Abstract:
This invention is directed toward the isolation of a novel retrovirus, the human immune deficiency virus type  2  (HIV-2, previously named LAV-2), from patients with acquired immune deficiency syndrome (AIDS) originating from West Africa. This virus is related to HIV-1, the causative agent of AIDS, both by its morphology and by its tropism and in vitro cytopathic effect on CD4 (T4) positive cell lines and lymphocytes. However, preliminary hybridization experiments indicated that there are substantiated differences between the sequences of the two genomes. Furthermore, the proteins of HIV-1 and HIV-2 have different sizes and their serological cross-reactivity is restricted to the major core protein, as the envelope glycoproteins of HIV-2 are not immunoprecipitated by HIV-1 positive sera. Overlapping molecular clones were obtained and the complete nucleotide sequence of the gag and env genes was ascertained. An antigenic envelope polypeptide having the following amino acid sequence was identified: NH 2 -VTAIEKYLEDQARLNSWGCAFRQVC-COOH. The peptide is useful for the detection of HIV-2-specific immunological reagents.

Description:
This is a continuation of application Ser. No. 08/468,093, filed Jun. 6, 1995 now U.S. Pat. No. 5,866,319, which is a continuation of application Ser. No. 07/754,903, filed Sep. 4, 1991, now U.S. Pat. No. 5,578,715, which is a divisional of application Ser. No. 07/003,764, filed Jan. 16, 1987, now U.S. Pat. No. 5,051,496, which is a continuation-in-part of application Ser. No. 06/933,184, filed Nov. 21, 1986, abandoned, which is a continuation-in-part of application Ser. No. 06/916,080, filed Oct. 6, 1986, abandoned, and a continuation-in-part of application Ser. No. 06/835,228, filed Mar. 3, 1986, now U.S. Pat. No. 4,839,288, all of which are incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     The invention relates to cloned DNA sequences analogous to the genomic RNA of a virus known as Lymphadenopathy-Associated Virus II (“LAV-II”), a process for the preparation of these cloned DNA sequences, and their use as probes in diagnostic kits. In one embodiment, the invention relates to a cloned DNA sequence analogous to the entire genomic RNA of HIV-2 and its use as a probe. The invention also relates to polypeptides with amino acid sequences encoded by these cloned DNA sequences and the use of these polypeptides in diagnostic kits. 
     According to recently adopted nomenclature, as reported in Nature, May 1986, a substantially-identical group of retroviruses which has been identified as one causative agent of AIDS are now referred to as Human Immunodeficiency Viruses I (HIV-1). This previously-described group of retroviruses includes Lymphadenopathy-Associated Virus I (LAV-I), Human T-cell Lymphotropic Virus-III (HTLV-III), and AIDS-Related Virus (ARV). 
     Lymphadenopathy-Associated Virus II has been described in U.S. application Ser. No. 835,228, which was filed Mar. 3, 1986, and is specifically incorporated herein by reference. Because LAV-II is a second, distinct causative agent of AIDS, LAV-II properly is classifiable as a Human Immunodeficiency Virus II (HIV-2). Therefore, “LAV-II” as used hereinafter describes a particular genus of HIV-2 isolates. 
     While HIV-2 is related to HIV-1 by its morphology, its tropism and its in vitro cytopathic effect on CD4 (T4) positive cell lines and lymphocytes, HIV-2 differs from previously described human retroviruses known to be responsible for AIDS. Moreover, the proteins of HIV-1 and 2 have different sizes and their serological cross-reactivity is restricted mostly to the major core protein, as the envelope glycoproteins of HIV-2 are not immune precipitated by HIV-1-positive sera except in some cases where very faint cross-reactivity can be detected. Since a significant proportion of the HIV infected patients lack antibodies to the major core protein of their infecting virus, it is important to include antigens to both HIV-1 and HIV-2 in an effective serum test for the diagnosis of the infection by these viruses. 
     HIV-2 was first discovered in the course of serological research on patients native to Guinea-Bissau who exhibited clinical and immunological symptoms of AIDS and from whom sero-negative or weakly sero-positive reactions to tests using an HIV-1 lysate were obtained. Further clinical studies on these patients isolated viruses which were subsequently named “LAV-II.” 
     One LAV-II isolate, subsequently referred to as LAV-II MIR, was deposited at the Collection Nationale des Cultures de Micro-Organismes (CNCM) at the Institut Pasteur in Paris, France on Dec. 19, 1985 under Accession No. I-502 nd has also been deposited at the British ECA CC under No. 87.001.001 on Jan. 9, 1987. A second LAV-II isolate was deposited at CNCM on Feb. 21, 1986 under Accession No. I-532 and has also been deposited at the British ECA CC under No. 87.001.002 on Jan. 9, 1987. This second isolate has been subsequently referred to as LAV-II ROD. Other isolates deposited at the CNCM on Dec. 19, 1986 are HIV-2 IRMO (No. I-642) and HIV-2 EHO (No. I-643). Several additional isolates have been obtained from West African patients, some of whom have AIDS, others with AIDS-related conditions and others with no AIDS symptoms. All of these viruses have been isolated on normal human lymphocyte cultures and some of them were thereafter propagated on lymphoid tumor cell lines such as CEM and MOLT. 
     Due to the sero-negative or weak sero-positive results obtained when using kits designed to identify HIV-1 infections in the diagnosis of these new patients with HIV-2 disease, it has been necessary to devise a new diagnostic kit capable of detecting HIV-2 infection, either by itself or in combination with an HIV-1 infection. The present inventors have, through the development of cloned DNA sequences analogous to at least a portion of the genomic RNA of LAV-II ROD viruses, created the materials necessary for the development of such kits. 
     SUMMARY OF THE INVENTION 
     As noted previously, the present invention relates to the cloned nucleotide sequences homologous or identical to at least a portion of the genomic RNA of HIV-2 viruses and to polypeptides encoded by the same. The present invention also relates to kits capable of diagnosing an HIV-2 infection. 
     Thus, a main object of the present invention is to provide a kit capable of diagnosing an infection caused by the HIV-2 virus. This kit may operate by detecting at least a portion of the RNA genome of the HIV-2 virus or the provirus present in the infected cells through hybridization with a DNA probe or it may operate through the immunodiagnostic detection of polypeptides unique to the HIV-2 virus. 
     Additional objects and advantages of the present invention will be set forth in part in the description which follows, or may be learned from practice of the invention. The objects and advantages may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims. 
     To achieve these objects and in accordance with the purposes of the present invention, cloned DNA sequences related to the entire genomic RNA of the LAV-II virus are set forth. These sequences are analogous specifically to the entire genome of the LAV-II ROD strain. 
     To further achieve the objects and in accordance with the purposes of the present invention, a kit capable of diagnosing an HIV-2 infection is described. This kit, in one embodiment, contains the cloned DNA sequences of this invention which are capable of hybridizing to viral RNA or analogous DNA sequences to indicate the presence of an HIV-2 infection. Different diagnostic techniques can be used which include, but are not limited to: (1) Southern blot procedures to identify cellular DNA which may or may not be digested with restriction enzymes; (2) Northern blot techniques to identify RNA extracted from cells; and (3) dot blot techniques, i.e., direct filtration of the sample through an ad hoc membrane such as nitrocellulose or nylon without previous separation on agarose gel. Suitable material for dot blot technique could be obtained from body fluids including, but not limited to, serum and plasma, supernatants from culture cells, or cytoplasmic extracts obtained after cell lysis and removal of membranes and nuclei of the cells by centrifugation as accomplished in the “CYTODOT” procedure as described in a booklet published by Schleicher and Schull. 
