GENE THERAPY FOR CYSTIC FIBROSIS TRANSMEMBRANE CONDUCTANCE REGULATOR ACTIVITY (CFTR)

Abstract: Methods and compositions for producing a mammal capable of expressing an exogenously supplied gene in cells of the airway are disclosed. Lipid carrier-nucleic acid complexes or nucleic acid alone are prepared then delivered via aerosol or systemically to the lung alone or lung plus extrapulmonary tissues. The invention provides a direct method for transforming pulmonary cells as a means for treating the manifestations of CF in the lung and involved extrapulmonary tissues.

Description: GENE THERAPY FOR CYSTIC FIBROSIS TRANSMENBRANE CONDUCTANCE REGULATOR ACTIVITY (tFTR) INTRODUCTION Technical Field The present invention relates to methods and compositions for producing a transgenic mammal which comprises exogenously supplied nucleic acid coding for a 10 molecule having cystic fibrosis transmembrane conductance regulator activity. The nucleic acid is supplied by aerosolized delivery, particularly to the airways and alveoli of the lung, or by systemic delivery. Background 15 Many genetic diseases are caused by the absence or mutation of the appropriate protein, for example as a result of deletions within the corresponding gene. One of the most common fatal genetic diseases in humans is cystic fibrosis (CF). Cystic fibrosis (CF), a spectrum of exocrine tissue dysfunction, which eventually leads to respiratory failure and death results from a mutation of the cystic fibrosis transmembrance conductance 20 regulator (CFTR) gene. The CFTR gene has now been localized to chromosome 7q31, and cloned. A 3 bp deletion, resulting in the loss of a phenylalanine residue at amino acid position 508, is present in approximately 70% of CF chromosomes, but is not seen on normal chromosomes. The other 30% of CF mutations are heterogenous and include deletion, missense, and splice-site mutations. Transfection of even a single normal copy of 25 the CFTR gene abolishes the CF secretory defect in CF cell lines, an observation which supports the feasibility of gene therapy for CF. These results demonstrate that expression of a wild-type CFTR transgene can exert a dominant positive effect in CF cells which concurrently express an endogenous mutant CFTR gene. Thus, expression of the wild-type CFTR transgene in the lungs of CF patients can correct the CF phenotype. However, to 30 date, the inability to produce hign level expression of transgenes in the lung by either •\ aerosol or intravenous (iv) administration has precluded the use of gene therapy for the treatment of CF. Expression of a wild-type CFTR transgene in cells from CF patients corrects the chloride secretory defect, the primary biochemical lesion of CF. Chloride secretion is normalized in cells of CF patients despite the presence of the mutant CFTR protein, indicating that when wild-type and mutant CFTR proteins are coexpressed in cells, the wild-type CFTR is dominant. To date, attempts to replace absent or mutated genes in human patients have relied on ex vivo techniques. Ex vivo techniques include, but are not limited to, transformation of cells in vitro with either naked DNA or DNA encapsulated in liposomes, followed by introduction into a suitable host organ ("ex vivo" gene therapy). The criteria for a suitable organ include that the target organ for implantation is the site of the relevant disease, the disease is easily accessible, that it can be manipulated in vitro, that it is susceptible to genetic modification methods and ideally, it should contain either non- replicating cells or cycling stem cells to perpetuate a genetic correction. It also should be possible to reimplant the genetically modified cells into the organism in a functional and stable form. A further requirement for ex vivo gene therapy, if for example a retroviral vector is used, is that the cells be pre-mitotic; post-mitotic cells are refractory to infection with retroviral vectors. There are several drawbacks to ex vivo therapy. For example, if only differentiated, replicating cells are infected, the newly introduced gene function will be lost as those cells mature and die. Ex vivo approaches also can be used to transfect only a limited number of cells and cannot be used to transfect cells which are not first removed from the body. Exemplary of a target organ which meets the criteria of in vivo gene transfer is mammalian bone marrow; mammalian lung is not a good candidate for ex vivo therapy. Retroviruses, adenoviruses and liposomes have been used in animal model studies in attempts to increase the efficiency of gene transfer. Liposomes have been used effectively to introduce drugs, radiotherapeutic agents, enzymes, viruses, transcription factors and other cellular effectors into a variety of cultured cell lines and animals. In addition, successful clinical trials examining the effectiveness of liposome-mediated drug delivery have been completed. Several strategies have been devised to increase the effectiveness of liposome-mediated drug delivery by targeting liposomes to specific tissues and specific cell types. However, while the basic methodology for using liposome-mediated vectors is well developed, the technique has not been perfected for liposome-based transfection vectors for in vivo gene therapy. In the studies published to date, injection of the vectors either intravenously, intratracheally or into specific tissues has resulted in low but demonstrable expression, but the expression has generally been limited to one tissue, typically either the tissue that was injected (for example muscle); liver or lung where iv injection has been used; or lung where intratracheal injection has been used, and less than 1% of all cells within these tissues were transfected. In vivo expression of transgenes has been restricted to injection of transgenes directly into a specific tissue, such as direct intratracheal, intramuscular or intraarterial injection of naked DNA or of DNA-cationic liposome complexes, or to ex vivo transfection of host cells, with subsequent reinfusion. Currently available gene delivery strategies consistently have failed to produce a high level and/or generalized transgene expression in vivo. Expression of introduced genes, either complexed to cationic vectors or packaged in adenoviral vectors has been demonstrated in the lungs of rodents after intratracheal (IT) instillation. However, IT injection is invasive and produces a non-uniform distribution of the instilled material; it also is too invasive to be performed repeatedly in humans. For CF patients wherein the defect is a primary life-threatening defect in the lung, it would be of interest to develop a non-invasive delivery technique which also results in deeper penetration of exogenous nucleic acid constructs into the lung than do other methods, and can be used to deposit the CFTR gene constructs throughout the distal airways, as well as transfecting both airway epithelial cell and airway sub-mucosal cell types. Where other organs in the CF patient are affected due to the presence of mutant CFTR gene, techniques for transformation of a wide variety of tissues would be of interest, in order to alleviate extrapulmonary organ dysfunction in CF patients. - ~ Relevant Literature EP 91301819.8 (publication number 0 446 017 Al) discloses full length isolated DNAs encoding cystic fibrosis transmembrance conductance regulator (CFTR) protein and a variety of mutants thereof. Transient expression of CFTR in transformed cultured COS-7 cells is also disclosed. Rich et al, Nature (1990) 247:358-363 and Gregory et al., Nature (1990) 247:382-386 disclosed expression of the cystic fibrosis transmembrance conductance regulator in cultured HeLa cells using a vaccinia virus vector. Yoshimura et al. disclose expression of the CFTR gene in mouse lung after intratracheal administration of a plasmid containing the gene, either as naked DNA or complexed to lipofectin. Brigham et al., Am. J. Med. Sci. (1989) 298:278-281, describes the in vivo transfection of murine lungs with the CAT gene using a liposome vehicle. Transfection was accomplished by intravenous, intratracheal or intraperitoneal injection. Both intravenous and intratracheal administration resulted in the expression of the CAT gene in the lungs. However, intraperitoneal administration did not. S^, also Werthers, Clinical Research (1991) 39:(Abstract). Canonico et al., Clin. Res. (1991) 22- * 219A describes the expression of the human α-1 antitrypsin gene, driven by the CMV promoter, in cultured bovine lung epithelial cells. The gene was added to cells in culture using cationic liposomes. The experimenters also detected the presence of α-1 antitrypsin in histological sections of the lung of New Zealand white rabbits following the intravenous delivery of gene constructs complexed to liposomes. Yoshimura et a/.disclose expression of the human cystic fibrosis transmembrane . conductance regulator gene in mouse lung after intratracheal plasmid-mediated gene transfer. Multiple approaches for introducing functional new genetic material into cells, both in vitro and in vivo have been attempted (Friedmann (1989) Science, 244:1275-1280). These approaches include integration of the gene to be expressed into modified retro viruses (Friedmann (1989) supra; Rosenberg (1991) Cancer Research 51(18), suppl.: 5074S-5079S); integration into non-retrόvirus vectors (Rosenfeld, et al. (1992) Cell, 68:143-155; Rosenfeld, et al. (1991) Science, 252:431-434): or delivery of a transgene linked to a heterologous promoter-enhancer element via liposomes (Friedmann (1989), supra; Brigham, et al. (1989) Am. J. Med. Sci., 298:278-281; Nabel, et al. (1990) Science, 242:1285-1288; Hazinski, et al. (1991) Am. J. Resp. Cell Molec. Biol., 4:206-209; and Wang and Huang (1987) Proc. Natl. Acad. Sci. (USA), 84:7851-7855); coupled to ligand-specific, cation-based transport systems (Wu and Wu (1988) J. Biol. Chem., 263:14621-14624) or the use of naked DNA expression vectors (Nabel et al. (1990), supra); Wolff et al. (1990) Science, 247:1465- 1468). Direct injection of transgenes into tissue produces only localized expression (Rosenfeld (1992) supra); Rosenfeld et al. (1991) supra; Brigham et al. (1989) supra; Nabel (1990) supra; and Hazinski et al. (1991) supra). The Brigham et al. group (Am. J. Med. Sci. (1989) 298:278-281 and Clinical Research (1991) 39 (abstract)) have reported in vivo transfection only of lungs of mice following either intravenous or intratracheal administration of a DNA liposome complex. An example of a review article of human gene therapy procedures is: Anderson, Science (1992) 256:808-813. PCT/US90/01515 (Feigner et al.) is directed to methods for delivering a gene coding for a pharmaceutical or immunogenic polypeptide to the interior of a cell of a vertebrate in vivo. Expression of the transgenes is limited to the tissue of injection. PCT/TJS90/05993 (Brigham) is directed to a method for obtaining expression of a transgene in mammalian lung cells following either iv or intratracheal injection of an expression construct. PCT 89/02469 and PCT 90/06997 are directed to ex vivo gene therapy, which is limited to expressing a transgene in cells that can be taken out of the body such as lymphocytes. PCT 89/12109 is likewise directed to ex vivo gene therapy. PCT 90/12878 is directed to an enhancer which provides a high level of expression both in transformed cell lines and in transgenic mice using ex vivo transformation. Debs et al. disclose pentamidine uptake in the lung by aerosolization and delivery in liposomes. Am Rev Respir Dis (1987) 135: 731-737. For a review of the use of liposomes as carriers for delivery of nucleic acids, sre, Hug and Sleight, Biochim. Biophys. Acta. (1991) 1097:1-17: Straubinger et al, in Methods ofEnzymology (1983), Vol. 101, pp. 512-527. SUMMARY Methods and compositions are provided for producing a mammal which comprises exogenously supplied nucleic acid encoding a molecule having the biological activity of wild type cystic fibrosis transmembrane conductance regulator (CFTR) in its lung cells. The nucleic acid may be either a sense or an antisense strand of DNA. Also provided is a transgenic mammal comprising the CFTR nucleic acid. The method includes the steps of contacting host cells in vivo with a construct comprising said nucleic acid in an amount sufficient to transform cells contacted by the construct. The exogenously supplied nucleic acid generally is provided in a transcription cassette or an expression cassette and includes the coding sequence for a CFTR molecule operably joined to regulatory sequences functional in the mammal. The methods and compositions find use particularly for in vivo gene therapy of cystic fibrosis. BRIEF DESCRIPTION OF THE FIGURES Figure 1 shows photomicrographs of frozen sections from lungs of control mice (Figures IB and ID) and mice treated with a plasmid containing the human CFTR gene (pZN32) complexed to DDABxholesterol (1:1) liposomes (Figures IA, 1C, and IE). Figures IA, 1C, and IE are lung sections from treated mice at 50X, 100X, and 250X magnification, respectively. Figures IB and ID are lung sections from untreated (control) mice at 50X and 100X magnification. lipid carriers were 1 to 1 molar DDAB:Chol (SUV). Lipid carrier-DNA complexes were 5 nanomoles cationic lipid to 1 μg DNA. . Figure 2A shows a section of mouse lung 48 hours following iv injection of PZN27:DDAB:Chol expression vector-cationic lipid carrier complexes. Lipid carrier composition was 1:1 molar DDAB:Chol. Lipid carrier plasmid ratio was 5 nanomoles cationic lipid to 1 μg DNA. A dose of 100 μg DNA was injected per mouse. This field shows alveoli and alveolar lining cells, the majority (50-70%) of which stain positively for the presence of CAT protein when probed with anti-CAT antibody and visualized using alialine phosphatase. The treated animals' lungs stain uniformly with diffuse involvement of alveolar and vascular endothelial cells. Airway epithelial staining is also seen indicating airway are also transfected. The CAT (chloramphenicol acetyl transferase) protein normally is not present in mammalian cells and therefore the presence of CAT protein in these cells indicates that they have been transfected in vivo. Figure 2B shows a section of mouse lung from a control animal treated with iv-injected lipid carriers only, and probed with anti-CAT antibody. Cells do not show significant staining, although low-level background staining is detectable in some alveolar macrophages, which possess endogenous alkaline phosphatase activity. Figure 3 shows construction of pZN20. Figure 4 shows an electron micrograph which demonstrates that cationic lipid carrier: DNA complexes (DOTMA:DOPE:pRSV-CAT) are internalized by cells via classical receptor-mediated endocytosis following binding to cell surface receptors. Lipid carriers were 1:1 DOTMA:DOPE. 20 μg DNA was complexed with 20 nmoles cation lipid. Figure 5 shows CAT gene expression in the indicated tissues following intravenous - injection of pZN20:DDAB:DOPE complexes. lipid carriers were DDAB:DOPE 1 to 1 molar. Two lipid carrier-to-plasmid ratios (nanomoles cationic lipid μg plasmid DNA) were used, MLV,6:1 and SUV, 3:1. Lanes 1-6 are samples from lung tissue; lanes 7-12, heart tissue; lanes 13-18, Ever; lanes 19-24, dney; lanes 25-30, spleen; lanes 31-36, lymph nodes. The first 3 samples of each tissue set were from animals injected with MLV, the next 3 samples of each tissue set were from animals injected with SUV. In lanes 1-18 the chromatograph runs from bottom to top, in lanes 19-36 the chromatograph runs from top to bottom. These results demonstrate that iv injection of pZN20:DDAB:DOPE complexes produces significant levels of CAT gene expression in six different tissues. Furthermore, MLV appear to mediate equal or greater levels of in vivo gene expression than do SUV composed of the same lipids. Figure 6 shows the results of iv injection of DOTMA:DOPE complexed to pSIS-CA plasmid does not produce detectable CAT expression in vivo. Figure 6A shows analysis of lung, spleen, liver and heart two days following iv injection with either lipid carrier alone (lanes 1-4) or lipid carrier plus DNA (lanes 5-8); Figure 6B shows the results at six days in mouse lung, spleen, liver and heart (lanes as in 6A. Lipid carriers were DOTMA:DOPE 1 to 1 molar. Cationic lipid to DNA ratio was 4 nanomoles to 1 μg. 100 μg DNA was injected per mouse. In both figures the chromatograph runs from bottom to top. Figure 7 shows the construction of plasmid pZN27. Figure 8 shows CAT gene expression in the indicated tissues following intravenous injection with pZN27 alone or pZN27:DDAB:Chol SUV complexes. Figure 8A lanes 1-10, lung; lanes 11-20, heart; lanes 21-30, liver; lanes 31-40, kidney; Figure 12B lanes 1-10, spleen; lanes 11-20, lymph nodes. Each tissue set of 10 contains samples treated with the following in order: 2 samples, 500 μg DNA; 2 samples, 1 mg DNA; 2 samples, 2 mg DNA; 2 samples, 500 μg DNA twice; 2 samples, lipid carrier-DNA complex 100 μg DNA. In Figure 8A lanes 1-20 the chromatograph runs from bottom to top; in Figure 8A lanes 21- 40 the chromatograph runs from top to bottom. In Figure 8B lanes 1-20 the chromatograph runs from bottom to top. Lipid carriers were 1 to 1 molar DDAB:Chol. Lipid carrier-DNA complex was 5 nanomoles cationic lipid to 1 μg DNA. Figure 9 shows CAT expression in the lung after intravenous injection of pRSV- CAT:L-PE:CEBA complexes. Lanes 1-3 are samples from untreated mouse lung, lane 4 is from a lung sample from a mouse treated with lipid carriers only, lane 5 is a sample from a mouse treated with the lipid carrier-DNA complex. Lipid carriers were 1 to 1 molar L- PE:CEBA. Lipid carrier-DNA complexes were 1 nanomole cationic lipid to 1 μg DNA. 100 μg DNA was injected per mouse. Chromatograph runs from bottom to top of Figure as shown. Figure 10 shows the construction of plasmid pZN32. Figure 11 shows the construction of plasmid pZN51. Figure 12 shows the construction of plasmids pZN60, pZN61, pZN62 and pZN63. Figure 12A shows the construction of intermediate plasmids pZN52, pZN54, pZN56 and pZN58. Figure 12B shows the construction of the final plasmids, pZN60 through pZN63, from the intermediates. Figure 13 shows an autoradiograph of the thin layer chromatograph of the CAT assay for six different plasmids injected intravenously in mice. Lanes 1-12 show the CAT activity in lung tissue; Lanes 13-24 show the CAT activity in liver tissue. Lanes 1, 2, 13, 14- pZN51; lanes 3, 4, 15, 16-pZN60; lanes 5, 6, 17, 18-pZN61; lanes 7, 8, 19, 20-pZN62; lanes 9, 10, 21, 22-pZN63; lanes 11, 12, 23, 24-pZN27. Lipid carriers were DDAB:Chol (1:1). Lipid carriers-DNA complexes were 5nmoles cationic lipid to lμg DNA. lOOμg DNA was injected per mouse. Each lane represents a single mouse. Chromatograph runs from bottom to top of Figure as shown. Figure 14(A-F) show CAT activity in heart (14A), spleen (14B), lung (14C), LN (14D), Mdney (14E), and liner (14F) in lungs from iininjected mice (lanes 1-3), mice injected IV with pBE3.8CAT (lanes 4-6), or pCIS-CAT (lanes 7-9). Figure 15 shows construction of pZN13. Figure 16 shows construction of pZN29. Figure 17 shows construction of pZN32. Figure 19 shows a full restriction map for HCMV (Towne) of the immediate early enhancer and promoter region of HCMV (Towne) in Figure 19A and HCMV(AD169) in Figure 19C. Figure 19B shows a sequence comparison of the two HCMV promoters. The sequence of the Towne strain is designated as hs5miel on