WO2014026033A1

WO2014026033A1 - Cross-reactive t cell epitopes of hiv, siv, and fiv for vaccines in humans and cats

Info

Publication number: WO2014026033A1
Application number: PCT/US2013/054191
Authority: WO
Inventors: Janet K. Yamamoto
Original assignee: University Of Florida Research Foundation, Inc.
Priority date: 2012-08-08
Filing date: 2013-08-08
Publication date: 2014-02-13
Also published as: US20150231230A1; WO2016130560A3; WO2014026033A9; US20180228890A1; US9913895B2; US10905757B2; WO2016130560A2

Abstract

The subject invention concerns methods and materials for inducing an immune response in an animal or person against an immunodeficiency virus, such as HIV, SIV, or FIV. In one embodiment, a method of the invention comprises administering one or more antigens to the person or animal wherein the antigen comprises one or more evolutionarily conserved epitopes of immunodeficiency viruses. In one embodiment, the epitope is one that is conserved between HIV and SIV, or between HIV and FIV. In another embodiment, the epitope is one that is conserved between HIV, SIV, and FIV.

Description

DESCRIPTION

CROSS-REACTIVE T CELL EPITOPES OF HIV, SIV, AND FIV FOR VACCINES IN

HUMANS AND CATS

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of U.S. Provisional Application Serial No. 61/841,122, filed June 28, 2013, U.S. Provisional Application Serial No. 61/684,592, filed August 17, 2012, and U.S. Provisional Application Serial No. 61/681,014, filed August 8, 2012, each of which is hereby incorporated by reference herein in its entirety, including any figures, tables, nucleic acid sequences, amino acid sequences, or drawings.

GOVERNMENT SUPPORT This invention was made with government support under grant numbers

R01-AI65276 and R01-AI30904 awarded by the National Institutes of Health. The government has certain rights in the invention.

BACKGROUND OF THE INVENTION An effective prophylactic HIV-1 vaccine is needed to eradicate the HIV/ AIDS pandemic but designing such a vaccine is a challenge. Despite many advances in vaccine technology and approaches to generate both humoral and cellular immune responses, major phase-II and -III vaccine trials against HIV/ AIDS have resulted in only moderate successes. The modest achievement of the phase-Ill RV144 prime -boost trial in Thailand re-emphasized the importance of generating robust humoral and cellular responses against HIV. While antibody-directed approaches are being pursued by some groups, others are attempting to develop vaccines targeting cell-mediated immunity, since evidence show CTLs to be important for the control of HIV replication. Phase-I and -Ila multi-epitope vaccine trials have already been conducted with vaccine immunogens consisting of known CTL epitopes conserved across HIV subtypes, but have so far fallen short of inducing robust and consistent anti-HIV CTL responses. Thus, a need remains in the art for an effective vaccine against HIV.

Domestic cats are subject to infection by several retroviruses, including feline leukemia virus (FeLV), feline sarcoma virus (FeSV), endogenous type C oncoronavirus (RD-114), and feline syncytia-forming virus (FeSFV). Of these, FeLV is the most significant pathogen, causing diverse symptoms including lymphoreticular and myeloid neoplasms, anemias, immune-mediated disorders, and an immunodeficiency syndrome that is similar to human acquired immune deficiency syndrome (AIDS). Recently, a particular replication-defective FeLV mutant, designated FeLV-AIDS, has been more particularly associated with immunosuppressive properties.

The discovery of feline T-lymphotropic lentivirus (now designated as feline immunodeficiency virus, FIV) was first reported in Pedersen et al. (1987). Characteristics of FIV have been reported in Yamamoto et al. (1988a); Yamamoto et al. (1988b); and Ackley et al. (1990). Seroepidemiologic data have shown that infection by FIV is indigenous to domestic and wild felines throughout the world. A wide variety of symptoms are associated with infection by FIV, including abortion, alopecia, anemia, conjunctivitis, chronic rhinitis, enteritis, gingivitis, hematochezia, neurologic abnormalities, periodontitis, and seborrheic dermatitis. The immunologic hallmark of domestic cats infected with FIV is a chronic and progressive depletion of feline CD4⁺ peripheral blood lymphocytes, a reduction in the CD4:CD8 cell ratio and, in some cases, an increase in CD8-bearing lymphocytes.