     In an alternate embodiment, the kit contains the poly-peptides created using these cloned DNA sequences. These poly-peptides are capable of reacting with antibodies to the HIV-2 virus present in sera of infected individuals, thus yielding an immunodiagnostic complex. 
     It is understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention as claimed. The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate one embodiment of the invention and, together with the description, serve to explain the principles of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 generally depicts the nucleotide sequence of a cloned complementary DNA (cDNA) to the genomic RNA of HIV-2. FIG. 1A depicts the genetic organization of HIV-1, position of the HIV-1 HindIII fragment used as a probe to screen the cDNA library, and restriction map of the HIV-2 cDNA clone, E2. FIG. 1B depicts the nucleotide sequence of the 3′ end of the 3′ LTR of HIV-2. The corresponding region of the HIV-1 LTR was aligned using the Wilbur and Lipman algorithm (window: 10; K-tuple: 7; gap penalty: 3) as described by Wilbur and Lipman in Proc. Natl. Acad. Sci. USA 80: 726-730 (1983), specifically incorporated herein by reference. The U3-R junction in HIV-1 is indicated and the poly A addition signal and potential TATA promotor regions are boxed. In FIG. 1A, the symbols B, H, Ps and Pv refer to the restriction sites BamHI, HindIII, PstI and PvuII, respectively. 
     FIG. 2 generally depicts the HIV-2 specificity of the E2 clone. FIGS. 2A and B are line drawings representing Southern Blots of DNA extracted from CEM cells infected with the following isolates; HIV-2 ROD  (a,c) HIV-2 DUL  (b,d) and HIV-1 BRU  (e,f). Blots a,b,f are PstI digested. Blots c,d,e are undigested. FIGS. 2C and D are line drawings representing dot blot hybridization of pelleted virions from CEM cells infected by the HIV-1 BRU (1), Simian Immunodeficiency Virus (SIV) isolate Mm 142-83 (3), HIV-2 DUL  (4), HIV-2 ROD  (5), and, HIV-1 ELI  (6). Dot 2 is a pellet from an equivalent volume of supernatant from uninfected CEM. Thus, FIGS. 2A and C depict hybridization with the HIV-2 cDNA (E2) and FIGS. 2B and D depict hybridization to an HIV-1 probe consisting of a 9.2 Kb SacI insert from HIV-1 BRU . 
     FIG. 3 generally depicts a restriction map of the HIV-2 ROD genome and its homology to HIV-1. FIG. 3A specifically depicts the organization of three recombinant phage lambda clones, ROD 4, ROD 27, and ROD 35. In FIG. 3A, the open boxes represent viral sequences, the LTR are filled, and the dotted boxes represent cellular flanking sequences (not mapped). Only some characteristic restriction enzyme sites are indicated. λROD 27 and λ35 are derived from integrated proviruses while λROD 4 is derived from a circular viral DNA. The portion of the lambda clones that hybridzes to the cDNA E2 is indicated below the maps. A restriction map of the λROD isolate was reconstructed from these three lambda clones. In this map, the restriction sites are identified as follows: B: BamHI; E: EcoRI; H: HindIlI; K: KpnI; Ps: PstI; Pv: PvuII; S: SacI; X: XbaI. R and L are the right and left BamHI arms of the lambda L47.1 vector. 
     FIG. 3B is a line drawing depicting dots 1-11 which correspond to the single-stranded DNA form of M13 subclones from the HIV-1 BRU  cloned genome. Their size and position on the HIV-1 genome, determined by sequencing is shown below the figure. Dot 12 is a control containing lambda phage DNA. The dot-blot was hybridized in low stringency conditions as described in Example 1 with the complete lambda λROD 4 clone as a probe, and successively washed in 2×SSC, 0.1% SDS at 25° C. (Tm −42° C.), 1×SSC, 0.1% SDS at 60° C. (Tm −20° C.), and 0.1×SSC, 0.1% SDS at 60° C. (Tm −30° C.) and exposed overnight. A duplicate dot blot was hybridized and washed in stringent conditions (as described in Example 2) with the labelled lambda J19 clone carrying the complete HIV-1 BRU  genome. HIV-1 and HIV-2 probes were labelled the same specific activity (10 8  cpm/μg). 
     FIG. 4 generally depicts the restriction map polymorphism in different HIV-2 isolates and shows comparison of HIV-2 to SIV. FIG. 4A is a line drawing depicting DNA (20 μg per lane) from CEM cells infected by the isolate HIV-2 DUL  (panel 1) or peripheral blood lymphocytes (PBL) infected by the isolates HIV-2 GOM  (panel 2) and HIV-2 MIR  (panel 3) digested with: EcoRI (a), PstI (b), and HindIII (c). Much less viral DNA was obtained with HIV-2 isolates propagated on PBL. Hybridization and washing were in stringent conditions, as described in Example 2, with 10 6  cpm/ml. of each of the E2 insert (cDNA) and the 5 kb. HindIII fragment of λROD 4, labelled to 10 9  cpm/μg. 
     FIG. 4B is a line drawing depicting DNA from HUT 78 (a human T lymphoid cell line) cells infected with SIV Mm 142-83. The same amounts of DNA and enzymes were used as indicated in panel A. Hybridization was performed with the same probe as in A, but in non-stringent conditions. As described in Example 1 washing was for one hour in 2×SSC, 0.1% SDS at 40° C. (panel 1) and after exposure, the same filter was re-washed in 0.1×SSC, 0.1% SDS at 60° C. (panel 2). The autoradiographs were obtained after over-night exposition with intensifying screens. 
     FIG. 5 depicts plasmids λROD 27, λROD 35 and λROD 4. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Reference will now be made in detail to the presently preferred embodiments of the invention, which, together with the following examples, serve to explain the principles of the invention. 
     The genetic structure of the HIV-2 virus has been analyzed by molecular cloning according to the method set forth herein and in the Examples. A restriction map of the genome of this virus is included in FIG.  5 . In addition, the partial sequence of a cDNA complementary to the genomic RNA of the virus has been determined. This cDNA sequence information is included in FIG.  1 . 
     Also contained herein is data describing the molecular cloning of the complete 9.5 kb genome of HIV-2, data describing the observation of restriction map polymorphism between different isolates, and an analysis of the relationship between HIV-2 and other human and simian retroviruses. From the totality of these data, diagnostic probes can be discerned and prepared. 
     Generally, to practice one embodiment of the present invention, a series of filter hybridizations of the HIV-2 RNA genome with probes derived from the complete cloned HIV-1 genome and from the gag and pol genes were conducted. These hybridizations yielded only extremely weak signals even in conditions of very low stringency of hybridization and washing. Thus, it was found to be difficult to assess the amount of HIV-2 viral and proviral DNA in infected cells by Southern blot techniques. 
     Therefore, a complementary DNA (cDNA) to the HIV-2 genomic RNA initially was cloned in order to provide a specific hybridization probe. To construct this cDNA, an oligo (dT) primed cDNA first-strand was made in a detergent-activated endogenous reaction using HIV-2 reverse transcriptase with virions purified from supernatants of infected CEM cells. The CEM cell line is a lymphoblastoid CD4+ cell line described by G. E. Foley et al. in Cancer 18: 522-529 (1965), specifically incorporated herein by reference. The CEM cells used were infected with the isolate ROD and were continuously producing high amounts of HIV-2. 
     After second-strand synthesis, the cDNAs were inserted into the TG130 m13 bacteria phage vector. A collection of 10 4  M13 recombinant phages was obtained and screened in situ with an HIV-1 probe spanning 1.5 kb. of the 3′ end of the LAV BRU  isolate (depicted in FIG.  1 A). Some 50 positive plaques were detected, purified, and characterized by end sequencing and cross-hybridizing the inserts. This procedure is described in more detail in Example 1 and in FIG.  1 . 
