874-85, the contents of which are herein incorporated by reference in their entirety. 
     Production of viral particles with baculovirus in an insect cell system may address known baculovirus genetic and physical instability. In one embodiment, the production system of the invention addresses baculovirus instability over multiple passages by utilizing a titerless infected-cells preservation and scale-up system. Small scale seed cultures of viral producing cells are transfected with viral expression constructs encoding the structural, non-structural, components of the viral particle. Baculovirus-infected viral producing cells are harvested into aliquots that may be cryopreserved in liquid nitrogen; the aliquots retain viability and infectivity for infection of large scale viral producing cell culture Wasilko D J et al. Protein Expr Purif. 2009 June; 65(2):122-32, the contents of which are herein incorporated by reference in their entirety. 
     A genetically stable baculovirus may be used to produce the source of one or more of the components for producing viral particles in invertebrate cells. In one embodiment, defective baculovirus expression vectors may be maintained episomally in insect cells. In such an embodiment the hacmid vector is engineered with replication control elements, including but not limited to promoters, enhancers, and/or cell-cycle regulated replication elements. 
     In one embodiment, baculoviruses may be engineered with a (non-) selectable marker for recombination into the chitinase/cathepsin locus. The chia/v-cath locus is non-essential for propagating baculovirus in tissue culture, and the V-cath (EC 3.4.22.50) is a cysteine endoprotease that is most active on Arg-Arg dipeptide containing substrates. The Arg-Arg dipeptide is present in densovirus and parvovirus capsid structural proteins but infrequently occurs in dependovirus VP1. 
     In one embodiment, stable viral replication cells permissive for baculovirus infection are engineered with at least one stable integrated copy of any of the elements necessary for AAV replication and viral particle production including, but not limited to, the entire AAV genome, Rep and Cap genes, Rep genes, Cap genes, each Rep protein as a separate transcription cassette, each VP protein as a separate transcription cassette, the AAP (assembly activation protein), or at least one of the baculovirus helper genes with native or non-native promoters. 
     Large-Scale Production Methods 
     In some embodiments, viral particle production may be modified to increase the scale of production. Large scale viral production methods according to the present invention may include any of those taught in U.S. Pat. Nos. 5,756,283, 6,258,595, 6,261,551, 6,270,996, 6,281,010, 6,365,394, 6,475,769, 6,482,634, 6,485,966, 6,943,019, 6,953,690, 7,022,519, 7,238,526, 7,291,498 and 7,491,508 or International Publication Nos, WO1996039530, WO1998010088, WO1999014354, WO1999015685, WO1999047691, WO2000055342, WO2000075353 and WO2001023597, the contents of each of Which are herein incorporated by reference by reference in their entirety. Methods of increasing viral particle production scale typically comprise increasing the number of viral replication cells. In some embodiments, viral replication cells comprise adherent cells. To increase the scale of viral particle production by adherent viral replication cells, larger cell culture surfaces are required. In some cases, large-scale production methods comprise the use of roller bottles to increase cell culture surfaces. Other cell culture substrates with increased surface areas are know) in the art. Examples of additional adherent cell culture products with increased surface areas include, but are not limited to CELLSTACK®, CELLCUBE® (Corning Corp., Corning, N.Y.) and NUNC™ CELL FACTORY™ (Thermo Scientific. Waltham, Mass.) In some cases, large-scale adherent cell surfaces may comprise from about 1,000 cm 2  to about 100,000 cm 2 . In some cases, large-scale adherent cell cultures may comprise from about 10 7  to about 10 9  cells, from about 10 8  to about 10 10  cells, from about 10 9  to about 10 12  cells or at least 10 12  cells. In some cases, large-scale adherent cultures may produce from about 10 9  to about 10 12 , from about  10   10  to about 10 13 , from about 10 11  to about 10 14 , from about 10 12  to about 10 15  or at least 10 15  viral particles. 
     In some embodiments, large-scale viral production methods of the present invention may comprise the use of suspension cell cultures. Suspension cell culture allows for significantly increased numbers of cells. Typically, the number of adherent cells that can be grown on about 10-50 cm 2  of surface area can be grown in about 1 cm 3  volume in suspension. 
     Transfection of replication cells in large-scale culture formats may be carried out according to any methods known in the art. For large-scale adherent cell cultures, transfection methods may include, but are not limited to the use of inorganic compounds (e.g. calcium phosphate,) organic compounds [e.g. polyethyleneimine (PEI)] or the use of non-chemical methods (e.g. electroporation). With cells grown in suspension, transfection methods may include, but are not limited to the use of calcium phosphate and the use of PEI. In some cases, transfection of large scale suspension cultures may be carried out according to the section entitled “Transfection Procedure” described in Feng, L. et al., 2008. Biotechnol Appl Biochem. 50:121-32, the contents of which are herein incorporated by reference in their entirety. According to such embodiments, PEI-DNA complexes may be formed for introduction of plasmids to be transfected. In some cases, cells being transfected with PEI-DNA complexes may be ‘shocked’ prior to transfection. ‘This comprises lowering cell culture temperatures to 4° C. for a period of about 1 hour. In some cases, cell cultures may be shocked for a period of from about 10 minutes to about 5 hours. In some cases, cell cultures may be shocked at a temperature of from about 0° C. to about 20° C., 
     In some cases, transfections may include one or more vectors for expression of an RNA effector molecule to reduce expression of nucleic acids from one or more payload construct. Such methods may enhance the production of viral particles by reducing cellular resources wasted on expressing payload constructs. In some cases, such methods may be carried according to those taught in US Publication No. US2014/0099666, the contents of which are herein incorporated by reference in their entirety. 
     Bioreactors 
     In some embodiments, cell culture bioreactors may be used for large scale viral production. In some cases, bioreactors comprise stirred tank reactors. Such reactors generally comprise a vessel, typically cylindrical in shape, with a stirrer (e.g. impeller). In some embodiments, such bioreactor vessels may be placed within a water jacket to control vessel temperature and/or to minimize effects from ambient temperature changes. Bioreactor vessel volume may range in size from about 500 nil to about 2 L, from about 1 L to about 5 L, from about 2.5 L to about 20 L, from about 10 L to about 50 L, from about 25 L to about 100 L, from about 75 L to about 500 L, from about 250 L to about 2,000 L, from about 1,000 L to about 10,000 L, from about 5,000 L to about 50,000 L or at least 50,000 L. Vessel bottoms may be rounded or flat. In some cases, animal cell cultures may be maintained in bioreactors with rounded vessel bottoms, 
     In some cases, bioreactor vessels may be warmed through the use of a thermocirculator. Thermocirculators pump heated water around water jackets. In some cases, heated water may be pumped through pipes (e.g, coiled pipes) that are present within bioreactor vessels. In some cases, warm air may be circulated around bioreactors, including, but not limited to air space directly above culture medium. Additionally, pH and CO2 levels may be maintained to optimize cell viability. 
     In some cases, bioreactors may comprise hollow-fiber reactors. Hollow-fiber bioreactors may support the culture of both anchorage dependent and anchorage independent cells. Further bioreactors may include, but are not limited to packed-bed or fixed-bed bioreactors. Such bioreactors may comprise vessels with glass beads for adherent cell attachment. Further packed-bed reactors may comprise ceramic beads. 
     In sonic cases, viral particles are produced through the use of a disposable bioreactor. In some embodiments, such bioreactors may include WAVE™ disposable bioreactors, 
     In some embodiments, viral particle production in animal cell bioreactor cultures may be carried out according to the methods taught in U.S. Pat. Nos. 5,064764, 6,194,191, 6,566,118, 8,137,948 or US Patent Application No. US2011/0229971, the contents of each of which are herein incorporated by reference in their entirety. 
     Cell Lysis 
     Cells of the invention, including, but not limited to viral production cells, may be subjected to cell lysis according to any methods known in the art. Cell lysis may be carried out to obtain one or more agents (e.g. viral particles) present within any cells of the invention. In some embodiments, cell lysis may be carried out according to any of the methods listed in U.S. Pat. Nos. 7,326,555, 7,579.181, 7,048,920, 6,410,300, 6,436,394, 7,732,129, 7,510,875, 7,445,930, 6,726,907, 6,194,191, 7,125,706, 6,995,006, 6,676,935, 7,968,333, 5,756,283, 6,258,595, 6,261,551, 6,270,996, 6,281,010, 6,365,394, 6,475,769, 6,482,634, 6,485,966, 6,943,019, 6,953,690, 7,022,519, 7,238,526, 7,291,498 and 7,491,508 or International Publication Nos. WO1996039530, WO1998010088, 101999014354, WO1999015685, WO1999047691, WO2000055342, WO2000075353 and WO2001023597, the contents of each of which are herein incorporated by reference in their entirety. Cell lysis methods may be chemical or mechanical. Chemical cell lysis typically comprises contacting one or more cells with one or more lysis agents. Mechanical lysis typically comprises subjecting one or more cells to one or more lysis conditions and/or one or more lysis forces. 
     In some embodiments, chemical lysis may be used to lyse cells. As used herein, the term “lysis agent” refers to any agent that may aid in the disruption of a cell. In some cases, lysis agents are introduced in solutions, termed lysis solutions or lysis buffers. As used herein, the term “lysis solution” refers to a solution (typically aqueous) comprising one or more lysis agents. In addition to lysis agents, lysis solutions may include one or more buffering agents, solubilizing agents, surfactants, preservatives, cryoprotectants, enzymes, enzyme inhibitors and/or chelators. Lysis buffers are lysis solutions comprising one or more buffering agents. Additional components of lysis solutions may include one or more solubilizing agents. As used herein, the term “solubilizing agent” refers to a compound that enhances the solubility of one or more components of a solution and/or the solubility of one or more entities to which solutions are applied. In some cases, solubilizing agents enhance protein solubility. In some cases, solubilizing agents are selected based on their ability to enhance protein solubility while maintaining protein conformation and/or activity. 
     Exemplary lysis agents may include any of those described in U.S. Pat. Nos. 8,685,734, 7,901,921, 7,732,129, 7,223,585, 7,125,706, 8,236,495, 8,110,351, 7,419,956, 7,300,797, 6,699,706 and 6,143,567, the contents of each of which are herein incorporated by reference in their entirety. In some cases, lysis agents may be selected from lysis salts, amphoteric agents, cationic agents, ionic detergents and non-ionic detergents. Lysis salts may include, but are not limited to sodium chloride (NaCl) and potassium chloride (KCl). Further lysis salts may include any of those described in U.S. Pat. Nos. 8,614,101, 7,326,555, 7,579,181, 7,048,920, 6,410,300, 6,436,394, 7,732,129, 7,510,875, 7,445,930, 6,726,907, 6,194,191, 7,125,706, 6,995,006, 6,676,935 and 7,968,333, the contents of each of which are herein incorporated by reference in their entirety. Concentrations of salts may be increased or decreased to obtain an effective concentration for rupture of cell membranes. Amphoteric agents, as referred to herein, are compounds capable of reacting as an acid or a base. Amphoteric agents may include, but are not limited to lysophosphatidylcholine, 3-((3-Cholamidopropyl)dimethylammonium)-1-propanesulfonate (CHAPS), ZWITTERGENT® and the like. Cationic agents may include, but are not limited to cetyltrimethylamtnonium bromide (C(16)TAB) and Benzalkonium chloride. Lysis agents comprising detergents may include ionic detergents or non-ionic detergents. Detergents may function to break apart or dissolve cell structures including, but not limited to cell membranes, cell walls, lipids, carbohydrates, lipoproteins and glycoproteins. Exemplary ionic detergents include any of those taught in U.S. Pat. Nos. 7,625,570 and 6,593,123 or US Publication No. US2014/0087361, the contents of each of which are herein incorporated by reference in their entirety. Some ionic detergents may include, but are not limited to sodium dodecyl sulfate (SDS), cholate and deoxycholate. In some cases, ionic detergents may be included in lysis solutions as a solubilizing agent. Non-ionic detergents may include, but are not limited to octylglucoside, digitonin, lubrol, C12E8, TWEEN®-20, TWEEN®-80, Triton X-100 and Noniodet P-40. Non-ionic detergents are typically weaker lysis agents, but may he included as solubilizing agents for solubilizing cellular and/or viral proteins. Further lysis agents may include enzymes and urea. In some cases, one or more lysis agents may be combined in a lysis solution in order to enhance one or more of cell lysis and protein solubility. In some cases, enzyme inhibitors may be included in lysis solutions in order to prevent proteolysis that may be triggered by cell membrane disruption. 
     In some embodiments, mechanical cell lysis is carried out. Mechanical cell lysis methods may include the use of one or more lysis conditions and/or one or more lysis forces. As used herein, the term “lysis condition” refers to a state or circumstance that promotes cellular disruption. Lysis conditions may comprise certain temperatures, pressures, osmotic purity, salinity and the like. In some cases, lysis conditions comprise increased or decreased temperatures. According to some embodiments, lysis conditions comprise changes in temperature to promote cellular disruption. Cell lysis carried out according to such embodiments may include freeze-thaw lysis. As used herein, the term “freeze-thaw lysis” refers to cellular lysis in which a cell solution is subjected to one or more freeze-thaw cycles. According to freeze-thaw lysis methods, cells in solution are frozen to induce a mechanical disruption of cellular membranes caused by the formation and expansion of ice crystals. Cell solutions used according to freeze-thaw lysis methods, may further comprise one or more lysis agents, solubilizing agents, buffering agents, cryoprotectants, surfactants, preservatives, enzymes, enzyme inhibitors and/or chelators. Once cell solutions subjected to freezing are thawed, such components may enhance the recovery of desired cellular products. In some cases, one or more cyroprotectants are included in cell solutions undergoing freeze-thaw lysis. As used herein, the term “cryoprotectant” refers to an agent used to protect one or more substances from damage due to freezing. Cryoprotectants of the invention may include any of those taught in US Publication No. US2013/0323302 or U.S. Pat. Nos. 6,503,888, 6,180,613, 7,888,096, 7,091,030, the contents of each of which are herein incorporated by reference in their entirety. In some cases, cryoprotectants may include, but are not limited to dimethyl sulfoxide, 1.2-propanediol, 2,3-butanediol, formamide, glycerol, ethylene glycol, 1,3-propanediol and n-dimethyl formamide, polyvinylpyrrolidone, hydroxy ethyl starch, agarose, dextrans, inositol, glucose, hydroxyethylstarch, lactose, sorbitol, methyl glucose, sucrose and urea. In some embodiments, freeze-thaw lysis may be carried out according to any of the methods described in U.S. Pat. No. 7,704,721, the contents of which are herein incorporated by reference in their entirety. 
     As used herein, the term “lysis force” refers to a physical activity used to disrupt a cell. Lysis forces may include, but are not limited to mechanical forces, sonic forces, gravitational forces, optical forces, electrical forces and the like. Cell lysis carried out by mechanical force is referred to herein as “mechanical lysis.” Mechanical forces that may be used according to mechanical lysis may include high shear fluid forces. According to such methods of mechanical lysis, a microfluidizer may be used. Microfluidizers typically comprise an inlet reservoirs where cell solutions may be applied. Cell solutions may then be pumped into an interaction chamber via a pump (e.g. high-pressure pump) at high speed and/or pressure to produce shear fluid forces. Resulting lysates may then be collected in one or more output reservoir. Pump speed and/or pressure may be adjusted to modulate cell lysis and enhance recovery of products (e.g. viral particles). Other mechanical lysis methods may include physical disruption of cells by scraping. 
     Cell lysis methods may be selected based on the cell culture format of cells to be lysed. For example, with adherent cell cultures, some chemical and mechanical lysis methods may be used. Such mechanical lysis methods may include freeze-thaw lysis or scraping. In another example, chemical lysis of adherent cell cultures may be carried out through incubation with lysis solutions comprising surfactant, such as Triton-X-100. In some cases, cell lysates generated from adherent cell cultures may be treated with one more nucleases to lower the viscosity of the lysates caused by liberated DNA. 
     In one embodiment, a method for harvesting AAV without lysis may be used for efficient and scalable AAV production. In a non-limiting example, viral particles may be produced by culturing an AAV lacking a heparin binding site, thereby allowing the AAV to pass into the supernatant, in a cell culture, collecting supernatant from the culture; and isolating the AAV from the supernatant, as described in US Patent Application 20090275107, the contents of which are incorporated herein by reference in their entirety. 