this comparison. The position of the Ncol site is indicated by an asterisk. Figure 20 demonstrates that aerosol administration of pRSV-CAT-DOTMA: cholesterol complexes resulted in expression of the CAT gene in mouse lungs. Lanes 1-3 were derived from mice receiving no treatment; lanes 4-6 represent mice administered 0.5 mg pRSV-CAT with 1.0 μmole DOTMA-cholesterol liposomes; lanes 7-9 were derived from mice receiving 2.0 mg pRSV-CAT alone; and lanes 10-12 represent mice given 2.0 mg pRSV-CAT with 4.0 μmol DOTMA-cholesterol liposomes in a 2 to 1 molar ratio. The CAT gene is not normally present in mammalian cells; the results thus indicate that the lung was successfully transfected by the pRSV-CAT DOTMA-cholesterol:liposome aerosol. The results also show that neither aerosol administration of the pRSV-CAT alone, nor a lower aerosol dose of pRSV-CAT: DOTMA-cholesterol complexes produce detectable expression of the CAT gene in mouse lungs. Thus, both the cationic liposome carrier, and a sufficient dose of DOTMA: liposome complexes are required to produce transgene expression in the lung after aerosol administration, maximum transgene expression is achieved by complexing the liposomes and DΝA together at an appropriate ratio dose and in an appropriate diluent. Figure 21 shows the results of an experiment where mice were administered 12 mg of pCIS-CAT complexed to 24 μmoles of DOTMA/DOPE 1:1 liposomes. Lanes 1-3 show the results from animals administered the aerosol in an Intox-designed nose-only aerosol exposure chamber; lanes 4-7 are derived from mice exposed to the aerosol in a modified mouse cage; and lanes 8-10 show the results from animals placed in a smaller modified cage after being put in restrainers originally constructed for use in the Intox chamber. Figure 22 shows the results of immunostaining for intracellular CAT protein in lung sections from mice sacrificed 72 hours after receiving an aerosol containing 12 mg of pCIS- CAT plasmid complexed to 24 μmols of DOTMA:DOPE liposomes (A,B,C,D), or from untreated mice (E,F). The section shown in d was treated with normal rabbit serum in place of anti-CAT antibody. Magnification: A,D (x 50); B,C,E (x 250). Figure 23 shows CAT activity in lung extracts from mice sacrificed 72 hours after receiving an aerosol containing either 12 mg of CMV-CAT plasmid alone or 12 mg of CMV-CAT plasmid complex to 24 μmols of DOTMA:DOPE (1:1) liposomes. Untreated mice were also assayed. Figure 24 shows (A) CAT activity in lung extracts from mice sacrificed from one to twenty-one days after receiving an aerosol containing 12 mg of pCIS-CAT plasmid complexed to 24 μmols of DOTMA:DOPE liposomes; and (B) shows CAT activity in several different tissue extracts from mice and indicates that expression of the transgene is lung-specific, after aerosolization of DNA-liposome complexes into normal mice sacrificed at the three day time point in Fig. 8A. Control extract contains CAT enzyme. Figure 25 shows Southern blot hybridization of genomic DNA from the lungs of mice sacrificed immediately after receiving an aerosol containing 12 mg of pCIS-CAT plasmid complexed to 24 μmols of DOTMA:DOPE liposomes (lanes 1-4, 6-9) and from an untreated control mouse (lane 5). Samples were digested with the restriction enzyme Hrødiπ and probed with a 1.6 kb CAT fragment (upper panel). The same membrane was hybridized with a 1.1 kb BSU 36-1 single copy probe from a mouse factor VDI.A genomic clone (lower panel). Figure 26(A-F) shows histological analysis of CAT activity in lung from mice injected with CMV-CAT (Figs. 21 A and 21D), CFTR-CAT (Figs. 21B and 21D) and central animals (Figs 21C and 21E). DESCRIPTION OF THE SPECIFIC EMBODIMENTS In accordance with the subject invention, nucleic acid constructs together with methods of preparation and use are provided which allow for in vivo modulation of phenotype and/or genotype of cells in the respiratory tract of a mammalian host following delivery of a sufficient dose of a lipid carrier-nucleic acid aerosol to the host mammal or systemic delivery of a sufficient dose of nucleic acid, either naked or complexed with a lipid carrier. The nucleic acid is a nucleotide sequence which codes for a molecule having the biological activity of wild-type CFTR or it is a sequence which when transcribed provides an mRNA sequence complementary to the normal transcription product of an amount and/or of a size sufficient to block express of an endogenous CFTR gene, particularly a mutant CFTR gene. Of particular interest is expression of wild-type CFTR in lung airway cells as well as extrapulmonary cells which are dysfunctional in CF patients. Accordingly, the term "nucleic acid" as used herein refers to either the sense or the antisense strand coding for a molecule having CFTR activity. The lipid carrier-nucleic acid aerosol is obtained by nebulization of a lipid carrier-nucleic acid sample mixture prepared in a biologically compatible fluid that m mizes aggregation of the lipid carrier-nucleic acid complexes. The methods and compositions can be used to produce a mammal comprising an exogenously supplied nucleic acid coding for a molecule having CFTR activity in lung tissue, particularly airway passage cells, as well as submucosal cells, and appropriate exocrine cell types in non-pulmonary tissues. Central to the present invention is the discovery that lung cells can be transfected via aerosol administration or systemic administration. The instant invention takes advantage of the use of lipid carriers as a delivery mechanism, although high doses of naked nucleic acid can also be used. lipid carriers are able to stably bind nucleic acid through charge interactions so that resulting complexes may be nebulized and delivered to specific pulmonary tissues may be injected or using a nebulization device. lipid carriers include but are not limited to liposomes and micelles, as well as biodegradable cationic compounds comprising modified phosphoglycerides, particularly alkylphosphaglycerides. lipid carriers, particularly liposomes, have been used effectively to introduce drugs, radiotherapeutic agents, enzymes, viruses, transcription factors and other cellular effectors into a variety of cultured cell lines and animals. In addition, successful clinical • trials examining the effectiveness of liposome-mediated delivery of small drug molecules and . peptides which act extracellularly have been reported. However, while the basic methodology for using liposome-mediated vectors is well developed and has been shown to be safe, the technique previously has not been developed for delivery of nucleic acid to pulmonary tissue and appropriate extra-pulmonary tissues for in vivo gene therapy of genetic disorers related to mutant CFTR genes. By in vivo gene therapy is meant transcription and/or translation of exogenously supplied nucleic acid to prevent, palliate and or cure a disease or diseases related to mutant or absent CFTR genes and gene products. Several factors have been identified that can affect the relative ability of lipid carrier-nucleic acid constructs to provide transfection of lung cells following aerosolized or systemic delivery of lipid carrier-nucleic acid constructs and to achieve a high level of expression. For aerosolized delivery, these factors include (1) preparation of a solution that prior to or during nebulization will not form macroaggregates and wherein the nucleic acid is not sheared into fragments and (2) preparation of both lipid carriers and expression constructs that provide for predictable transformation of host lung cells following aerosolization of the lipid carrier-nucleic acid complex and administration to the host animal. Other factors include the diluent used to prepare the solution and for either aerosolized or systemic delivery the lipidic vectoπnucleic acid ratio solution for nebulization. Aerosol delivery of nucleic acid-lipid carrier complexes provides a number of advantages over other modes of administration. For example, aerosol administration can serve to reduce host toxicity. Such an effect has been observed with the delivery of substances such as pentamidine and cytokines, which can be highly toxic when delivered systematically, but are well tolerated when aerosolized, gee, for example, Debs et al. , Antimicrob. Agents Chemother. (1987) 21:37-41; Debs et al., Amer. Rev. Respir. Dis. (1987) 135:731-737; Debs et al, J. Immunol. (1988) 140:3482-3488; Montgomery et al, Lancet (1987) U:480-483; Montgomery et al. , Chest (1989) 25:747-751; Leoung et al. , N. Eng. J. Med. (1990) 222:769-775. Additionally, rapid clearance of circulating lipid carriers by the liver and spleen reticuloendothelial system is avoided, thereby allowing the sustained presence of the administered substance at the site of interest, the lung. Serum induced inactivation of the therapeutic agent is also reduced. This method of transfecting lung cells also avoids exposure of the host mammal's gonads, thus avoiding transfection of germ line cells. Other advantages of the subject invention include ease of administration i.e., the host mammal simply inhales the aerosolized lipid carrier-nucleic acid solution into the intended tissue, the lung. Further, by varying the size of the nebulized particles some control may also be exercised over where in the lung the aerosol is delivered. Delivery may be extended over a long time period. Thus, there is a significant increase in the time period that target cells are exposed to the nucleic acid constructs. Distribution of the aerosol is even throughout areas of the lung accessible to the spray. These advantages are significant, particularly when compared to other routes of administration such as intratracheal delivery which is invasive, the nucleic acid expression constructs are delivered in a bolus, which may disrupt the mucous barrier and additionally may result in pooling of the introduced fluid in areas of the lung at lower elevation. Damage from insertion of the intratracheal tube may alter the ability of cells coming into contact with the nucleic acid constructs to be transfected. The type of vector used in the subject application also is an advantage over other available systems. For example, most gene therapy strategies have relied on transgene insertion into retroviral or DNA virus vectors. Potential disadvantages of retrovirus vectors, as compared to the use of lipid carriers, include the limited ability of retroviruses to mediate in vivo (as opposed to ex vivo) transgene expression; the inability of retrovirus vectors to transfect non-dividing cells; possible recombination events in replication-defect of retrovirus vectors, resulting an infectious retroviruses; possible activation of oncogenes or inhibition of tumor suppressor genes due to the random insertion of the transgene into host cell genomic DNA; size limitations (less than 15 kb of DNA can be packaged in a retrovirus vector, whereas lipid carriers can be used to deliver sequences of DNA of > 250 kb to mammalian cells) and potential immunogenicity of the traditional vectors leading to a host immune response against the vector. In addition, all ex vivo approaches require that the cells removed from the body be maintained in culture for a period of time. While in culture, cells may undergo deleterious or potentially dangerous phenotypic and/or genotypic changes. Adenovirus and other DNA viral vectors share several of the above potential limitations. Particularly for human use, but also for repeated veterinary use, biodegradable lipid carriers, which are noninfectious, nonimmunogenic, and nonmutogenic may be used which are either metabolized or excreted by the host mammal to naturally occurring compounds that are non- toxic to the host and/or are readily excreted. The constructs for use in the invention include several forms, depending upon the intended use of the construct. Thus, the constructs include vectors, trancriptional cassettes, expression cassettes and plasmids. The transcriptional and translational initiation region (also sometimes referred to as a "promoter,"), preferably comprises a transcriptional initiation regulatory region and a translational initiation regulatory region of untranslated 5' sequences, "ribosome binding sites," responsible for binding mRNA to ribosomes and translational initiation. It is preferred that all of the transcriptional and translational functional elements of the initiation control region are derived from or obtainable from the same gene. In some embodiments, the promoter will be modified by the addition of sequences, such as enhancers, or deletions of nonessential and/or undesired sequences. By "obtainable" is intended a promoter having a DNA sequence sufficiently similar to that of a native promoter to provide for the desired specificity of transcription of a DNA sequence of interest. It includes natural and synthetic sequences as well as sequences which may be a combination of synthetic and natural sequences. The nucleic acid constructs generally will be provided as transcriptional cassettes. An intron optionally may be included in the construct, preferably > 100 bp and placed 5' to the coding sequence. Generally it is preferred that the construct not become integrated into the host cell genome and the construct is introduced into the host as part of a non-integrating expression cassette. A coding sequence is "operably linked to" or "under the control of transcriptional regulatory regions in a cell when DNA polymerase will bind the promoter sequence and transcribe the coding sequence into mRNA, either a sense strand or an antisense strand. Thus, the nucleic acid sequence includes DNA sequences which encode polypeptides have the biological activity of CFTR which are directly or indirectly responsible for a therapeutic effect, as well as nucleotide sequences coding for nucleotide sequences such as antisense sequences and ribozymes. In some cases, it may be desirable to use constructs that produce long-term effects in vivo, either by integration into host cell genomic DNA at high levels or by persistence of the transcription cassette in the nucleus of cells in vivo in stable, episomal form. Integration of the transcription cassette into genomic DNA of host cells in vivo may be facilitated by administering the transgene in a linearized form (either the coding region alone, or the coding region together with 5' and 3' regulatory sequences, but without any plasmid sequences present). Additionally, in some instances, it may be desirable to delete or inactivate a mutant CFTR gene and replace it with a coding sequence for a biologically functional CFTR molecule. The constructs for use in the invention include several forms, depending upon the intended use of the construct. Thus, the constructs include vectors, trancriptional cassettes, expression cassettes and plasmids. The transcriptional and translational initiation region (also sometimes referred to as a "promoter,"), preferably comprises a transcriptional initiation regulatory region and a translational initiation regulatory region of untranslated 5' sequences, "ribosome binding sites," responsible for binding mRNA to ribosomes and translational initiation. It is preferred that all of the transcriptional and translational functional elements of the initiation control region are derived from or obtainable from the same gene. Li some embodiments, the promoter will be modified by the addition of sequences, such as enhancers, or deletions of nonessential and/or undesired sequences. By "obtainable" is intended a promoter having a DNA sequence sufficiently similar to that of a native promoter to provide for the desired specificity of transcription of a DNA sequence of interest. It includes natural and synthetic sequences as well as sequences which may be a combination of synthetic and natural sequences. For the transcriptional initiation region, or promoter element, any region may be used with the proviso that it provides the desired level of transcription of the DNA sequence of interest. The transcriptional initiation region may be native to or homologous to the host cell, and/or to the DNA sequence to be transcribed, or foreign or heterologous to the host cell and/or the DNA sequence to be transcribed. By foreign to the host cell is intended that the transcriptional initiation region is not found in the host into which the construct comprising the transcriptional initiation region is to be inserted. By foreign to the DNA sequence is intended a transcriptional initiation region that is not normally associated with the DNA sequence of interest. Efficient promoter elements for transcription initiation include the S V40 (simian virus 40) early promoter, the RS V (Rous sarcoma virus) promoter, the Adenovirus major late promoter, and the human CMV (cytomegalovirus) immediate early 1 promoter. Inducible promoters also find use with the subject invention where it is desired to control the timing of transcription. Examples of promoters include those obtained from a 3-interferon gene, a heat shock gene, a metallothionein gene or those obtained from steroid hormone-responsive genes, including insect genes such as that encoding the ecdysone receptor. Such inducible promoters can be used to regulate transcription of the transgene by the use of external stimuli such as interferon or glucocorticoids. Since the arrangement of eukaryotic promoter elements is highly flexible, combinations of constitutive and inducible elements also can be used. Tandem arrays of two or more inducible promoter elements may increase the level of induction above baseline levels of transcription which can be achieved when compared to the level of induction above baseline which can be achieved with a single inducible element. Generally, the regulatory sequence comprises DNA up to about 1.5 Kb 5' of the transcriptional start of a gene, but can be significantly smaller. This regulatory sequence may be modified at the position corresponding to the first codon of the desired protein by site-directed mutagenesis (Kunkel TA, 1985, Proc. Natl. Acad. Sci. (USA), £2:488-492) or by introduction of a convenient linker oligonucleotide by ligation, if a suitable restriction site is found near the N-terminal codon. In the ideal embodiment, a coding sequence with a compatible restriction site may be ligated at the position corresponding to codon #1 of the gene. This substitution may be inserted in such a way that it completely replaces the native coding sequence and thus the substituted sequence is flanked at its 3' end by the gene terminator and polyadenylation signal. Transcriptional enhancer elements optionally may be included in the expression cassette. By transcriptional enhancer elements is intended DNA sequences which are primary regulators of transcriptional activity and which can act to increase transcription from a promoter element, and generally do not have to be in the 5' orientation with respect to the promoter in order to enhance transcriptional activity. The combination of promoter and enhancer element(s) used in a particular expression cassette can be selected by one skilled in the art to maximize specific effects. Different enhancer elements can be used to produce a desired level of transgene expression in a wide variety of tissue and cell types. For example, the human CMV immediate early promoter-enhancer element can be used to produce high level transgene expression in many different tissues in vivo. Examples of other enhancer elements which confer a high