     The different clones were found to be complementary to the 3′ end of a polyadenylated RNA having the AATAAA signal about 20 nucleotides upstream of the poly A tail, as found in the long terminal repeat (LTR) of HIV-1. The LTR region of HIV-1 has been described by S. Wain Hobson et al. in Cell 40: 9-17 (1985), specifically incorporated herein by reference. The portion of the HIV-2 LTR that was sequenced was related only distantly to the homologous domain in HIV-1 as demonstrated in FIG.  1 B. Indeed, only about 50% of the nucleotides could be aligned and about a hundred insertions/deletions need to be introduced. In comparison, the homology of the corresponding domains in HIV-1 isolates from USA and Africa is greater than 95% and no insertions or deletions are seen. 
     The largest insert of this group of M13 clones was a 2 kb. clone designated E2. Clone E2 was used as a probe to demonstrate its HIV-2 specificity in a series of filter hybridization experiments. Firstly, this probe could detect the genomic RNA of HIV-2 but not HIV-1 in stringent conditions as shown in FIGS. 2, C and D. Secondly, positive signals were detected in Southern blots of DNA from cells infected with the ROD isolate as well as other isolates of HIV-2 as shown in FIG. 2, A and FIG. 4, A. No signal was detected with DNA from uninfected cells or HIV-1 infected cells, confirming the exogenous nature of HIV-2. In undigested DNA from HIV-2 infected cells, an approximately 10 kb. species, probably corresponding to linear unintegrated viral DNA, was principally detected along with a species with an apparent size of 6 kb., likely to be the circular form of the viral DNA. Conversely, rehybridization of the same filter with an HIV-1 probe under stringent conditions showed hybridization to HIV-1 infected cells only as depicted in FIG. 2, B. 
     To isolate the remainder of the genome of HIV-2, a genomic library in lambda phage L47.1 was constructed. Lambda phage L47.1 has been described by W. A. M. Loenen et al. in Gene 10: 249-259 (1980), specifically incorporated herein by reference. The genomic library was constructed with a partial Sau3AI restriction digest of the DNA from the CEM cell line infected with HIV-2 ROD . 
     About 2×10 6  recombinant plaques were screened in situ with labelled insert from the E2 cDNA clone. Ten recombinant phages were detected and plaque purified. Of these phages, three were characterized by restriction mapping and Southern blot hybridization with the E2 insert and probes from its 3′ end (LTR) or 5′ end (envelope), as well as with HIV-1 subgenomic probes. In this instance, HIV-1 probes were used under non-stringent conditions. 
     A clone carrying a 9.5 kb. insert and derived from a circular viral DNA was identified as containing the complete genome and designated λROD 4. Two other clones, λROD 27 and λROD 35 were derived from integrated proviruses and found to carry an LTR and cellular flanking sequences and a portion of the viral coding sequences as shown in FIG. 3, A. 
     Fragments of the lambda clones were subcloned into a plasmid vector p UC 18. 
     Plasmid pROD 27-5′ is derived from λROD 27 and contains the 5′ 2 Kb of the HIV-2 genome and cellular flanking sequences (5′ LTR and 5′ viral coding sequences to the EcoRI site) 
     Plasmid pROD 4.8 is dervied from λROD 4 and contains the about 5 kb HindIII fragments that is the central part of the HIV-2 genome. 
     Plasmid pROD 27-5′ and pROD 4.8 inserts overlap. 
     Plasmid pROD 4.7 contains a HindIII 1.8 Kb fragment from λROD 4. This fragment is located 3′ to the fragment subcloned into pROD 4.8 and contains about 0.8 Kb of viral coding sequences and the part of the lambda phage (λL47.1) left arm located between the BamHl and HindIII cloning sites. 
     Plasmid pROD 35 contains all the HIV-2 coding sequences 3′ to the EcoRI site, the 3′ LTR and about 4 Kb of cellular flanking sequences. 
     Plasmid pROD 27-5′ and pROD 35 in  E. coli  strain HB 101 are deposited respectively under No. I-626 and I-633 at the CNCM, and have also been deposited at the NCIB (British Collection). These plasmids are depicted in FIG.  5 . Plasmid pROD 4.7 and pROD 4.8 in  E. coli  strain TG1 are deposited respectively under No. I-627 and I-628 at the CNCM. 
     To reconstitute the complete HIV-2 ROD genome, pROD 35 is linearized with EcoRI and the EcoRI insert of pROD 27-5′ is ligated in the correct orientation into this site. 
     The relationship of HIV-2 to other human and simian retroviruses was surmised from hybridization experiments. The relative homology of the different regions of the HIV-1 and 2 genomes was determined by hybridization of fragments of the cloned HIV-1 genome with the labelled λROD 4 expected to contain the complete HIV-2 genome (FIG. 3, B). Even in very low stringency conditions (Tm −42° C.), the hybridization of HIV-1 and 2 was restricted to a fraction of their genomes, principally the gag gene (dots 1 and 2), the reverse transcriptase domain in pol (dot 3), the end of pol and the Q (or sor) genes (dot 5) and the F gene (or 3′ orf) and 3′ LTR (dot 11). The HIV-1 fragment used to detect the HIV-2 cDNA clones contained the dot 11 subclone, which hybridized well to HIV-2 under non-stringent conditions. Only the signal from dot 5 persisted after stringent washing. The envelope gene, the region of the tat gene and a part of pol thus seemed very divergent. These data, along with the LTR sequence obtained (FIG. 1, B), indicated that HIV-2 is not an envelope variant of HIV-1 as described by Alizon et al.,  Cell  40:63-74 (1986). 
     It was observed that HIV-2 is related more closely to the Simian Immunodeficiency Virus (SIV) than it is to HIV-1. This correlation has been described by F. Clavel et al. in C.R. Acad. Sci. (Paris) 302: 485-488 (1986) and F. Clavel et al. in Science 233: 343-346 (1986), both of which are specifically incorporated herein by reference. Simian Immunodeficiency Virus (also designated Simian T-cell Lymphotropic Virus Type 3, STLV-3) is a retrovirus first isolated from captive macaques with an AIDS-like disease in the USA. This simian virus has been described by M. D. Daniel et al. in Science 228: 1201-1204 (1985), specifically incorporated herein by reference. 
     All the SIV proteins, including the envelope, are immune precipitated by sera from HIV-2 infected patients, whereas the serological cross-reactivity of HIV-1 to 2 is restricted to the core proteins. However SIV and HIV-2 can be distinguished by slight differences in the apparent molecular weight of their proteins. 
     In terms of nucleotide sequence, it also appears that HIV-2 is closely related to SIV. The genomic RNA of SIV can be detected in stringent conditions as shown in FIG. 2, C by HIV-2 probes corresponding to the LTR and 3′ end of the genome (E2) or to the gag or pol genes. Under the same conditions, HIV-1 derived probes do not detect the SIV genome as shown in FIG. 2, D. 
     In Southern blots of DNA from SIV-infected cells, a restriction pattern clearly different from HIV-2 ROD  and other isolates is seen. All the bands persist after a stringent washing, even though the signal is considerably weakened, indicating a sequence homology throughout the genomes of HIV-2 and SIV. It has recently been shown that baboons and macaques could be infected experimentally by HIV-2, thereby providing an interesting animal model for the study of the HIV infection and its preventive therapy. Indeed, attempts to infect non-human primates with HIV-1 have been successful only in chimpanzees, which are not a convenient model. 