     Clarification 
     Cell lysates comprising viral particles may be subjected to clarification. Clarification refers to initial steps taken in purification of viral particles from cell lysates. Clarification serves to prepare lysates for further purification by removing larger, insoluble debris. Clarification steps may include, but are not limited to centrifugation and filtration. During clarification, centrifugation may be carried out at low speeds to remove larger debris, only. Similarly, filtration may be carried out using filters with larger pore sizes so that only larger debris is removed. In some cases, tangential flow filtration may be used during clarification. Objectives of viral clarification include high throughput processing of cell lysates and to optimize ultimate viral recovery. Advantages of including a clarification step include scalability for processing of larger volumes of lysate. In some embodiments, clarification may be carried out according to any of the methods presented in U.S. Pat. Nos. 8,524,446, 5,756,283, 6,258,595, 6,261,551, 6,270,996, 6,281,010, 6,365,394, 6,475,769, 6,482,634, 6,485,966, 6,943,019, 6,953,690, 7,022,519; 7;238,526, 7,291,498; 7,491;508, US Publication Nos. US2013/0045186, US2011/0263027, US2011/0151434, US2003/0138772, and International Publication Nos. WO2002012455, WO1996039530, WO1998010088, WO1999014354, WO1999015685, WO1999047691, WO2000055342, WO2000075353 and WO2001023597; the contents of each of which are herein incorporated by reference in their entirety. 
     Methods of cell lysate clarification by filtration are well understood in the art and may be carried out according to a variety of available methods including, but not limited to passive filtration and flow filtration. Filters used may comprise a variety of materials and pore sizes. For example, cell lysate filters may comprise pore sizes of from about 1 μM to about 5 μM, from about 0.5 μM to about 2 μM, from about 0.1 μM to about 1 μM, from about 0.05 μM to about 0.5 μM and from about 0.001 μM to about 0.1 μM. Exemplary pore sizes for cell lysate filters may include,but are not limited to, 2.0, 1.9, 1.8, 1.7, 1.6. 1.5, 1.4, 1.3, 1.2, 1.1, 1, 0.9, 0.8, 0.7, 0.6, 0.5. 0.4, 0.3, 0.2, 0,1, 0.95, 0.9, 0.85, 0.8, 0.75, 0.7, 0.65, 0.6, 0.55, 0.5, 0.45. 0.4, 0.35, 0.3, 0.25 0.15, 0.1, 0.05, 0.22, 0.21, 0.20, 0.19, 0.18, 0.17, 0.16, 0.15, 0.14, 0.13, 0.12, 0.11, 0.1, 0.09, 0.08, 0.07, 0.06, 0.05, 0.04, 0.03, 0.02, 0.01, 0.02, 0.019, 0.018, 0.017, 0.016, 0.015, 0.014, 0.013, 0.012, 0.011, 0.01, 0.009, 0.008, 0.007, 0.006, 0.005, 0.004, 0.003, 0.002, 0.001 and 0.001 μM. In one embodiment, clarification may comprise filtration through a filter with 2.0 μM pore size to remove large debris, followed by passage through a filter with 0.45 μM pore size to remove intact cells. 
     Filter materials may be composed of a variety of materials. Such materials may include, but are not limited to polymeric materials and metal materials (e.g. sintered metal and pored aluminum). Exemplary materials may include, but are not limited to nylon, cellulose materials (e.g. cellulose acetate), polyvinylidene fluoride (PVDF), polyethersulfone, polyamide, polysulfone, polypropylene and polyethylene terephthalate. In some cases, filters useful for clarification of cell lysates may include, but are not limited to ULTIPLEAT PROFILE™ filters (Pall Corporation, Port Washington N.Y.), SUPOR™ membrane filters (Pall Corporation Port Washington, N.Y.) 
     In some cases, flow filtration may be carried out to increase filtration speed arid/or effectiveness. In some cases, flow filtration may comprise vacuum filtration. According to such methods, a vacuum is created on the side of the filter opposite that of cell lysate to be filtered. In some cases, cell lysates may be passed through filters by centrifugal forces. In some cases, a pump is used to force cell lysate through clarification filters. Flow rate of cell lysate through one or more filters may be modulated by adjusting one of channel size and/or fluid pressure. 
     According to some embodiments, cell lysates may be clarified by centrifugation. Centrifugation may be used to pellet insoluble particles in the lysate. During clarification, centrifugation strength [expressed in terms of gravitational units (g), which represents multiples of standard gravitational force]may be lower than in subsequent purification steps. In some cases, centrifugation may be carried out on cell lysates at from about 200 g to about 800 g, from about 500 g to about 1500 g, from about 1000 g to about 5000 g, from about 1200 g to about 10000 g or from about 8000 g to about 15000 g. In sonic embodiments, cell lysate centrifugation is carried out at 8000 g for 15 minutes. In some cases, density gradient centrifugation may be carried out in order to partition particulates in the cell lysate by sedimentation rate. Gradients used according to methods of the present invention may include, but are not limited to cesium chloride gradients and iodixanol step gradients. 
     Purification Chromatography 
     In some cases, viral particles may be purified from clarified cell lysates by one or more methods of chromatography. Chromatography refers to any number of methods known in the art for separating out one or more elements from a mixture. Such methods may include, but are not limited to ion exchange chromatography (e.g. cation exchange chromatography and anion exchange chromatography,) immunoaffinity chromatography and size-exclusion chromatography. In some embodiments, methods of viral chromatography may include any of those taught in U.S. Pat. Nos. 5,756,283, 6,258,595, 6,261,551, 6,270,996, 6,281,010, 6,365,394, 6,475,769, 6,482,634, 6,485,966, 6,943,019, 6,953,690, 7,022,519, 7,238,526, 7,291,498 and 7,491,508 or international Publication Nos, WO1996039530, ‘WO199801.0088, WO1999014354, WO1999015685, WO1999047691, WO2000055342, WO2000075353 and WO2001023597, the contents of each of which are herein incorporated by reference by reference in their entirety. 
     In some embodiments, ion exchange chromatography may be used to isolate viral particles. Ion exchange chromatography is used to bind viral particles based on charge-charge interactions between capsid proteins and charged sites present on a stationary phase, typically a column through which viral preparations (e.g, clarified lysates) are passed. After application of viral preparations, bound viral particles may then be eluted by applying an elution solution to disrupt the charge-charge interactions. Elution solutions may be optimized by adjusting salt concentration and/or to enhance recovery of bound viral particles. Depending on the charge of viral capsids being isolated, cation or anion exchange chromatography methods may be selected. Methods of ion exchange chromatography may include, but are not limited to any of those taught in U.S. Pat. Nos. 7,419,817, 6,143,548, 7,094,604, 6,593,123, 7,015,026 and 8,137,948, the contents of each of which are herein incorporated by reference in their entirety. 
     In some embodiments, immunoaffinity chromatography may be used. Immunoaffinity chromatography is a form of chromatography that utilizes one or more immune compounds (e.g. antibodies or antibody-related structures) to retain viral particles. Immune compounds may bind specifically to one or more structures on viral particle surfaces, including, but not limited to one or more viral coat proteins. In some cases, immune compounds may be specific for a particular viral variant. In some cases, immune compounds may bind to multiple viral variants. In some embodiments, immune compounds may include recombinant single-chain antibodies. Such recombinant single chain antibodies may include those described in Smith, R. H. et al., 2009. Mol Ther. 17(11):1888-96, the contents of which are herein incorporated by reference in their entirety. Such immune compounds are capable of binding to several AAV capsid variants, including, but not limited to AAV1, AAV2, AAV6 and AAV8. 
     In some embodiments, size-exclusion chromatography (SEC) may be used. SEC may comprise the use of a gel to separate particles according to size. In viral particle purification, SEC filtration is sometimes referred to as “polishing.” In some cases, SEC may be carried out to generate a final product that is near-homogenous. Such final products may in some cases be used in pre-clinical studies and/or clinical studies (Kotin, R. M. 2011. Human Molecular Genetics. 20(1):R2-R6, the contents of which are herein incorporated by reference in their entirety). In some cases, SEC may be carried out according to any of the methods taught in U.S. Pat. Nos. 6,143,548, 7,015,026, 8,476,418, 6,410,300, 8,476,418, 7,419,817, 7,094,604, 6,593,123, and 8,137,948, the contents of each of which are herein incorporated by reference in their entirety. 
     In one embodiment, the compositions comprising at least one viral particle may be isolated or purified using the methods described in U.S. Pat. No. 6,146,874, the contents of which are herein incorporated by reference in their entirety. 
     In one embodiment, the compositions comprising at least one viral particle may be isolated or purified using the methods described in U.S. Pat. No. 6,660,514, the contents of which are herein incorporated by reference in their entirety. 
     In one embodiment, the compositions comprising at least one viral particle may be isolated or purified using the methods described in U.S. Pat. No. 8,283,151, the contents of which are herein incorporated by reference in their entirety. 
     In one embodiment, the compositions comprising at least one viral particle may be isolated or purified using the methods described in U.S. Pat. No. 8,524,446, the contents of which are herein incorporated by reference in their entirety. 
     VII. TREATMENT AND PHARMACEUTICAL COMPOSITIONS 
     The present disclosure additionally provides a method for treating a disease, disorder and/or condition in a mammalian subject, including a human subject, comprising administering to the subject any of the above-described AAV polynucleotides or AAV genomes or AAV comprising a chimeric Rep binding sequence region or administering to the subject a vector comprising the AAV polynucleotide or AAV genome, or administering to the subject any of the described compositions, including pharmaceutical compositions. In one embodiment, the disease, disorder and/or condition is a neurological disease, disorder and/or condition. In one embodiment, the neurological disease, disorder and/or condition is Parkinson&#39;s disease. In another embodiment, the neurological disease, disorder and/or condition is Friedreich&#39;s Ataxia. In another embodiment, the neurological disease, disorder and/or condition is Amyotrophic lateral sclerosis (ALS). In another embodiment, the disease, disorder and/or condition is a muscular or cardiac disease, disorder and/or condition. In another embodiment, the disease, disorder and/or condition is an immune system disease, disorder and/or condition. 
     The present disclosure provides a composition comprising an AAV polynucleotide or AAV genome or AAV particle comprising an engineered Rep binding sequence region and at least one excipient. 
     The present disclosure also provides a pharmaceutical composition comprising an adeno-associated virus (AAV) comprising any of the above-described AAV polynucleotides or AAV genomes and one or more pharmaceutically acceptable excipients. 
     Although the descriptions of pharmaceutical compositions, e.g., those viral vectors comprising a payload to be delivered, provided herein are principally directed to pharmaceutical compositions which are suitable for administration to humans, it will be understood by the skilled artisan that such compositions are generally suitable for administration to any other animal, e.g., to non-human animals, e.g. non-human mammals. Modification of pharmaceutical compositions suitable for administration to humans in order to render the compositions suitable for administration to various animals is well understood, and the ordinarily skilled veterinary pharmacologist can design and/or perform such modification with merely ordinary, if any, experimentation. Subjects to which administration of the pharmaceutical compositions is contemplated include, but are not limited to, humans and/or other primates; mammals, including commercially relevant mammals such as cattle, pigs, horses, sheep, cats, dogs, mice, and/or rats; and/or birds, including commercially relevant birds such as poultry, chickens, ducks, geese, and/or turkeys. 
     In some embodiments, compositions are administered to humans, human patients or subjects. For the purposes of the present disclosure, the phrase “active ingredient” generally refers either to the viral particle carrying the payload or to the payload molecule delivered by the viral particle as described herein. 
     Formulations of the pharmaceutical compositions described herein may be prepared by any method known or hereafter developed in the art of pharmacology. In general, such preparatory methods include the step of bringing the active ingredient into association with an excipient and/or one or more other accessory ingredients, and then, if necessary and/or desirable, dividing, shaping and/or packaging the product into a desired single- or multi-dose unit. 
     Relative amounts of the active ingredient, the pharmaceutically acceptable excipient, and/or any additional ingredients in a pharmaceutical composition in accordance with the invention will vary, depending upon the identity, size, and/or condition of the subject treated and further depending upon the route by which the composition is to be administered. 
     Formulation 
     The viral particles of the invention can be formulated using one or more excipients to: 
     (1) increase stability; (2) increase cell transfection or transduction; (3) permit the sustained or delayed release; (4) alter the biodistribution (e.g., target the viral particle to specific tissues or cell types); (5) increase the translation of encoded protein in vivo; and/or (6) alter the release profile of encoded protein in vivo. 
     Formulations of the present invention can include, without limitation, saline, lipidoids, liposomes, lipid nanoparticles, polymers, lipoplexes, core-shell nanoparticles, peptides, proteins, cells transfected with viral vectors (e.g., for transplantation into a subject), nanoparticle mimics and combinations thereof. Further, the viral vectors of the present invention may be  - formulated using self-assembled nucleic acid nanoparticles. 
     Formulations of the pharmaceutical compositions described herein may be prepared by any method known or hereafter developed in the art of pharmacology. In general, such preparatory methods include the step of associating the active ingredient with an excipient and/or one or more other accessory ingredients. 
     A pharmaceutical composition in accordance with the present disclosure may be prepared, packaged, and/or sold in bulk, as a single unit dose, and/or as a plurality of single unit doses. As used herein, a “unit dose” refers to a discrete amount of the pharmaceutical composition comprising a predetermined amount of the active ingredient. The amount of the active ingredient is generally equal to the dosage of the active ingredient which would be administered to a subject and/or a convenient fraction of such a dosage such as, for example, one-half or one-third of such a dosage. 
     Relative amounts of the active ingredient (e.g, scAAV), the pharmaceutically acceptable excipient, and/or any additional ingredients in a pharmaceutical composition in accordance with the present disclosure may vary, depending upon the identity, size, and/or condition of the subject being treated and further depending upon the route by which the composition is to be administered. For example, the composition may comprise between 0.1% and 99% (w/w) of the active ingredient. By way of example, the composition may comprise between 0.1% and 100%, e.g., between 0.5 and 50%, between 1-30%, between 5-80%, at least 80% (w/w) active ingredient. 
     In some embodiments, the formulations described herein may contain at least one payload molecule. As a non-limiting example, the formulations may contain 1, 2, 3, 4 or .5 payload molecules. In one embodiment the formulation may contain a payload construct encoding proteins selected from categories such as, but not limited to, human proteins, veterinary proteins, bacterial proteins, biological proteins, antibodies, immunogenic proteins, therapeutic peptides and proteins, secreted proteins, plasma membrane proteins, cytoplasmic and cytoskeletal proteins, intracellular membrane bound proteins, nuclear proteins, proteins associated with human disease and/or proteins associated with non-human diseases. In one embodiment, the formulation contains at least three payload construct encoding proteins. 
     The formulations of the invention can include one or more excipients, each in an amount that together increases the stability of the viral particle, increases cell transfection or transduction by the viral particle, increases the expression of viral particle encoded protein, and/or alters the release profile of viral particle encoded proteins. In some embodiments, a pharmaceutically acceptable excipient may be at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% pure. In some embodiments, an excipient is approved for use for humans and for veterinary use. In some embodiments, an excipient may be approved by United States Food and Drug Administration. In some embodiments, an excipient may be of pharmaceutical grade. In some embodiments, an excipient may meet the standards of the United States Pharmacopoeia (USP), the European Pharmacopoeia (EP), the British Pharmacopoeia, and/or the International Pharmacopoeia, 
     Excipients, which, as used herein, includes, but is not limited to, any and all solvents, dispersion media, diluents, or other liquid vehicles, dispersion or suspension aids, surface active agents, isotonic agents, thickening or emulsifying agents, preservatives, and the like, as suited to the particular dosage form desired. Various excipients for formulating pharmaceutical compositions and techniques for preparing the composition are known in the art (see Remington: The Science and Practice of Pharmacy, 21 st  Edition, A. R., Gennaro, Lippincott, Williams &amp; Wilkins, Baltimore, Md., 2006; incorporated herein by reference in its entirety). The use of a conventional excipient medium may be contemplated within the scope of the present disclosure, except insofar as any conventional excipient medium may be incompatible with a substance or its derivatives, such as by producing any undesirable biological effect or otherwise interacting in a deleterious manner with any other component(s) of the pharmaceutical composition. 
     Diluents may include, but are not limited to, calcium carbonate, sodium carbonate, calcium phosphate, dicalcium phosphate, calcium sulfate, calcium hydrogen phosphate, sodium phosphate lactose, sucrose, cellulose, microcrystalline cellulose, kaolin, mannitol, sorbitol, inositol, sodium chloride, dry starch, cornstarch, powdered sugar, etc., and/or combinations thereof. 
     Additives include physiologically biocompatibie buffers (e.g., trimethylamine hydrochloride), addition of chelants (such as, for example, DTPA or DTPA-bisamide) or calcium chelate complexes (as for example calcium DTPA, CaNaDTPA-bisamide), or, optionally, additions of calcium or sodium salts (for example, calcium chloride, calcium ascorbate, calcium gluconate or calcium lactate). In addition, antioxidants and suspending agents can be used. 