level of transcription on linked genes in a number of different cell types from many species include enhancers from SV40 and RSV-LTR. The SV40 and RSV-LTR are essentially constitutive. They may be combined with other enhancers which have specific effects, or the specific enhancers may be used alone. Thus, where specific control of transcription is desired, efficient enhancer elements that are active only in a tissue-, developmental-, or cell-specific fashion include immunoglobulin, interleukin-2 (IL-2) and β-globin enhancers are of interest. Tissue-, developmental-, or cell-specific enhancers can be used to obtain transgene expression in particular cell types, such as B-lymphocytes and T-lymphocytes, as well as myeloid, or erythroid progenitor cells. Alternatively, a tissue-specific promoter such as that derived from the human cystic fibrosis transmembrane conductance regulator (CFTR) gene can be fused to a very active, heterologous enhancer element, such as the SV40 enhancer, in order to confer both a high level of transcription and tissue-specific transgene transcription. In addition, the use of tissue-specific promoters, such as LCK, may allow targeting of transgene transcription to T lymphocytes. Tissue specific transcription of the transgene may be important, particularly in cases where the results of transcription of the transgene in tissues other than the target tissue would be deleterious. Tandem repeats of two or more enhancer elements or combinations of enhancer elements may significantly increase transgene expression when compared to the use of a single copy of an enhancer element; hence enhancer elements find use in the expression cassette. The use of two different enhancer elements from the same or different sources flanking or within a single promoter can in some cases produce transgene expression in each tissue in which each individual enhancer acting alone would have an effect, thereby increasing the number of tissues in which transcription is obtained. In other cases, the presence of two different enhancer elements results in silencing of the enhancer effects. Evaluation of particular combinations of enhancer elements for a particular desired effect or tissue of expression is within the level of skill in the art. Although generally it is not necessary to include an intron in the expression cassette, an intron comprising a 5' splice site (donor site) and a 3' splice site (acceptor site) separated by a sufficient intervening sequence to produce high level, extended in vivo expression of a transgene administered iv or ip can optionally be included. Generally, an intervening sequence of about lOObp produces the desired expression pattern and/or level, but the size of the sequence can be varied as needed to achieve a desired result. The optional intron placed 5' to the coding sequence results in high level extended in vivo expression of a transgene administered iv or ip but generally is not necessary to obtain expression. Cφti ally, the 5' intron specifically lacks cryptic splice sites which result in aberrantly spliced mRNA sequences. If used, the intron splice donor and splice acceptor sites, arranged from 5' to 3' respectively, are placed between the transcription initiation site and the translational start codon as diagrammed in (1), below. Consensus sequences for the 5' and 3' splice sites used in RNA splicing 5' exon intron 3' exon 1 I I C A U U ϋ ϋ ϋ ϋ U ϋ ϋ ϋ ϋ G (1) 5' A GH orA G U- or or or or or or or or or or or N or or- -3' A """""'" G ' c ' cccccccccc u A consensus sequence for consensus sequence for 3' splice site 5' splice site ("donor site") ("acceptor site") 1 The sequence given is that for the RNA chain; the nearly invariant GU and AG dinucleotides at either end of the intron are shaded. Alternatively, the intervening sequence may be placed 3' to the translational stop codon and the transcriptional terminator or inside the coding region. The intron can be a hybrid intron with an intervening sequence or an intron taken from a genomic coding sequence. An intron 3' to the coding region, a 5' intron which is of less than 100 bp, or an intron which contains cryptic splice sites may under certain condition substantially reduce the level of transgene expression produced in vivo. However, unexpectedly, a high level of in vivo expression of a transgene can be achieved using a vector that lacks an intron. Such vectors therefore are of particular interest for in vivo transfection. Downstream from and under control of the transcriptional initiation regulatory regions is a multiple cloning site for insertion of a nucleic acid sequence of interest which will provide for one or more alterations of host genotype and modulation of host phenotype. Conveniently, the multiple cloning site may be employed for a variety of nucleic acid sequences in an efficient manner. The nucleic acid sequence inserted in the cloning site may have any open reading frame encoding a polypeptide of interest, for example, an enzyme, with the proviso that where the coding sequence encodes a polypeptide of interest, it should lack cruptic splice sites which can block production of appropriate mRNA molecules and/or produce aberrantly spliced or abnormal mRNA molecules. The nucleic acid sequence may be DNA; it also may be a sequence complementary to a genomic sequence, where the genomic sequence may be one or more of an open reading frame, an intron, a non-coding leader sequence, or any other sequence where the complementary sequence will inhibit transcription, messenger RNA processing, for example splicing, or translation. The incidence of integration of the transcription cassette into genomic DNA may be increased by incorporating a purified retroviral enzyme, such as the HTV-1 integrase enzyme, into the lipid carrier-DNA complex. Appropriate flanking sequences are placed at the 5' and 3' ends of the nucleic acid. These flanking sequences have been shown to mediate integration of the fflV-l DNA into host cell genomic DNA in the presence of fflV- 1 integrase. Alternatively, the duration of the expression of the exogenous nucleic acid in vivo can be prolonged by the use of constructs that contain non-tι_msfo____ing sequences of a virus such as Epstein-Barr virus, and sequences such as oriP and EBNA-1 which appear to be sufficient to allow heterologous DNA to be replicated as an episome in mammalian cells (Buhans et al, Cell (1986) 52:955). The termination region which is employed primarily will be one of convenience, since termination regions appear to be relatively interchangeable. The termination region may be native to the intended nucleic acid sequence of interest, or may be derived from another source. Convenient termination regions are available and include the 3' end of a gene terminator and polyadenylation signal from the same gene from which the 5' regulatory region is obtained. Adenylation residues, preferably more than 32 and up to 200 or more as necessary may be included in order to stabilize the mRNA. Alternatively, a terminator and polyadenylation signal from different gene/genes may be employed with similar results. Specific sequences which regulate post-transcriptional mRNA stability may optionally be included. For example, certain polyA sequences (Volloch ςt od. Cell (1981) 23:509) and β- globin mRNA elements can increase mRNA stability, whereas certain AU-rich sequences in mRNA can decrease mRNA stability (Shyu et al. Genes and Devel. (1989) 3:60). In addition, AU regions in 3' non-coding regions may be used to destabilize mRNA if a short half-life mRNA is desirable for the gene of interest. Isolation of Genes and Construction of Vectors Nucleic acid sequences for use in the present invention, can be derived from known sources, for example by isolating the nucleic acid from cells containing the desired gene, using standard techniques. Similarly, the gene sequence can be generated synthetically, using standard modes of polynucleotide synthesis, well known in the art. See, e.g. Edge, M.D., Nature (1981) 292:756; Nambair, et al, Science (1984) 223:1299; Jay, Ernest, J Biol Chem (1984) 259:6311. Generally, synthetic oligonucleotides are prepared by either the phosphotriester method as described by Edge et al. , Nature (supra) and Duckworth et al., Nucleic Acids Res (1981)2:1691, or the phosphoramidite method as described by Beaucage, S.L., and Caruthers, M.H., Tet. Letts. (1981) 22:1859, and Matteucci, M.D., and Caruthers, M.H., J. Am. Chem. Soc. (1981) 102:3185, and can be prepared using commercially available automated oligonucleotide synthesizers. The gene sequence can be designed with the appropriate codons for the particular amino acid sequence. In general, one will select preferred codons for expression in the intended host. The complete sequence is assembled from overlapping oligonucleotides prepared by standard methods and assembled into a complete coding sequence. £__§, e.g.. Edge (1981) Nature 292:756; Nambair et al. , (1984) Science 2 1299; Jay et al. , (1984) J. Biol. Chem. 259:6311. Partial CFTR cDNA clones Til T16-1 T16-4.5 and Cl-1/5 (Riordan et al, Science (1989) 241:1066-1073) are available from the American Type Culture Collection (Roc land, Maryland). Full length isolated DNAs encoding CFTR protein and a variety of mutants thereof are disclosed in EP Application 91301819.8. Si also, Goodfellow, P., Nature (1989) 241:102-103; Rommens, et al., Science (1989) 245:1059-1054; Beardsley, et al. , Sci. Am. (1989) 26J.:28-30. It may be desirable to produce mutants or analogs of the proteins of interest. Mutants or analogs may be prepared by the deletion of a portion of the sequence encoding the protein, by insertion of a sequence, and/or by substitution of one or more nucleotides within the sequence. The mutation can be one that affects secretion of a normally secreted protein, so as to eliminate or decrease systemic side effects of the protein. Techniques for modifying nucleotide sequences, such as site-directed mutagenesis, are well known to those skilled in the art. See, e.g.. Sambrook et al. , infra; DNA Cloning, Vols. I and π, supra; Nucleic Acid Hybridization, infra. A particularly convenient method for obtaining nucleic acid for use in the lipid carrier-nucleic acid preparations, is by recombinant means. Thus, the CFTR gene can be excised from a plasmid carrying the desired gene, using standard restriction enzymes and procedures. Site specific DNA cleavage is performed by treating with the suitable restriction enzyme (or enzymes) under conditions which are generally understood in the art, and the particulars of which are specified by the manufacturer of these commercially available restriction enzymes. See, e.g., New England Biolabs, Product Catalog. If desired, size separation of the cleaved fragments may be performed by polyacrylamide gel or agarose gel electrophoresis using standard techniques. A general description of size separations is found in Methods in E zymology (1950) 65:499-560. Restriction cleaved fragments may be blunt ended by treating with the large fragment of E. coli DNA polymerase I (Klenow) in the presence of the four deoxynucleotide triphosphates (dNTPs) using standard techniques. The Klenow fragment fills in at 5' single- stranded overhangs but chews back protruding 3' single strands, even though the four dNTPs are present. If desired, selective repair can be performed by supplying only one of the, or selected, dNTPs within the limitations dictated by the nature of the overhang. After treatment with Klenow, the mixture can be extracted with e.g. phenol/chloroform, and ethanol precipitated. Treatment under appropriate conditions with SI nuclease or BAL-31 results in hydrolysis of any single-stranded portion. Once coding sequences for the desired proteins have been prepared or isolated, they can be cloned into any suitable vector or replicon. Numerous cloning vectors are known to those of skill in the art; the selection of an appropriate cloning vector is known to those of skill in the art, and the selection of an appropriate cloning vector is a matter of choice. Ligation to other sequences is performed using standard procedures, known in the art. For example, ligations can be accomplished in 20 mM Tris-Cl pH 7.5, 10 mM MgCl 2 , lOmM DTT, 33 μg/ml BSA, 10 mM-50 mM NaCl, and either 40 uM ATP, 0.01- 0.02 (Weiss) units T4 DNA ligase at 0°C (for "sticky end" ligation) or ImM ATP, 0.3-0.6 (Weiss) units T4 DNA ligase at 14° C (for "blunt end" ligation). Intermolecular "sticky end" ligations are usually performed at 30-100 μg/ml total DNA concentration (5-100 nM total end concentration). The nucleic sequence is placed under the control of a promoter, ribosome binding site and, optionally, an operator (collectively referred to herein as "control" elements), so that the coding sequence is transcribed into RNA in the host tissue transformed by the lipid carrier-nucleic acid. The coding sequence may or may not contain a signal peptide or leader sequence. A "promoter sequence" is a DNA regulatory region capable of binding RNA polymerase in a cell and initiating transcription of a downstream (3' direction) coding sequence. For purposes of defining the present invention, the promoter sequence is bound at the 3' terminus by the transcription start codon (ATG) of a coding sequence and extends upstream (5' direction) to include the minimum number of bases or elements necessary to initiate transcription at levels detectable above background. Within the promoter sequence is a transcription initiation site (conveniently defined by mapping with nuclease SI), as well as protein binding domains (consensus sequences) responsible for the binding of RNA polymerase. Nucleic acid "control sequences" or "regulatory regions" refer collectively to promoter sequences, ribosome binding sites, polyadenylation signals, transcription termination sequences, upstream regulatory domains, enhancers, and the like, which collectively provide for the transcription and translation of a coding sequence in a host cell. The choice of regulatory elements will depend on the host cell which is to be transformed and the type of nucleic acid preparation used. Thus, if the host cells' endogenous transcription and translation machinery will be used to express a CFTR • molecule, control elements functional in the particular host and which provide for expr ession are used. Several promoters for use in mammalian cells are known in the art and include, but are not limited to, a SV40 (Simian Virus 40) early promoter, a RSV (Rous Sarcoma Virus) promoter, an Adenovϊrus major late promoter, and a human CMV (Cytomegalovirus) immediate early one promoter. Other promoters which may be used include those derived from mouse mammary tumor virus (MMTV, T7, T3, and the like). Particularly useful in the present invention are the RSV promoter and the CMV promoter, particularly the immediate early promoter from the AD169 strain of CMV. In addition to the above sequences, it may be desirable to add to the nucleic acid construct regulatory sequences which allow for regulation of the expression of the CFTR molecule. Regulatory sequences are known to those of skill in the art, and examples include those which cause the expression of a gene to be turned on or off in response to a chemical or physical stimulus, including the presence of a regulatory compound. Such promoters can be used to regulate expression of the transgene by the use of external stimuli such as interferon or glucocorticoids. Other types of regulatory elements may also be present in the plasmid, for example, enhancer sequences. Such regulatory elements include those obtainable from β- interferon, heat shock, metallothionein or steroid hormone responsive genes, including insect genes such as the ecdysone receptor gene. Since the arrangement of eukaryotic promoter elements is highly flexible, combinations of constitutive and inducible elements can be used. Tandem arrays of two or more inducible promoter elements may increase the level of induction above baseline levels of transcription which can be achieved with a single inducible element. By transcription enhancer elements are intended DNA sequences which are primary regulators of transcriptional activity which can act to increase transcription from a promoter element, and generally do not have to be in the 5' orientation with respect to the promoter in order to enhance transcriptional activity. The combination of promoter and enhancer elements used in a particular nucleic acid construct can be selected by one skilled in the art to maximize specific effects; different enhancer elements can be used to produce a desired level of transcription. For example, a tissue specific promoter such as that derived from the human cystic fibrosis transmembrane conductance regulator (CFTR) gene can be used flanking a very active, heterologous enhancer element, such as the SV40 enhancer, in order to obtain both a high level of expression and expression of the nucleic acid primarily in lung. Tandem repeats of two or more enhancer elements or combinations of enhancer elements may significantly increase transcription when compared to the use of a single copy of an enhancer element. The use of two different enhancer elements from the same or different sources, flanking or within a single promoter may be used. Evaluation of particular combinations of enhancer elements for a particular desired effect or expression level is within the knowledge of one skilled in the art. Promoter-enhancer elements which are least partially derived from CMV Townes and or AD169 strains are of particular interest for providing a high level of expression of exogenous nucleic acid. The termination region which is employed primarily will be one of convenience, since termination regions appear to be relatively interchangeable. The termination region may be native to the CFTR gene, or may be derived from another source. Convenient termination regions are available and include the 3' end of a gene terminator and polyadenylation signal from the same gene from which the 5' regulatory region is obtained. Adenylation residues, preferably more than 32 kb and up to 200 kb or more if necessary may be included in order to stabilize the mRNA. Alternatively, terminator and polydenylation signals from a gene/genes other than the CFTR gene may be employed with similar results. Specific sequences which regulate post-transcriptional mRNA stability may optionally be included. For example, certain polyA sequences (Volloch et al., Cell (1981) 22:509) and 3-globin mRNA elements can increase mRNA stability, whereas certain AU-rich sequences in mRNA can decrease mRNA stability (Shyu et al, Genes and Development (1989) 2:60). i addition, AU regions in 3' non-coding regions may be used to destabilize mRNA if a short half life mRNA is desirable. A 3 '-intron should be avoided, particularly a SV40 3'-intron. If used, the 3'-intron should be greater than about 70 bp. The nucleic acid construct may include sequences for selection, such as a neomycin resistance gene, dihydrofolate reductase gene, and/or signal sequences to generate recombinant proteins that are targeted to different cellular compartment, more particularly to provide for secretion of the nucleic acid expression product. Any of a variety of signal sequences may be used which are well known to those skilled in the art, for example, a basic sequence of amino acids may be encoded which results in nucleic localization? of the protein. A transcription vector is constructed