     From an initial survey of the restriction maps for certain of the HIV-2 isolates obtained according to the methods described herein, it is already apparent that HIV-2, like HIV-1, undergoes restriction site polymorphism. FIG. 4A depicts examples of such differences for three isolates, all different one from another and from the cloned HIV-2 ROD . It is very likely that these differences at the nucleotide level are accompanied by variations in the amino-acid sequence of the viral proteins, as evidenced in the case of HIV-1 and described by M. Alizon et al. in Cell 46: 63-74 (1986), specifically incorporated herein by reference. It is also to be expected that the various isolates of HIV-2 will exhibit other minor amino acid heterogeneities. See, for example, Clavel et al.,  Nature  324 (18):691-695 (1986), specifically incorporated herein by reference. 
     Further, the chacterization of HIV-2 will also delineate the domain of the envelope glycoprotein that is responsible for the binding of the surface of the target cells and the subsequent internalization of the virus. This interaction was shown to be mediated by the CD4 molecule itself in the case of HIV-1 and similar studies tend to indicate that HIV-2 uses the same receptor. Thus, although there is wide divergence between the env genes of HIV-1 and 2, small homologous domains of the envelopes of the two HIV could represent a candidate receptor binding site. This site could constitute a target for use to raise a protective immune response against this group of retroviruses. 
     From the data discussed herein, certain nucleotide sequences have been identified which are capable of being used as probes in diagnostic methods to obtain the immunological reagents necessary to diagnose an HIV-2 infection. In particular, these sequences may be used as probes in hybridization reactions with the genetic material of infected patients to indicate whether the RNA of the HIV-2 virus is present in these patient&#39;s lymphocytes or whether an analogous DNA is present. In this embodiment, the test methods which may be utilized include Northern blots, Southern blots and dot blots. One particular nucleotide sequence which may be useful as a probe is the combination of the 5 kb. HindIII fragment of ROD 4 and the E2 cDNA used in FIG.  4 . 
     In addition, the genetic sequences of the HIV-2 virus may be used to create the polypeptides encoded by these sequences. Specifically, these polypeptides may be created by expression of the cDNA obtained according to the teachings herein in hosts such as bacteria, yeast or animal cells. These polypeptides may be used in diagnostic tests such as immunofluorescence assays (IFA), radioimmunoassays (RIA) and Western Blot tests. 
     Moreover, it is also contemplated that additional diagnostic tests, including additional immunodiagnostic tests, may be developed in which the DNA probes or the polypeptides of this invention may serve as one of the diagnostic reagents. The invention described herein includes these additional test methods. 
     In addition, monoclonal antibodies to these polypeptides or fragments thereof may be created. The monoclonal antibodies may be used in immunodiagnostic tests in an analogous manner as the polypeptides described above. 
     The polypeptides of the present invention may also be used as immunogenic reagents to induce protection against infection by HIV-2 viruses. In this embodiment, the polypeptides produced by recombinant-DNA techniques would function as vaccine agents. 
     Also, the polypeptides of this invention may be used in competitive assays to test the ability of various antiviral agents to determine their ability to prevent the virus from fixing on its target. 
     Thus, it is to be understood that application of the teachings of the present invention to a specific problem or environment will be within the capabilities of one having ordinary skill in the art in light of the teachings contained herein. Examples of the products of the present invention and representative processes for their isolation and manufacture appear above and in the following examples. 
     EXAMPLES 
     Example 1 
     Cloning of a cDNA Complementary To Genomic RNA From HIV-2 Virions 
     HIV-2 virions were purified from 5 liters of supernatant from a culture of the CEM cell line infected with the ROD isolate and a cDNA first strand using oligo (dT) primer was synthesized in detergent activated endogenous reaction on pelleted virus, as described by M. Alizon et al. in Nature, 312: 757-760 (1984), specifically incorporated herein by reference. RNA-cDNA hybrids were purified by phenol-chloroform extraction and ethanol precipitation. The second-strand cDNA was created by the DNA polymerase I/RNAase H method of Sanger et al. described in Proc. Nat&#39;l. Acad. Sci. USA, 74: 5463-5467 (1977), specifically incorporated herein by reference. The double-stranded cDNA was bluntended with T4 DNA polymerase using a commercial cDNA synthesis kit (obtained from Amersham). After attachment of EcoRI linkers (obtained from Pharmacia), EcoRI digestion, and ligation into EcoRI-digested dephosphorylated M13 tg 130 vector (obtained from Amersham), a cDNA library was obtained by transformation of the  E. coli  TG1 strain. Recombinant plaques (10 4 ) were screened in situ on replica filters with the 1.5 kb. HindIII fragment from clone J19, corresponding to the 3′ part of the genome of the LAV BRU  isolate of HIV-1,  32 P labelled to a specific activity of 10 9  cpm/μg. The filters were prehybridized in 5×SSC, 5×Denhardt solution, 25% formamide, and denatured salmon sperm DNA (100 μg/ml.) at 37° C. for 4 hours and hybridized for 16 hours in the same buffer (Tm −42° C.) plus 4×10 7  cpm of the labelled probe (10 6  cpm/ml. of hybridization buffer). The washing was done in 5×SSC, 0.1% SDS at 25° C. for 2 hours. 20×SSC is 3M NaCl, 0.3M Na citrate. Positive plaques were purified and single-stranded M13 DNA prepared and end-sequenced according to the method of Sanger et al., supra. 
     Example 2 
     Hybridization of DNA From HIV-1 and HIV-2 Infected Cells and RNA From HIV-1 and 2 and SIV Virons With a Probe Derived From an HIV-2 Cloned cDNA 
     DNA was extracted from infected CEM cells continuously producing HIV-1 or 2. The DNA digested with 20 μg of PstI or undigested, was electrophoresed on a 0.8% agarose gel, and Southern-transferred to nylon membrane. Virion dot-blots were prepared in duplicate, as described by F. Clavel et al. in Science 233: 343-346 (1986), specifically incorporated herein by reference, by pelleting volumes of supernatant corresponding to the same amount of reverse transcriptase activity. Prehybridization was done in 50% formamide, 5×SSC, 5×Denhardt solution, and 100 mg./ml. denatured salmon sperm DNA for 4 hours at 42° C. Hybridization was performed in the same buffer plus 10% Dextran sulphate, and 10 6  cpm/ml. of the labelled E2 insert (specific activity 10 9  cpm/μg) for 16 hours at 42° C. Washing was in 0.1×SSC, 0.1% SDS for 2×30 mn. After exposition for 16 hours with intensifying screens, the Southern blot was dehybridized in 0.4 N NaOH, neutralized, and rehybridized in the same conditions to the HIV-1 probe labelled to 10 9  cpm/μg. 
     Example 3 
     Cloning in Lambda Phage of the Complete Provirus DNA of HIV-2 
     DNA from the HIV-2 ROD  infected CEM (FIG. 2, lanes a and c) was partially digested with Sau3AI. The 9-15 kb. fraction was selected on a 5-40% sucrose gradient and ligated to BamHI arms of the lambda L47.1 vector. Plaques (2×10 6 ) obtained after in vitro packaging and plating on  E. coli  LA 101 strain were screened in situ with the insert from the E2 cDNA clone. Approximately 10 positive clones were plaque purified and propagated on  E. coli  C600 rec BC. The ROD 4, 27, and 35 clones were amplified and their DNA characterized by restriction mapping and Southern blotting with the HIV-2 cDNA clone under stringent conditions, and gag-pol probes from HIV-1 used under non stringent conditions. 
     Example 4 
     Sequences of the Coding Regions for the Evelope Protein and GAG Product of the ROD HIV-2 Isolate 
     Additional experimental analysis of the HIV-2 ROD isolate was performed and has yielded the following sequences for the env ar gag sequences. Regions coding for amino acid sequences corresponding to known proteins characterized by apparent molecular weights have been identified within the gag sequence: p. 16 (nucleotides 1-405), p. 26 (406-1155) and p. 12 (1156-1566). 
     