     Cryoprotectants 
     In some embodiments, viral particle formulations may comprise cyroprotectants. As used herein, the term “cryoprotectant” refers to one or more agents that when combined with a given substance, helps to reduce or eliminate damage to that substance that occurs upon freezing. In some embodiments, cryoprotectants are combined with viral particles in order to stabilize them during freezing. Frozen storage between −20° C. and −80° C. may be advantageous for long term (e.g. 36 months) stability of viral particles. In some embodiments, cryoprotectants are included in viral particle formulations to stabilize them through freeze/thaw cycles and under frozen storage conditions. Cryoprotectants of the present invention may include, but are not limited to sucrose, trehalose, lactose, glycerol, dextrose, raffinose and/or mannitol. Trehalose is listed by the Food and Drug Administration as being generally regarded as safe (GRAS) and is commonly used in commercial pharmaceutical formulations. 
     Bulking Agents 
     In some embodiments, viral particle formulations may comprise bulking agents. As used herein, the term “bulking agent” refers to one or more agents included in formulations to impart a desired consistency to the formulation and/or stabilization of formulation components. In some embodiments, bulking agents are included in lyophilized viral particle formulations to yield a “pharmaceutically elegant” cake, stabilizing the lyophilized viral particles during long term (e.g. 36 month) storage. Bulking agents of the present invention may include, but are not limited to sucrose, trehalose, mannitol, glycine, lactose and/or raffinose. In some embodiments, combinations of cryoprotectants and bulking agents (for example, sucrose/glycine or trehalose/mannitol) may be included to both stabilize viral particles during freezing and provide a bulking agent for lyophilization. 
     Inactive Ingredients 
     In some embodiments, formulations may comprise at least one excipient which is an inactive ingredient. As used herein, the term “inactive ingredient” refers to one or more inactive agents included in formulations. In some embodiments, all, none or some of the inactive ingredients which may be used in the formulations of the present invention may be approved by the US Food and Drug Administration (FDA). 
     Formulations of viral particles disclosed herein may include cations or anions. In one embodiment, the formulations include metal cations such as, but not limited to, Zn2+, Ca2+, Cu2+, Mg+ and combinations thereof. 
     Administration 
     The viral particles of the present invention may be administered by any route which results in a therapeutically effective outcome. These include, but are not limited to enteral (into the intestine), gastroenteral, epidural (into the dura matter), oral (by way of the mouth), transdermal, peridural, intracerebral (into the cerebrum), intracerebroventricular (into the cerebral ventricles), epicutaneous (application onto the skin), intradermal, (into the skin itself), subcutaneous (under the skin), nasal administration (through the nose), intravenous (into a vein), intravenous bolus, intravenous drip, intraarterial (into an artery), intramuscular (into a muscle), intracardiac (into the heart), intraosseous infusion (into the bone marrow), intrathecal (into the spinal canal), intraperitoneal, (infusion or injection into the peritoneum), intravesical infusion, intravitreal, (through the eye), intracavernous injection (into a pathologic cavity) intracavitary (into the base of the penis), intravaginal administration, intrauterine, extra-amniotic administration, transdermal (diffusion through the intact skin for systemic distribution), transmucosal (diffusion through a mucous membrane), transvaginal, insufflation (snorting), sublingual, sublabial, enema, eye drops (onto the conjunctiva), in ear drops, auricular (in or by way of the ear), buccal (directed toward the cheek), conjunctival, cutaneous, dental (to a tooth or teeth), electro-osmosis, endocervical, endosinusial, endotracheal, extracorporeal, hemodialysis, infiltration, interstitial, intra-abdominal, intra-amniotic, intra-articular, intrabiliary, intrabronchial, intrabursal, intracartilaginous (within a cartilage), intracaudal (within the cauda equine), intracisternal (within the cisterna magna cerebellomedularis), intracorneal (within the cornea), dental intraconal, intracoronary (within the coronary arteries), intracorporus cavernosum (within the dilatable spaces of the corporus cavernosa of the penis), intradiscal (within a disc), intraductal (within a duct of a gland), intraduodenal (within the duodenum), intradural (within or beneath the dura), intraepidermal (to the epidermis), intraesophageal (to the esophagus), intragastric (within the stomach), intragingival (within the gingivae), intraileal (within the distal portion of the small intestine), intralesional (within or introduced directly to a localized lesion), intraluminal (within a lumen of a tube), intralymphatic (within the lymph), intramedullary (within the marrow cavity of a bone), intrameningeal (within the meninges), intraocular (within the eye), intraovarian (within the ovary), intrapericardial (within the pericardium), intrapleural (within the pleura), intraprostatic (within the prostate gland), intrapulmonary (within the lungs or its bronchi), intrasinal (within the nasal or periorbital sinuses), intraspinal (within the vertebral column), intrasynovial (within the synovial cavity of a joint), intratendinous (within a tendon), intratesticular (within the testicle), intrathecal (within the cerebrospinal fluid at any level of the cerebrospinal axis), intrathoracic (within the thorax), intratubular (within the tubules of an organ), intratumor (within a tumor), intratympanic (within the aurus media), intravascular (within a vessel or vessels), intraventricular (within a ventricle), iontophoresis (by means of electric current where ions of soluble salts migrate into the tissues of the body), irrigation (to bathe or flush open wounds or body cavities), laryngeal (directly upon the larynx), nasogastric (through the nose and into the stomach), occlusive dressing technique (topical route administration which is then covered by a dressing which occludes the area), ophthalmic (to the external eye), oropharyngeal (directly to the mouth and pharynx), parenteral, percutaneous, periarticular, peridural, perineural, periodontal, rectal, respiratory (within the respiratory tract by inhaling orally or nasally for local or systemic effect), retrobulbar (behind the pons or behind the eyeball), soft tissue, subarachnoid., subconjunctival, submucosal, topical, transplacental (through or across the placenta), transtracheal (through the wall of the trachea), transtympanic (across or through the tympanic cavity), ureteral (to the ureter), urethral (to the urethra), vaginal, caudal block, diagnostic, nerve block, biliary perfusion, cardiac perfusion, photopheresis or spinal. In specific embodiments, compositions may be administered in a way which allows them cross the blood-brain barrier ;  vascular barrier, or other epithelial barrier. In one embodiment, a formulation for a route of administration may include at least one inactive ingredient. 
     Dosing 
     The present invention provides methods comprising administering viral particles and their payload or complexes in accordance with the invention to a subject in need thereof. Viral particle pharmaceutical, imaging, diagnostic, or prophylactic compositions thereof, may be administered to a subject using any amount and any route of administration effective for preventing, treating, diagnosing, or imaging a disease, disorder, and/or condition (e.g., a disease, disorder, and/or condition relating to working memory deficits). The exact amount required will vary from subject to subject, depending on the species, age, and general condition of the subject, the severity of the disease, the particular composition, its mode of administration, its mode of activity, and the like. Compositions in accordance with the invention are typically formulated in unit dosage form for ease of administration and uniformity of dosage. It will be understood, however, that the total daily usage of the compositions of the present invention may be decided by the attending physician within the scope of sound medical judgment. The specific therapeutically effective, prophylactically effective, or appropriate imaging dose level for any particular patient will depend upon a variety of factors including the disorder being treated and the severity of the disorder: the activity of the specific compound employed; the specific composition employed; the age, body weight, general health, sex and diet of the patient; the time of administration, route of administration ;  and rate of excretion of the specific payload employed; the duration of the treatment; drugs used in combination or coincidental with the specific compound employed; and like factors well known in the medical arts. 
     In certain embodiments, viral particle pharmaceutical compositions in accordance with the present invention may be administered at dosage levels sufficient to deliver from about 00001 mg/kg to about 100 mg/kg, from about 0.001 mg/kg to about 0.05 mg/kg, from about 0.005 mg/kg to about 0.05 mg/kg, from about 0.001 mg/kg to about 0.005 mg/kg, from about 0.05 mg/kg to about 0.5 mg, from about 0.01 rag/kg to about 50 mg/kg, from about 0.1 mg/kg to about 40 mg/kg, from about 0.5 ma/kg to about 30 mg/kg, from about 0.01 mg/kg to about 10 m,,/kg, from about 0.1 mg/kg to about 10 mg/kg, or from about 1 mg/kg to about 25 mg/kg, of subject body weight per day, one or more times a day, to obtain the desired therapeutic, diagnostic, prophylactic, or imaging effect, 
     The desired dosage may be delivered three tithes a day, two tithes a day, once a day, every other day, every third day, every week, every two weeks, every three weeks, or every four weeks. In certain embodiments, the desired dosage may be delivered using multiple administrations (e.g, two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen, fourteen, or more administrations). When multiple administrations are employed, split dosing regimens such as those described herein may be used. As used herein, a “split dose” is the division of single unit dose or total daily dose into two or more doses, e.g., two or more administrations of the single unit dose. As used herein, a “single unit dose” is a dose of any therapeutic administered in one dose/at one time/single route/single point of contact, i.e., single administration event. As used herein, a “total daily dose” is an amount given or prescribed in 24 hour period. It may be administered as a single unit dose. In one embodiment, the viral particles of the present invention are administered to a subject in split doses. The viral particles may be formulated in buffer only or in a formulation described herein. 
     A pharmaceutical composition described herein can be formulated into a dosage form described herein, such as a topical, intranasal, pulmonary, intratracheal, or injectable (e.g., intravenous, intraocular, intravitreal, intramuscular, intracardiac, intraperitoneal, and subcutaneous). 
     Combinations 
     The viral particles may be used in combination with one or more other therapeutic, prophylactic, diagnostic, or imaging agents. By “in combination with,” it is not intended to imply that the agents must be administered at the same time and/or formulated for delivery together, although these methods of delivery are within the scope of the present disclosure. Compositions can be administered concurrently with, prior to, or subsequent to, one or more other desired therapeutics or medical procedures. In general, each agent will be administered at a dose and/or on a time schedule determined for that agent. In some embodiments, the present disclosure encompasses the delivery of pharmaceutical, prophylactic, diagnostic, or imaging compositions in combination with agents that may improve their bioavailability, reduce and/or modify their metabolism, inhibit their excretion, and/or modify their distribution within the body. 
     Delivery 
     Delivery to Cells 
     The present disclosure provides a method of delivering to a cell or tissue any of the above-described engineered Rep proteins or AAV polynucleotides, AAV genomes, or AAV comprising an engineered Rep protein comprising contacting the cell or tissue with the Rep protein or AAV polynucleotide or AAV genome or AAV, or contacting the cell or tissue with a particle comprising the AAV polynucleotide or AAV genome, or contacting the cell or tissue with any of the described compositions, including pharmaceutical compositions. The method of delivering the AAV polynucleotide or AAV genome or AAV to a cell or tissue can be accomplished in vitro, ex vivo, or in vivo. 
     Delivery to Subjects 
     The present disclosure additionally provides a method of delivering to a subject, including a mammalian subject, any of the above-described AAV polynucleotides or AAV genomes or AAV comprising an engineered Rep binding sequence region comprising administering to the subject the AAV polynucleotide or AAV genome or AAV, or administering to the subject a particle comprising the AAV polynucleotide or AAV genome, or administering to the subject any of the described compositions, including pharmaceutical compositions. 
     The pharmaceutical compositions of viral particles described herein may be characterized by one or more of bioavailability, therapeutic window and/or volume of distribution. 
     Bioavailability 
     Viral particles of the present invention, when formulated into compositions with delivery/formulation agents or vehicles as described herein, may exhibit increased bioavailability as compared to compositions lacking delivery agents as described herein. As used herein, the term “bioavailability” refers to the systemic availability of a given amount of a particular agent administered to a subject. Bioavailability may be assessed by measuring the area under the curve (AUC) or the maximum serum or plasma concentration (C max ) of the unchanged form of a compound following administration of the compound to a mammal. AUC is a determination of the area under the curve plotting the serum or plasma concentration of a compound along the ordinate (Y-axis) against time along the abscissa (X-axis). Generally, the AUC for a particular compound (e.g., scAAV) may be calculated using methods known to those of ordinary skill in the art and as described in G. S. Banker, Modem Pharmaceutics, Drugs and the Pharmaceutical Sciences, v. 72, Marcel Dekker, New York, Inc., 1996, the contents of which are herein incorporated by reference in their entirety. 
     C max  values are maximum concentrations of compounds achieved in serum or plasma of a subject following administration of compounds to the subject. C max  values of particular compounds may be measured using methods known to those of ordinary skill in the art. As used herein, the phrases “increasing bioavailability” or “improving the pharmacokinetics,” refer to actions that may increase the systemic availability of a viral particle of the present invention (as measured by AUC, C max , or C min ) in a subject. In some embodiments, such actions may comprise co-administration with one or more delivery agents as described herein. In some embodiments, the bioavailability of viral particles (e.g., scAAV) may increase by at least about 2%, at least about 5%, at least about 10%, at least about 15%, at least about 20%, at least about 25%, at least about 30%, at least about 35%, at least about 40%, at least about 45?, at least about 50%, at least about 55%, at least about 60%, at least about 65%, at least about 70%, at least about 75%, at least about 80%, at least about 85f/h, at least about 90%, at least about 95% or about 100%. 
     Therapeutic Window 
     Viral particles of the present invention, when formulated with one or more delivery agents as described herein, may exhibit increases in the therapeutic window of compound and/or composition administration as compared to the therapeutic window of viral particles administered without one or more delivery agents as described herein. As used herein, the term  - therapeutic window” refers to the range of plasma concentrations, or the range of levels of therapeutically active substance at the site of action, with a high probability of eliciting a therapeutic effect. In some embodiments, therapeutic windows of viral particles when administered in a formulation may increase by at least about 2%, at least about 5%, at least about 10%, at least about 15%, at least about 20%, at least about 25%, at least about 30%, at least about 35%, at least about 40%, at least about 45%, at least about 50%, at least about 55%, at least about 60%, at least about 65%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95% or about 100%. 
     Volume of Distribution 
     Viral particles e.g., scAAV) of the present invention, when formulated with one or more delivery agents as described herein, may exhibit an improved volume of distribution (V dist ), e.g., reduced or targeted, relative to formulations lacking one or more delivery agents as described herein. V dist  relates the amount of an agent in the body to the concentration of the same agent in the blood or plasma. As used herein, the term “volume of distribution” refers to the fluid. volume that would be required to contain the total amount of an agent in the body at the same concentration as in the blood or plasma: V dist  equals the amount of an agent in the body/concentration of the agent in blood or plasma. For example, for a 10 mg dose of a given agent and a plasma concentration of 10 mg/L, the volume of distribution would be 1 liter. The volume of distribution reflects the extent to which an agent is present in the extravascular tissue. Large volumes of distribution reflect the tendency of agents to bind to the tissue components as compared with plasma proteins. In clinical settings, V dist  may be used to determine loading doses to achieve steady state concentrations. In some embodiments, volumes of distribution of viral particle compositions of the present invention when co-administered with one or more delivery agents as described herein may decrease at least about 2%, at least about 5%&#39;©, at least about 10%, at least about 15%, at least about 20%, at least about 25%, at least about 30%, at least about 35%, at least about 40%, at least about 45%, at least about 50%, at least about 55 0 , at least about 60%, at least about 65%, at least about 70%. 
     Kits and Devices 
     The invention provides a variety of kits for conveniently and/or effectively carrying out methods of the present invention. Typically kits will comprise sufficient amounts and/or numbers of components to allow a user to perform multiple treatments of a subject(s) and/or to perform multiple experiments. 
     In one aspect, the present invention provides kits comprising the molecules (viral particles) of the invention. In one embodiment, the kit comprises one or more functional antibodies or function fragments thereof. 
     Said kits can be for viral particle production. The kit may further comprise packaging and instructions and/or a delivery agent to form a formulation composition. The delivery agent may comprise a saline, a buffered solution, or any delivery agent disclosed herein. 
     In one embodiment, the buffer solution may include sodium chloride, calcium chloride, phosphate and/or EDTA. In another embodiment, the buffer solution may include, but is not limited to, saline, saline with 2 mM calcium, 50 sucrose, 5% sucrose with 2 mM calcium, 5% Mannitol, 5% Mannitol with 2 mM calcium, Ringer&#39;s lactate, sodium chloride, sodium chloride with 2 mM calcium and mannose (See e.g., U.S. Pub. No, 20120258046; herein incorporated by reference in its entirety). In a further embodiment, the buffer solutions may be precipitated or may be lyophilized. The amount of each component may be varied to enable consistent, reproducible higher concentration saline or simple buffer formulations. The components may also be varied in order to increase the stability of the viral particle or any expression construct taught herein in the buffer solution over a period of time and/or under a variety of conditions. 
     In one aspect, the present invention provides kits for viral particle production, comprising: an expression particle and a payload construct particle provided in an amount effective to produce a desired amount of a viral particle when introduced into a target cell and packaging and instructions. 