so that the particular coding sequence is located in the vector with the appropriate regulatory sequences, the positioning and orientation of the coding sequence with respect to the control sequences being such that the coding sequence is transcribed under the "control" of the control sequences. Modification of the sequences encoding the particular protein of interest may be desirable to achieve this end. For example, in some cases it may be necessary to modify the sequence so that it may be attached to the control sequences with the appropriate orientation; or to maintain the reading frame. The control sequences and other regulatory sequences may be ligated to the coding sequence prior to insertion into a vector. Alternatively, the coding sequence can be cloned directly into an expression vector which already contains the control sequences and an appropriate restriction site which is in reading frame with and under regulatory control of the control sequences. Preparation of Lipid carriers Lipid carriers for use in the instant invention include cationic (positively charged), anionic (negatively charged) and neutral preparations. However, cationic lipid carriers are particularly preferred because a tight charge complex can be formed between the cationic lipid carrier and the polyanionic nucleic acid. For example, this results in a lipid carrier-nucleic acid complex which will withstand both the forces of nebulization and the environment within the lung airways and be capable of transfecting lung cells after the aerosolized DNA:lipid carrier complex has been deposited in the lung. Cationic lipid carriers have been shown to mediate intracellular delivery of plasmid DNA (Feigner, et al , Proc. Natl. Acad. Sci. USA (1987) £4:7413-7416); mRNA (Malone, et al, Proc. Natl Acad. Sci. USA (1989) £6:6077-6081); and purified transcription factors (Debs, et al , J. Biol. Chem. (1990) 26^:10189-10192), in functional form. Particular cells within the lung and extrapulmonary organs may be targeted by modifying the lipid carriers to direct them to particular types of cells using site-directing molecules. Thus antibodies or ligands for particular receptors may be employed, to target a cell associated with a particular surface protein. A particular ligand or antibody may be conjugated to the lipid carrier in accordance with conventional ways, either by conjugating the site-directing molecule to a lipid for incorporation into the lipid bilayer or by providing for a linking group on a lipid present in the bilayer for linking to a functionality of the site- directing compound. Such techniques are well known to those skilled in the art. Precise intrapulmonary targeting also may be achieved by a) altering aerosol particle size to preferentially direct the aerosol to alveoli or proximal versus distal airways or (b) to covalently couple monoclonal antibodies to the lipid carrier surface, thereby targeting lung cells expressing the corresponding cell surface antigen. The various lipid carrier-nucleic acid complexes wherein the lipid carrier is a liposome are prepared using methods well known in the art. §&e, e.g.. Straubinger et al , in Methods of Immunology (1983), Vol. 101, pp. 512-527. By "lipid carrier-nucleic acid complex" is meant a nucleic acid sequence as described above, generally bound to the surface of a lipid carrier preparation, as discussed below. The lipid carrier preparation can also contain other substances, such as enzymes necessary for integration, transcription and translation, cofactors, etc. Furthermore, the lipid carrier-nucleic acid complex can include targeting agents to deliver the complex to particular cell or tissue types. Where it is desired to entrap the nucleic acid, MLVs containing nucleic acid can be prepared by depositing a thin firm of phospholipid on the walls of a glass tube and subsequently hydrating with a solution of the material to be encapsulated and vortexing. The nucleic acid material is added to a suspension of preformed MLVs or SLVs only after the lipid carriers have been prepared and then vortexed. When using lipid carriers containing cationic lipids, the dried lipid film is resuspended in an appropriate mixing solution such as sterile water or an isotonic buffer solution such as lOmM Tris/NaCl, or 5% dextrose in sterile water, sonicated, and then the preformed lipid carriers are mixed directly with the DNA. The lipid carrier and DNA form a very stable complex due to binding of the negatively charged DNA to the cationic lipid carriers. SUVs find use with small nucleic acid fragments as well as large regions of DNA (≥ 250 kfe). In preparing the lipid carrier-nucleic acid complex, care should be taken to exclude any compounds from the mixing solution which may promote the formation of aggregates of the lipid carrier-nucleic acid complexes. For aerosol administration, large particles generally will not be aerosolized by the nebulizer and even if aerosolized would be too large to penetrate beyond the large airways. Aggregation of the lipid carrier-nucleic acid complex is prevented by controlling the ratio of DNA to lipid carrier, m mizing the overall concentration of DNA:lipid carrier complex in solution, usually less than 5 mg DNA/8 ml solution, and the avoiding chelating agents as EDTA, and significant amounts of salt which tend to promote macroaggregation. The preferred excipient is water, dextrose water or another solution having low or no ionic strength. Further, the volume must be adjusted to the minimum for deposition in the lungs of the host mammal, but taking care not to make the solution too concentrated so that aggregates form. The choice of lipid carriers and the concentration of lipid carrier-nucleic acid complexes thus, involves a two step process. The first step is to identify lipid carriers and concentration of lipid carrier-nucleic acid complexes that do not aggregate when the components are combined or during the significant agitation of the mixture that occurs during the nebulization step. The second step is to identify among those that are identified as of interest at the first step (i.e. do not aggregate) those complexes that provide for a high level of transfection and expression of a gene of interest in target cells in the lung. The level of expression and the cell types in which expression of the recombinant gene is obtained may be determined at the mRNA level and/or at the level of polypeptide or protein Gene product may be quantitated by measuring its biological activity in tissues. For example, enzymatic activity can be measured by biological assay or by identifying the gene product in transfected cells by immunostaining techniques such as probing with an antibody which specifically recognizes the gene product or a reported gene product present in the expression cassette. As an example, a reporter gene CAT (which encodes chloramphenicol acetyl transferase) can be inserted in the expression cassette and used to evaluate each lipid carrier composition of interest. The DNA:lipid carrier complexes must be mixed in solutions which do not themselves induce aggregation of the DNA:lipid carrier complexes such as sterile water. The expression cassette (DNA) is mixed together with the lipid carriers to be tested in multiple different ratios, ranging as an example from 4:1 to 1:10 (micrograms DNA to nanomoles cationic lipid). The results provide information concerning which ratios result in aggregation of the DNA:lipid carrier complexes and are therefore not useful for use in vivo, and which complexes remain in a form suitable for aerosolization. The ratios which do not result in aggregation are tested in animal models to determine which of the DNA:lipid carrier ratios confer the highest level of transgene expression in vivo. For example, the optimal DNA:lipid carrier ratios for SUV for DOTMA/DOPE DDAB:Chol, are 1:1 or 1:2 and ethylphosphatidylcholine (E-PC and ethyl-dimyristylphosphatidylcholine (E-DMPC). Aerosol Administration The mammalian host may be any mammal having symptoms of a genetically- based disorder. Thus, the subject application finds use in domestic animals, feed stock, such as bovine, ovine, and porcine, as well as primates, particularly humans. In the method of the invention, transformation in vivo is obtained by introducing a non-integrating therapeutic plasmid into the mammalian host complexed to a lipid carrier, particularly a cationic lipid carrier more particularly, for human use or for repeated applications a biodegradable lipid carrier. For introduction into the mammalian host any physiologically acceptable medium may be employed for administering the DNA or lipid carriers, such as deionized water, 5% dextrose in water, and the like. Other components may be included in the formulation such as stabilizers, biocides, etc, providing that they meet the criteria outlined above, i.e. do not cause aggregation of the complexes. The various components listed above find extensive exemplification in the literature and need not be described in particular here. For aerosol delivery in humans or other primates, the aerosol is generated by a medical nebulizer system which delivers the aerosol through a mouthpiece, facemask, etc. from which the mammalian host can draw the aerosol into the lungs. Various nebulizers are known in the art and can be used in the method of the present invention. See, for example, BoiarsM, et al, U.S. Patent No. 4,268,460; Lehmbeck, et al., U.S. Patent No. 4,253,468; U.S. Patent No. 4,046,146; Havstad, et al., U.S. Patent No. 3,826,255; Knight, et al, U.S. Patent No. 4,649,911; Bordoni, et al., U.S. Patent No. 4,510,829. The selection of a nebulizer system depends on whether alveolar or airway delivery (i.e., trachea, primary, secondary or tertiary bronchi, etc.), is desired. A convenient way to insure effective deEvery of the nucleic acid to the alveoE is to select a nebulizer which produces sufficiently smaE particles for example, particles with a mean particle diameter of less than 5.0 microns (μm). More preferably the particles have a mean particle diameter of about 0.2 to about 4.0 μm, and most preferably the particles have mean diameter of about 0.2 to about 2 μm, since larger particles (≥ 5 μm) are generaEy deposited in the proximal airways or nasopharynx. As an alternative to selecting small mean particle diameters to achieve substantial alveoE deposition, a very high dosage of the Epid carrier-nucleic acid preparation can be administered, with a larger mean particle diameter. A proviso to such an approach is that the particular Epid carrier-nucleic acid complex is chosen that is not too irritating at the required dosage and that there be a sufficient number of particles in the total particle population having a diameter in the 0.5 to about 5 μm range to aUow for deposition in the alveoE. For proximal airway deEvery, the mean particle size wiE be larger. For example, suitable mean particle diameters wiE generaEy be less than about 15 μm, more preferably from about 4 μm, and most preferably from about 5 μm to about 10 μm. Examples of nebulizers useful for alveolar deEvery include the Acorn 1 ® nebulizer, and the Respirgard H Nebulizer System, both available commerciaEy from Marquest Medical Products, Inc., Inglewood, CO. Other commerciaEy available nebulizers ® for use with the instant invention include the UltraVent nebulizer available from MaEinckrodt, Inc. (Maryland Heights, MO); the Wright nebulizer (Wright, B.M., .Lancet (1958) 1:24-25); and the DeVEbiss nebulizer (Mercer et al. , Am. Ind. Hyg. Assoc. J. (1968) 29:66-78; T.T. Mercer, Chest (1981) £0:6 (Sup) 813-817). Nebulizers useful for airway deEvery include those typically used in the treatment of asthma. Such nebulizers are also commerciaEy available. One of skiE in the art can determine the usefulness of a particular nebulizer by measuring the mean par * '__.- size generated thereby with for example, a 7 stage Mercer cascade impactor (Intox Products, Albuquerque, NM). Concentrations of the Epid carrier-nucleic acid complex from the impactor plates can be determined by eluting the complex therefrom and assessing the optical density at an appropriate wavelength and comparing the standard curves. Results are generaEy expressed as mass median aerodynamic diameter +. geometric standard deviation (Raabe, J . Aerosol Sci. (1971) 2:289- 303). The amount of Epid carriers used wiE be an amount sufficient to provide for adequate transfection of ceEs after entry of the DNA or complexes into the lung and to provide for a therapeutic level of transcription and/or translation in transfected cells. A therapeutic level of transcription and/or translation is a sufficient amount to prevent, treat, or palliate a disease of the host mammal foEowing administration of the Epid carrier-nucleic acid complex to the host mammal's lung, particularly the alveoE or airway. Thus, an "effective amount" of the aerosolized Epid carrier-nucleic acid preparation, is a dose sufficient to effect treatment, that is, to cause aEeviation or reduction of symptoms, to inhibit the worsening of symptoms, to prevent the onset of symptoms, and the like. The dosages of the present compositions which constitute an effective amount can be determined in view of this disclosure by one of ordinary skiE in the art by running routine trials with appropriate controls. Comparison of the appropriate treatment groups to the controls wiE indicate whether a particular dosage is effective in preventing or reducing particular symptoms. Appropriate doses are discussed further below. While there is no direct method of measuring the actual amount of Epid carrier-nucleic acid complex deEvered to the alveoE, bronchoalveolar lavage (BAL) can be used to indirectly measure alveolar concentrations of any expressed and secreted protein, usuaEy 18-24 hrs after inhalation to allow clearance of the protein deposited in the larger airways and bronchi. The total amount of nucleic acid deEvered to a mammaEan host wiE depend upon many factors, including the total amount aerosolized, the type of nebulizer, the particle size, breathing patterns of the mammalian host, severity of lung disease, concentration and mean diameter of the Epid carrier-nucleic acid complex in the aerosolized solution, and length of inhalation therapy. Thus, the amount of expressed protein measured in the airways may be substantiaEy less than what would be expected to be expressed from the amount of nucleic acid present in the aerosol, since a large portion of the complex may be exhaled by the subject or trapped on the interior surfaces of the nebulizer apparatus. For example, approximately one third of the Epid carrier-nucleic acid dose that is placed into the nebulizer remains in the nebulizer and associated tubing after inhalation is completed. This is true regardless of the dose size, duration of inhalation, and type of nebulizer used. Moreover, resuspension of the residue and read-ministration does not significantly increase the dose deEvered to the subject; about one third remains in the nebulizer. AdditionaEy, efficiency of expression of the encoded protein wiE vary widely with the expression system used. Despite the interacting factors described above, one of ordinary skiE in the art wiE be able readEy to design effective protocols, particularly if the particle size of the aerosol is optimized. Based on estimates of nebulizer efficiency, an effective dose deEvered usuaEy Ees in the range of about 1 mg/treatment to about 500 mg/treatment, although more or less may be found to be effective depending on the subject and desired result. It is generaEy desirable to administer higher doses when treating more severe conditions. GeneraEy, the nucleic acid is not integrated into the host ceE genome, thus if necessary, the treatment can be repeated on an ad hoc basis depending upon the results achieved. If the treatment is repeated, the mammaEan host is monitored to ensure that there is no adverse immune response to the treatment. The frequency of treatments depends upon a number of factors, such as the amount of Epid carrier-nucleic acid complex aclministered per dose, as weE as the health and history of the subject. As used herein, with reference to dosages, "Epid carrier-nucleic acid aerosol" refers to the amount of Epid carrier-nucleic acid complex that is placed in the nebulizer and subjected to aerosolization. The "amount nebulized" or "amount aerosolized" of the complex means the amount that actuaEy leaves the apparatus as an aerosol, i.e., the amount placed into the apparatus less the amount retained in the reservoir and on the inner surfaces of the apparatus at the conclusion of a treatment session. To treat pulmonary infections such as bronchitis and pneumonia, it wiE usuaEy be necessary to administer at least one dose per day over a period of about 4 to about 21 consecutive days or longer. The treatment is usuaEy carried out on consecutive days because new areas of the lungs open up to penetration and deposition of the nucleic acid with increasing resolution of the infection. The success of the treatment can be monitored and the administration regimen altered by assessing conventional clinical criteria; e.g., clearing of radiographic infiltrate, improved arterial PO 2 (e.g., >70 mmHg), reduction in dyspnea, respiratory rate and/or fever. For the treatment of genetic disorders, such as cystic fibrosis, the Epid carrier-nucleic acid complex wiE be administered at regular intervals, from once a week to once every one to several months, in order to replace the normal CRTR protein in critical host airway ceEs, since these ceEs continue to turn over. It may also be possible to stably transfect the CFTR gene into appropriate lung stem ceEs, which would then provide a continuous source of normal airway ceEs without requiring Efelong treatment. Potential therapeutic effects of the gene product can be measured, by deterrnining the effects of gene expression on survival of transgenic host mammals in which the transgene is expressed. Production of significant amounts of a transgene product wiE substantiaEy prolong the survival and improve the quaEty of Efe of the afflicted host. Where expression of the polypeptide/protein or even the mRNA itself confers a changed biochemical phenotype upon the host, the presence of a new phenotype or absence of an old phenotype may be evaluated; for example, as a result of transformation of the host ceEs, there may be enhanced production of pre-existing desirable products formerly produced in insufficient quantities or there may be reduction or even suppression of an undesirable gene product using antisense, ribozyme or co-suppression technologies; in the case of reduction or suppression, a reduction or eEmination of the gene product may be determined. The potential toxicity of the treatment may be evaluated by behavioral manifestations, and where appropriate, by analysis of biopsy specimens. Thus, behavioral activity which evidences distress, such as changes in activity level, changes in eating and drinking patterns and the like, can be monitored, as weE as evidence of necrosis, edema or inflammation in biopsy specimens. The subject compositions can be provided for use in one or more procedures. Kits wiE usuaEy include the DNA either as naked DNA or complexed to Epid carriers. AdditionaEy, Epid carriers ma * , be provided in a separate container for complexing with the provided DNA. The DNA or the Epid carrier/DNA complexes may be present as concentrates which may be