       
         
               
               
             
           
               
                 Envelope sequence: 
                   
               
               
                 Met Met Asn Gln Leu Leu lle Ala Ile Leu Leu Ala Ser Ala Cys 
               
               
                 ATGATGAATCAGCTGCTTATTGCCATTTTATTAGCTAGTGCTTGC 
               
               
                   
               
               
                 Leu Val Tyr Cys Thr Gln Tyr Val Thr Val Phe Tyr Gly Val Pro 
               
               
                 TTAGTATATTGCACCCAATATGTAACTGTTTTCTATGGCGTACCC 
               
               
                   
               
               
                 Thr Trp Lys Asn Ala Thr Ile Pro Leu Phe Cys Ala Thr Arg Asn 
               
               
                 ACGTGGAAAAATGCAACCATTCCCCTCTTTTGTGCAACCAGAAAT 
               
               
                   
               
               
                          100 
               
               
                 Arg Asp Thr Trp Gly Thr Ile Gln Cys Leu Pro Asp Asn Asp Asp 
               
               
                 AGGGATACTTGGGGAACCATACAGTGGTTGCCTGACAATGATGAT 
               
               
                   
               
               
                 Tyr Gln Glu Ile Thr Leu Asn Val Thr Glu Ala Phe Asp Ala Trp 
               
               
                 TATCAGGAAATAACTTTGAATGTAACAGAGGCTTTTGATGCATGG 
               
               
                   
               
               
                                       200 
               
               
                 Asn Asn Thr Val Thr Glu Gln Ala Ile Glu Asp Val Trp His Leu 
               
               
                 AATAATACAGTAACAGAACAAGCAATAGAAGATGTCTGGCATCTA 
               
               
                   
               
               
                 Phe Glu Thr Ser Ile Lys Pro Cys Val Lys Leu Thr Pro Leu Cys 
               
               
                 TTCGAGACATCAATAAAACCATGTGTGAAACTAACACCTTTATGT 
               
               
                   
               
               
                                                     300 
               
               
                 Val Ala Met Lys Cys Ser Ser Thr GIu Ser Ser Thr Gly Asn Asn 
               
               
                 GTAGCAATGAAATGCAGCAGCACAGAGAGCAGCACAGGGAACAAC 
               
               
                   
               
               
                 Thr Thr Ser Lys Ser Thr Ser Thr Thr Thr Thr Thr Pro Thr Asp 
               
               
                 ACAACCTCAAAGAGCACAAGCACAACCACAACCACACCGAGAGAC 
               
               
                   
               
               
                                                                  400 
               
               
                 Gln Glu Gln Glu Ile Ser Glu Asp Thr Pro Cys Ala Arg Ala Asp 
               
               
                 CAGGAGCAAGAGATAAGTGAGGATACTCCATGCGCACGCGCAGAC 
               
               
                   
               
               
                 Asn Cys Ser Gly Leu Gly Glu Glu Glu Thr Ile Asn Cys Gln Phe 
               
               
                 AACTGCTCAGGATTGGGAGAGGAAGAAACGATCAATTGCCAGTTC 
               
               
                   
               
               
                 Asn Met Thr Gly Leu Glu Arg Asp Lys Lys Lys Gln Tyr Asn Glu 
               
               
                 AATATGACAGGATTAGAAAGAGATAAGAAAAAACAGTATAATGAA 
               
               
                   
               
               
                   500 
               
               
                 Thr Trp Tyr Ser Lys Asp Val Val Cys Glu Thr Asn Asn Ser Thr 
               
               
                 ACATGGTACTCAAAAGATGTGGTTTGTGAGACAAATAATAGCACA 
               
               
                   
               
               
                 Asn Gln Thr Gln Cys Tyr Met Asn His Cys Asn Thr Ser Val Ile 
               
               
                 AATCAGACCCAGTGTTACATGAACCATTGCAACACATCAGTCATC 
               
               
                                 600 
               
               
                 Thr Glu Ser Cys Asp Lys His Tyr Trp Asp Ala Ile Arg Phe Arg 
               
               
                 ACAGAATCATGTGACAAGCACTATTGGGATGCTATAAGGTTTAGA 
               
               
                   
               
               
                 Tyr Cys Ala Pro Pro Gly Tyr Ala Leu Leu Arg Cys Asn Asp Thr 
               
               
                 TACTGTGCACCACCGGGTTATGCCCTATrAAGATGTAATGATACC 
               
               
                                              700 
               
               
                 Asn Tyr Ser Gly Phe Ala Pro Asn Cya Ser Lys Val Val Ala Ser 
               
               
                 AATTATTCAGGCTTUGCACCCAACTGTTCTAAAGTAGTAGCTTCT 
               
               
                   
               
               
                 Thr Cys Thr Arg Met Met Glu Thr GIn Thr Ser Thr Trp Phe Gly 
               
               
                 ACATGCACCAGGATGATGGAAACGCAAACTTCCACATGGTTTGGC 
               
               
                                                           800 
               
               
                 Phe Asn Gly Thr Arg Ala Glu Asn Arg Thr Tyr Ile Tyr Trp His 
               
               
                 TTTAATGGCACTAGAGCAGAGAATAGAACATATATCTATTGGCAT 
               
               
                   
               
               
                 Gly Arg Asp Asn Arg Thr Ile Ile Ser Leu Asn Lys Tyr Tyr Asn 
               
               
                 GGCAGAGATAATAGAACTATCATCAGCTTAAACAAATATTATAAT 
               
               
                   
               
               
                                                                         900 
               
               
                 Leu Ser Leu His Cys Lys Arg Pro Gly Asn Lys Thr Val Lys Gln 
               
               
                 CTCAGTTTGCATTGTAAGAGGCCAGGGAATAAGACAGTGAAACAA 
               
               
                   
               
               
                 Ile Met Leu Met Ser Gly His Val Phe His Ser His Tyr Gln Pro 
               
               
                 ATAATGCTTATGTCAGGACATGTGTTTCACTCCCACTACCAGCCG 
               
               
                   
               
               
                 Ile Asn Lys Arg Pro Arg Gln Ala Trp Cys Trp Phe Lys Gly Lys 
               
               
                 ATCAATAAAAGACCCAGACAAGCATGGTGCTGGTTGAAAGGCAAA 
               
               
                   
               
               
                         1000 
               
               
                 Trp Lys Asp Ala Met Gln Glu Val Lys Thr Leu Ala Lys His Pro 
               
               
                 TGGAAAGACGCCATGCAGGAGGTGAAGACCCTTGCAAAACATCCC 
               
               
                   
               
               
                 Arg Tyr Arg Gly Thr Asn Asp Thr Arg Asn Ile Ser Phe Ala Ala 
               
               
                 AGGTATAGAGGAACCAATGACACAAGGAATATTAGCTTTGCAGCG 
               
               
                   
               
               
                                      1100 
               
               
                 Pro Gly Lys Gly Ser Asp Pro Glu Val Ala Tyr Met Trp Thr Asn 
               
               
                 CCAGGAAAAGGCTCAGACCCAGAAGTAGCATACATGTGGACTAAC 
               
               
                   
               
               
                 Cys Arg Gly Glu Phe Leu Tyr Cys Asn Met Thr Trp Phe Leu Asn 
               
               
                 TGCAGAGGAGAGTTTCTCTACTGCAACATGACTTGGTTCCTCAAT 
               
               
                   
               
               
                                                   1200 
               
               
                 Trp Ile Glu Asn Lys Thr His Arg Asn Tyr Ala Pro Cys His Ile 
               
               
                 TGGATAGAGAATAAGACACACCGCAATTATGCACCGTGCCATATA 
               
               
                   
               
               
                 Lys Gln Ile Ile Asn Thr Trp His Lys Val Gly Arg Asn Val Tyr 
               
               
                 AAGCAAATAATTAACACATGGCATAAGGTAGGGAGAAATGTATAT 
               
               
                   
               
               
                                                                 1300 
               
               
                 Leu Pro Pro Arg Glu Gly Glu Leu Ser Cys Asn Ser Thr Val Thr 
               
               
                 TTGCCTCCCAGGGAAGGGGAGCTGTCCTGCAACTCAACAGTAACC 
               
               
                   
               
               
                 Ser Ile Ile Ala Asn Ile Asp Trp Gln Asn Asn Asn Gln Thr Asn 
               
               
                 AGCATAATTGCTAACATTGACTGGCAAAACAATAATCAGACAAAC 
               
               
                   
               
               
                 Ile Thr Phe Ser Ala Glu Val Ala Glu Leu Tyr Arg Leu Glu Leu 
               
               
                 ATTACCTTTAGTGCAGAGGTGGCAGAACTATACAGATTGGAGTTG 
               
               
                   