     Any of the particles, constructs, polynucleotides or polypeptides of the present invention may be comprised in a kit. In some embodiments, kits may further include reagents and/or instructions for creating and/or synthesizing compounds and/or compositions of the present invention. In some embodiments, kits may also include one or more buffers. In some embodiments, kits of the invention may include components for making protein or nucleic acid arrays or libraries and thus, may include, for example, solid supports. 
     In some embodiments, kit components may be packaged either in aqueous media or in lyophilized form. The container means of the kits will generally include at least one vial, test tube, flask, bottle, syringe or other container means, into which a component may be placed, and preferably, suitably aliquoted. Where there are more than one kit component, (labeling reagent and label may be packaged together), kits may also generally contain second, third or other additional containers into which additional components may be separately placed. In some embodiments, kits may also comprise second container means for containing sterile, pharmaceutically acceptable buffers and/or other diluents. In some embodiments, various combinations of components may be comprised in one or more vial. Kits of the present invention may also typically include means for containing compounds and/or compositions of the present invention, e.g., proteins, nucleic acids, and any other reagent containers in close confinement for commercial sale. Such containers may include injection or blow-molded plastic containers into which desired vials are retained, 
     In some embodiments, kit components are provided in one and/or more liquid solutions. In some embodiments, liquid solutions are aqueous solutions, with sterile aqueous solutions being particularly preferred. In some embodiments, kit components may be provided as dried powder(s). When reagents and/or components are provided as dry powders, such powders may be reconstituted by the addition of suitable volumes of solvent. In some embodiments, it is envisioned that solvents may also be provided in another container means. In some embodiments, labeling dyes are provided as dried powders. In some embodiments, it is contemplated that 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 120, 120, 130, 140, 150, 160, 170, 180, 190, 200, 300, 400, 500, 600, 700, 800, 900, 1000 micrograms or at least or at most those amounts of dried dye are provided in kits of the invention. In such embodiments, dye may then be resuspended in any suitable solvent, such as DMSO, 
     In some embodiments, kits may include instructions for employing kit components as well the use of any other reagent not included in the kit. Instructions may include variations that may be implemented. 
     Devices 
     In some embodiments, compounds and/or compositions of the present invention may be combined with, coated onto or embedded in a device. Devices may include, but are not limited to, dental implants, stents, bone replacements, artificial joints, valves, pacemakers and/or other implantable therapeutic devices. 
     The present invention provides for devices which may incorporate viral particles that encode one or more payload molecules. These devices contain in a stable formulation the viral particles which may be immediately delivered to a subject in need thereof, such as a human patient. 
     Devices for administration may be employed to deliver the viral particles of the present invention according to single, multi- or split-dosing regimens taught herein. 
     Method and devices known in the art for multi-administration to cells, organs and tissues are contemplated for use in conjunction with the methods and compositions disclosed herein as embodiments of the present invention. These include, for example, those methods and devices having multiple needles, hybrid devices employing for example lumens or catheters as well as devices utilizing heat, electric current or radiation driven mechanisms. 
     In one embodiment, the chimeric polynucleotide is administered subcutaneously or intramuscularly via at least 3 needles to three different, optionally adjacent, sites simultaneously, or within a 60 minutes period (e.g., administration to 4, 5, 6, 7, 8, 9, or 10 sites simultaneously or within a 60 minute period). 
     VIII. DEFINITIONS 
     At various places in the present specification, substituents of compounds of the present disclosure are disclosed in groups or in ranges. It is specifically intended that the present disclosure include each and every individual sub-combination of the members of such groups and ranges. The following is a non-limiting list of term definitions. 
     Activity: As used herein, the  - term “activity” refers to the condition in which things are happening or being done. Compositions of - the invention may have activity and this activity may involve one or more biological events. 
     Administered in combination: As used herein, the term “administered in combination” or “combined administration” refers to simultaneous exposure to two or more agents (e.g., scAAV) administered at the same time or within an interval such that the subject is at some point in time simultaneously exposed to both and/or such that there may be an overlap in the effect of each agent on the patient. In some embodiments, at least one dose of one or more agents is administered within about 24 hours, 12 hours, 6 hours, 3 hours, 1 hour, 30 minutes, 15 minutes, 10 minutes, 5 minutes, or 1 minute of at least one dose of one or more other agents. In some embodiments, administration occurs in overlapping dosage regimens. As used herein, the term “dosage regimen” refers to a plurality of doses spaced apart in time. Such doses may occur at regular intervals or may include one or more hiatus in administration. In some embodiments, the administration of individual doses of one or more compounds and/or compositions of the present invention, as described herein, are spaced sufficiently closely together such that a combinatorial (e.g., a synergistic) effect is achieved. 
     Animal: As used herein, the term “animal” refers to any member of the animal kingdom. In some embodiments,  - animal” refers to humans at any stage of development. In some embodiments, “animal” refers to non-human animals at any stage of development. In certain embodiments, the non-human animal is a mammal (e.g., a rodent, a mouse, a rat, a rabbit, a monkey, a dog, a cat, a sheep, cattle, a primate, or a pig). In some embodiments, animals include, but are not limited to, mammals, birds, reptiles, amphibians, fish, and worms. In some embodiments, the animal is a transgenic animal, genetically-engineered animal, or a clone. 
     Approximately: As used herein, the term “approximately” or “about,” as applied to one or more values of interest, refers to a value that is similar to a stated reference value. In certain embodiments, the term “approximately” or “about” refers to a range of values that fall within 25%, 20%, 19%, 18%, 17%, 16%, 15%, 14%, 13%, 12%, 11%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, or less in either direction (greater than or less than) of the stated reference value unless otherwise stated or otherwise evident from the context (except where such number would exceed 100% of a possible value). 
     Associated with: As used herein, the terms “associated with,” “conjugated,” “linked,” “attached,” and “tethered,” when used with respect to two or more moieties, mean that the moieties are physically associated or connected with one another, either directly or via one or more additional moieties that serve as linking agents, to form a structure that is sufficiently stable so that the moieties remain physically associated under the conditions in which the structure is used, e.g.. physiological conditions. An “association” need not be strictly through direct covalent chemical bonding. It may also suggest ionic or hydrogen bonding or a hybridization based connectivity sufficiently stable such that the “associated” entities remain physically associated. 
     Biomolecule: As used herein, the term “biomolecule” is any natural molecule which is amino acid-based, nucleic acid-based, carbohydrate-based or lipid-based, and the like. 
     Biologically active: As used herein, the phrase “biologically active” refers to a characteristic of any substance (e.g., an scAAV) that has activity in or on a biological system and/or organism. For instance, a substance that, when administered to an organism, has a biological effect on that organism, is considered to be biologically active. In particular embodiments, a compounds and/or compositions of the present invention may be considered biologically active if even a portion of is biologically active or mimics an activity considered to biologically relevant. 
     Biological system: As used herein, the term “biological system” refers to a group of organs, tissues, cells, intracellular components, proteins, nucleic acids, molecules (including, but not limited to biomolecules) that function together to perform a certain biological task within cellular membranes, cellular compartments, cells, tissues, organs, organ systems, multicellular organisms, or any biological entity. In some embodiments, biological systems are cell signaling pathways comprising intracellular and/or extracellular cell signaling biomolecules. In some embodiments, biological systems comprise growth factor signaling events within the extracellular/cellular matrix and/or cellular niches. 
     Compound: As used herein, the term “compound,” refers to a distinct chemical entity. In some embodiments, a particular compound may exist in one or more isomeric or isotopic forms (including, but not limited to stereoisomers, geometric isomers and isotopes). In some embodiments, a compound is provided or utilized in only a single such form. In some embodiments, a compound is provided or utilized as a mixture of two or more such forms (including, but not limited to a racemic mixture of stereoisomers). Those of skill in the art appreciate that some compounds exist in different such forms, show different properties and/or activities (including, but not limited to biological activities). In such cases it is within the ordinary skill of those in the art to select or avoid particular forms of the compound for use in accordance with the present invention. For example, compounds that contain asymmetrically substituted carbon atoms can be isolated in optically active or racemic forms. Methods on how to prepare optically active forms from optically active starting materials are known in the art, such as by resolution of racemic Mixtures or by stereoselective synthesis. 
     Conserved: As used herein, the term “conserved” refers to nucleotides or amino acid residues of polynucleotide or polypeptide sequences, respectively, that are those that occur unaltered in the same position of two or more sequences being compared. Nucleotides or amino acids that are relatively conserved are those that are conserved among more related sequences than nucleotides or amino acids appearing elsewhere in the sequences. 
     In some embodiments, two or more sequences are said to be “completely conserved” if they are 100% identical to one another. In some embodiments, two or more sequences are said to be “highly conserved” if they are at least 70% identical, at least 80% identical, at least 90% identical, or at least 95% identical to one another. In some embodiments, two or more sequences are said to be “highly conserved” if they are about 70% identical, about 80% identical, about 90% identical, about 95%, about 98%, or about 99% identical to one another. In some embodiments, two or more sequences are said to be “conserved” if they are at least 30% identical, at least 40% identical, at least 50% identical, at least 60% identical, at least 70% identical, at least 80% identical, at least 90% identical, or at least 95% identical to one another. In some embodiments, two or more sequences are said to be “conserved” if they are about 30° c identical, about 40% identical, about 50% identical, about 60% identical, about 70% identical, about 80° c identical, about 90% identical, about 95% identical, about 98% identical, or about 99% identical to one another. Conservation of sequence may apply to the entire length of an oligonucleotide or polypeptide or may apply to a portion, region or feature thereof. 
     In one embodiment, conserved sequences are not contiguous. Those skilled in the art are able to appreciate how to achieve alignment when gaps in contiguous alignment are present between sequences, and to align corresponding residues not withstanding insertions or deletions present. 
     Delivery: As used herein, “delivery” refers to the act or manner of delivering a compound, substance, entity, moiety, cargo or payload to a target. Such target may be a cell, tissue, organ, organism, or system (whether biological or production). 
     Delivery Agent: As used herein, “delivery agent” refers to any agent which facilitates, at least in part, the in vivo delivery of one or more substances (including, but not limited to a compounds and/or compositions of the present invention, e.g., viral particles or expression vectors) to targeted cells. 
     Destabilized As used herein, the term “destable,” “destabilize,” or “destabilizing region” means a region or molecule that is less stable than a starting, reference, wild-type or native form of the same region or molecule. 
     Detectable label: As used herein, “detectable label” refers to one or more markers, signals, or moieties which are attached, incorporated or associated with another entity, which markers, signals or moieties are readily detected by methods known in the art including radiography, fluorescence, chemiluminescence, enzymatic activity, absorbance, immunological detection and the like. Detectable labels may include radioisotopes, fluorophores, chromophores, enzymes, dyes, metal ions, ligands, biotin, avidin, streptavidin and haptens, quantum dots, polyhistidine tags, myc tags, flag tags, human influenza hemagglutinin (HA) tags and the like. Detectable labels may be located at any position in the entity with which they are attached, incorporated or associated. For example, when attached, incorporated in or associated with a peptide or protein, they may be within the amino acids, the peptides, or proteins, or located at the N- or C-termini. 
     Engineered: used herein, embodiments of the invention are engineered” when they are designed to have a feature or property, whether structural or chemical, that varies from a starting point, wild-type or native molecule. Thus, engineered agents or entities are those whose design and/or production include an act of the hand of man. 
     Epitope: As used herein, an “epitope” refers to a surface or region on a molecule that is capable of interacting with a biomolecule. For example a protein may contain one or more amino acids, e.g., an epitope, which interacts with an antibody, e.g., a biomolecule. In some embodiments, when referring to a protein or protein module, an epitope may comprise a linear stretch of amino acids or a three dimensional structure formed by folded amino acid chains. 
     eRBSR: As used herein, an “eRBSR” is an engineered Rep binding sequence region. eRBSRs may range in size from 4-160 nucleotides. When making reference to any of Rep binding sequence, Rep binding sequence region, or eRBSR, it is understood that these sequences and or regions may be substantially double stranded and therefor the recited lengths or sizes may be greater. 
     Expression: As used herein, “expression” of a nucleic acid sequence refers to one or more of the following events: (1) production of an RNA template from a DNA sequence (e.g., by transcription); (2) processing of an RNA transcript (e.g., by splicing, editing, 5’ cap formation, and/or 3′ end processing); (3) translation of an RNA into a polypeptide or protein; (4) folding of a polypeptide or protein; and (5) post-translational modification of a polypeptide or protein. 
     Feature: As used herein, a “feature” refers to a characteristic, a property, or a distinctive element. 
     Formulation: As used herein, a “formulation” includes at least a compound and/or composition of the present invention (e.g., a vector, scAAV particle, etc.) and a delivery agent. 
     Fragment: A “fragment,” as used herein, refers to a contiguous portion of a whole. For example, fragments of proteins may comprise polypeptides obtained by digesting full-length protein isolated from cultured cells. In some embodiments, a fragment of a protein includes at least 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 2.5, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 150, 200, 250 or more amino acids. In some embodiments, fragments of an antibody include portions of an antibody subjected to enzymatic digestion or synthesized as such. 
     Functional: As used herein, a “functional” biological molecule is a biological entity with a structure and in a form in which it exhibits a property and/or activity by which it is characterized. 
     Homology: As used herein, the term “homology” refers to the overall relatedness between polymeric molecules, e.g. between nucleic acid molecules (e.g. DNA molecules and/&#39;or RNA molecules) and/or between polypeptide molecules. In some embodiments, polymeric molecules are considered to be “homologous” to one another if their sequences are at least 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, or 99f/6 identical or similar. The term “homologous” necessarily refers to a comparison between at least two sequences (polynucleotide or polypeptide sequences). In accordance with the invention, two polynucleotide sequences are considered to be homologous if the polypeptides they encode are at least about 50%, 60%, 70%, 80%, 90%, 95%, or even 99% for at least one stretch of at least about 20 amino acids. In some embodiments, homologous polynucleotide sequences are characterized by the ability to encode a stretch of at least 4-5 uniquely specified amino acids. For polynucleotide sequences less than 60 nucleotides in length, homology is typically determined by the ability to encode a stretch of at least 4--5 uniquely specified amino acids. In accordance with the invention, two protein sequences are considered to be homologous if the proteins are at least about 50%, 60%, 70%, 80%, or 90% identical for at least one stretch of at least about 20 amino acids. In many embodiments, homologous protein may show a large overall degree of homology and a high degree of homology over at least one short stretch of at least 3.4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 25, 30, 35, 40, 45, 50 or more amino acids. In many embodiments, homologous proteins share one or more characteristic sequence elements. As used herein, the term “characteristic sequence element” refers to a motif present in related proteins. In some embodiments, the presence of such motifs correlates with a particular activity (such as biological activity). 
     Identity: As used herein, the term “identity” refers to the overall relatedness between polymeric molecules, e.g., between oligonucleotide molecules (e.g. DNA molecules and/or RNA molecules) nd/or between polypeptide molecules. Calculation of the percent identity of two polynucleotide sequences, for example, may be performed by aligning the two sequences for optimal comparison purposes (e.g., gaps can be introduced in one or both of a first and a second nucleic acid sequences for optimal alignment and non-identical sequences can be disregarded for comparison purposes). In certain embodiments, the length of a sequence aligned for comparison purposes is at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, or 100% of the length of the reference sequence. The nucleotides at corresponding nucleotide positions are then compared. When a position in the first sequence is occupied by the same nucleotide as the corresponding position in the second sequence, then the molecules are identical at that position. The percent identity between the two sequences is a function of the number of identical positions shared by the sequences, taking into account the number of gaps. and the length of each gap, which needs to be introduced for optimal alignment of the two sequences. The comparison of sequences and determination of percent identity between two sequences can be accomplished using a mathematical algorithm. For example, the percent identity between two nucleotide sequences can be determined using methods such as those described in Computational Molecular Biology, Lesk, A. M., ed.. Oxford University Press, New York, 1988; Biocomputing: Informatics and Genome Projects, Smith, D. W., ed., Academic Press, New York, 1993; Sequence Analysis in Molecular Biology, von Heinje, G., Academic Press, 1987; Computer Analysis of Sequence Data, Part I. Griffin, A. M., and Griffin, H. G., eds., Humana Press, New Jersey, 1994; and Sequence Analysis Primer, Gribskov, M. and Devereux, J., eds., M Stockton Press, New York, 1991; each of which is incorporated herein by reference. For example, the percent identity between two nucleotide sequences can be determined, for example using the algorithm of Meyers and Miller (CABIOS, 1989, 4:11-17), which has been incorporated into the ALIGN program (version 2.0) using a PAM120 weight residue table, a gap length penalty of 12 and a gap penalty of 4. The percent identity between two nucleotide sequences can, alternatively, be determined using the GAP program in the GCG software package using an NWSgapdna.CMP matrix. Methods commonly employed to determine percent identity between sequences include, but are not limited to those disclosed in Carillo, H., and Lipman, D., SIAM J Applied Math., 48:1073 (1988); incorporated herein by reference. Techniques for determining identity are codified in publicly available computer programs. Computer software to determine homology between two sequences include, but are not limited to, GCG program package, Devereux, J., et al.,  Nucleic Acids Research,  12(1), 387 (1984)), BLASTP, BLASTN, and FASTA Altschul, S. F. et al.  J. Molec. Biol.,  215, 403 (1990)). 