further diluted prior to use or they may be provided at the concentration of use, where the vials may include one or more dosages. Conveniently, single dosages may be provided in sterilized containers suitable for use with a nebulizer, so that the physician or veterinarian may employ the containers directly with a nebulizer, where the containers wiE have the desired amount and concentration of agents. Thus, the kit may have a pluraEty of containers containing the DNA or the DNA/Epid carrier complexes in appropriate proportional amounts, and optionaEy, appropriate diluent and mixing solutions. When the containers contain the formulation for direct use, usuaEy there wiE be no need for other reagents for use with the method. Systemic administration The recombinant coding-sequence flanked at its 5' end by the promoter and regulatory sequences and at its 3' end by a terminator and regulatory sequences may be introduced into a suitable cloning plasmid (e.g., pUC18, pSP72) for use in direct DNA uptake in host ceEs foEowing introduction of the expression plasmid alone into the host. The nucleic acid construct also may be complexed with a carrier such as Epid carriers, particularly cationic Epid carriers. lipid carriers can be prepared from a variety of cationic Epids, including DOTAP, DOTMA, DDAB, L-PE, and the Eke. lipid carriers containing a cationic Epid, such as (N(l-(2,3-dioleyloxy) propyl}-N,N,N-triethylammonium} chloride (DOTMA) also known as "Epofectin", dimethyl dioctadecyl ammonium bromide (DDAB), 1, 2-dioleoyloxy-3-(ti-_methyIammonio) propane (DOTAP) or lysinyl- phosφ ratidylethanolamine (L-PE) and a second Epid, such as distearoylphosphatidylethanolamine (DOPE) or cholesterol (Choi), are of particular interest. DOTMA synthesis is described in Feigner, et al., Proc. Nat. Acad. Sciences, (USA) (1987) 84:7413-7417. DOTAP synthesis is described in Stamatatos, et al., Biochemistry (1988) 27:3917. DOTMA:DOPE Epid carriers can be purchased from, for example, BRL. DOTAP:DOPE Epid carriers can be purchased from Boehringer ISfennheim. Cholesterol and DDAB are commerciaEy available from Sigma Corporation. DOPE is commerciaEy available from Avanti Polar Iipids. DDAB:DOPE can be purchased from Promega. Biodegradable cationic amphiphEes also have been shown to form stable complexes with polyanionic DNA. Cationic Eposomes have been shown to be capable of mediating high level ceEular expression of transgenes or mRNA by deEvering the nucleic acid into a wide variety of ceEs in culture. The use of specific cationic Epids can confer specific advantages for in vivo deEvery. For example, iv injection of DOTAP-containing Eposomes can target transgene expression primarily to the lung. Furthermore, DOTAP, E-DC, and E-DPMC, as weE as L-PE and CEBA, are fuEy metabolized or excreted by cells, whereas DOTMA cannot be fuEy metabolized by cells. Therefore, DOTAP, E-PC, E-DPMC, and L-PE, but not DOTMA, are suitable for repeated injection into mammalian hosts. AdditionaEy, complexing the cationic Epid with a second Epid, primarily either cholesterol or DOPE can maximize transgene expression in vivo. For example, mixing a steroid, such as cholesterol, instead of DOPE with DOTAP, E-DC, E-DPMC, DOTMA, or DDAB, substantiaEy increases transgene expression in vivo. Particular ceEs and tissues may be targeted, depending upon the route of administration and the site of administration. For example, transfection of a tissue which is closest to the site of injection in the direction of blood flow may be transfected in the absence of any specific targeting. Specific cationic Epid can target cationic Epid carriers to specific ceE types in vivo after systemic injection. AdditionaEy, if desired, the Epid carriers may be modified to direct the Epid carriers to particular types of ceEs using site-directing molecules. Thus antibodies or Egands for particular receptors may be employed, with a target ceE associated with a particular surface protein. For example, with the AIDS virus, the AIDS virus is primarily directed to ceEs having the CD4 surface protein. By having anti-CD4 antibody bound to the surface of the Epid carrier, the Epid carrier may be directed primarily to T-helper ceEs. A particular Egand or antibody may be conjugated to the Epid carrier in accordance with conventional ways, either by conjugating the site-directing molecule to a Epid for incorporation into the Epid bEayer or by providing for a linking group on a Epid present in the bEayer for linking to a functionaEty of the site-directing compound. Such techniques are weE known to those skilled in the art. Ligand-directed DNA-polycation complexes have been shown to transfect to hepatocytes in the Ever after iv injection; the abiEty to transfect other ceE types or tissue types by this approach has not been demonstrated. Non-cationic Epid carriers, particularly pH sensitive Eposomes, offer another potentiaEy attractive approach to in vivo gene therapy. However, as compared to cationic Eposomes, pH sensitive Eposomes are less efficient in capturing DNA and deEvering DNA intraceEularly and may be inactivated in the presence of serum, thus Emiting their iv use. Unexpectedly, either the Eposomal Epid composition or the mean diameter of the Epid carriers (when in particle form such as a Eposome) injected can dramaticaEy affect the level of transgene expression produced in vivo. Thus, the Eposomal Epid compositions generaEy have a composition of 50% molar ratio of cationic Epid to non-cationic Epid, but may range from 5% to 100%. The diameter of the Epid carriers should generaEy be within the range of 100 nm to 10 microns. Cationic Epid carrier-DNA complexes wherein the Epid carriers range from 100 nanometers to several microns in diameter can produce significant levels of transgene expression after systemic introduction into a mammalian host. The use of Epid carriers of greater than 500 nanometers (in other words multilamellar vesicles (MLV) or large unilamellar vesicles (LUV)) can in certain cases significantly increase the level of transgene expression achieved in a mammalian host when compared to small unilamellar vesicles (SUV). MLV and LUV are prepared by vortexing rather than sonicating after addition of the aqueous material to the dry Epid film. If desired, the resulting Epid earners can be extruded under high pressure through sized polycarbonate membranes to achieve more uniform size distributions. Also unexpectedly, the use of particular nucleic acid to Epid carrier ratio also is essential; the ratios used determine whether and to what level transgenes are expressed in vivo and needs to be optimized, depending upon various factors including the nature of the construct, the size and Epid composition of the Epid carrier and whether it is MLV or SUV, the route of administration and the host mammal. As an example, using a reporter gene CAT (chloramphenicol acetyl transferase), an approximately 1:1 (range 0.5:1 to 2:1) DNA to Epid carrier ratio (μg DNA to nmoles of the cationic Epid) produces the highest levels of gene expression in a mouse in aE organs after ip administration, and an approximately 1:4 ratio, (range 2:1 to 1:7) produces the highest levels of gene expression in aE organs after iv administration. In addition to achieving a high level of transgene expression in a wide variety of tissues using optimal conditions, the majority of aE ceEs present in the lung, spleen, lymph nodes and bone marrow are transfected in vivo, as weE as the majority of aE endothelial cells present in the heart. The DNA:Epid carrier ratio determines whether or not, and at what level, transgenes are expressed in mammalian hosts after systemic injection of the complexes. Several factors are important in order optimize the DNA:Epid carrier ratio. Thus, specific DNA:Eρid carrier ratios are required for each type of cationic Epid used as weE as for each different Epid carrier size used. To optimize, for each Epid carrier composition used, DNA must be mixed together with the Epid carriers in multiple different ratios, ranging from 4:1 to 1:10 (micrograms DNA to nanomoles cationic Epid), in order to determine which ratios result in aggregation of the DNA:Epid carrier complexes. Ratios which result in aggregation cannot be used in vivo. The ratios which do not result in aggregation are tested in animal models to determine which of the DNA:Epid carrier ratios confers the highest level of transgene expression in vivo. For example, the optimal DNA:Epid carrier ratios for SUV for DOTMA/DOPE, DDAB/DOPE, DOTAP/DOPE, DOTAP/Chol, LPE:CEBA, DDAB:Chol, L-PE-.DOPE, and E-PC/chol are 1:4, 1:3, (very low activity at aE ratios), 1:6, 1:1, 1:5, 2:1, and 2:1, respectively. DNA:Epid carrier complexes must be made in appropriate physiologic solutions. The DNA:Epid carrier complexes must be mixed in physiologic solutions (approximately 290 miEiosmoles) which do not themselves induce aggregation of the DNA:Epid carrier complexes. The solutions include 5% dextrose in water or normal saline. The construction of the vector itself is also critical for producing high level in vivo expression of the transgene after aerosol or systemic administration. OptimaEy, the vector either lacks an intron or contains an expanded 5" intron which does not result in aberrant spEcing. E addition, a strong promoter-enhancer element, such as the AD169 strain of HEMV or the addition of a strong heterologous enhancer from for example an SV.40 or HCMVEEI gene to a weak promoter, such as that from a CFTR gene confers high level in vivo expression of the transgene. Using appropriately constructed vectors, high level in vivo expression may be obtained after systemic injection of the vector alone, or more efficiently, when complexed to a cationic Epid carrier. Furthermore, use of the CFTR promoter together with a heterobgols enhancer can be used to produce significant transgene expression in a tissue and ceE-type specific fashion which approximates the endogenous pattern of FTR gene expression. CeE surface receptors for cationic Epid carriers can be used to both regulate and confer target ceE specificity on transgene expression in mammaEan hosts. Cationic Epid carrier:DNA complexes are internalized by ceEs by a classical receptor-mediated endocytosis (see Figure 7) using ceE surface receptors which contain specific binding sites for, and are able to internalize, cationic molecules. Using agents such as cytokines, growth factors, other soluble proteins and certain drugs, it is thus possible to selectively up or down regulate these cation-binding receptors. The rate of up or down regulation of these receptors by the appropriate agent wiE aEow selection of specific ceEs for enhanced or reduced levels of transfection in vivo. Furthermore, surprisingly ceE surface receptors for naked DNA can be used both to regulate and to confer target ceEs specificity on transgenic expression in mammaEan host. The most frequent interaction between DOTMA Epid carriers, either the uni- or multilamellar Epid carriers, complexed to plasmid DNA and the various ceE types (for example, CV-1 monkey kidney ceEs, U937 human myelomonocytic leukemia ceEs, K562, MEL (murine erythroblastic leukemia ceEs), rat alveolar macrophages, and alveolar type π ceEs), is that of Epid carrier adhesion and internalization. This interaction is common to weE-defined examples of receptor-mediated endocytosis. AE cells which appear to have contacted cationic Epid carrieπDNA complexes ingest the complexes after binding to the plasma membrane. AE these ceE types demonstrate the same classical receptor-mediated endocytic pathway of internalization. The mammalian host may be any mammal, particularly a mammal having symptoms of a geneticaEy-based disorder. Thus, the subject appEcation finds use in domestic animals, feed stock, such as bovine, ovine, and porcine, as weE as primates, particularly humans. The mammaEan host may be pregnant, and the intended recipient of the gene-based therapy may be either the gravid female or the fetus or both. In the method of the invention, transfection in vivo is obtained by introducing a therapeutic transcription or expression vector into the mammalian host, either as naked DNA or complexed to Epid carriers, particularly cationic Epid carriers. The constructs may provide for integration into the host ceE genome for stable maintenance of the transgene or for episomal expression of the transgene. The introduction into the mammalian host may be by any of several routes, including intravenous or intraperitoneal injection, intratracheaEy, mtrathecaEy, parenteraEy, intraarticularly, intramuscularly, etc. Of particular interest is the introduction of a therapeutic expression vector into a circulating bodEy fluid. Thus, iv administration and intrathecal administration are of particular interest since the vector may be widely disseminated foEowing such a route of administration. Any physiologicaEy acceptable medium may be employed for adnEnistering the DNA or Epid carriers, such as deionized water, saline, phosphate-buffered saline, 5% dextrose in water, and the like, depending upon the route of administration Other components may be included in the formulation such as buffers, stabilizers, biocides, etc. These components have found extensive exempEfication in the Eterature and need not be described in particular here. The amount of Epid carriers used wiE be sufficient to provide for adequate dissemination to a variety of tissues after entry of the DNA or complexes into the bloodstream and to provide for a therapeutic level of expression in transfected tissues. A therapeutic level of expression is a sufficient amount of expression to treat or palliate a disease of the host mammal. In addition, the dose of the plasmid DNA expression vector used must be sufficient to produce significant levels of transgene expression in multiple tissues in vivo for example, > lmg of an expression plasmid alone is injected into a mouse to achieve high level expression of the CAT gene in multiple tissues. Other DNA sequences, such as adenovirus VA genes can be included in the administration medium and be co-transfected with the gene of interest. The presence of genes coding for the adenovirus VA gene product may significantly enhance the translation of mRNA transcribed from the plasmid. The level and tissues of expression of the recombinant gene may be determined at the mRNA level and/or at the level of polypeptide or protein. Gene product may be quantitated by measuring its biological activity in tissues. For example, enzymatic activity can be measured by biological assay or by identifying the gene product in transfected ceEs by immunostaining techniques such as probing with an antibody which specificaEy recognizes the gene product or a reporter gene product present in the expression cassette. Alternatively, potential therapeutic effects of the gene product can measured, for example where the DNA sequence of interest encodes GM-CSF, by determining the effects of gene expression on survival of lethaEy irradiated animals in which the GM-CSF transgene is expressed. Production of significant amounts of a transgene product wiE substantiaEy prolong the survival of these mice. Where expression of the polypeptide/protein or even the mRNA itself confers a changed biochemical phenotype upon the host, the presence of a new phenotype or absence of an old phenotype may be evaluated; for example, as a result of transfection of the host ceEs, there may be enhanced production of pre-existing desirable products formerly produced in insufficient quantities or there may be reduction or even suppression of an undesirable gene product using antisense, ribozyme or co-suppression technologies; in the case of suppression, a reduction of the gene product may be determined. TypicaEy, the therapeutic cassette is not integrated into the host ceE genome. If necessary, the treatment can be repeated on an ad hoc basis depending upon the results achieved. If the treatment is repeated, the mammaEan host can be monitored to ensure that there is no adverse immune response to the treatment. The subject compositions can be provided for use in one or more procedures. Kits wiE usuaEy include the DNA either as naked DNA or complexed to Epid carriers. AdditionaEy, Epid carriers may be provided in a separate container for complexing with the provided DNA. The DNA either for direct injection or for complexing with Epid carriers, or the Epid carrier/DNA complexes may be present as concentrates which may be further dEuted prior to use or they may be provided at the concentration of use, where the vials may include one or more dosages. Conveniently, single dosages may be provided in syringes, contained in sterilized containers, so that the physicians or veterinarian may employ the syringes directly, where the syringes wiE have the desired amount and concentration of agents. Thus, the kit may have a pluraEty of syringes containing the DNA or the DNA/Epi carrier complexes in appropriate proportional amounts. When the syringes contain the formulation for direct use, usuaEy there wiE be no need for other reagents for use with the method. The invention finds use in in vivo treatment and/or palliation of a number of diseases. In vivo replacement of a gene can be accompEshed by techniques such as homologous recombination or initial knockout of the aberrant gene and subsequent replacement with the desired transgene. Uses Uses of the subject invention include but are not limited to the foEowing. The present invention is particularly useful for the deEvery of substances into the lung and appropriate extrapulmonary tissues for the prevention and or treatment of the multi-organ system manifestations of CF. SpecificaEy, it is useful for the prevention, treatment, and cure of the disease manifestations of CF in tissues, including the lung, Ever, pancreas, and colon. For the treatment of cystic fibrosis a functional CFTR gene, or a nucleic acid sequence encoding a molecule having wEd-type CFTR activity is administered. The gene can be administered prophylacticaEy, as weE as in response to clinical manifestations of the disease, for both the prevention and/or treatment of this disorder. The invention also finds use for the deEvery of substances into the systematic circulation via the lung. The amount of CFTR produced can be controlled by modifying the dose administered, the frequency and duration of dosing, the strength of the promoter and enhancer elements used to direct transcription of the transgenes and the efficiency and target specificity of the Epid carrier user. The instant methods also find use in antisense therapy, for the deEvery of oEgonucleotides able to hybridize to specific complementary sequences of a defective or mutant CFTR gene, thereby inhibiting the transcription and/or translation of these sequences. Thus, DNA or RNA coding for proteins necessary for the progress of a particular disease, can be targeted, thereby disrupting the disease process. For a review of antisense therapy and oEgonucleotides useful in the same, £«ϊ, Uhlmann, E. and Peyman, A., Chem. Rev. (1990) 911:543-584. The foEowing examples are provided for illustrative purposes only and are no intended to Emit the scope of the present invention. EXAMPLES The practice of the present invention employs unless otherwise indicated, conventional techniques of ceE culture, molecular biology, microbiology, recombinant DNA, and immunology, which are within the skEl of the art. Such techniques are explained fully in the