               
               
                  1400 
               
               
                 Gly Asp Tyr Lys Leu Val Glu Ile Thr Pro Ile Gly Phe Ala Pro 
               
               
                 GGAGATTATAAATTGGTAGAAATAACACCAATTGGCTTCGCACCT 
               
               
                   
               
               
                 Thr Lys Glu Lys Arg Tyr Ser Ser Ala His Gly Arg His Thr Arg 
               
               
                 ACAAAAGAAAAAAGARACTCCTCTGCTGACGGGAGACATAGAAGA 
               
               
                   
               
               
                               1500 
               
               
                 Gly Val Phe Val Leu Gly Phe Leu Gly Phe Leu Ala Thr Ala Gly 
               
               
                 GGTGTGTTCGTGCTAGGGTTCTTGGGTTTCTCGCAACAGCAGGT 
               
               
                   
               
               
                 Ser Ala Met Gly Ala Arg Ala Ser Leu Thr Val Ser Ala Gln Ser 
               
               
                 TCTGCAATGGGCGCTCGAGCGTCCCTGACCGTGTCGGCTCAGTGC 
               
               
                   
               
               
                                             1600 
               
               
                 Arg Thr Leu Leu Ala Gly Ile Val Gln Gln Gln Gln Gln Leu Leu 
               
               
                 CGGACTTTACTGGCCGGGATAGTGCAGCAACAGGAACAGCTGTTG 
               
               
                   
               
               
                 Asp Val Val Lys Arg Gln Gln Glu Leu Leu Arg Leu Thr Val Trp 
               
               
                 GACGTGGTCAAGAGACAACAAGAACTGTTGCGACTGACCGTCTGG 
               
               
                   
               
               
                                                          1700 
               
               
                 Gly Thr Lys Asn Leu Gln Ala Arg Val Thr Ala Ile Glu Lys Tyr 
               
               
                 GGAACGAAAAACCTCCAGGCAAGAGTCACTGCTATAGAGAAGTAC 
               
               
                   
               
               
                 Leu Glu Asp Gln Ala Arg Leu Asn Ser Trp Gly Cys Ala Phe Arg 
               
               
                 CTACAGGACCAGGCGCGGCTAAATTCATGGGGATGTGCGTTTAGA 
               
               
                   
               
               
                                                                       1800 
               
               
                 Gln Val Cys His Thr Thr Val Pro Trp Val Asn Asp Ser Leu Ala 
               
               
                 CAAGTCTGCCACACTACTGTACCATGGGTTAATGATTCCTTAGGA 
               
               
                   
               
               
                 Pro Asp Trp Asp Asn Met Thr Trp Gln Glu Trp Glu Lys Gln Val 
               
               
                 CCTGACTGGGACAATATGACGTGGCAGGAATGGGAAAAACAAGTC 
               
               
                   
               
               
                 Arg Tyr Leu Glu Ala Asn Ile Ser Lys Ser Leu Glu Gln Ala Gln 
               
               
                 CGCTACCTGGAGGCAAATATCAGTAAAAGTTTAGAACAGGCACAA 
               
               
                   
               
               
                         1900 
               
               
                 ILe Gln Gln Glu Lys Asn Met Tyr Glu Leu Gln Lys Leu Asn Ser 
               
               
                 ATTCAGCAAGAGAAAAATATGTATGAACTACAAAAATTAAATAGC 
               
               
                   
               
               
                 Trp Asp Ile Phe Gly Asn Trp Phe Asp Leu Thr Ser Trp Val Lys 
               
               
                 TGGGATATTTTTGGCAATTGGTTTGACTTAACCTCCTGGGTCAAG 
               
               
                   
               
               
                                      2000 
               
               
                 Tyr Ile Gln Tyr Gly Val Leu Ile Ile Val Ala Val Ile Ala Leu 
               
               
                 TATATTCAATATGGAGTGCTTATAATAGTAGCAGTAATAGCTTTA 
               
               
                   
               
               
                 Arg Ile Val Ile Tyr Val Val Gln Met Leu Ser Arg Leu Arg Lys 
               
               
                 AGAATAGTGATATATGTAGTACAAATGTTAAGTAGGCTTAGAAAG 
               
               
                   
               
               
                                                   2100 
               
               
                 Gly Tyr Arg Pro Val Phe Ser Ser Pro Pro Gly Tyr Ile Gln *** 
               
               
                 GGCTATAGGCCTGTTTTCTCTTCCCCCCCCGGTTATATCCAATAG 
               
               
                   
               
               
                 Ile His Ile His Lys Asp Arg Gly Gln Pro Ala Asn Glu Glu Thr 
               
               
                 ATCCATATCCACAAGGACCGGGGACAGCCAGCCAACGAAGAAACA 
               
               
                   
               
               
                                                                 2200 
               
               
                 Glu Glu Asp Gly Gly Ser Asn Gly Gly Asp Arg Tyr Trp Pro Trp 
               
               
                 GAAGAAGACGGTGGAAGCAACGGTGGAGACAGATACTGGCCCTGG 
               
               
                   
               
               
                 Pro Ile Ala Tyr Ile His Phe Leu Ile Arg Gln Leu Ile Arg Leu 
               
               
                 GCGATAGCATATATACATTTCCTGATCCGCCAGCTGATTCGCCTC 
               
               
                   
               
               
                 Leu Thr Arg Leu Tyr Ser Ile Cys Arg Asp Leu Leu Ser Arg Ser 
               
               
                 TTGACCAGACTATACAGCATCTGCAGGGACTTACTATCCAGGAGC 
               
               
                   
               
               
                  2300 
               
               
                 Phe Leu Thr Leu GIn Leu IIe Tyr GIn Asn Leu Arg Asp Trp Leu 
               
               
                 TTCCTGACCCTCCAACTCATCTACCAGAATCTCAGAGACTGGCTG 
               
               
                   
               
               
                 Arg Leu Arg Thr Ala Phe Leu Glu Tyr Gly Cys Glu Trp Ile Gln 
               
               
                 AGACTTAGAACAGCCTTCTTGCAATATGGGTGCGAGTGGATCCAA 
               
               
                   
               
               
                               2400 
               
               
                 Glu Ala Phe Gln Ala Ala Ala Arg Ala Thr Arg Glu Thr Leu Ala 
               
               
                 GAAGCATTCCAGGCCGCCGCGAGGGCTACAAGAGAGACTCTTGCG 
               
               
                   
               
               
                 Gly Ala Cys Arg Gly Leu Trp Arg Val Leu Glu Arg Ile Gly Arg 
               
               
                 GGCGCGTGCAGGGGCTTGTGGAGGGTATTGGAACGAATCGGGAGG 
               
               
                   
               
               
                                             2500 
               
               
                 Gly Ile Leu Ala Val Pro Arg Arg Ile Arg Gln Gly Ala Glu Ile 
               
               
                 GGAATACTCGCGGTTCCAAGAAGGATCAGACAGGGAGCAGAAATC 
               
               
                   
               
               
                 Ala Leu Leu *** Gly Thr Ala Val Ser Ala Gly Arg Leu Tyr Glu 
               
               
                 GCCCTCCTGTGAGGGACGGCAGTATCAGCAGGGAGACTTTATGAA 
               
               
                   
               
               
                                                          2600 
               
               
                 Tyr Ser Met Glu Gly Pro Ser Ser Arg Lys Gly Glu Lys Phe Val 
               
               
                 TACTCCATGGAAGGACCCAGCAGCAGAAAGGGAGAAAAATTTGTA 
               
               
                   
               
               
                 Gln Ala Thr Lys Tyr Gly 
               
               
                 CAGGCAACAAAATATGGA 
               
             
          
         
       
     
     
       
         
               
               
             
           
               
                 GAG sequence: 
                   
               
               