     Inhibit expression of a gene: As used herein, the phrase “inhibit expression of a gene” means to cause a reduction in the amount of an expression product of the gene. The expression product may be RNA transcribed from the gene (e.g. mRNA) or a polypeptide translated from snRNA transcribed from the gene. Typically a reduction in the level of mRNA results in a reduction in the level of a polypeptide translated therefrom. The level of expression may be determined using standard techniques for measuring mRNA or protein. 
     In vitro: As used herein, the term “in vitro” refers to events that occur in an artificial environment, e.g., in a test tube or reaction vessel, in cell culture, in a Petri dish, etc., rather than within an organism (e.g., animal, plant, or microbe). 
     In vivo: As used herein, the term “in vivo” refers to events that occur within an organism (e.g., animal, plant, or microbe or cell or tissue thereof). 
     Isolated: As used herein, the term “isolated” is synonymous with “separated,” but carries with it the inference separation was carried out by the hand of man. In one embodiment, an isolated substance or entity is one that has been separated from at least some of the components with which it was previously associated (whether in nature or in an experimental setting). Isolated substances may have varying levels of purity in reference to the substances from which they have been associated. Isolated substances and/or entities may be separated from at least about 10%, about 20%, about 30%, about 40%, about 50%, about 60%, about 70%, about 80%, about 90%, or more of the other components with which they were initially associated. In some embodiments, isolated agents are more than about 80%, about 85%, about 90%, about 91%, about 92%, about 93%, about 94%, about 950, about 96%, about 97%, about 98%, about 99%, or more than about 99° pure. As used herein, a substance is “pure” if it is substantially free of other components, 
     Substantially isolated: By “substantially isolated” is meant that the compound is substantially separated from the environment in which it was formed or detected. Partial separation can include, for example, a composition enriched in the compound of the present disclosure. Substantial separation can include compositions containing at least about 50%, at least about 60%, at least about 70%, at least about 80%, at least about 90%, at least about 95%, at least about 97%, or at least about 99% by weight of the compound of the present disclosure, or salt thereof. Methods for isolating compounds and their salts are routine in the art. In some embodiments, isolation of a substance or entity includes disruption of chemical associations and/or bonds. In some embodiments, isolation includes only the separation from components with which the isolated substance or entity was previously combined and does not include such disruption. 
     Linker: As used herein, a linker refers to a moiety that connects two or more domains, moieties or entities. In one ethbodiment, a linker may comprise 10 or more atoms. In a further embodiment, a linker may comprise a group of atoms, e.g., 10-1,000 atoms, and can be comprised of the atoms or groups such as, but not limited to, carbon, amino, alkylamino, oxygen, sulfur, sulfoxide, sulfonyl, carbonyl, and imine. In some embodiments, a linker may comprise one or more nucleic acids comprising one or more nucleotides. In some embodiments, the linker may comprise an amino acid, peptide, polypeptide or protein. In some embodiments, a moiety bound by a linker may include, but is not limited to an atom, a chemical group, a nucleoside, a nucleotide, a nucleobase, a sugar, a nucleic acid, an amino acid, a peptide, a polypeptide, a protein, a protein complex, a payload (e.g., a therapeutic agent marker (including, but not limited to a chemical, fluorescent, radioactive or bioluminescent marker). The linker can be used for any useful purpose, such as to form multimers or conjugates, as well as to administer a payload, as described herein. Examples of chemical groups that can be incorporated into the linker include, but are not limited to, alkyl, alkenyl, alkynyl, amino, amino, ether, thioether, ester, alkylene, heteroaklene, aryl, or heterocyclyl, each of which can be optionally substituted, as described herein. Examples of linkers include, but are not limited to, unsaturated alkanes, polyethylene glycols (e.g., ethylene or propylene glycol monomeric units, e.g., diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, tetraethylene glycol, or tetraethylene glycol), and dextran polymers. Other examples include, but are not limited to, cleavable moieties within the linker, such as, for example, a disulfide bond (—S—S—) or an azo bond (—N═N—), which can be cleaved using a reducing agent or photolysis. Non-limiting examples of a selectively cleavable bonds include an amido bond which may be cleaved for example by the use of tris(2-carboxyethyl)phosphine (TCEP), or other reducing agents, and/or photolysis, as well as an ester bond which may be cleaved for example by acidic or basic hydrolysis. 
     Modified: As used herein, the term “modified” refers to a changed state or structure of a molecule or entity as compared with a parent or reference molecule or entity. Molecules may be modified in many ways including chemically, structurally, and functionally. In some embodiments, compounds and/or compositions of the present invention are modified by the introduction of non-natural amino acids, or non-natural nucleotides. 
     Mutation: As used herein, the term “mutation” refers to a change and/or alteration. In some embodiments, mutations may be changes and/or alterations to proteins (including peptides and polypeptides) and/or nucleic acids (including polynucleic acids). In some embodiments, mutations comprise changes and/or alterations to a protein and/or nucleic acid sequence. Such changes and/or alterations may comprise the addition, substitution and or deletion of one or more amino acids (in the case of proteins and/or peptides) and/or nucleotides (in the case of nucleic acids and or polynucleic acids). In embodiments wherein mutations comprise the addition and/or substitution of amino acids and/or nucleotides, such additions and/or substitutions may comprise 1 or more amino acid and/or nucleotide residues and may include modified amino acids and/or nucleotides. 
     Naturally occurring: As used herein, “naturally occurring” means existing in nature without artificial aid, or involvement of the hand of man. 
     Non-human vertebrate: As used herein, a “non-human vertebrate” includes all vertebrates except Homo sapiens, including wild and domesticated species. Examples of non-human vertebrates include, but are not limited to, mammals, such as alpaca, banteng, bison, camel, cat, cattle, deer, dog, donkey, gayal, goat, guinea pig, horse, llama, mule, pig, rabbit, reindeer, sheep water buffalo, and yak, 
     Off-target: As used herein, “off target” refers to any unintended effect on any one or more target, gene and/or cellular transcript. 
     Operably linked: As used herein, the phrase “operably linked” refers to a functional connection between two or more molecules, constructs, transcripts, entities, moieties or the like. 
     Particle: As used herein, a “particle” is a virus comprised of at least two components, a protein capsid and a polynucleotide sequence enclosed within the capsid. 
     Patient: As used herein, “patient” refers to a subject who may seek or be in need of treatment, requires treatment, is receiving treatment, will receive treatment, or a subject who is under care by a trained (e.g., licensed) professional for a particular disease or condition. 
     Payload construct: As used herein, “payload construct” is one or more polynucleotide regions encoding or comprising a payload molecule of interest, e.g., a transgene, a polynucleotide encoding a polypeptide or multi-polypeptide or a modulatory or regulatory nucleic acid, that that is flanked on one or both sides by an inverted terminal repeat (ITR) sequence. A vector which comprises a payload construct is a “payload construct vector.” 
     Payload construct expression vector: As used herein, a “payload construct expression vector” is a vector which comprises a payload construct and which further comprises one or more polynucleotide regions encoding or comprising components for viral expression in a viral replication cell. 
     Peptide: As used herein, the term “peptide” refers to a chain of amino acids that is less than or equal to about 50 amino acids long, e.g., about 5, 10, 15, 20, 25, 30, 35, 40, 45, or 50 amino acids long. 
     Pharmaceutically acceptable: The phrase “pharmaceutically acceptable” is employed herein to refer to those compounds, materials, compositions, and/or dosage forms which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of human beings and animals without excessive toxicity, irritation, allergic response, or other problem or complication, commensurate with a reasonable benefit/risk ratio. 
     Pharmaceutically acceptable excipients: As used herein, the term “pharmaceutically acceptable excipient,” as used herein, refers to any ingredient other than active agents (e.g., as described herein) present in pharmaceutical compositions and having the properties of being substantially nontoxic and non-inflammatory in subjects. In some embodiments, pharmaceutically acceptable excipients are vehicles capable of suspending and/or dissolving active agents. Excipients may include, for example: antiadherents, antioxidants, binders, coatings, compression aids, disintegrants, dyes (colors), emollients, emulsifiers, fillers (diluents), film formers or coatings, flavors, fragrances, glidants (flow enhancers), lubricants, preservatives, printing inks, sorbents, suspending or dispersing agents, sweeteners, and waters of hydration. Excipients include, but are not limited to: butylated hvdroxytoluene (BHT), calcium carbonate, calcium phosphate (dibasic), calcium stearate, croscarmellose, crosslinked polyvinyl pyrrolidone, citric acid, crospovidone, cysteine, ethylcellulose, gelatin, hydroxy - propyl cellulose, hydroxypropyl methylcellulose, lactose, magnesium stearate, maltitol, mannitol, methionine, methylcellulose, methyl paraben, microcrystalline cellulose, polyethylene glycol, polyvinyl pyrrolidone, povidone, pregelatinized starch, propyl paraben, retinyl palmitate, shellac, silicon dioxide, sodium carboxymethyl cellulose, sodium citrate, sodium starch glycolate, sorbitol, starch (corn), stearic acid, sucrose, talc, titanium dioxide, vitamin A, vitamin E, vitamin C, and. 
     Pharmaceutically acceptable salts: Pharmaceutically acceptable salts of the compounds described herein are forms of the disclosed compounds wherein the acid or base moiety is in its salt form (e.g., as generated by reacting a free base group with a suitable organic acid). Examples of pharmaceutically acceptable salts include, but are not limited to, mineral or organic acid salts of basic residues such as amines; alkali or organic salts of acidic residues such as carboxylic acids; and the like. Representative acid addition salts include acetate, adipate, alginate, ascorbate, aspartate, benzenesulfonate, benzoate, bisulfate, borate, butyrate, camphorate, camphorsulfonate, citrate, cyclopentanepropionate, digluconate, dodecylsulfate, ethanesulfonate, fumarate, glucoheptonate, glycerophosphate, hemisulfate, heptonate, hexanoate, hydrobromide, hydrochloride, hydroiodide, 2-hydroxy-ethanesulfonate, lactobionate, lactate, laurate, lauryl sulfate, malate, maleate, malonate, methanesulfonate, 2-naphthalenesulfonate, nicotinate, nitrate, oleate, oxalate, palmitate, pamoate, pectinate, persulfate, 3-phenylpropionate, phosphate, picrate, pivalate, propionate, stearate, succinate, sulfate, tartrate, thiocyanate, toluenesulfonate, undecanoate, valerate salts, and the like. Representative alkali or alkaline earth metal salts include sodium, lithium, potassium, calcium, magnesium, and the like, as well as nontoxic ammonium, quaternary ammonium, and amine cations, including, but not limited to ammonium, tetramethylammonium, tetraethylammonium, methylamine, dimethylamine, trimethylamine, triethylamine, ethylamine, and the like. Pharmaceutically acceptable salts include the conventional non-toxic salts, for example, from non-toxic inorganic or organic acids. In some embodiments a pharmaceutically acceptable salt is prepared from a parent compound which contains a basic or acidic moiety by conventional chemical methods. Generally, such salts can be prepared by reacting the free acid or base forms of these compounds with a stoichiometric amount of the appropriate base or acid in water or in an organic solvent, or in a mixture of the two; generally, nonaqueous media like ether, ethyl acetate, ethanol, isopropanol, or acetonitrile are preferred. Lists of suitable salts are found in  Remington&#39;s Pharmaceutical Sciences,  17th ed., Mack Publishing Company, Easton, Pa., 1985, p. 1418,  Pharmaceutical Salts: Properties, Selection, and Use , P. H. Stahl and C. G. Wermuth (eds.), Wiley-VCH, 2008, and Berge et al.,  Journal of Pharmaceutical Science,  66, 1-19 (1977), each of which is incorporated herein by reference in its entirety. Pharmaceutically acceptable solvate: The term “pharmaceutically acceptable solvate,” as used herein, refers to a crystalline form of a compound wherein molecules of a suitable solvent are incorporated in the crystal lattice. For example, solvates may be prepared by crystallization, recrystallization, or precipitation from a solution that includes organic solvents, water, or a. mixture thereof. Examples of suitable solvents are ethanol, water (for example, mono-, di-, and tri-hydrates), N-methylpyrrolidinone (NMP), dimethyl sulfoxide (DMSO), N,N′-dimethylformamide (DMF), N,N′-dimethylacetamide (DMAC), 1,3-dimethyl-2-imidazolidinone (DMEU), 1,3-dimethyl-3,4,5,6-tetrahydro-2-(1H)-pyrimidinone (DMPU), acetonitrile (ACN), propylene glycol, ethyl acetate, benzyl alcohol, 2-pyrrolidone, benzyl benzoate, and the like. When water is the solvent, the solvate is referred to as a “hydrate.” in some embodiments, the solvent incorporated into a solvate is of a type or at a level that is physiologically tolerable to an organism to which the solvate is administered (e.g., in a unit dosage form of a pharmaceutical composition). 
     Pharmacokinetic: As used herein, “pharmacokinetic” refers to any one or more properties of a molecule or compound as it relates to the determination of the fate of substances administered to living organisms. Pharmacokinetics are divided into several areas including the extent and rate of absorption, distribution, metabolism and excretion. This is commonly referred to as ADME where: (A) Absorption is the process of a substance entering the blood circulation; (D) Distribution is the dispersion or dissemination of substances throughout the fluids and tissues of the body; (M) Metabolism (or Biotransformation) is the irreversible transformation of parent compounds into daughter metabolites; and (E) Excretion (or Elimination) refers to the elimination of the substances from the body. In rare cases, some drugs irreversibly accumulate in body tissue. 
     Physicochemical: As used herein, “physicochemical” means of or relating to a physical and/or chemical property. 
     Preventing: As used herein, the term  - preventing” refers to partially or completely delaying onset of an infection, disease, disorder and/or condition; partially or completely delaying onset of one or more symptoms, features, or clinical manifestations of a particular infection, disease, disorder, and/or condition; partially or completely delaying onset of one or more symptoms, features, or manifestations of a particular infection, disease, disorder, and/or condition; partially or completely delaying progression from an infection, a particular disease, disorder and/or condition; and/or decreasing the risk of developing pathology associated with the infection, the disease, disorder, and/or condition. 
     Prolitrates As used herein, the term “proliferate” means to grow, expand, replicate or increase or cause to grow, expand, replicate or increase. ‘Proliferative” means having the ability to proliferate. “Anti-proliferative” means having properties counter to or in opposition to proliferative properties. 
     Protein of interest: As used herein, the terms “proteins of interest” or “desired proteins” include those provided herein and fragments, mutants, variants, and alterations thereof. 
     Purified: As used herein, the term “purify” means to make substantially pure or clear from unwanted components, material defilement, admixture or imperfection. “Purified” refers to the state of being pure. “Purification” refers to the process of making pure. 
     Region: As used herein, the term  - region” refers to a zone or general area. In some embodiments, when referring to a protein or protein module, a region may comprise a linear sequence of amino acids along the protein or protein module or may comprise a three dimensional area, an epitope and/or a cluster of eptiopes. In some embodiments, regions comprise terminal regions. As used herein, the term  - terminal region” refers to regions located at the ends or termini of a given agent. When referring to proteins, terminal regions may comprise N- and/or C-termini. N-termini refer to the end of a protein comprising an amino acid with a free amino group. C-termini refer to the end of a protein comprising an amino acid with a free carboxyl group. N- and/or C-terminal regions may there for comprise the N- and/or C-termini as well as surrounding amino acids. In some embodiments, N- and/or C-terminal regions comprise from about 3 amino acid to about 30 amino acids, from about 5 amino acids to about 40 amino acids, from about I( )amino acids to about 50 amino acids, from about 20 amino acids to about 100 amino acids and/or at least 100 amino acids. In some embodiments, N-terminal regions may comprise any length of amino acids that includes the N-terminus, but does not include the C-terminus. In some embodiments, C-terminal regions may comprise any length of amino acids, which include the C-terminus, but do not comprise the N-terminus. 