Cloning and sequence analysis of FIV has been reported in Olmsted et al. (1989a); Olmsted et al. (1989b); and Talbott et al. (1989). Hosie and Jarrett (1990) described the serological response of cats infected with FIV. FIV virus subtypes can be classified according to immunotype based on the level of cross-neutralizing antibodies elicited by each strain (Murphy and Kingsbury, 1990). Recently, viruses have been classified into subtypes according to genotype based on nucleotide sequence homology. Although HIV and FIV subtyping is based on genotype (Sodora et al., 1994; Rigby et al., 1993; and Louwagie et al., 1993), little is known about the correlation between the genotype and immunotype of subtypes. FIV viral isolates have been classified into five FIV subtypes: A, B, C, D, and E (Kakinuma et al., 1995; Yamamoto et al., 2007; Yamamoto et al., 2010). Infectious isolates and infectious molecular clones have been described for all FIV subtypes except for subtypes C and E (Sodora et al., 1994). Subtype C FIV has originally been identified from cellular DNA of cats from Canada (Sodora et al., 1994; Rigby et al., 1993; Kakinuma et al., 1995). Examples of FIV strains identified in the art include (subtype of the strain is shown in parenthesis) Petaluma (A), Dixon (A), UK8 (A), Dutchl 13 (A), Dutchl9K (A), UK2 (A), SwissZ2 (A), Sendai-1 (A), USCAzepyOlA (A), USCAhnkyl lA (A), USCAtt-lOA (A), USCAlemyOl (A), USCAsam-OlA (A), PPR (A), France Wo, Netherlands, Bangston (A/B), Aomori-1 (B), Aomori-2 (B), USILbrny03B (B), TM2 (B), Sendai-2 (B), USCKlgri02B (B), Yokohama (B), USMAsboy03B (B), USTXmtex03B (B), USMCglwd03B (B), CABCpbar03C (C), CABCpbar07C (C), CABCpady02C (C), Shizuoka (D), Fukuoka (D), LP3 (E), LP20 (E), and LP24 (E).

The commercial release of an effective HIV-1 vaccine is not imminent even after completion of four major phase IIB-III vaccine trials against HIV/ AIDS (Saunders et al. (2012)). Our limited understanding about the mechanisms of vaccine protection (Plotkin (2008)) and the identity of the protective viral epitopes (Mothe et al. (2011); Koff (2010)) further hampers the development of an effective vaccine. Initial studies focused on antibody-based vaccine designs with an emphasis on generating broadly virus neutralizing antibodies (bNAbs) (Stamatatos (2012)). However, two phase-Ill vaccine trials using envelope (Env) immunogens failed (Flynn et al. (2005); Pitisuttithum et al. (2006)). Subsequent focus was placed on the T-cell-based vaccines that generate protective cell-mediated immunity (CMI) against global HIV-1 isolates (Buchbinder et al. (2008)). The CMI responses, essential for an effective vaccine, most likely include cytotoxic T lymphocyte (CTL) activities that specifically target HIV-1 infected cells (Ogg et al. (1998); Walker et al. (1988); Belyakov et al. (2012)). Unlike NAb epitopes which reside exclusively on the Env proteins, the selection of specific vaccine epitopes for the development of T-cell-based vaccines is more difficult to achieve. A vast number of CTL-associated epitopes can be found to span the whole length of most HIV proteins (Los Alamos National Laboratory (LANL) database, hiv- web.lanl.gov/content/immunology/maps/ maps.html) (Llano et al. (2009)). The goal to develop T-cell-based vaccines is challenged by the capacity of the virus to evade antiviral immunity through mutation(s) for resistance (Li et al. (2011); Leslie et al. (2004)). A recent phase III trial consisting of priming with a gag-pr-gp41-gpl20 canarypox vectored vaccine and boosting with Env gpl20 induced both humoral immunity and CMI and conferred a modest overall efficacy (Rerks-Ngarm et al. (2009)). However, phase I and II vaccine trials consisting of cross-subtype conserved CTL- associated peptide epitopes have shown minimal CMI responses (Sanou et al. (2012); Hanke et al. (2007); Salmon-Ceron et al. (2010)). Therefore, a thorough selection of potent anti-HIV T cell-associated epitopes, which are conserved among HIV-1 subtypes and do not mutate without negatively affecting viral fitness (Troyer et al. (2009); Goulder et al. (2008); Rolland et al. (2007)), would be valuable for an effective HIV-1 vaccine. One approach is to select conserved, non-mutable CTL epitopes on essential viral structural proteins or enzymes that also persist on the older subgenuses of the lentivirinae which have survived evolutionary pressure (Yamamoto et al. (2010)). Such an approach was successfully used in the development of the initial smallpox vaccines (Jenner (1798)). In line with this strategy, the recognition of conserved epitopes on other lentivirus species has been made by the PBMC from HIV-1 positive (HIV+) humans (Balla-Jhagjhoorsingh et al. (1999)), HIV-2 vaccinated and SIV-challenged non-human primates (Walther-Jallow et al. (2001)), and HIV-1 p24-vaccinated and FIV-challenged cats (Abbott et al. (2011); Coleman et al. (2005)).