Eterature. See, e.g.. Sambrook, et al. , Molecular Cloning: A Laboratory Manual, Second Edition (1989) Vols. 1-3; DNA Cloning (1985) Vols. I and H, D.N. Glover (ed.); Nucleic Acid Hybridization (1984), B.D. Hames, et al , (eds.); Perbal, B., A Practical Guide to Molecular Cloning (1984); Methods in Enzymology (the series), Academic Press, Inc.; Vectors: A Survey of Molecular Cloning Vectors and Their Uses (1987), R.L. Rodriguez, et al, (eds.), Butterworths; and M ler, J.H., et al., Experiments in Molecular Genetics (1972) Cold Spring Harbor Laboratory. We have not modified the INTOX chamber. Up to 48 mice can be exposed simultaneously to an aerosol dose. Approximately 0.02% of the total volume of DNA:Eposome complex solution placed in the nebulizer is actually deposited in the lungs of each individual mouse. Example 1 Preparation of Plasmids for in vivo Gene Therapy Details regarding the plasmids that have been used for transfection of mammaEan ceEs are as foEows. pRSVCAT: construction of this plasmid is described in Gorman et al, Proc. Nat. Acad. Sciences (USA) (1982), 79:6777-6781. In the pRSVCAT plasmid, the 3'-RSVLTR is juxtaposed as a promoter upstream from CAT encoding sequences. The distance between the LTR transcriptional start site and the CAT initiation codon (the first AUG downstream from the start site) is about 70 bp. p5'PRL3-CAT: construction of this plasmid is described in Sakai et al. , Genes and Development (1988) 2: 1144-1154. pSIS-CAT: construction of this plasmid is described in Huang and Gorman, Nucleic Acids Research (1990) l£:937-948. pZN20: construction of this plasmid is Elustrated in Figure 3. The plasmid was prepared as foEows. pCATwt760 (Stinski and Roehr (1985) /. Virol 55:431-441) was treated with Hinά and the fragment containing the HCMV base IE 1 enhancer and promoter element purified. The isolated fragment was then cloned into the HinάJR site of pSP72 (Promega) creating pZN9. Clones were screened in which the enhancer and promoter element is as shown in Figure 3. FoEowing partial flrπdlll digestion of pZN9, the blunt ends were fiEed in with DNA polymerase I Klenow fragment. The resulting clone pZN12 has lost the fl dm site 5' to the enhancer and promoter element. pZN12 was then treated with Ncø 1 and _St7jdIII and the large Ncol-HinSSL fragment purified and Egated to a purified smaE Ncol-HinάHL fragment from pBC12/CMV/IL-2 (CuEen, Cell (1986) 46:973- 982. pBC12/CMV IL-2 contains the HCMV promoter from the AD169 strain. The resulting clone was pZΝ13. pZN13 was partiaEy digested with IfømHl, fiEed in with DNA polymerase I Klenow fragment and the resulting clones screened for the clone which has lost the BamΞ site at the 5' end of the enhancer and promoter element. The resulting clone was caEed pZN17. pZN17 was treated with HindUL and BamSL and the resulting HindUl- BamΗL large fragment was purified and Egated to a purified smaE HindUL -BamHI fragment obtained from pSV2-CAT (Gorman et al. (1982), Molecular Cell Biology, 2:1044-1051). The resulting clone was pZN20. The fuE restriction map of HCMV (Towne) is shown in Figure 19A. HCMV (AD169) is shown in Figure 19C. A comparison of the two promoters is shown in Figure 6B. Significantly more expression is obtained when a promoter from the AD 169 strain is used as compared to one from the Towne strain. p2__T20 contains a composite promoter which has the Towne sequence 5' of the Ncol site and the AD169 sequence 3' of the Ncol site. The Ncol site is indicated by the asterisk in Figure 19B. pZN20 has this composite HCMV promoter foEowed by the CAT gene, SV40 t-intron and SV40 polyA addition site. pZN27: Construction of this plasmid is illustrated in Figure 7. pZN27 contains the composite HCMV promoter foEowed in order by the SV40 t-intron, the CAT coding ' sequence and the SV40 polyA addition site. pZN46: Construction of this plasmid is shown in Figure 27A and Figure 27B. pZN46 contains the composite HCMV promoter, foEowed by the human IL-2 gene, rat preproinsulin 2 intron and polyA addition site from the rat preproinsuEn 2 gene. These last three components were derived from pBC12/CMV/IL-2 plasmid of CuEen (CeE 46:973-982 (1986). The rat preproinsuliiώ intron was modified by deleting an internal 162 base pair Ndel fragment. pZN32: Construction of this plasmid is shown in Figure 10. pZN32 contains the composite HCMV promoter foEowed in order by the modified rat preproinsuEn2 intron described for pZN46, CFTR cDNA, and rat preproinsulin2 gene polyA addition site as described for pZN46. CFTR cDNA was obtained from ρBQ4.7 from F. ColEns (Univ. of Michigan). pZN51: Construction of this plasmid is shown in Figure 11. pZN51 contains the composite HCMV promoter foEowed by the CAT coding sequence and the SV40 polyA site. pZN60 r pZN61. pZN62. pZN63: Construction of these plasmids is shown in Figure 19. pZN60 contains the HCMV composite promoter foEowed by the modified rat preproinsulin 2 intron, the CAT coding sequence, and the SV40 polyA addition site. pZN61 is identical to pZN60 but contains an additional 166 base pairs 5' to the intron. This additional DNA is the 166 BP immediately 5' of the intron in the pBC12/CMV/IL-2 plasmid and may contain rat preproinsuEn 2 gene coding sequence. pZN62 is simEar to pZN60 except that the intron is 3' of the CAT coding sequence rather than 5' as in pZN60. pZN63 is identical to pZN62 except for the additional 166 base pairs 5' to the intron. This is the same additional sequence described for pZN61. Example 2 Expression of chloramphenicol acetyltransferase (CAT) gene, in rodent lungs foEowing aerosolized deEvery of Epid carrier-nucleic acid complexes. The Epid carriers used were plasmid pRSV-CAT, as described by Gorman, et al, Proc. Natl. Acad. Sci. USA (1982) 7^:6777-6781; and Juang, and Gorman, Mol. Cell. Biol. (1990) 10:1805-1810; a plasmid containing the CAT gene driven by the RSV long terminal repeat; and plasmid pRSV-j8-gal, as described by Hazinski et al. , Am. J. Respir. Cell Mol Biol. (1991) 4:206-209. The pRSV-CAT plasmid was complexed to Epid carriers and administered to 25 gram female BALB/c mice as foEows. Two mg of pRSV-CAT was mixed with 4 μmoles of DOTMA (GIBCO BRL, Grand Island, NY)/cholesterol (2:1) smaE unilameEar Eposomes in phosphate buffered saline and then nebulized in an Acorn I nebulizer (Marquest Medical Products, Inc., Inglewood, CO) to groups of rats or mice in an Intox nose-only exposure chamber (Intox Products, Albuquerque, NM). The same procedure was foEowed with 0.5 mg pRSV-CAT mixed with 1.0 μmol DOTMA-cholesterol (2:1), as weE as 2.0 mg pRSV¬ CAT alone. Two to five days later, animals were sacrificed and lungs coEected. Lungs were also coEected from untreated controls. The lungs were homogenized and ceEs disrupted with three freeze-thaw cycles. CAT activity in aEquots from the lung extracts was measured using a standard assay as described by Wolff, et al, Science (1990) 247:1465- 1468. Results As can be seen in Figure 20, animals administered 2.0 mg RSV-CAT with 4.0 μmol DOTMA/cholesterol (2:1) expressed the CAT protein whEe the control animals, as weE as animals receiving RSV-CAT DNA abre and animals receiving a lower dose of RSV-CAT- DOTMA:chol complexes did not. A similar procedure was foEowed with respect to pRSV- /_ -gal, with the exception that 50 mg of pRSV-/S-gal was mixed with 50 μmoles of DOTMA/cholesterol (2:1). The presence of /S-gal activity was determined using a standard histochemical staining procedure, β-gal activity was present in the airway epitheEal ceEs of exposed rats. Also tested was a plasmid containing the CAT gene driven by the CMV promoter. This plasmid was made as described in Huang, M.T.F. and Gorman, CM. Nuc. Acids Res. (1990) l£:937-947, with the exception that a CMV promoter and a hybrid intron sequence were used rather than the SV40 promoter in the plasmid pML.LCAT, described therein. Briefly, the CAT Epid carrier was constructed by first making a pML-based plasmid containing the CMV promoter immediately foEowed by a portion of the 5'- untranslated leader from the adenovirus-major late (AML) region. This region contained aE but the first 13 nucleotides of the first exon of the tripartite leader plus a portion of an intervening sequence (IVS) from the AML region. A synthetic oEgonucleotide was inserted which merged with the adeno virus intron to provide a functional spEce acceptor sequence derived from an IgG variable region. BothweE, et al. , Cell (1981) 24:625-637. This plasmid was then cut at two restriction sites bordering the intron fClal and Psfl) to remove a 292 bp fragment. A matching synthetic oEgonucleotide linker was inserted. The plasmid was termed pCIS-CAT. To test for expression of the CAT gene using pCIS-CAT, 12 mg pCIS-CAT was mixed with 24 μmoles of DOTMA DOPE (1: 1). Female ICR mice were placed in three different aerosol receiving chambers. AE mice received the same amount of the CAT expression plasmid complexed to Eposomes, as described above. Animals 1-3 were exposed to the aerosol in an Intox designed aerosol chamber. Animals 4-7 were exposed to the aerosol in a modified rat cage containing dividers for individual mice. Animals 8-10 were placed in a smaEer, similarly modified mouse cage after being put in the restrainers used in the Intox chamber. 48 hours foEowing aerosolization, the animals were sacrificed and whole lungs assayed for CAT expression using the chromatographic CAT assay. As can be seen in Figure 21, a single aerosol dose of a CAT gene-expression plasmid complexed to cationic Eposomes can produce high-level transgene expression in the lungs of mice. Significant levels of transgene expression are present in the lungs of aE 7 mice (numbers 1-3 and 8-10) which were exposed to the aerosol mist in Intox nose-only exposure tubes which were constructed to maximize the amount of aerosol that the mice inhaled. The amount of variation seen here is comparable to that seen in other aerosol experiments and may have several explanations, including variations in exposure to the aerosol mist, individual variations in efficiency of nasal filtration, etc. Example 2 Preparation of Lipid carriers and DNA Complexing with Lipid carriers Lipid carriers containing a cationic Epid, such as {N(l-2-3-dioleyloxy) propyl}-N,N,N-triethylammonium} (DOTMA), dimethyl dioctadecyl ammonium bromide (DDAB), or l,2-dioleoyloxy-3-(trimethylammonio)propane (DOTAP) or lysinyl-phosphatidylethanolamine and a second Epid, such as dioylphosphatidylethanolamine (DOPE) or cholesterol, were prepared as foEows. Preparation of Epid carriers: Lipids, e.g. DDAB, L-lysinyl-phosphatidylethanolamine (L-PE), E-PC, E-DMPC, cholesterol-ester-3-alanine (CEBA), DOTAP, and cholesterol (Choi) were dissolved in chloroform. Proper amounts of each Epid (determined by the desired molar ratio of each Epid in the final Epid carrier formulation usuaEy 1 to 1 moles cationic Epid to moles non- cationic Epid but ranging from 5 to 1 to 1 to 5) were mixed together and evaporated to dryness on a rotary evaporator. The Epid film was then resuspended by vortexing after the addition of 5% dextrose in water or Epid carrier buffer (25 mM Tris-HCl pH7.4, 100 μM ZnCl 2 isotonic solution) to make a final Epid concentration of 20mM of multi-lamellar vesicles (MLV). For the preparation of smaE unilamellav vesicles (SUV), the mixture was then sonicated in a bath sonicator for 15 min, and the Epid carriers were stored under argon at 4°C until use. Plasmid Preparation: The E. coli strain which carries the plasmid was grown in TB at 37°C. The method of plasmid purification is a modification of the protocol of "lysis by alkaE" and "purification of plasmid DNA by precipitation with polyethylene glycol" described by Sambrook, et al. (Molecular Cloning, 2nd edition, 1989, Cold Spring Harbor Laboratory Press). The modification is that the precipitation of DNA by PEG is omitted. The final DNA preparation is dissolved in lOmM Tris-HCl pH8.0. Preparation of Epid carrier-plasmid complexes: Plasmids were dEuted separately in 5% dextrose in water solution to the desired concentration (usuaEy 1 μg/μl). The Epid carriers were also dEuted in 5% dextrose in water to the same volume as the plasmid. The amounts of Epid carriers used were determined based on the ratio of moles of Eposomal Epid to μg of plasmid added, e.g. for Epid ca__rier:plasmid=l:l, one nanomole of cationic Epid is mixed with 1 μg of plasmid DNA. Plasmid and Epid carriers were then mixed together to form DNA:Epid carrier complexes. Dose injected. At least 50 μg, and routinely 100 μg of plasmid DNA complexed to cationic Epid carriers is injected per mouse. For injection of plasmid alone, at least 500 μg and routinely 2 mg of plasmid DNA is injected by taE vein per mouse. Example 3 Demonstration by Immunohistochemistry of CAT Gene Expression in the Lung After Intravenous (iv. injection of pZN27-DDAB: Cholesterol lipid carrier Complexes Lipid carrier: DDAB:Chol=l:l τ stock 20 mM in Epid carrier buffer. Plasmid: ρZN27. DNA.Lipid carrier Ratio: Epid carrier:plasmid=5 nanomoles cationic Epid:l μg DNA DNA dose: 100 μg plasmid DNA in 200 μl 5% dextrose in water was injected iv by taE vein per mouse. Mice: ICR, female, 25 grams. Immunohistochemical staining to detect CAT protein in lung sections of mice treated in vivo. Procedure: Forty eight hours after injection of the pZN27-DDAB:Chol complexes, tl lungs are removed, perfused with 33% O.C.T., embedded in O.C.T. and snap frozen. Frozen tissues are sectioned at 6 microns, coEected onto glass sEdes, fteed for 10 minutes in 4°C acetone and then placed in 0.2% Triton X- 100 to permeabilize membranes. Sections are then incubated for 12-48 hours with the monoclonal anti-CAT antibody (avaEable from Dr. Parker Antin, Univ. of Arizona) or isotype negative control antibody at the appropriate dEution. After washing, 1) a biotinylated antibody directed against the primary antibody (Zymed, S. San Francisco) is added for a minimum of 60 minutes, 2) foEowed by appEcation of the streptavidin-alkaline phosphatase complex (Zymed) for 60 minutes and 3) appEcation of the substrate- chromogen appropriate for the enzyme label per manufacturers instructions. SEdes are then coversEpped in water-soluble mounting media for examination. Results: The results are shown in Fig. 2A, 2B and demonstrate diffuse staining of the lung. The stain localizes to the alveolar waEs, indication that greater than 70% of pulmonary vascular endothelial ceEs, as weE as alveolar lining ceEs, including type I and type II ceEs and alveolar macrophages are transfected by a single iv injection of DNA Epid carrier complexes. In addition, significant numbers of bronchiolar airway lining ceEs stain positively for CAT protein, and are therefore transfected in vivo by iv injection of Epid carrieπDNA complexes. Thus, the great majority of aE ceEs in the lung transfected by a iv injection of pZN27-DDAB:CHOL complexes. Example 4 Expression of pZN20 FoEowing Eitraperitoneal Administration Effect of the Amount of pZN20-cationic Epid carrier complexes injected ip on the level of CAT gene expression in vivo. Female ICR mice (Simonson Labs, Gilroy, CA) were injected ip with 1 ml of 5% dextrose in water containing 0.01, 0.1 or 1 mg of pZN20 expression plasmid complexed to 0.01, 0.1 or 1 μmoles, respectively of DDAB.DOPE Epid carriers. Mice were sacrificed 48 hours later, the organs removed, and tissues were homogenized in 0.25M Tris-HCL buffer pH 7.8, using a hand-held homogenizer. Cytoplasmic extracts were made, normalized by protein content and level of CAT protein was then measured. The experiments comprise three animals per group and the results show the mean dpm ± SEM of acetylated chloramphenicol. Methods: Lipid carriers containing DDAB were prepared in 1:1 molar ratio with DOPE, as foEows: 10 μmoles of DOPE dissolved in chloroform and 10 μmoles of the cationic Epid, dissolved in ethanol wer evaporated to dryness on a rotary evaporator. One ml sterile of water was added, and the mixture was sonicated in a bath sonicator (Laboratory Supply, HicksviEe, NY) for 20 min. lipid carriers had mean diameters of approximately 100 ±25 nm. For CAT assay, ceE extracts were made, and their protein content determined by the Coomasie blue assay (BioRad, Richmond, CA). One hundred μg of protein from the lung, spleen, Ever, and heart extracts, and 50 μg of lymph node extract were reacted with 14 C labeled chloramphenicol and chromatographed as previously described (Gorman, supra). To calculate dpm, both the acetylated and unacetylated species were cut from TLC plates and radioactivity counted in a scintillation coτmter. The ratio between acetylated and unacetylated counts was used to calculate the mean dpm. The mean dpm from tissues of untreated control animals were subtracted from each treated animal for each tissue. Results: To assess potential dose-response relationships in vivo, animals were injected animals in groups of three with 0.01 mg, 0.1 mg, or 1 mg of pZN20 plasmid complexed to 0.01 μmole, 0.1 μmole, or 1 μmole respectively of DDAB:DOPE Epid carriers. Both the 0.1 mg and 1 mg DNA doses produced highly significant levels of CAT protein (p < 0.005) in aE the organs assayed. Maximal levels of CAT gene expression in each organ were produced by the 1 mg DNA dose: increasing the DNA-Epid carrier dose 10 fold resulted in an approximately 2 fold increase in lymph node CAT levels and a 3 fold increase the spleen. Intraperitoneal injection of 1 mg of the pZN20 plasmid alone did not produce detectable CAT protein above background levels. Example 5 Demonstration of CAT gene expression in the spleen after intravenous (iv) injection of p5'PRL3-CAT:T.-PF--CF_BA complexes. Lipid carrier: L-PE:CEBA=1:1, stock 20 mM in Epid carrier buffer. Plasmid: p5'PRL3-CAT. DNA:Lipid carrier Ration: Epid carrier:plasmid=l nanomole cationic Epid: 1 μg plasmid DNA. DNA dose: 200 μg plasmid DNA in 200 μl 5% dextrose in water was injected by taE vein per mouse. Mice: BalB/c, female, 25 grams. Tissue extraction procedure: Forty eight hours after taE vein injection, mice were sacrificed, whole spleen was homogenized in 1ml of 0.25M Tris-HCl pH 7.8, 5mM EDTA, 80 μg/ml PMSF and the resulting extract was centrifuged and then the supernatant was subjected to 3 cycles of freeze-thaw and then heated to 65 °C for 20 min. CAT assay procedure: 100 μl of extract-. 10 μl of 20 mM acetyl CoA+4 μl of 14 C- chloramphenicol (25 μCi ml, 55 mCi/mmole, Amersham) were incubated together at 37°C for 6 hr. At 3 hours, an additional 10 μl of acetyl CoA was added. Results: The results are lane 2 (Epid carriers only) and lane 5 (Epid carrier-DNA complex), and indicate that a significant level of CAT activity is present in the spleen extract of the treated animal, but not in the extract of control spleen, taken from an animal injected with Epid carrier alone. Demonstration of CAT gene expression in the lung after intravenous (iv) injection of pRSV- CAT:L-PE:CEBA complexes. Lipid carrier: L-PE: CEBA= 1:1, stock 20 mM in Epid carrier buffer. Plasmid: pRSV-CAT. DNA:Lipid carrier Ratio: Epid carrier:plasmid=l nanomole cationic Epid: 1 μg plasmid DNA. DNA dose: 100 μg plasmid DNA in 200 μl 5% dextrose in water was injected by taE vein per mouse. Mice: BalB/c, female, 25 grams. Tissue extraction procedure: Forty eight hours after taE vein injection, the animals were sacrificed, whole lung was homogenized in 1ml of 0.25M Tris-HCl pH 7.8, 5mM EDTA, 80 μg/ml PMSF and the resulting extract was centrifuged and then the supernatant was subjected to 3 cycles of freeze-thaw and then heated to 65°C for 20 min.. CAT assay procedure: 100 μl of extract-. 