     In some embodiments, when referring to a polynucleotide, a region may comprise a linear sequence of nucleic acids along the polynucleotide or may comprise a three dimensional area, secondary structure, or tertiary structure. In some embodiments, regions comprise terminal regions. As used herein, the term “terminal region” refers to regions located, at the ends or termini of a given agent. When referring to polynucleotides, terminal regions may comprise 5′ and 3′ termini. 5′ termini refer to the end of a polynucleotide comprising a nucleic acid with a free phosphate group. 3′ termini refer to the end of a polynucleotide comprising a nucleic acid with a free hydroxyl group, 5′ and 3′ regions may there for comprise the 5′ and 3′ termini as well as surrounding nucleic acids. In some embodiments, 5′ and 3′ terminal regions comprise from about 9 nucleic acids to about 90 nucleic acids, from about 15 nucleic acids to about 120 nucleic acids, from about 30 nucleic acids to about 150 nucleic acids, from about 60 nucleic acids to about 300 nucleic acids and/or at least 300 nucleic acids. In some embodiments, 5′ regions may comprise any length of nucleic acids that includes the 5′ terminus, but does not include the 3′ terminus. In some embodiments, 3′ regions may comprise any length of nucleic acids, which include the 3′ terminus, but does not comprise the 5′ terminus, 
     Rep binding sequence: As used herein, a “Rep binding sequence” is a series of linked nucleosides which interact with one or more Rep proteins. Rep binding sequences may range from 4-160 nucleotides. 
     Rep binding sequence region: As used herein, a “Rep binding sequence region” is a nucleotide sequence which interacts with one or more Rep proteins. A Rep binding sequence region may range from 4-160 nucleotides. In one embodiment, the Rep binding region is a nucleotide sequence located within an inverted terminal repeat (ITR). 
     Sample: As used herein, the  - term “sample” refers to an aliquot or portion taken from a source and/or provided for analysis or processing. In some embodiments, a sample is from a biological source such as a tissue, cell or component part (e.g. a body fluid, including but not limited to blood, mucus, lymphatic fluid, synovial fluid, cerebrospinal fluid, saliva, amniotic fluid, amniotic cord blood, urine, vaginal fluid and semen). In some embodiments, a sample may be or comprise a homogenate, lysate or extract prepared from a whole organism or a subset of its tissues, cells or component parts, or a fraction or portion thereof, including but not limited to, for example, plasma, serum, spinal fluid, lymph fluid, the external sections of the skin, respiratory, intestinal, and genitourinary tracts, tears, saliva, milk, blood cells, tumors, organs. In some embodiments, a sample is or comprises a medium, such as a nutrient broth or gel, which may contain cellular components, such as proteins or nucleic acid molecule. In some embodiments, a “primary” sample is an aliquot of the source. In some embodiments, a primary sample is subjected to one or more processing (e.g., separation, purification, etc) steps to prepare a sample for analysis or other use. 
     Self-complementary genome: As used herein, a “self-complementary genome” is a polynucleotide comprising, in the 5′ to 3′ direction, a first parvoviral inverted terminal repeat sequence, a first heterologous sequence, a parvoviral inverted terminal repeat (ITR) nucleotide sequence comprising an engineered Rep binding sequence region, a second heterologous sequence, wherein the second heterologous sequence is complementary to the first heterologous sequence, and a second parvoviral inverted terminal repeat sequence. 
     Self-complementary viral particle: As used herein, a “self-complementary viral particle” is a particle comprised of at least two components, a protein capsid and a polynucleotide sequence encoding a self-complementary genome enclosed within the capsid. 
     Signal Sequences: As used herein, the phrase “signal sequences” refers to a sequence which can direct the transport or localization. 
     Single unit dose: As used herein, a. “single unit dose” is a dose of any therapeutic administered in one dose/at one time/single route/single point of contact, i.e., single administration event. In some embodiments, a single unit dose is provided as a. discrete dosage form (e.g., a tablet, capsule, patch, loaded syringe, vial, etc.). 
     Similarity: As used herein, the term “similarity” refers to the overall relatedness between polymeric molecules, e.g. between polynucleotide molecules (e.g. DNA molecules and/or RNA molecules) and/or between polypeptide molecules. Calculation of percent similarity of polymeric molecules to one another can be performed in the same manner as a calculation of percent identity, except that calculation of percent similarity takes into account conservative substitutions as is understood in the art. 
     Split dose: As used herein, a “split dose” is the division of single unit dose or total daily dose into two or more doses. 
     Stable: As used herein “stable” refers to a compound or entity that is sufficiently robust to survive isolation to a useful degree of purity from a reaction mixture, and preferably capable of formulation into an efficacious therapeutic agent. 
     Stabilized: As used herein, the term “stabilize,” “stabilized,” “stabilized region” means to make or become stable. In some embodiments, stability is measured relative to an absolute value. In some embodiments, stability is measured relative to a reference compound or entity. 
     Subject: As used herein, the term “subject” or “patient” refers to any organism to which a composition in accordance with the invention may be administered, e.g., for experimental, diagnostic, prophylactic, and/or therapeutic purposes. Typical subjects include animals (e.g., mammals such as mice, rats, rabbits, non-human primates, and humans) and/or plants. 
     Substantially As used herein, the term “substantially” refers to the qualitative condition of exhibiting total or near-total extent or degree of a characteristic or property of interest. One of ordinary skill in the biological arts will understand that biological and chemical phenomena rarely, if ever, go to completion and&#39;or proceed to completeness or achieve or avoid an absolute result. The term “substantially” is therefore used herein to capture the potential lack of completeness inherent in many biological and chemical phenomena. 
     Substantially equal: As used herein as it relates to time differences between doses, the term means plus/minus 2%. 
     Substantially simultaneously: As used herein and as it relates to plurality of doses, the term typically means within about 2 seconds. 
     Suffering from: An individual who is “suffering from” a disease, disorder, and/or condition has been diagnosed with or displays one or more symptoms of a disease, disorder, and/or condition. 
     Susceptible to: An individual who is “susceptible to” a disease, disorder, and/or condition has not been diagnosed with and/or may not exhibit symptoms of the disease, disorder, and/or condition but harbors a propensity to develop a disease or its symptoms. In some embodiments, an individual who is susceptible to a disease, disorder, and/or condition example, cancer) may be characterized by one or more of the following: (1) a genetic mutation associated with development of the disease, disorder, and/or condition; (2) a genetic polymorphism associated with development of the disease, disorder, and/or condition; (3) increased and/or decreased expression and/or activity of a protein and/or nucleic acid associated with the disease, disorder, and/or condition; (4) habits and/or lifestyles associated with development of the disease, disorder, and/or condition; (5) a family history of the disease, disorder, and/or condition; and (6) exposure to and/or infection with a microbe associated with development of the disease, disorder, and/or condition. In some embodiments, an individual who is susceptible to a disease, disorder, and/or condition will develop the disease, disorder, and/or condition. In some embodiments, an individual who is susceptible to a disease, disorder, and/or condition will not develop the disease, disorder, and/or condition. 
     Synthetic: The term “synthetic” means produced, prepared, and/or manufactured by the hand of man. Synthesis of polynucleotides or polypeptides or other molecules of the present invention may be chemical or enzymatic. 
     Targeted Cells: As used herein, “targeted cells” refers to any one or more cells of interest. The cells may be found in vitro, in vivo, in situ or in the tissue or organ of an organism. The organism may he an animal, preferably a mammal, more preferably a human and most preferably a patient. 
     Therapeutic Agent: The term “therapeutic agent” refers to any agent that, when administered to a subject, has a therapeutic, diagnostic, and/or prophylactic effect and/or elicits a desired biological and/or pharmacological effect. 
     Therapeutically effective amount: As used herein, the term “therapeutically effective amount” means an amount of an agent to be delivered (e.g., nucleic acid, drug, therapeutic agent, diagnostic agent, prophylactic agent, etc.) that is sufficient, when administered to a subject suffering from or susceptible to an infection, disease, disorder, and/or condition, to treat, improve symptoms of, diagnose, prevent, and/or delay the onset of the infection, disease, disorder, and/or condition. In some embodiments, a therapeutically effective amount is provided in a single dose. In some embodiments, a therapeutically effective amount is administered in a dosage regimen comprising a plurality of doses. Those skilled in the an will appreciate that in some embodiments, a unit dosage form may be considered to comprise a therapeutically effective amount of a particular agent or entity if it comprises an amount that is effective when administered as part of such a dosage regimen. 
     Therapeutically effective outcome: As used herein, the term “therapeutically effective outcome” means an outcome that is sufficient in a subject suffering from or susceptible to an infection, disease, disorder, and/or condition, to treat, improve symptoms of, diagnose, prevent, and/or delay the onset of the infection, disease, disorder, and/or condition, 
     Total daily dose: As used herein, a “total daily dose” is an amount given or prescribed in a 24 hour period. It may be administered as a single unit dose. 
     Treating: As used herein, the term “treating” refers to partially or completely alleviating, ameliorating, improving, relieving, delaying onset of, inhibiting progression of, reducing severity of, and/or reducing incidence of one or more symptoms or features of a particular infection, disease, disorder, and/or condition. For example, “treating” cancer may refer to inhibiting survival, growth, and/or spread of a tumor. Treatment may be administered to a subject who does not exhibit signs of a disease, disorder, and/or condition anchor to a subject who exhibits only early signs of a disease, disorder, and/or condition for the purpose of decreasing the risk of developing pathology associated with the disease, disorder, and/or condition. 
     Unmodified: As used herein, “unmodified” refers to any substance, compound or molecule prior to being changed in any way. Unmodified may, but does not always, refer to the wild-type or native form of a biomolecule or entity. Molecules or entities may undergo a series of modifications whereby each modified product may serve as the “unmodified” starting molecule or entity for a subsequent modification. 
     Vector: As used herein, a “vector” is any molecule or moiety which transports, transduces or otherwise acts as a carrier of a heterologous molecule. 
     Viral construct expression vector: As used herein, a “viral construct expression vector” is a vector which comprises one or more polynucleotide regions encoding or comprising Rep and or Cap that further comprises one or more polynucleotide regions encoding or comprising components for viral expression in a viral replication cell. Viral vectors of the present invention may be produced recombinantly and may be based on and/or may comprise adeno-associated virus (AAV) parent or reference sequence. Such parent or reference AAV sequences may serve as an original, second, third or subsequent sequence for engineering viral vectors. In non-limiting examples, such parent or reference AAV sequences may comprise any one or more of the following sequences: a polynucleotide sequence encoding a polypeptide or multi-polypeptide, which may be wild-type or modified from wild-type and which may encode full-length or partial sequence of a protein, protein domain, or one or more subunits of a protein; a polynucleotide comprising a modulatory or regulatory nucleic acid which may he wild-type or modified from wild-type; and a transgene that may or may not be modified from wild-type sequence . These AAV sequences may serve as either the “donor” sequence of one or more codons (at the nucleic acid level) or amino acids (at the polypeptide level) or “acceptor” sequences of one or more codons (at the nucleic acid level) or amino acids (at the polypeptide level). 
     Viral construct vector: As used herein, a “viral construct vector” is a vector which comprises one or more polynucleotide regions encoding or comprising Rep and or Cap. 
     Viral genome: As used herein, a “viral genome” is a payload construct that has been rescued from a payload construct expression vector and is packaged within a viral particle. 
     Equivalents and Scope 
     Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments in accordance with the invention described herein. The scope of the present invention is not intended to be limited to the above Description, but rather is as set forth in the appended claims. 
     In the claims, articles such as “a,” “ and “the” may mean one or more than one unless indicated to the contrary or otherwise evident from the context. Claims or descriptions that include “or” between one or more members of a group are considered satisfied if one, more than one, or all of the group members are present in, employed in, or otherwise relevant to a given product or process unless indicated to the contrary or otherwise evident from the context. The invention includes embodiments in which exactly one member of the group is present in, employed in, or otherwise relevant to a given product or process. The invention includes embodiments in which more than one, or the entire group members are present in, employed in, or otherwise relevant to a given product or process. 
     It is also noted that the term “comprising” is intended to be open and permits but does not require the inclusion of additional elements or steps. When the term “comprising” is used herein, the term “consisting of is thus also encompassed and disclosed. 
     Where ranges are given, endpoints are included. Furthermore, it is to be understood that unless otherwise indicated or otherwise evident from the context and understanding of one of ordinary skill in the art, values that are expressed as ranges can assume any specific value or subrange within the stated ranges in different embodiments of the invention, to the tenth of the unit of the lower limit of the range, unless the context clearly dictates otherwise. 
     in addition, it is to be understood that any particular embodiment of the present invention that falls within the prior art may he explicitly excluded from any one or more of the claims. Since such embodiments are deemed to be known to one of ordinary skill in the art, they may be excluded even if the exclusion is not set forth explicitly herein. Any particular embodiment of the compositions of the invention (e.g., any nucleic acid or protein encoded thereby; any method of production; any method of use; etc.) can be excluded from any one or more claims, for any reason, whether or not related to the existence of prior art. 
     All cited sources, for example, references, publications, databases, database entries, and art cited herein, are incorporated into this application by reference, even if not expressly stated in the citation. In case of conflicting statements of a cited source and the instant application, the statement in the instant application shall control, 
     Section and table headings are not intended to be limiting. 
     IX. EXAMPLES 
     Example 1 
     eRBSR Design 
     To identify the Rep binding sequence regions at the genomic sequence level, the genome sequences of several different AAV serotypes and species including AAV1, AAV2, AAV4, AAV5, AAV7, AAV8, Bat AAV, Bovine AAV, Snake AAV, Avian AAV DA-1, and Avian AAV VR865 (SEQ ID NO: 280-291) were obtained from the NCBI Genome database. The 5′ and 3′ inverted terminal repeat sequences of selected genomes were aligned with the Clustal Omega multiple sequence alignment program using either AAV2 or AAV5 as the parent sequence, as shown in  FIG. 3  and  FIG. 4 , respectively. Additional Rep binding sequence regions found in the ITR sequences of other parvoviral serotypes and species, including AAV8 5′ ITR (SEQ ID NO: 253), AAV8 3′ ITR (SEQ ID NO: 254), Bat AAV 5′ ITR (SEQ ID NO: 261). Bat AAV 3′ ITR (SEQ ID NO: 262) are obtained in the same manner using this alignment program. 
     Based on the genomic sequence alignments, two groups of Rep binding sequence regions, “AAV2-like” and “AAV5-like,” were identified as regions of interest with  FIG. 3  showing the sequences having the AAV2-like Rep binding sequence region and  FIG. 4  showing the sequences having the AAV5-like Rep binding sequence region, in which the underlined regions represent the complementary Rep binding sequence region in the 5’ and 3′ ITR regions. The Rep binding sequence regions share a consensus GCTC motif that is repeated four to five times. In total, the identified consensus Rep binding sequence regions are about 16-20 nucleotides in length. 
     In some embodiments, eRBSRs comprise one, two, or three GCTC consensus motif(s). In other embodiments, eRBSRs comprise four or five GCTC consensus motifs in which at least one nucleotide in one or more of the consensus motif(s) is altered to a motif sequence selected from the group consisting of (1) NCTC, (2) GNTC, (3) GCNC, (4) GCTN, and (.5) in the case of two or more altered motif sequences, any combination of these modified altered motifs, wherein N is any naturally or non-naturally occurring nucleoside selected from adenosine, guanosine, uridine, cytidine, thymidine. In a further embodiment, eRBSRs comprise four or five GCTC: consensus motifs in which at least one nucleotide in one or more of the GCTC consensus motif(s) contains at least one nucleotide which is chemically modified. 
     Table 1 provides the Rep binding sequence regions of these different AAV serotypes and species (SEQ ID NOs: 1-20). Table 2 provides engineered Rep binding sequence regions which can function as an eRBSR (SEQ ID NOs: 21-66). Table 3 provides oligonucleotide sequences that comprise Rep protein binding properties which may therefore function as an eRBSR (SEQ ID NOs: 79-197) (Chiorini et al. 1995 Journal of Virology- 69(11) 7334-7338). Any of SEQ ID NOs: 1-20, 21-66, and/or 79-197 can be used as an eRBSR, for example, by replacing a native or wild-type Rep binding sequence region with any heterologous sequence of SEQ ID NOs: 1-20, 21-66, and/or 79-197. For example, any of the native Rep binding sequence regions found in AAV1, AAV2, AAV3, AAV4, AAV5, AAV6, AAV7, AAV8, AAV9, AAV10, AAV11, AAV12, AAVrh8, AAVrh10, AAV-DJ, and AAV-a18 can be replaced with any of SEQ ID NOs: 1-20, 21-66, and/or 79-197 as long as the eRBSR is derived from a different AAV serotype or species than that of the AAV ITR. Alternatively, any of SEQ ID NOs: 1-20, 21-66, and/or 79-197 can be used as an eRBSR by altering or modifying one or more nucleotides in any of the sequences. 