                 Met Gly Ala Arg Asn Ser Val Leu Arg Gly Lys Lys Ala Asp Gla 
               
               
                 ATGGGCGCGAGAAACTCCGTCTTGAGAGGGAAAAAAGCAGATGAA 
               
               
                   
               
               
                 Leu Glu Arg Ile Arg Leu Arg Pro Gly Gly Lys Lys Lys Tyr Arg 
               
               
                 TTAGAAAGAATCAGGTTACGGCCCGGCGGAAAGAAAAAGTACAGG 
               
               
                   
               
               
                 Leu Lys His Ile Val Trp Ala Ala Asn Lys Leu Asp Arg Phe Gly 
               
               
                 CTAAAACATATTGTGTGGGCAGCGAATAAATTGGACAGATTCGGA 
               
               
                   
               
               
                          100 
               
               
                 Leu Ala Glu Ser Leu Leu Glu Ser Lys Glu Gly Cys Gln Lys Ile 
               
               
                 TTAGCAGAGAGCCTGTTGGAGTCAAAAGAGGGTTGTCAAAAAATT 
               
               
                   
               
               
                 Leu Thr Val Leu Asp Pro Met Val Pro Thr Gly Ser Glu Asn Leu 
               
               
                 CTTACAGTTTTAGATCCAATGGTACCGACAGGTTCAGAAAATTTA 
               
               
                   
               
               
                                      200 
               
               
                 Lys Ser Leu Phe Asn Thr Val Cys Val Ile Trp Cys Ile His Ala 
               
               
                 AAAAGTCTTTTTAATACTGTCTGCGTCATTTGGTGCATACAGGCA 
               
               
                   
               
               
                 Glu Glu Lys Val Lys Asp Thr Glu Gly Ala Lys Gln Ile Val Arg 
               
               
                 GAAGAGAAAGTGAAAGATACTGAAGGAGCAAAACAAATAGTGCGG 
               
               
                   
               
               
                                                     300 
               
               
                 Arg His Leu Val Ala Glu Thr Gly Thr Ala Glu Lys Met Pro Ser 
               
               
                 AGACATCTAGTGGCAGAAACAGGAACTGCAGAGAAAATGCCAAGG 
               
               
                   
               
               
                 Thr Ser Arg Pro Thr Ala Pro Ser Ser Glu Lys Gly Gly Asn Tyr 
               
               
                 ACAAGTAGACCAACAGCACCATCTAGCGAGAAGGGAGGAAATTAC 
               
               
                   
               
               
                                    400 
               
               
                 Pro Val Gln His Val Gly Gly Asn Tyr Thr His Ile Pro Leu Ser 
               
               
                 CCAGTGCAACATGTAGGCGGCAACTACACCCATATACCGCTQAGT 
               
               
                   
               
               
                 Pro Arg Thr Leu Asn Ala Trp Val Lys Leu Val Glu Glu Lys Lys 
               
               
                 CCCCGAACCCTAAATGCCTGGGTAAAATTAGTAGAGGAAAAAAAG 
               
               
                   
               
               
                 Phe Gly Ala Glu Val Val Pro Gly Phe Gln Ala Leu Ser Glu Gly 
               
               
                 TTCGGGGCAGAAGTAGTGCCAGGATTTCAGGCACTCTCAGAAGGC 
               
               
                   
               
               
                   500 
               
               
                 Cys Thr Pro Tyr Asp Ile Asn Gln Met Leu Asn Cys Val Gly Asp 
               
               
                 TGCACGCCCTATGATATCAACCAAATGCTTAATTGTGTGGGCGAC 
               
               
                   
               
               
                 His Gln Ala Ala Met Gln Ile Ile Arg Glu Ile Ile Asn Glu Glu 
               
               
                 CATCAAGCAGCCATGCAGATAATCAGGGAGATTATCAATGAGGAA 
               
               
                   
               
               
                                   600 
               
               
                 Ala Ala Glu Trp Asp Val Gln His Pro Ile Pro Gly Pro Leu Pro 
               
               
                 GCAGCAGAATGGGATGTGCAACATCCAATACCAGGCCCCTTACCA 
               
               
                   
               
               
                                                 700 
               
               
                 Thr Ser Thr Val Glu Glu Gln Ile Gln Trp Met Phe Arg Pro Gln 
               
               
                 ACAAGCACAGTAGAAGAACAGATCCAGTGGATGTTTAGGCCAGAA 
               
               
                   
               
               
                 Asn Pro Val Pro Val Gly Asn Ile Tyr Arg Arg Trp Ile Gln Ile 
               
               
                 AATCCTGTACCAGTAGGAAACATCTATAGAAGATGGATCCAGATA 
               
               
                   
               
               
                                                           800 
               
               
                 Gly Leu Gln Lys Cys Val Arg Met Tyr Asn Pro Thr Asn Ile Leu 
               
               
                 GGATTGCAGAAGTGTGTCAGGATGTACAACCCGACCAACATCCTA 
               
               
                   
               
               
                 Asp Ile Lys Gln Gly Pro Lys Glu Pro Phe Gln Ser Tyr Val Asp 
               
               
                 GACATAAAACAGGGACCAAAGGAGCCGTTCCAAAGCTATGTAGAT 
               
               
                   
               
               
                                                                         900 
               
               
                 Arg Phe Tyr Lys Ser Leu Arg Ala Glu Gln Thr Asp Pro Ala Val 
               
               
                 AGATTCTACAAAAGCTTGAGGGCAGAACAAACAGATCCAGCAGTG 
               
               
                   
               
               
                 Lys Asn Trp Met Thr Gln Thr Leu Leu Val Gln Asn Ala Asn Pro 
               
               
                 AAGAATTGGATGACCCAAACACTGCTAGTACAAAATGCCAACCCA 
               
               
                   
               
               
                 Asp Cys Lys Leu Val Leu Lys Gly Leu Gly Met Asn Pro Thr Leu 
               
               
                 GACTGTAAATTAGTGCTAAAAGGACTAGGGATGAACCCTACCTTA 
               
               
                   
               
               
                         1000 
               
               
                 Glu Glu Met Leu Thr Ala Cys Gln Gly Val Gly Gly Pro Gly Gln 
               
               
                 GAAGAGATGCTGACCGCCTGTCAGGGGGTAGGTGGGCCAGGCCAG 
               
               
                   
               
               
                 Lys Ala Arg Leu Met Ala Glu Ala Leu Lys Glu Val Ile Gly Pro 
               
               
                 AAAGCTAGATTAATGGCAGAGGCCCTGAAAGAGGTCATAGGACCT 
               
               
                   
               
               
                                      1100 
               
               
                 Ala Pro Ile Pro Phe Ala Ala Ala Gln Gln Arg Lys Ala Phe Lys 
               
               
                 GCCCCTATCCCATTCGCAGCAGCCCAGGAGAGAAAGGCATTTAAA 
               
               
                   
               
               
                 Cys Trp Asn Cys Gly Lys Glu Gly His Ser Ala Arg Gln Cys Arg 
               
               
                 TGCTGGAACTGTGGAAAGGAAGGGCACTCGGCAAGACAATGCCGA 
               
               
                   
               
               
                                                   1200 
               
               
                 Ala Pro Arg Arg Gln Gly Cys Trp Lys Cys Gly Lys Pro Gly His 
               
               
                 GCACCTAGAAGGCAGGGCTGCTGGAAGTGTGGTAAGCCAGGACAC 
               
               
                   
               
               
                 Ile Met Thr Asn Cys Pro Asp Arg Gln Ala Gly Phe Leu Gly Leu 
               
               
                 ATCATGACAAACTGCCCAGATAGACAGGCAGGTTTTTTAGGACTG 
               
               
                   
               
               
                                                                 1300 
               
               
                 Gly Pro Trp Gly Lys Lys Pro Arg Asn Phe Pro Val Ala Gln Val 
               
               
                 GGCCCTTGGGGAAAGAAGCCCCGCAACTTCCCCGTGGCCCAAGTT 
               
               
                   