10 μl of 20 mM acetyl CoA+ 4 μl of 14 C- chloramphenicol (25 μCi ml, 55 mCi/mmole, Amersham) were incubated together at 37°C for 6 hr. At 3 hours, an additional 10 μl of acetyl CoA was added. Results: The results are shown in Figure 9, and indicate that a significant level of CAT activity (indicative of expression of the transgene) was present in the lung of the animal injected with Epid carrieπDNA complexes (lane 5), but not present in the lungs from control animals (lanes 1-4). Demonstration of CAT gene expression in multiple tissues after intravenous (iv) injection of pZN20:DDAB:DOPE complexes. Lipid carrier: - DDAB:DOPE=l:l, stock lOmM in 5% dextrose. Plasmid: pZN20. DNA:Lipid carrier Ratio: Epid carrier:plasmid=(A) 3 nanomole cationic Epid:l μg plasmid DNA (SUV);(B) 6 nanomole cationic Epid:l μg plasmid DNA (MLV). DNA dose: 100 μg plasmid DNA in 200 μl 5% dextrose in water was injected by taE vein per mouse. Three mice each received this dose of MLV:pZN20 and 3 mice each this dose of SUV:pZN20. Tissue extraction procedure: Each organ was homogenized in 0.3 ml of 0.25 M Tris-HCl pH 7.8, 5 mM EDTA, and the resulting extract was centrifuged and then the supernatant was subjected to 3 cycles of freeze-thaw and then heated to 65°C for 20 min.. CAT assay procedure: The protein concentration of each tissue extract was quantitated using a Coomasie blue-based protein assay (Bio-Rad, Richmond, CA), and the same amount of total protein from each tissue extract was added in the CAT assay, together with 10 μl of 20 mM acetyl CoA+12μl of 14 C-chloramρhenicol (25 μCi ml, 55 mCi mmole, Amersham), at 37°C for 13 hrs. Results: The results are shown in Figure 5, and demonstrate that iv injection of pZN20:DDAB:DOPE complexes significant levels of CAT gene expression in each of 6 different tissues including lung, heart, Ever, spleen, kidney and lymph nodes. Furthermore, MLV Epid carriers mediate equal or higher levels of in vivo transgene expression than do SUV Epid carriers composed of the same Epids. Demonstration of CAT gene expression in vivo after intravenous (iv. injection of pZN20 alone. Plasmid: pZN20. DNA:Lipid carrier Ratio: Plasmid DNA alone, without Epid carriers, was injected. DNA dose: 300 μg plasmid DNA in 200 μl 5% dextrose in water was injected by taE vein per mouse. Mice: ICR, female, 25 grams. Tissue extraction procedure: each organ was homogenized in 0.3 ml of 0.25 M Tris HCl pH 7.8, 5 mM EDTA, and the resulting extract was centrifuged and then subjected to 3 cycles of freeze-thaw and then heated to 65 °C for 20 min. CAT assay procedure: the protein concentration of each tissue extract was quantitated using a ninhydrin-based protein assay (Bio-Rad, Richmond, CA), and same amount of total protein from each tissue extract was added in the CAT assay, together with 10 μl of 20 mM acetyl CoA+12 μl of 1 C-chloramphenicol (25 μCi ml, 55 mCi/mmole, Amersham) at 37°C for 13 hrs. Example 6 Injection of DOTMA:DOPE+pSIS-CAT Plasmid Clearly Did Not Produce Detectable CAT Gene Expression in vivo) Lipid carrier: DOTMA:DOPE=l:l, in 5% dextrose in water Plasmid: pSIS-CAT (Huang, M. T. F. and C. M. Gorman, 1990, Nucleic Acids Research 18:937-947). Ratio: Cationic Epid:plasmid=4 nmoles: 1 μg, dose: 100 μg DNA in 200 μl 5% dextrose in water. Mouse: ICR, female, 25 grams. Injection: taE vein. Tissue coEection and processing: Mice were sacrificed at day 2 and day 6, and lung, spleen, Ever, and heart were coEected. The whole organs were homogenized in 0.5 ml, except Evers which were homogenized in 2.0 ml, of 0.25M Tris-HCl pH 7.8, 5 mM EDTA, 2 μg/ml aprotintin, 1 μg ml E-64, and 0.5 μg/ml leupeptin (aE protease inhibitors were purchased from Boehringer Mannheim). Extracts were subjected to three cycles of freeze-thaw, then heated to 65°C for 10 min. CAT assay: 100 μl of extracts for each assay with 0.3 μCi of 14 C-chloramphenicol and 10 μl of 20 mM acetyl CoA at 37°C for either 5 hrs or 24.5 hrs, and the materials were then extracted using ethyl acetate and analyzed on TLC plates. Result: There were no acetylated chloramphenicol species presented as determined by comparing the extracts from treated animals with that from control animals. Thus, under similar experimental conditions that produce high level expression of pZN27, the use of the pSIS-CAT expression vector does not result in any detectable expression of the Enked-CAT gene in any of the tissues assε d in v 'o. The lack of expression of pSIS-CAT in vivo may be due either to a different promoter-enhancer eler (SV40) or to a different intron sequence when compared to the pZN27 vector, which yie high level in vivo expression. The results are shov. in Figure 6. Example 7 Interaction Of DNA: Lipid carrier Complexes With CeE Surface Receptors CeEs and ceE culture: CV-1 (African green monkey kidney), U937 (human myelocytic leukemia), murine erythroleukemia (MEL) ceEs, and K562 ceEs (human erythroleukemia ceEs were obtained from the American Type Culture CoEection (RockviEe, MD). CV-1 and MEL ceEs were maintained in Dulbecco minimum essential medium (DME)- H-21 with 5% fetal bovine serum (FBS) at 37°C and 7% CCt,. Rat alveolar type π ceEs and rat alveolar macrophages were isolated and purified as previously described. (Debs et al. Amer. Rev. Respiratory Disease (1987) 125:731-737; Dobbs, L. Amer. Rev. Respiratory Disease (1986) 124:141-145) Type π ceEs were maintained in DME-H-16 with 5% FBS at 37°C and 7% CO 2 . Twenty nanomoles of DOTMA:DOPE Epid carriers complexed to 20 μg of pRS V-CAT plasmid DNA were added to 2 million ceEs growing in 60 mm Falcon plastic dishes (either SUV or MLV), and fixed for EM at time points from 15 minutes to 2 hours thereafter. Fixation and Processing for Electron Microscopy DOTMA Epid carriers and ceEs in tissue culture or freshly isolated from blood or pulmonary alveoE were fixed in 1.5% glutaraldehyde in 0.1 molar sodium cacodylate buffer containing 1% sucrose, pH 7.4, at room temperature for 1 hr. FoEowing tannic acid and uranyl acetate enhancement, tissue was dehydrated in a graded series of alcohols and embedded in epoxy 812 resin (Ernest F. FuEam, Inc., Latham, NY) sectioned on an MT 2 microtome using diamond knives and examined with a Jeol 100CX transmission electronmicroscope operating at 80 kv. The results are shown in Figure 4. Results The most frequent interaction between DOTMA Epid carriers, either uni- or multilammelar Epid carriers, complexed to plasmid DNA and the various ceE types (CV-1 monkey kidney cells, U937 human myelomonocytic leukemia ceEs, K562, MEL erythroblastic leukemia ceEs, rat alveolar macrophages, and alveolar type π ceEs), is that of Epid carrier adhesion and internalization in a typical coated vesicle pathway (Fig. 4 a-f). This interaction is common to weE defined examples of receptor-mediated endocytosis. All ceEs which appear to have contacted cationic Epid carrieπDNA complexes ingest the complexes after binding to the plasma membrane. AE these ceE types demonstrate the same classical receptor-mediated endocytic pathway of internalization. Human ceEs are more efficiently transfected than are other ceEs, such as rodent cells. Example 8 Demonstration of High Level CAT Gene Expression in Multiple Tissues After Intravenous (iv. Injection of pZN27 Alone, or pZN27:DDAB:cholesterol SUV Complexes. Lipid carrier: DDAB:Chol=l:l, stock lOmM in 5% dextrose. After addition of 5% dextrose to the dried Epid film, the SUV were prepared by sonication in a bath sonicator for 20 minutes. Plasmid: pZN27. DNA:Lipid carrier Ratio: Cationic Epid:plasmid DNA = 5 nanomoles: 1 μg DNA. DNA dose: pZN27 alone: Individual mice received 500 μg, 1 mg, 2 mg, or 500 μg, foEowed 4 hours later by a second 500 μg dose, respectively of pZN27 in 200 μl 5% dextrose in water by taE vein injection. pZN27 complexed to Epid carriers: 100 μg plasmid DNA complexed to 500 nanomoles to DDAB:Chol SUV Epid carriers in 200 μl 5% dextrose in water was injected by taE vein per mouse. Mice: ICR, female, 25 grams. Tissue extraction procedure: Each organ was homogenized in 0.3 ml of 0.25 M Tris-HCl pH 7.8, 5 mM EDTA, and the resulting extract was centrifuged and the supernatant was then subjected to 3 cycles of freeze-thaw and then heated to 65 °C for 20 min. CAT assay procedure: The protein concentration of each tissue extract was quantitated using a Coomasie blue-based protein assay (Bio-Rad, Richmond, CA), and same amount of total protein from each tissue extract was added in the CAT assay, together with 10 μl of 20 mM acetyl CoA+12 μl of 14 C-chloramphenicol (25 μCi ml, 55 mCi/mmole, Amersham)), at 37°C for 13 hrs. Results: The results are shown in Figure 8. Significant levels of CAT gene expression were seen in each of the 6 different tissues (lung, heart, Ever, kidney, spleen and lymph nodes) assayed after injection of either pZN27 alone, or pZN27 complexed to DDABxholesterol Epid carriers. Expression of a transgene in multiple tissues in vivo after systemic injection of a naked expression plasmid has not been demonstrated previously. Example 9 High level airway expression of the human Ci. TK. gene in mouse lungs after aerosol administration of DDABxholesterol Eposome-pZN32 complexes Animals. Two months old, female, ICR mice obtained from Simonsen, Gilroy, CA, were used. Preparation of plasmid DNA. The plasmid used, pZN32, contains the human CFTR gene coding region fused to the human cytomegalovirus immediate early promoter-enhancer element shown in Figures 3-5 attached hereto. A fuE restriction map of the immediate early enhancer and promoter region of HCMV (Towne) and HCMV (AD169) is provided in Figs. 19A and 19C. The two sequences are compared in Fig. 19B. pZN32 was purified using aEcaline lysis and ammonium acetate precipitation, and the nucleic acid concentration measured by UV absorption at 260 nm. Preparation of cationic lipid carriers. lipid carriers were prepared as smaE unilamellar vesicles (approximately 100 nm in diameter) containing the cationic Epid DDAB (dimethyl dioctadecyl ammonium bromide) as DDAB: cholesterol in a 1:1 molar ratio. DDAB was purchased from Sigma, St. Louis, MO, and cholesterol was purchased from CalBioChem, San Diego, CA. Stock solutions of the Epids were dissolved in chloroform. Iipids were mixed in a round-bottomed flask and evaporated to dryness on a rotary evaporator under reduced pressure. Double distilled water was added to produce final Epid concentrations of 10 mM each, and the resulting mix was sonicated for approximately 20 minutes in a bath sonicator (Laboratory SuppEes, HicksviEe, NY). Aerosol deEvery of plasmid Iipid carrier complexes to mice. Twelve mg of pZN32 complexed to 24 μmols of DDAB:cholesterol (1:1) Eposomes was aerosolized over two different aerosol periods on the same day. To prevent aggregation and precipitation of the oppositely charged components, the Eposomes and DNA were dEuted separately in sterile water prior to mixing. Six mg of plasmid DNA and 12 μmols of DDAB holesterol (1:1) Eposomes were each dEuted to 8 ml with water and mixed. Four ml of the DNA-Eposome mixture was then placed into two Acorn I nebulizers (Marquest, Englewood, CO), and the animals placed in an Intox smaE animal exposure chamber (Albuquerque, NM). An air flow rate of 4 L min "1 was used to generate the aerosol. Ninety minutes were required to aerosolize this volume (4 ml) of DNA-Eposome mixture. The animals were removed from the chamber for 1-2 hours and then the above procedure was repeated with a second 4 ml dose. __mmunobistr____τnical staining for the human C JL'K protein in mouse lungs. At selected time points foEowing aerosolization, mice were sacrificed and their lungs immediately removed. ' The lungs were slowly inflated with phosphate buffered saline (PBS) containing 3.3% by volume OCT (MEes, Inc.), then placed in a tissue cassette fiEed with OCT, and frozen in 2-methylbutane chiEed in a dry ice/ethanol bath. Cryosections were cu at 5 μm and coEected onto sialinized sEdes. CFTR protein was detected after fixation o cryosections for 10 minutes in either 4% acetone or 2% paraformaldehyde in PBS containin 0.1 % Tween 20 (PBST). AE subsequent dilutions and washes were done in PBST. FoEowin fixation, sections were washed three times (5 minutes each) with PBST then covered with 10 normal rabbit serum for 10 minutes at 20°C. Immunolocalization of CFTR was then performe using an affinity purified rabbit polyclonal anti-CFTR antibody, α-1468, provided by Dr Jonathan Conn, Duke University. The serum was replaced with α-1468, dEuted (1: 1000). Th antibody-covered section was gently overlaid with a siEconized coversEp and incubated in humid chamber at 4°C for 24 hours. SEdes were then warmed to 20°C and washed thre times. The presence of bound rabbit antibody against CFTR was detected by covering section with biotinylated, affinity-purified, goat anti-rabbit antibody (Lipid carrier Laboratories), dEute 1:300 for 1 hour, foEowed by washing (3 x 10 minutes) and replacement with streptavidi labeEed with alkaline phosphatase (Zymed, South San Francisco) for 20 minutes. ImmobiEze alkaEne phosphatase was detected using AP-red (Zymed) as the chromogen; endogenous alkalin phosphatase was inhibited with levamisole (Zymed). Other controls, run concunently, include the use of normal rabbit serum in place of primary antibody and the use of lung tissue fro untreated mice. Photo-microscopy was performed using Kodak Ektachrome 64T film at X5 and X250. Results Photomicrographs of frozen sections (viewed at different magnifications) o mouse lung 48 hours foEowing aerosol exposure to pZN32-DDAB:cholesterol (1:1) Eposom complexes and lung from untreated control are shown in Figs. 11A-11E. As demonstrated by the intense staining with the polyclonal anti-CFTR antibody, α-1468, the overwhelming majority of the airways were transfected with the human CFTR gene. See Figs. 11 A, 11C and HE. By visual inspection, essentiaEy aE the ceEs in transfected airways stain positively, demonstrating that the overwhelming majority of airway ceEs are transfected with the human CFTR gene in vivo with a single aerosol dose of pZN32 complexed to DDAB-cholesterol (1:1) Eposomes. Representative sections are shown in Figure 11. There was no histologic evidence of lung damage, inflammation or edema present in any of the p__N32-DDAB:cholesterol (1:1) Eposome-treated animals. pZN32-DDAB:cholesterol (1 : 1) Eposome-treated and control animals could not be distinguished histologicaEy. Significant expression of the human CFTR gene is present in at least 50% of aE the airways and at least 50% of aE of the airway lining ceEs (by visual inspection) in mouse lungs for at least 60 days foEowing a single aerosol dose of pZN32 complexed to DDAB-cholesterol (1: 1) Eposomes. Frozen sections of mouse lungs from control animals (Figs. HB and HD) do not show any detectable staining for CFTR, ∞n_____ming that aE tfae CFTR expression present in Fig. HA, HC and HE is due to transfection of lung ceEs with the human CFTR gene. Example 10 Demonstration of CAT Gene Expression in Lung and Liver After Intravenous Injection of Different CAT gene-Containing Plasmids Lipid carrier: DDAB:Chol= 1:1, stock 5mM in 5% dextrose in water. Plasmids: Plasmids are indicated below. DNA-Iipid carrier Ratio: cationic Epid: plasmid DNA = 1 nanomole: lμg Dose: lOOμg DNA in 200ul volume injected intravenously by taE vein injection. Mice: ICR, female, 25 g Procedure: The animals were sacrificed 24 hours after injection. The tissue extraction procedure and CAT assay were as described in Example 12 except that the CAT assay was incubated for 3 hr at 37°C and 2.0mM paraoxon (Lai, C.-C. et al. Carcinogenesis 9_: 1295-1302 (1988)) was added to the Ever samples. The results are shown in Figure 13. Lanes 1-12 are lung samples, lanes 13-24 are Ever samples. Lanes 1, 2, 13, 14 are pZN51; lanes 3, 4, 15, 16 are pZN60; lanes 5, 6, 17, 18 are pZN61; lanes 7, 8, 19, 20 are pZN62; lanes 9, 10, 21, 22 are pZN63; and lanes 11, 12, 23, 24 are pZN27. pZN51, which does not contain an intron, is expressed as weE as or better than plasmids containing an intron. Example 11 Generalized versus tissue and ceE type-specific CAT gene expression produced by iv injection of CMV-CAT-Eposome or CFTR-CAT-Eposome complexes, respectively. Mouse: ICR female, 25 grams. Liposome: DDAB:Cholesterol=l:l SUV, lOmM in 5% dextrose in water. Plasmid: 1) pZN27 or 2) pBE3.8CAT (see Chou et al. , J. Biol Chem 266:24471, 1991 for construction). Procedure: Mice in groups of 3 received 1) no treatment, or a single iv taE vein injection of DDAB:CHOL Eposomes complexed to 100 μg of 2) a 3.8 kb sequence ofthe 5' upstream region of the human CFTR gene fused to the CAT gene (pBE3.8CAT) or 2) pZN27. Mice were sacrificed 24 hours later and CAT activity assayed in lung, Ever, spleen, lymph nodes, kidney and heart, as described in Example 12. Immunohistochemical analysis of lung section from each of the groups was performed as described in Example 11. Results: Figure 14A-F CAT assay demonstrated that CMV-CAT produced significant CAT gene expression in the lung, Ever, heart, spleen, lymph nodes and kidney, whereas CFTR- CAT produced lung-specific gene expression. Thus, the CMV promoter induces expression of a linked gene in a wide range of tissues, whereas the 5' flanking region of the human CFTR gene directs tissue-specific transgene expression after iv, Eposome-based administration. Immunohistochemical staining of frozen lung sections from these mice showed that iv injection of CMV-CAT-Eposome complexes produced CAT gene expression in endotheEal, alveolar and airway ceEs within the lung. In contrast, CFTR-CAT-Eposome complexes produced CAT gene expression primarily in airway epithelial ceEs. (This approximates the pattern of endogenous CFTR gene expression in rat lung, as determined by in situ hybridization studies (Trezise and Buchwald, Nature, 353:434, 1991). This is the first demonstration that transgenes can be expressed within mouse lung in either a generalized or ceE type-specific fashion after iv injection, depending on the regulatory element used. Results are shown in Figure 26A-E. Example 12 High level, lung specific expression of a transgene complexed to cationic Eposomes foEowing aerosol administration Animals. Two month old, female, ICR mice were used in aE experiments. Preparation of plasmi TiNA . The chloramphenicol acetyltransferase (CAT) gene was used as a reporter to measure transgene expression levels (Gorman et al , .Proc. Nat'lAcad Sci (USA) (1982) 79: 6777- 6781). The plasmid used contains the CAT gene fused to the human cytomegalovirus (CMV) immediate early promoter-enhancer element (pCIS-CAT). The plasmid was purified using alkaline lysis and ammonium acetate precipitation (Sambrook et al. (1989) supra), and the nucleic acid concentration measured by UV absorption at 260 nm. The CAT gene is not present in eukaryotic ceEs. Its product is an enzyme which catalyzes the transfer of acetyl groups from acetylCoA to the substrate chloramphenicol. Preparation of cationic lipid carriers. lipid carriers were prepared as smaE unilamellar vesicles (approximately 100 nm in diameter) containing the cationic Epid DOTMA as DOTMA:DOPE (1:1 mole ratio). DOTMA is (N[l-2,3-dioleyloxy)propyl]-N,N,N-triethyIammonium (Syntex Corporation), and DOPE is the neutral Epid dioleoylphosphatidylethanolamine (Avanti Polar Lipids). Stock solutions of the Epids were dissolved in chloroform and stored under argon at -20°C. Lipids