     Example 2 
     eRBSR with Reduced Binding Affinity for Rep Protein 
     Any of the eRBSRs provided in Example 1 or elsewhere herein can be tested to confirm its reduced binding to Rep protein by determining the dissociation constant or Kd. The Kd of wild-type Rep78 protein for its cognate Rep binding sequence region in AAV2 is approximately 1 nM as measured by electro-mobility shift assay (EMSA) (Chiorini et al. 1994, Sequence Requirements for Stable Binding and Function of Rep68 on the Adeno-Associated Virus Type 2 Inverted Terminal Repeats, Journal of Virology 68:11; 7448-7457). Decreased binding is measured as an increase in the dissociation constant, Kd, over wild-type, i.e., a Kd greater than 1 nM. 
     In previous experiments, the 5-5/EGR oligonucleotide (SEQ ID NO:71) shown in  FIG. 11C  exhibits stable, but weaker binding affinity for Rep78, the wild-type Rep found in AAV2, (5-10-fold less binding) than wild-type AAV2 Rep binding sequence region (Chiorini et al. Journal of Virology 1995, 7334-7338). In the same experiments it was found that alpha-PAL (SEQ ID NO: 68) and JcDNV NS1 (SEQ ID NO: 74) sequences, shown in  FIGS. 11A and 11E  respectively, were determined to exhibit weak, non-specific binding to Rep78 in EMSA experiments 
     The binding affinity of three different eRBSRs are tested in comparison with the binding of the known AAV2 Rep binding sequence region, JcDNV (SEQ ID NO: 74), ∞PAL (SEQ ID NO: 68), and 5-5/EGR (SEQ ID NO: 71) oligonucleotides are individually inserted into AAV2 ITR sequence by swapping them into (replacing) the native Rep binding sequence region of the AAV2 ITR, which has the formula [GCGC]-[GCTC] 3 . (SEQ ID NO: 311),  FIG. 11F ,  FIG. 11B , and  FIG. 11D , respectively. The wild-type AAV2 ITR having the native AAV2 Rep binding sequence region is used as a positive control. All of the sequences are first designed in sale( )and then synthesized using standard molecular biology techniques well known to those of skill in the art See, e.g., Sambrook et al, Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Press (Cold Spring Harbor, N.Y.). Rep protein utilized in binding assays as described herein are expressed from polynucleotides transfected into  E. coli  cells and purified by methods known to those of skill in the art. Polypeptides can also be synthesized by well-known solid phase peptide synthesis methods (Merrifield, J. Am. Chem. Soc., 85:2149 (1962); Stewart and Young, Solid Phase Peptide Synthesis (Freeman, San Francisco, 1969) pp.27-62). These and other suitable production methods are within the knowledge of those of skill in the art and are not a limitation of the present invention. 
     To determine initial binding, the modified AAV2 ITRs having the various described sequences are chemically synthesized and purified according to standard procedures. Double-stranded DNA probes are individually generated by annealing primers to the modified AAV2 ITRs comprising the ∞PAL eRBSR, 5-5/EGR eRBSR, and. JcDNV eRBSR sequences, as well as the wild-type AAV2 ITR, and extending the sequence with the Klenow fragment of DNA polymerase and radiolabeled nucleotides. 
     An in vitro binding assay is performed in which the radio-labeled double-stranded AAV2 ITRs comprising ∞PAL eRBSR, 5-5/EGR eRBSR, and JcDNV eRBSR sequences, as well as wild-type AAV2 ITR having the native AAV2 Rep binding sequence region, are combined with varying concentrations of wild-type Rep protein (Rep78) under conditions which favor Rep protein binding to the AAV2 Rep binding sequence region substrate. Chiorini et al. Journal of Virology 1995. 7334-7338 describes a Rep78 protein available for use in various experiments (see also, Chiorini et al. ;  1994, J. Virol., 68:797-804; Chiorini et al., J. Virol., 68: 7448-7457). The resultant protein-DNA complexes formed in the binding experiments are separated on a non-denaturing polyacrylamide gel under conditions known for electro-mobility shift assay. The concentrations of bound and free radiolabeled eRBSR are determined using a PhosphoImager (Molecular Dynamics). A plot of the ratio of bound eRBSR versus Rep protein concentration is used to determine the Kd of each eRBSR. 
     To determine the binding affinities (Kd) of ∞PAL eRBSR, 5-5/EGR eRBSR, and JcDNV eRBSR binding, competition binding EMSA experiments are performed, in which radio-labeled double-stranded wild-type AAV2 ITR is incubated with Rep78 in the presence of 5-, 10-, or 15-fold excess of the following unlabeled competitor sequences: (1) AAV2 ITR having the native AAV2 Rep binding sequence region (positive control), (2) modified AAV2 ITR having the ∞PAL sequence, (3) modified _AAV2 FIR having the 5-5/EGR sequence (eRBSR), and (4) modified AAV2 ITR having the JcDNV eRBSR sequence. The resultant protein-DNA complexes formed in the competition binding experiments are determined by EMSA. The concentrations of bound radiolabeled wild-type AAV2 ITR in the presence of various concentrations of unlabeled competitor DNA (eRBSRs) is determined using a PhosphoImager (Molecular Dynamics). A plot of the ratio of bound AAV2 ITR probe in the presence or absence of various concentrations of unlabeled competitor eRBSR DNA is used to determine the Kd of each eRBSR —  eRBSR sequences having a Kd greater than that of the wild-type AAV2 ITR (with native Rep binding sequence region) bind with less affinity to Rep protein than the native Rep binding sequence region and are candidates for use in generating self-complementary viral particles. EMSA methods are provided in Chiorini et al. 1995 Determination of Adeno-Associated Virus Rep68 and Rep78 Binding Sites by Random Sequence Oligonucleotide Selection, Journal of Virology 69:11, 7334-7338, the contents of which are incorporated herein in their entirety. 
     Example 3 
     eRBSR with Reduced Banding Affinity for Rep Protein 
     Another technique used to test the binding of an eRBSR is surface plasmon resonance, which is a label free technique used to determine the binding affinity (Kd) between molecules. Briefly, a first molecule is immobilized on a biosensor adjacent to an internal reference surface. White light reflected from the two surfaces creates an interference pattern that is shifted when a second molecule is bound to the first. The second molecule in a first solution is passed over the biosensor in a constant flow to determine the rate of association with the  - first molecule until the signal is saturated to determine the K a  value of the binding interaction. A second solution devoid of the second molecule is then passed over the biosensor to determine the K d  value of the binding interaction. 
     The binding affinities of the following polypeptide-polynucleotide pairs are determined using an Octet surface plasmon resonance instrument (ForteBio, Menlo Park, Calif.): (1) AAV2 wild-type Rep protein (Rep78) and AAV2 wild-type ITR containing the native Rep binding sequence region; (2) AAV2 wild-type Rep protein (Rep78) and modified AAV2 ITR having the ∞PAL eRBSR sequence, (3) AAV2 wild-type Rep protein (Rep78) and modified AAV2 ITR having the 5-5/EGR, eRBSR sequence, and (4) AAV2 wild-type Rep protein (Rep78) and modified AAV2 ITR having the JcDNV eRBSR sequence. The wild-type Rep protein (Rep78) is immobilized on the biosensor layer. A solution containing either (1) AAV2 wild-type ITR containing the native Rep binding sequence region; (2) modified AAV2 ITR having the ∞PAL eRBSR sequence; (3) modified AAV2 ITR having the 5-5/EGR eRBSR sequence; or (4) modified AAV2 ITR having the JcDNV eRBSR sequence is passed over the biosensor having immobilized Rep78 protein to determine the rate of association for each of the polynucleotides. A second solution devoid of the polynucleotide is passed over the saturated biosensor layer to determine the rate of dissociation. 
     Example 4 
     Chimeric Nicking Stem Loop Design 
     To identify the Rep nicking stem loop at the genomic sequence level, the genome sequences of several different AAV serotypes and species including AAV1, AAV2, AAV3, AAV4, AAV5, AAV7, AAV8, Bat AAV, Bovine AAV, Snake AAV, Avian AAV DA-1, and Avian AAV VR865 (SEQ :ID NO: 280-291) were obtained from the NCBI Genome database. The 5′ and 3′ inverted terminal repeat sequences of selected genomes were aligned with the Clustal Omega multiple sequence alignment program using either AAV2 or AAV5 as the parent sequence, as shown in  FIG. 3  and  FIG. 4 , respectively. Additional Rep nicking stem loops found in the ITR sequences of other parvoviral serotypes and species, including AAV8 5′ ITR (SEQ ID NO: 253). AAV8 3′ ITR (SEQ ID NO: 254), Bat AAV 5′ ITR (SEQ ID NO: 261), Bat AAV 3′ ITR (SEQ ID NO: 262) are obtained in the same manner using this alignment program. 
     Based on the genomic sequence alignments, several different Rep nicking stein loops were identified (see boxed sequence in  FIG. 3  and FIG, 4), The Rep nicking stem loops for AAV2, AAV1, AAV3, and AAV7 share the same nicking stem loop: AGAGGGAGTGGCCAACTCCATCA (SEQ ID NO:198) on the 5′ ITR and its reverse complement TGATGGAGTTGGCCACTCCCTCT (SEQ ID NO:199) on the 3′ITR. AAV-4 has the same nicking sequence on the 5′ ITR and a slightly different sequence on the 3′ ITR, (TGATGGAGTTGGCCACATTAGCT; SEQ ID NO: 207). The Rep nicking stem loop for AAV5 is GGGGGAGAGTGCCACACTCTCA (SEQ ID NO: 200) on the 5′ ITR and its reverse complement is TGAGAGTGTGGCACTCTCCCCC (SEQ ID NO: 201) on the 3′ ITR. The Rep nicking stem loop for bovine AAV is GGGGGGGAGTGCCACACTCTCT (SEQ ID NO: 214) on the 5′ ITR and its reverse complement is AGAGAGTGTGGCACTCCCCCCC (SEQ ID NO: 215) on the 3′ ITR. The Rep nicking stem loop for snake AAV is TGGGGCGAGTGCCCTGCTC (SEQ ID NO: 216) on the 5′ ITR and its reverse complement is GAGCAGGGCACTCGCCCCA (SEQ ID NO: 217) on the 3′ ITR. The Rep nicking stem loop for avian AAV (AAVDA1 and VR865) is ACTGGCCAGCACTCCGGTGA (SEQ ID NO: 210) on the 5′ ITR and its reverse complement is TCACCGGAGTGCTGGCCAGT (SEQ ID NO: 211) on the 3′ ITR. 
     A chimeric nicking stern loop is achieved by swapping the nicking stem loop sequence of one parvoviral serotype or species with the native nicking stern loop sequence of a different parvoviral serotype or species. For example, the chimeric nicking stem loop for _AAV5 (SEQ ID NO: 201) is swapped into (replaces) the native nicking stern loop sequence in any of the following ITR sequences: AAV4, AAV5, AAV6, AAV8, AAV9, AAV 10, AAV11, AAV12, AAVrh8. AAVrh10, AAV-DJ, and AAV-DJ8 ITR. In one embodiment, the chimeric nicking stem loop for AAV5 (SEQ ID NO: 201) is swapped into (replaces) the native nicking stem loop sequence in AAV2 (SEQ ID NO: 199). Additional nicking stem loop sequences are shown in Table 4. The sequences for certain chimeric nicking stem loop ITR sequences are provided in Table 5. 
     Example 5 
     Design of Engineered Rep Protein 
     The Rep protein is altered so as to decrease its binding with its cognate Rep binding sequence region. Residues in the Rep protein that contact the phosphate backbone, one or more nucleosides, or both the phosphate backbone and one or more nucleosides are altered. 
     Modified Rep protein design was performed in silico utilizing structural and sequence analysis of the Rep protein interaction with the AAV Rep binding sequence region.  FIG. 7  is a schematic depicting a 3-dimensional model showing Rep protein binding to the Rep binding domain of the AAV5 ITR. A crystal structure showing the binding interaction between AAV5 Rep protein residues 1-197 and a double stranded oligonucleotide sequence encoding the AAV5 Rep binding sequence region (SEQ ID NOs: 3-4) was previously analyzed (Hickman et al 2004 The Nuclease Domain of Adeno-Associated Virus Rep Coordinates Replication Initiation Using Two Distinct DNA Recognition interfaces,  Molecular Cell  13:403-414, the contents of which are referenced herein in their entirety). According to these studies, five Rep protein monomers bind independently to the Rep binding sequence region on the ITR and spiral around the DNA axis, off-set by four base pairs. As discussed elsewhere herein a repeated GCTC tetranucleotide sequence is necessary for recognition by Rep protein. The two structural elements of Rep protein that are important for binding are the surface loop between the β4 and β5 (referred to as the β4/β5 loop; residues 135-144) and the α-helix C (residues 101-118), which are located along one edge of the central β sheet. The β4/β5 loop interacts with four bases from the major groove side. Of the eight residues that form direct side chain interactions with the Rep binding sequence region, seven are strictly conserved among serotypes AAV2-6. There are three consecutive amino acids in the β4/β5 loop that are highly conserved- Gly-139, Gly-140, and Ala-141 (in AAV5), which correlate with three sequential Glycines in AAV2-6. Other conserved residues in the β4/β5 loop are Asp-142, Lys-135, Lys-137, and Lys-138. Conserved residues in the α-helix C are Met-102, Arg-106, Ser-109, and Glu-110. Arg-106 and Lys-137 provide important base contacts and Lys-135 forms a salt bridge to the phosphate backbone. Mutations of three residues: Arg-106, Lys-135, and Lys-137 results in complete loss of Rep binding (Hickman et al, 2004 Molecular Cell 13:403-414). 
     An alignment of the polynucleotide sequences encoding Rep protein from different AAV serotypes (AAV5, AAV2Rep68, AAV2Rep78, AAV2Rep40, AAV2Rep52, AAV1, AAV3, AAV4, AAV7, and AAV8) and AAV species (Avian AAVDA-1, Avian AAVVR865, Bat, and Bovine) was constructed to identify those amino acids having conserved specificity and conserved affinity in areas of Rep protein secondary structure (α-helix and β sheet) at the sequence level.  FIG. 8  shows the sequence alignment. Amino acids having conserved specificity and conserved affinity in Rep proteins found in the genomes of other parvoviral serotypes and species, including snake AAV (SEQ ID NO: 279), are obtained in the same manner using this alignment program. An analysis of the correlation between structural features of the Rep binding sequence region in the ITR and the degree of conservation of the Rep protein sequence was performed in silico. The combination of sequence and structural analysis of Rep proteins identified nine conserved residues of the α-helix C and β-sheet 4/β-sheet 5 loop. which were identified as targets for modification (see Table 6 and Table 7). 
     Residues in the Rep protein identified for alteration or modification are listed here. The residue numbering is that of AAV5, and which corresponding residues in other AAV serotypes and species can be obtained using the sequence alignment in  FIG. 8 . ( 1 ) the amino acid corresponding to Gly-I39 can be substituted with a Proline, Alanine, or Serine residue; (2) the amino acid corresponding to Gly-140 can be substituted with a Proline, Alanine, or Serine residue; (3) the amino acid corresponding to Ala-141 can be substituted with a Serine, Glycine, Threonine, Cysteine, or Valine residue; (4) the amino acid corresponding to Lys-138 can be substituted with Arginine, Glutamine, Glutamic acid, Asparagine, and Serine; (5) the amino acid corresponding to Met-102 can be substituted with Leucine, Isoleucine, Glutamine, Valine, or Phenylalanine; (6) the amino acid corresponding to Ser-109 can be substituted with Threonine, Alanine, Asparagine, Aspartic acid, Glutamine, Glutamic acid, Glycine, Lysine, or Threonine; (7) the amino acid corresponding to Glu-110 can be substituted with Arginine, Asparagine, Aspartic acid, Histidine, Lysine, or Serine; (8) the amino acid corresponding with Asp 142 can be substituted with Asparagine, Aspartic acid, Serine, Glutamine, or Glutamic acid. 
     Example 6 
     Engineered Rep Protein with Reduced Binding Affinity for Native Rep Binding Sequence Region 
     Rep protein affinity for a Rep binding sequence region is reduced by modification of one or more highly conserved residues that have been shown to contact the DNA and are highly conserved across all Rep proteins. The identified residues contact either the phosphodiester backbone and/or the nucleosides, contributing to stabilized protein-DNA interaction of a Rep protein binding site. 
     Residues K135 and N142 of the AAV5 Rep 22 protein β4/β5 loop, are identified as contributing to DNA binding affinity. K135 and N142 are altered to either Glycine or Threonine. The following modifications are tested to determine the effect on DNA binding: (1) K135G, (2) K135T, (3) N142G, (4) N142T, (5) K135G-N142G, (6) K 35G-N142T, (7) K135T-N142G, and/or (8) K135T-N1,42T. Engineered Rep protein polynucleotide sequences comprising modified residues are designed in vitro and synthesized by standard techniques as described herein. The modified Rep proteins are expressed in  e. coli  and purified according to standard procedures. An in vitro binding assay is performed with one or more of the listed engineered Rep proteins and a radiolabeled AAV5 Rep binding sequence region oligonucleotide probe (SEQ ID NO: 3-4) at varying concentrations. The resultant protein-DNA complexes are separated on a non-denaturing polyacrylamide gel. The concentrations of bound and free probe is determined using a PhosphoImager (Molecular Dynamics). A plot of the ratio of bound-free probe versus protein concentration is used to determine the Kd of each modified Rep protein. 