               
               
                 Pro Gln Gly Leu Thr Pro Thr Ala Pro Pro Val Asp Pro Ala Val 
               
               
                 CCGCAGGGGCTGACACCAACAGCACCCCCAGTGGATCCAGCAGTG 
               
               
                   
               
               
                 Asp Leu Leu Glu Lys Tyr Met Gln Gln Gly Lys Arg Gln Arg Glu 
               
               
                 GATCTACTGGAGAAATATATGCAGCAAGGGAAAAGACAGAGAGAG 
               
               
                   
               
               
                  1400 
               
               
                 Gln Arg Glu Arg Pro Tyr Lys Glu Val Thr Glu Asp Leu Leu His 
               
               
                 CAGAGAGAGAGACCATACAAGGAAGTGACAGAGGACTTACTGCAC 
               
               
                   
               
               
                 Leu Glu Gln Gly Glu Thr Pro Tyr Arg Glu Pro Pro Thr Glu Asp 
               
               
                 CTCGAGCAGGGGGAGACACCATACAGGGAGCCACCAACAGAGGAC 
               
               
                   
               
               
                                1500 
               
               
                 Leu Leu  His Leu Asn Ser Leu Phe Gly Lys Asp Gln 
               
               
                 TTGCTGCACCTCATTTCTCTCTTTGGAAAAGACCAG 
               
             
          
         
       
     
     Example 5 
     Peptide Sequences Encoded By the ENV and GAG Sequences 
     The following coding regions for antigenic peptides, identified by nucleotide numbers within the gene sequences of Example 4, are of particular interest. 
     env1 (1735-1809) 
     
       
         
               
             
           
               
                 Val Thr Ala Ile Glu Lys Tyr Leu Glu Asp Gln Ala 
               
               
                 GTCACTGCTATAGAGAAGTAGCTACAGGACCAGGCG 
               
               
                   
               
               
                 Arg Leu Asn Ser Trp Gly Cys Ala Phe Arg Gln Val 
               
               
                 CGCCTAAATTCATGGGGATGTGCGTTTAGACAAGTC 
               
               
                                           1800 
               
               
                   
               
               
                 Cys 
               
               
                 TGC 
               
               
                   
               
               
                 env2 (1912-1983) 
               
               
                   
               
               
                 Ser Lys Ser Leu Glu Gln Ala Gln Ile Gln Gln Glu 
               
               
                 AGTAAAAGTTTAGAACAGGCACAAATTCAGCAAGAG 
               
               
                                          1940 
               
               
                   
               
               
                 Lys Asn Met Tyr Glu Leu Gln Lys Leu Asn Ser Trp 
               
               
                 AAAAATATGTATGAACTACAAAAATTAAATAGCTGG 
               
               
                 env3 (1482-1530) 
               
               
                   
               
               
                 Pro Thr Lys Glu Lys Arg Tyr Ser Ser Ala His Gly 
               
               
                 CCTACAAAAGAAAAAAGATACTCCTCTGCTCACGGG 
               
               
                               1500 
               
               
                   
               
               
                 Arg His Thr Arg 
               
               
                 AGACATACAAGA 
               
               
                   
               
               
                 env4 (55-129) 
               
               
                   
               
               
                 Cys Thr Gln Tyr Val Thr Val Phe Tyr Gly Val Pro 
               
               
                 TGCACCCAATATGTAACTGTTTTCTATGGCGTACCC 
               
               
                   
               
               
                 Thr Trp Lys Asn Ala Thr Ile Pro Leu Phe Cys Ala Thr 
               
               
                 ACGTGGAAAAATGCAACCATTCCCCTGTTTTGTGCA ACC 
               
               
                        100 
               
               
                   
               
               
                 env5 (175-231) 
               
               
                   
               
               
                 Asp Asp Tyr Gln Glu Ile Thr Leu Asn Val Thr Glu 
               
               
                 GATGATTATCAGGAAATAACTTTGAATGTAACAGAG 
               
               
                                        200 
               
               
                   
               
               
                 Ala Phe Asp Ala Trp Asn Asn 
               
               
                 GCTTTTGATGCATGGAATAAT 
               
               
                   
               
               
                 env6 (274-330) 
               
               
                   
               
               
                 Glu Thr Ser Ile Lys Pro Cys Val Lys Leu Thr Pro 
               
               
                 GAGACATCAATAAAACCATGTGTGAAACTAACACCT 
               
               
                                         300 
               
               
                   
               
               
                 Leu Cys Val Ala Met Lys Cys 
               
               
                 TTATGTGTAGCAATGAAATGC 
               
               
                   
               
               
                 env7 (607-660) 
               
               
                   
               
               
                 Asn His Cys Asn Thr Ser Val Ile Thr Glu Ser Cys 
               
               
                 AACCATTGCAACACATCAGTCATCACAGAATCATGT 
               
               
                  610 
               
               
                   
               
               
                 Asp Lys His Tyr Trp Asp 
               
               
                 GACAAGCACTATTGGGAT 
               
               
                   
               
               
                 env8 (661-720) 
               
               
                   
               
               
                 Ala Ile Arg Phe Arg Tyr Cys Ala Pro Pro Gly Tyr 
               
               
                 GCTATAAGGTTTAGATACTGTGCACCACGGGGTTAT 
               
               
                   
               
               
                 Ala Leu Leu Arg Cys Asn Asp Thr 
               
               
                 GCCCTATTAAGATGTAATGATACC 
               
               
                  700 
               
               
                   
               
               
                 env9 (997-1044) 
               
               
                 Lys Arg Pro Arg Gln Ala Trp Cys Trp Phe Lys Gly 
               
               
                 AAAAGACCCAGACAAGCATGGTGCTGGTTCAAAGGC 
               
               
                 1000 
               
               
                   
               
               
                 Lys Trp Lys Asp 
               
               
                 AAATGGAAAGAC 
               
               
                   
               
               
                 env10 (1132-1215) 
               
               
                   
               
               
                 Lys Gly Ser Asp Pro Glu Val Ala Tyr Met Trp Thr 
               
               
                 AAAGGCTCAGACCCAGAAGTAGCATACATGTGGACT 
               
               
                   
               
               
                 Asa Cys Arg Gly Glu Phe Leu Tyr Cys Asn Met Thr 
               
               
                 AACTGCAGAGGAGAGTTTCTCTACTGCAACATGACT 
               
               
                                              1200 
               
               
                   
               
               
                 Trp Phe Leu Asn 
               
               
                 TGGTTCCTCAAT 
               
               
                   
               
               
                 env11 (1237-1305) 
               
               
                   
               
               
                 Arg Asn Tyr Ala Pro Cys His Ile Lys Gln Ile Ile 
               
               
                 CGCAATTATGCACCGTGCCATATAAAGCAAATAATT 
               
               
                   
               
               
                 Asn Thr Trp His Lys Val Gly Arg Asn Val Tyr 
               
               
                 AACACATGGCATAAGGTAGGGAGAAATGTATAT 
               
               
                                         1300 
               
               
                   
               
               
                 gag1 (991-1053) 
               
               
                   
               
               
                 Asp Cys Lys Leu Val Leu Lys Gly Leu Gly Met Asn 
               
               
                 GACTGTAAATTAGTGCTAAAAGOACTAGGGATGAAC 
               
               
                       1000 
               
               
                   
               
               
                 Pro Thr Leu Glu Glu Met Leu Thr Ala 
               
               
                 CCTACCTTAGAAGAGATGCTGACCGCC 
               
             
          
         
       
     
     Of the foregoing peptides, env1, env2, env3 and gag1 are particularly contemplated for diagnostic purposes, and env4, env5, env6, env7, env8, env9, env10 and env11 are particularly contemplated as protecting agents. The foregoing peptides can be synthesized by conventional protein synthesis techniques, such as that of Merrifield. 
     It will be apparent to those skilled in the art that various modifications and variations can be made in the processes and