were mixed in a round-bottomed flask and evaporated to dryness on a rotary evaporator under reduced pressure. Double-distiEed water was added to produce final Epid concentrations of lOmM each, and the resulting mix was sonicated for approximately 20 minutes in a bath sonicator (Laboratory SuppEes, HicksvEle, NY). The Eposomes were stored under argon at 4°C until use. Aerosol delivery of plasmid/lipjd carrier complexes to mice. Twelve mg of plasmid complexed to 24 μmols of DOTMA:DOPE (1:1) Eposomes was aerosolized and administered to mice over two different aerosol periods on the same day. Ei order to prevent aggregation and precipitation of the oppositely charged components, the plasmid and the Eposomes were dEuted separately in sterile water prior to mixing. Six mg of plasmid DNA and 12 μmols of DOTMA:DOPE (1:1) Eposomes were each dEuted to 8 ml with water and mixed. Four ml was then placed into each of two Acorn I nebulizers (Marquest, Englewood, CO), the animals placed into an Intox smaE animal exposure chamber (Albuquerqae, NM), and an air flow rate of 4 L min "1 used to generate the aerosol. Approximately 90 minutes were required to aerosolize 4 ml. The animals were removed from the chamber for 1-2 hours and then the above procedure was repeated with a second 4 ml dose. Radiometric Assay of CAT Activity. Organs were dissected from animals sacrificed in a CO 2 chamber at periods from 1 to 21 days foEowing aerosolization, washed in cold phosphate buffered saline (PBS), and homogenized using a hand-held tissue homogenizer in 250 mM Tris-HCl, pH. 7.5, containing 5 mM EDTA for lungs and spleen and 250 mM Tris-HCl, pH 7.5, containing 5 mM EDTA plus the protease inhibitors aprotinin, E-64, and leupeptic (Boehringer Mannheim) for Ever, heart and kidneys. The inhibitors prevent degradation of acetylated chloramphenicol species generated during the assay, thereby aEowing optimal detection of CAT expression. FoEowing homogenization of the tissue, ceEs were lysed by three freeze/thaw cycles, the lysate heated (65°C for 10 minutes), and centrifugated (16,000 x g, 2 minutes). The protein concentrations of the extracts were measured using a Coomassie blue-based assay (Bio-Rad). Protein concentrations were normalized and a volume of extract added to 10 μl of 100 mM acetylCoA (Sigma), 0.3 μCi of [ 14 C]-labeEed chloramphenicol (Amersham), and distiEed water to a final volume of 180 μl, and aEowed to react at 37°C for 8-10 hours (Gorman et al. (1982) supra). FoEowing the reaction, the acetylated and unacetylated chloramphenicol species were extracted with cold ethyl acetate, spotted on si ca TLC plates, and developed with a chloroform:methanol (95:5v/v) solvent. The TLC plates were exposed to photographic film (Kodak X-OMAT) for one to three days and then read visuaEy. Preparation of Genomic DNA and Southern Hybridisation. Immediately foEowing aerosolization, mice were sacrificed and their lungs removed. Genomic DNA was isolated and analyzed by Southern hybridization (Sambrook et al (1989) supra) using a Hybond N + membrane (Amersham). A CAT probe was prepared from a 1.6 kb fragment of the CAT gene labeEed with α-[ 32 P]dATP by random priming, which yielded a probe with an approximate specific activity of 2 x 10 9 dpm μg. After hybridization, the membrane was washed three times in 2xSSC, 0.1%SDS at 65°C for 20 minutes and exposed to film for 24 hours. In order to determine the approximate transfected CAT gene copy number, blots were also hybridized with a 1.1 kb BSU 36-1 single copy probe from a mouse factor Vm-A genomic clone (Levinson et al, Genomics (1992) 13: 862-865). Relative amounts of the CAT plasmid deposited in individual mouse lungs were quantitated by phosphorimagimng analysis using a Molecular dynamics 400A phosphorimaginer (Johnson et al, Electrophoresis (1990) 11: 355-360). The amount of retained probe in each lane foEowing hybridization with the CAT probe was normalized to the amount of DNA loaded per lane using the counts measured after hybridization with a Factor VDI-A single copy probe. Tn Situ Tmmunochemiriil Staining for CAT enzyme. At selected time points foEowing aerosolization, mice were sacrificed and their lungs immediately removed. The lungs were slowly inflated with phosphate buffered saline (PBS) containing 33 % by volume OCT (MEes, Inc.), placed in a tissue cassette fiEed with OCT, and frozen in 2-methylbutane chiEed in a dry ice/ethanol bath. Cryosections were cut at 5 μm and coEected onto salinized sEdes. CAT was detected after fixation of cryosections for 10 minutes in either 4% acetone or 2% paraformaldehyde in PBS containing 0.1% Tween 20 (PBS ). AE subsequent dilutions and washes were also done in PBST. FoEowing fixation, sections were washed three times (5 minutes each) then covered with 10% normal rabbit serum for 10 minutes at 20°C. The serum was replaced with dEuted (1:500) rabbit polyclonal antibody against CAT (Drs. Parker Antin and David Standring, UCSF Medical Center). The antibody covered section was gently overiaid with a siEconized coversEp and incubated in a humid chamber at 4°C for 24 hours. SEdes were then warmed to 20°C and washed three times. The presence of bound rabbit antibody against CAT was detected by covering sections with biotinylated, affinity purified, goat anti- rabbit antibody (Vector Laboratories) dEuted 1:300 for 1 hour, foEowed by washing (3 x 10 minutes) and replacement with streptavidin labeEed with alkaline phosphatase (Zymed, South San Francisco) for 20 minutes. Immobilized alkaline phosphatase was detected using AP-red (Zymed) as the chromogen, with endogenous alkaline phosphatase being inhibited with levamisole (Zymed). To control for potential spurious adherence of the streptavidin conjugate to bronchiolar epitheEum, some sections were treated with free avidin and biotin prior to appEcation of the primary antibody. Other controls, run concunently, included the use of normal rabbit serum in place of primary antibody and the use of lung tissue from untreated mice. Photo-microscopy was performed using Kodak Ektachrome 64T film X50 (Fig. 6 A,D) and X250 (Fig. 6 B,C,E,F). Results InitiaEy, mice were exposed either to an aerosol generated from a solution containing 12 mg of a CMV-CAT expression plasmid alone or to an aerosol generated from a solution contaEiing 12 mg of CMV-CAT complexed to 24 μmoles of DOTMA:DOPE (1:1) Eposomes. Aerosols were administered to animals after they were placed individuaEy in nose-out cones and inserted into an Intox smaE animal exposure chamber. The mice showed no apparent l effects or respiratory distress either during or after aerosol exposure. Figure 7 shows the results of CAT assays from extracts of the lungs of mice sacrificed 72 hours foEowing aerosol administration. Significant CAT gene expression was seen only in mice exposed to aerosolized DNA/Epid carrier complexes. How long CAT protein was present in the lungs of mice and whether expression of the reporter gene was Emited to the lung was also investigated. Despite inter- animal variation, high levels of CAT activity are present for at least 21 days foEowing a single aerosol dose of DNA/Epid carrier complexes (Fig. 24 A). No CAT activity was detectable in extracts from the heart, spleen, kidneys or Ever of animals that showed high level expression in the lung (Fig. 24B), suggesting that transgene expression foEowing aerosol deEvery is restricted to the lung. This is consistent with prior observations showing that penetration of very high molecular weight substances through the respiratory epitheEum of normal animals is very Emited. Plasmid DNA/Epid carrier complexes have molecular weights greater than 10 6 daltons. Although the smaE animal exposure chamber used in these experiments is designed to efficiently deEver a uniform aerosol dose to multiple animals up to 48 individual animals, we have observed significant variations in the level of CAT activity in the lungs of mice within a single experiment. One possible explanation for this variabiEty is that the amount of DNA Eposome complex deposited in the lungs of mice is not uniform. In order to test this hypothesis, initial lung deposition of Eposomes was measured using fluorescence analysis and initial lung deposition of DNA was measured ushig Southern blot analysis. Aerosolized cationic Eposomes alone or DNA/Eposome alone or DNA Eposome complexes containing 0.5 mole percent of a fluorescently labeEed Epid, rhcKlamine-phosphatidylethanolamine, were administered to mice. Immediately foEowing aerosolization, the animals were sacrificed and their lungs removed, homogenized and rhodamine fluorescence measured using a fluorimeter. The recovered fluorescence per animal was 0.06% ± 0.02 (S.D.) of the total amount aerosolized. This suggests that less than 10 μg out of the 12 mg of DNA aerosolized per experiment was actuaEy deposited in the lung. In addition, there was no significant difference in Epid deposition between animals receiving Eposomes alone and those receiving the DNA/Eposomes complexes. Since it is possible that a disruption of the complex could have occurred during nebulization, the amount of CAT gene deposited during aerosolization (Fig. 25) was also assessed. Immediately foEowing aerosol deEvery of DNA/Epid carrier complexes, mice were sacrificed and total lung DNA prepared. Southern blots were probed with α[ 32 P]-labeEed CAT gene. LabeEed bands were scanned and demonstrated less than a 4-fold difference in plasmid deposition between animals in the same experiment (Fig. 25). These results suggest that the mouse to mouse variation in CAT gene levels foEowing aerosol deEvery (up to ten¬ fold) is not only a function of the amount of complex initiaEy deposited in the lung, but also may reflect differences in the site of uptake, rate of lung clearance, and/or variation in the abiEty of different lung ceE types to express the transgene. To determine the types and percentage of lung ceEs which were transfected in vivo, lungs of mice sacrificed 72 hours foEowing exposure to an aerosol containing DNA/Eposome complexes were cryosectioned, probed with a polyclonal anti-CAT antibody and counterstained to detect intraceEular CAT protein (Fig. 22). Lung sections taken from DNA/Epid carrier treated mice had a diffuse immunostaining pattern involving bronchiolar and alveolar components. The bronchiolar epithelial cytoplasm stained with greatest intensity and uniformity. CAT antigen was detected (as demonstrated by red staining) in nearly aE conducting airways with only rare individual or 2-3 ceE clusters not staining (Fig. 22A, 22B). The diffuse alveolar pattern was due to moderately intense staining of the majority of alveolar lining cells (Fig. 22C). These areas occasionaEy faded into smaE, randomly scattered regions where lining ceE staining was faint. Focal, intense staining (arrows) occurred in the cytoplasm of scattered, individual, alveolar lining ceEs (Fig. 22C). Controls included substitution of the primary antibody with normal rabbit serum (Fig. 22D) and use of lung sections from untreated animals (Fig. 22E, 22F). Immunostaining was not detectable in either of the control preparations. Examination of multiple sections of lung from treated and control mice demonstrated no significant lesions which would indicate adverse effects of the aerosol treatment. As shown by the above results, a single aerosol dose of an expression Eposome, containing a gene of interest, complexed to cationic Eposomes transfects the majority of the ceEs Ening both the conducting airways and the alveoE of the lung, the gene product is present in the lung for at least 60 days, the expression appears to be lung-specific, and there is no histological evidence of damage foEowing exposure. Thus, the aerosolized cationic Eposomes mediate efficient transfection of non-dividing as weE as dividing ceEs. This is important because many airway epitheEal ceEs are weE differentiated and divide slowly or not at aE. The Epid carriers appear to be both weE tolerated and non- immunogenic. Furthermore, the appearance, behavior and Efe span of mice treated with either aerosolized or injected pZN32: DDAB-cholesterol (1:1) complexes appear normal and are indistinguishable from untreated, normal control animals, demonstrating the lack of toxicity of these carrier constructs, and the overexpression of the human CFTR gene in mammals. AdditionaEy, the effects of repeated aerosol admimstration of the DNA/Eposome complexes is effective and is non-toxic. The cationic Eposome-mediated DNA deEvery by aerosol provides high level, lung-specific transgene expression in vivo. AE pubEcations and patent appEcations are herein incorporated by reference to the same extent as if each individual publication or patent appEcation was specificaEy and individuaEy indicated to be incorporated by reference. The invention now being fuEy described, it wiE be apparent to one of ordinary skiE in the art that many changes and modifications can be made thereto without departing from the spirit or scope of the appended claims.

Claims: WHAT TS rπ-.ATMπn TS 1. A composition for use in a method of treatment or therapy of a disease in the human or animal body, said disease relating to an insufficient amount of endogenous production of wEd-type cystic fibrosis transmembrane conductance regulator, said composition comprising a transcription cassette or an expression cassette in a pharmaceuticaEy acceptable carrier or dEuent wherein said transcription cassette or said expression cassette comprises a DNA sequence capable of producing a transcription product of an open reading frame encoding a molecule having wEd-type cystic fibrosis transmembrane conductance regulator activity in ceEs transfected with said transcription cassette or said expression cassette. 2. The composition for use according to Claim 1, wherein said transcription cassette or expression cassette is associated with a cationic Epid carrier. 3. The composition for use according to Claim 2, wherein said composition is nebulized foEowing said association of said transcription cassette or said expression cassette and said cationic Epid carrier. 4. The composition for use according to Claim 2 or 3, wherein said ceEs transfected are distal airway ceEs or airway submucosal ceEs. 5. The composition for use according to Claim 2 or 3, wherein said ceEs are tracheal cells. 6. The composition for use according to Claim 4 or 5, wherein from 20 to 100 percent of said ceEs are transfected. 7. The composition for use according to Claim 1 or 2, wherein said DNA sequence comprises an inducible promoter. 8. The composition for use according to Claim 1 or 2, wherein said inducible promoter is a ceE specific promoter, a tissue specific promoter, or a hormone responsive promoter. 9. The composition for use according to any one of Claims 1, 2 or 8, wherein said ceE specific promoter promoter or siad tissue specific promoter is a promoter from a cystic fibrosis transmembrane conductance regulator gene. 10. The composition for use according to any one of Claims 1, 2, 8 or 9, wherein said DNA sequence comprises an SV40 enhancer element whereby transcription from said promoter is enhanced. 11. The composition for use according to any one of claims 2 to 10, wherein said cationic Epid carrier comprises a Epid selected from the group consisting of N[l-2,3- dioleyloxy)propyl]-N,N,N-triethylammonium (DOTMA); dimethyl dioctadecyl ammonium bromide (DDAB); l,2-dioleoyloxy-3-(trimethylammonio) propane (DOTAP); lysinylphosphatidyl-ethanolamine (L-PE); dstearoylphosphatidylethanolamine (DOPE); and cholesterol (Choi). 12. The composition for use according to any one of Claims 2 to 10, wherem said cationic Epid carrier comprises cholesterol and a Epid selected from the group consisting of N[l-2,3-dioleyloxy)propyl]-N,N,N-triethylammonium (DOTMA) ; dimethyldioctadecylammoniumbromide (DDAB); l,2-dioleoyloxy-3- (trimethylammonio)propane (DOTAP); and lysinylphosphatidyl-ethanolamine (L-PE). 13. The composition for use according to any one of Claims 2 to 10, wherein said cationic Epid carrier comprises distearoyl-phosphatidylethanolamine (DOPE) and a Epid selected from the group consisting of N[l-2,3-dioleyloxy)propyl]-N,N,N-triethylammonium (DOTMA); dimethyldioctadecylammoniumbromide (DDAB); l,2-dioleoyloxy-3- (trimethylammonio)propane (DOTAP); and lysinylphosphatidyl-ethanolamine (L-PE). 14. The composition for use according to any one of Claims 2 to 10, wherein said cationic Epid carriers are smaE unilameEar vesicles. 15. The composition for use according to Claim 14, wherein said smaE unilameEar vesicles comprise (a) hstearoyl-phos hatidyletl-anolamine (DOPE) and N[l-2,3- dioleyloxy)propyl]-N,N,N-triethylammonium (DOTMA) or (b) dimethyldioctadecyl- ammoniumbromide (DDAB) and cholesterol. 16. The composition for use according to any one of Claims 2 to 10, wherein said transcription cassettes or expression cassettes and said cationic Epid carriers are present in said mixture in a ratio in the range of from about 1:1 to 1:2 micrograms DNA to nanomoles of cationic Epid. 17. A kit for use in a method of treatment or therapy according to any one of Claims 2 to 16, said kit comprising in combination: a container containing said transciption cassettes or expression cassettes; another container containing a specific amount of cationic Epid carriers; and instructions. 18. The composition for use according to any one of Claims 1 to 16, wherein said open reading frame is intron-free. 19. The composition for use according to any one of Claims 1 to 16, wherein said DNA sequence comprises an intron 5' to said open reading frame. 20. The composition for use according to any one of Claims 1 to 16, wherein said DNA sequence comprises an expanded intron 3' to said open reading frame. 21. The composition for use according to Claim 1 or 2, wherein said method of treatment or therapy is intraoral or intranasal administration foEowing nebulization of said composition. 22. The composition for use according to Claim 1 or 2, wherein said method of treatment or therapy is intravenous injection of said composition. 23. The composition for use according to Claim 1 or 2, wherein said method of treatment or therapy is a combination of intraoral or intranasal administration foEowing nebulization of said composition and intravenous injection of said composition. 24. The composition for use according to Claim 9, wherem cystic fibrosis transmembrane conductance regulator (CFTR) gene is a human wEd-type gene. 25. The composition for use according to any one of Claims 1 to 24, wherein said open reading frame encodes a molecule having the biological activity of wEd-type human CFTR. 26. The composition for use according to any one of Claims 1 to 24, wherein said open reading frame is from a wEd-type human CFTR gene. 27. The composition for use according to any one of Claims 9, or 24-26, wherein said DNA sequence comprises one or more enhancer elements from a gene other than a CFTR gene. 28. A kit for use in a method of treatment or therapy according to any one of Claims 2 to 27, said kit comprising in combination: a container containing said transciption cassettes or expression cassettes; another container containing a specific amount of cationic Epid carriers; and instructions.

Inventors: DEBS ROBERT J, ZHU NING, DEBS, ROBERT, J., ZHU, NING
Applicants: UNIV CALIFORNIA, THE REGENTS OF THE UNIVERSITY OF CALIFORNIA
Application year: 1992
Main classification: A61K47
IPC codes: A61K9, A61K31, A61K39, A61K47, A61K48, C07K14, C12N15