     The DNA binding affinity of the engineered Rep proteins can also be measured using surface plasmon resonance (ForteBio, Menlo Park, Calif.) using the following engineered Rep protein and DNA species: (1) AAV5 wild-type Rep protein and AAV5 wild-type ITR containing the native Rep binding sequence region (SEQ ID NO: 3-4) and (2) any of the engineered Rep proteins listed above and AAV5 wild-type ITR containing the native Rep binding sequence region (SEQ ID NO: 3-4). The polynucleotide encoding the wild-type AAV5 Rep binding sequence region is immobilized on the biosensor layer. A solution is prepared comprising AAV5 wild-type Rep protein or any of the engineered Rep proteins listed above, which is then passed over the biosensor to determine the rate of association. A second solution devoid of the engineered Rep protein or wild-type Rep protein is passed over the saturated biosensor layer to determine the rate of dissociation. 
     Example 7 
     Engineered Rep Protein with Reduced Binding Affinity for eRBSR 
     Rep protein affinity for a Rep binding sequence region is reduced by modification of one or more highly conserved residues that have been shown to contact the DNA and are highly conserved across all Rep proteins. The identified residues contact either the phosphodiester backbone and/or the nucleosides, contributing to stabilized protein-DNA interaction of a. Rep protein binding site. 
     Residues K135 and N142 of the AAV5 Rep 22 protein β4/β5 loop, are identified as contributing to DNA binding affinity. K135 and N142 are altered to either Glycine or Threonine. The following modifications are tested to determine the effect on DNA binding: (1) K135G, (2) K135T, (3) N142G, (4) N142T, (5) K135G-N142G, (6) K135G-N142T, (7) K135T-N142G, and/or (8) K135T-N142T. Engineered Rep protein polynucleotide sequences comprising modified residues are designed in vitro and synthesized by standard techniques as described herein. The modified. Rep proteins are expressed in  E. coli  and purified according to standard procedures. An in vitro binding assay is performed with one or more of the listed engineered Rep proteins and a radiolabeled oligonucleotide probe comprising an eRBSR at varying concentrations. The resultant protein-DNA complexes are separated on a non-denaturing polyacrylamide gel. The concentrations of bound and free probe is determined using a. PhosphoImager (Molecular Dynamics). A plot of the ratio of bound-free probe versus protein concentration is used to determine the Kd of each modified Rep protein. 
     The DNA binding affinity of the engineered Rep proteins can also be measured using surface plasmon resonance (ForteBio, Menlo Park, Calif.) using the following engineered Rep DNA species: (1) AAV2 ITR having the native AAV2 Rep binding sequence region (SEQ ID NOs: 1-2), (2) modified AAV2 ITR having the ∞PAL sequence (eRBSR) (SEQ ID NO: 68), (3) modified AAV2 ITR having the 5-5/EGR sequence (eRBSR) (SEQ ID NO: 71), (4) modified AAV2 ITR having the JcDNV NS1 sequence (eRBSR) (SEQ ID NO: 74). The polynucleotide encoding either the wild-type or engineered Rep binding sequence region is immobilized on the biosensor layer. :A solution is prepared comprising AAV5 wild-type Rep protein or any of the engineered Rep proteins listed above, which is then passed over the biosensor to determine the rate of association. A second solution devoid of the engineered Rep protein or wild-type Rep protein is passed over the saturated biosensor layer to determine the rate of dissociation. 
     Example 8 
     Determination of Production of Recombinant scAAV 
     scAAV is produced utilizing vectors comprising eRBSRs, engineered Rep protein, or chimeric nicking stem loops and combinations thereof. The relative production of scAAV using any of the disclosed sequences of the invention alone or in combination is quantified in the following manner. 
     A culture of 293 cells engineered to produce helper components required for AAV production is co-transfected with the viral construct expression vector, comprising any engineered Rep protein, and payload construct expression vector, comprising any eRBSR, chimeric nicking stern loop, or combination thereof. The culture is maintained for 48 hours while scAAV is produced and released into the medium. 
     The viral replication cells are lysed using the Microfluidizer™ (Microfluidics International Corp., Newton, Mass.), high shear force fluid processor. The resultant cell lysate is clarified by low speed centrifugation followed by tangential flow filtration. The resultant clarified lysate is then processed by ethanol precipitation to isolate the scAAV genomes. 
     The titer of AAV particles produced and purified by the methods described herein is determined by real-time quantitative polymerase chain reaction (qPCR) on a thermal cycler equipped with an excitation source filters, and detector for quantification of the reaction such as, but not limited to, the 7500 FAST Real-Time PCR system (Applied Biosystems, Foster City Calif.). AAV particles produced and purified by the methods described herein is treated with proteinase K, serially diluted, and PCR-amplified using a fluor such as, but not limited to, SYBR green (Applied Biosystems, Foster City, Calif.) with primers specific to the NAV genome ITR sequences. Linearized AAV vector genome is used as a copy number standard. The cycling conditions are: 95° C. for 3 min, followed by 35 cycles of 95° C. for 30 sec, 60° C. for 30 sec, and 72° C. for 30 sec. 
     The production of scAAV genomes is assessed by gel electrophoresis. The genomes isolated as described above are separated by denaturing (alkaline) gel electrophoresis. Analysis of the DNA content banding pattern has shown multiple sizes of viral genomes including scAAV, scAAV intermediate species, ssAAV monomer, and an ssAAV repaired from scAAV. Quantitation of the relative amounts of intermediate species is determined by densitometry and the efficiency of scAAV production quantified as a ratio of scAAV produced by wild-type versus eRBSR, engineered Rep protein, chimeric nicking stem loop constructs, and combinations thereof. 
     Example 9 
     Gene Expression 
     The level of transgene expression by AAV particles produced and purified by the methods described herein is determined by real-time quantitative polymerase chain reaction (qPCR). A culture of 293 cells engineered to produce helper components required for AAV production is infected by scAAV particles produced as described herein. 
     The target 293 cells are harvested at a series of time points, lysed and the mRNA is purified. The level of transgene expressed is determined by reverse transcription (qPCR) on a thermal cycler equipped with an excitation source filters, and detector for quantification of the reaction such as, but not limited to, the 7500 FAST Real-Time PCR system (Applied Biosystems, Foster City Calif.). AAV particles produced and purified by the methods described herein is treated with proteinase K, serially diluted, and PCR-amplified using a fluor such as, but not limited to. SYBR green (Applied Biosystems, Foster City, Calif.) with primers specific to the transgene sequence. A reference transgene oligonucleotide is used as a copy number standard. The cycling conditions are: 95° C. for 3 min, followed by 35 cycles of 95° C. for 30 sec, 60° C. for 30 sec, and 72° C. for 30 sec. 
     Example 10 
     Recombinant scAAV Production in Invertebrate Cells 
     The AAV viral construct vector encodes the three structural cap proteins, VP1, VP2, and VP3, in a single open reading frame regulated by utilization of both alternative splice acceptor and non-canonical translational initiation codon(s). In-frame and out-of-frame ATG triplets preventing translation initiation at a position between the VP1 and VP2 start codons are eliminated. Both Rep78 and Rep52 are translated from a single transcript: Rep78 translation initiates at a non-AUG codon and Rep52 translation initiates at the first AUG in the transcript. 
     The nucleotides that encode the structural VP 1, VP2, and VP3 capsid proteins and non-structural Rep78 and Rep52 proteins are contained on one viral expression construct under control of the baculovirus major late promoter. 
     The payload construct vector encodes two ITR sequences flanking a transgene polynucleotide encoding a polypeptide or modulatory nucleic acid. The ITR sequences allow for replication of a polynucleotide encoding the transgene and ITR sequences alone that will be packaged within the capsid of the viral vector. The replicated polynucleotide encodes ITR sequences on the 5′ and 3′ ends of the molecule. The 3′ [FR encodes an eRBSR that exhibits a ten-fold reduction in binding affinity as compared to a wild-type Rep binding sequence region. The reduced binding affinity of Rep protein for the eRBSR results in reduced nicking of the terminal resolution site located in the nicking stem loop. A failure to resolve the intermediate replication structure by nicking of the stem loop results in an alternative replication pathway and generation of the self-complementary AAV genome species of the polynucleotide encoding the payload and ITR sequences. 
     The payload construct vector and viral construct vector each comprise a Tn7 transposon element that transposes the [FR-payload sequences or the Rep and Cap sequences respectively to a bacmid that comprises the attTn7 attachment site. Competent bacterial DH10 cells are transfected with either the payload construct vector or viral construct vector. The resultant viral construct expression vector and payload construct expression vector produced in the competent cell are then purified by detergent lysis and purification on DNA columns. 
     Separate seed cultures of Sf9 cells in serum free suspension culture are transfected with the viral construct expression vector or payload construct expression vector. The cultures are maintained for 48 hours while baculovirus is produced and released into the medium. The baculovirus released into the media continue to infect Sf9 cells in an exponential manner until all of the Sf9 cells in the culture are infected at least once. The baculoviral infected insect cells (BIIC) and media of the seed culture is harvested and divided into aliquots before being frozen in liquid nitrogen. 
     A naïve population of un-transfected Sf9 cells is expanded in serum free suspension cell culture conditions. Once the culture growth has reached peak log phase in 1 L of media as measured by optical density the culture is added to a large volume 20 L bioreactor. The bioreactor culture is co-inoculated with a frozen viral construct expression vector and payload construct expression vector BIIC aliquot. The conditions of the Sf9 cell suspension culture is monitored by instruments that measure and/or control external variables that support the growth and activity of viral replication cells such as mass, temperature, CO2, O2, pH, and/or optical density (OD) The Sf9 culture is maintained at optimal conditions until cell population growth has reached peak log phase and before cell growth has plateaued, as measured by optical density. 
     In each viral replication cell that has been infected with both baculoviruses the payload flanked on one end with an ITR sequence containing an eRBSR is replicated by an alternative pathway producing a self-complementary AAV genome and packaged in a capsid assembled from the proteins VP1, VP2, and VP3. 
     The viral replication cells are lysed using the Microfluidizer™ (Microfluidics International Corp., Newton, Mass.), high shear force fluid processor. The resultant cell lysate is clarified by low speed centrifugation followed by tangential flow filtration. The resultant clarified lysate is filtered by a size exclusion column to remove any remaining haculoviral particles from solution. The final steps utilize ultracentrifugation and sterile filtration to produce viral particles suitable for use as described herein. 
     The titer of AAV particles produced and purified by the methods described herein is determined by real-time quantitative polymerase chain reaction (qPCR) on a thermal cycler equipped with an excitation source filters, and detector for quantification of the reaction such as, but not limited to, the 7500 FAST Real-Time PCR system (Applied Biosystems, Foster City Calif.). AAV particles produced and purified by the methods described herein is treated with proteinase K, serially diluted, and PCR-amplified using a fluor such as, but not limited to, SYBR green (Applied Biosystems, Foster City, Calif.) with primers specific to the AAV genome ITR sequences. Linearized AAV vector genome is used as a copy number standard. The cycling conditions are: 95° C. for 3 min, followed by 35 cycles of 95° C. for 30 sec, 60° C. for 30 sec, and 72° C. for 30 sec. 
     Example 11 
     Recombinant AAV Production in Mammalian Cells 
     The AAV viral construct vector encodes the three structural cap proteins, VP1, VP2, and VP3, in a single open reading frame regulated by utilization of both alternative splice acceptor and non-canonical translational initiation codon(s). In-frame and out-of-frame ATG triplets preventing translation initiation at a position between the VP1 and VP2 start codons are eliminated. Both Rep78 and Rep52 are translated from a single transcript: Rep78 translation initiates at a non-AUG codon and Rep52 translation initiates at the first AUG in the transcript. 
     The nucleotides that encode the structural VP1, VP2, and VP3 capsid proteins and non-structural Rep78 and Rep52 proteins are contained on one viral expression construct under control of the CMV promoter. 
     The payload construct vector encodes two ITR sequences flanking a transgene polynucleotide encoding a polypeptide or modulatory nucleic acid. The ITR sequences allow for replication of a polynucleotide encoding the transgene and ITR sequences alone that will be packaged within the capsid of the viral vector. The replicated polynucleotide encodes ITR sequences on the 5′ and 3′ ends of the molecule. The 3′ ITR encodes an eRBSR that exhibits a ten-fold reduction in binding affinity as compared to a wild-type Rep binding sequence region. The reduced binding affinity of Rep protein for the eRBSR results in reduced nicking of the terminal resolution site located in the nicking stern loop. A failure to resolve the intermediate replication structure by nicking of the stem loop results in an alternative replication pathway and generation of the self-complementary AAV genome species of the polynucleotide encoding the payload and ITR sequences. 
     The payload construct vector and viral construct vector each comprise a Tn7 transposon element that transposes the ITR-payload sequences or the Rep and Cap sequences respectively to a bacmid that comprises the attTn7 attachment site. Competent bacterial DH1O cells are transfected with either the payload construct vector or viral construct vector. The resultant viral construct expression vector and payload construct expression vector produced in the competent cell are then purified by detergent lysis and purification on DNA columns. 
     A seed culture of Chinese Hamster Ovary (CHO) cells adapted for growth in serum free suspension culture is co-transfected with the viral construct expression vector and payload construct expression vector. The culture is maintained for 48 hours while two baculoviruses are produced and released into the medium, one containing the payload construct vector and a second containing the viral expression construct. The baculovirus released into the media continue to infect CHO cells in an exponential manner until all of the CHO cells in the culture are infected at least once with both baculoviruses. In each viral replication cell that has been infected with both baculoviruses the payload flanked on either end with an ITR sequence is replicated and packaged in a capsid assembled from the proteins VP1, VP2, and VP3. The cells and media of the seed culture is harvested and divided into aliquots before being frozen in, for example, liquid nitrogen. 
     A naïve population of un-transfected CHO cells is expanded in serum free suspension cell culture conditions. Once the culture growth has reached peak log phase in 1 L of media as measured by optical density the culture is added to a large volume 20 L bioreactor. The bioreactor culture is inoculated with a frozen aliquot from the baculovirus seed culture. The conditions of the CHO cell suspension culture is monitored by instruments that measure and/or control external variables that support the growth and activity of viral replication cells such as mass, temperature, CO2, O2, pH, and/or optical density (OD). The CHO culture is maintained at optimal conditions until cell population growth has reached peak log phase and before cell growth has plateaued, as measured by optical density. 
     The viral replication cells are lysed using the Microfluidizer™ (Microfluidics International Corp., Newton, Mass.), high shear force fluid processor. The resultant cell lysate is clarified by low speed centrifugation followed by tangential flow filtration. The resultant clarified lysate is filtered by a size exclusion column to remove any remaining baculoviral particles from solution. The final steps utilize ultracentrifugation and sterile filtration to produce viral particles suitable for uses described herein. 
     Example 12 
     Large Scale PEI Transfection 
     Polyethyleneimine (PEI) is used to form PEI-DNA complexes. Plasmids being transfected are combined with PEI in PBS and allowed to incubate at room temperature for 10 minutes. HEK 293 cell cultures being transfected are ‘shocked’ at 4° C. for 1 hour before being returned to the 37° C. incubator for a period of 6-24 hours (to arrest cell cycle at the junction between G2 phase and M phase). PEI-DNA transfection complexes are then added to the cells under shaking conditions and allowed to incubate 6 hours. After incubation, an equal volume of fresh medium is added and cells are incubated for 24-96 hours. 
     Example 13 
     Central Nervous System AAV Delivery 
     Viral particles are produced as taught herein and prepared for delivery to the central nervous system. In one aspect, preparation for CNS delivery is according to the method of Foust et al (Foust, K. D, et al., 2009, Nat Biotechnol 27:59-65, the contents of which are herein incorporated by reference in their entirety). 
     According to the Foust method, AAV9 viral particles delivered by venous injection are transported across the blood brain barrier (BBB) and carry out astrocyte transduction. Viruses are produced and purified by cesium chloride gradient purification, followed by dialysis against phosphate buffered saline (PBS), Resulting preparations are formulated with 0.001% Pluronic-F68 to discourage viral aggregation, Viral preparations are titrated following quantitative-PCR analysis of viral levels. Purity of viral preparations is further assessed by gel electrophoresis and subsequent silver staining (Invitrogen, Carlsbad, Calif.) Viral preparations are then delivered to subjects by intravenous injection. Viral payloads are delivered to cells of the CNS.