The viral enzyme, reverse transcriptase (RT), is one of the most conserved viral proteins by possessing the lowest entropy value among the HIV-1 proteins from various subtypes (Yusim et al. (2002)) and contains many CTL-associated epitopes (Walker et al. (1988)). The RT proteins of HIV-1 and FIV also share the highest degree of identity in their amino acid (aa) sequences (Yamamoto et al. (2010)). The current studies were undertaken to identify the conserved CTL-associated epitopes on FIV and HIV-1 RT proteins which are recognized by the PBMC and T cells from HIV+ subjects. The major objective of such studies is to identify evolutionarily-conserved CMI epitopes that may be more resistant to mutation, and thus useful in the development of an effective, T-cell- based HIV-1 vaccine. BRIEF SUMMARY OF THE INVENTION

The subject invention concerns methods and materials for inducing an immune response in an animal or person against an immunodeficiency virus, such as HIV, SIV, or FIV. In one embodiment, a method of the invention comprises administering one or more antigens to the person or animal wherein the antigen comprises one or more evolutionarily conserved epitopes of immunodeficiency viruses. In one embodiment, the epitope is one that is conserved between HIV and SIV, or between HIV and FIV. In another embodiment, the epitope is one that is conserved between HIV, SIV, and FIV. In one embodiment, the epitope is a T-cell epitope. In a specific embodiment, the T-cell epitope is a cytotoxic T lymphocyte (CTL) and T-helper (Th) epitope.

The subject invention also concerns evolutionarily conserved epitopes of immunodeficiency viruses. In one embodiment, the epitope is one that is conserved between HIV and SIV, or is one that is conserved between HIV and FIV. In another embodiment, the epitope is one that is conserved between HIV, SIV, and FIV. In one embodiment, the epitope is a T-cell epitope. In a specific embodiment, the T-cell epitope is a cytotoxic T lymphocyte (CTL) and T-helper (Th) epitope.

The subject invention also concerns antibodies that bind to HIV, SIV, and/or FIV epitopes. In one embodiment, an antibody of the invention binds specifically to an HIV protein, e.g., an HIV p24 protein. In another embodiment, an antibody of the invention binds specifically to an FIV protein, e.g., an HIV p24 protein. In a further embodiment, an antibody of the invention binds specifically to both an HIV and an FIV protein, i.e., the antibody cross-reacts with both an HIV and an FIV protein, such as a p24 protein.

BRIEF DESCRIPTION OF THE DRAWINGS

The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Patent and Trademark Office upon request and payment of the necessary fee.

Figures 1A and IB. NetCTL-1.2 prediction of HIV, SIV, and FIV CTL epitopes.NetCTL-1.2, which is based on proteosomic C-terminal cleavage, TAP transport efficiency, and epitope binding to MHC class I alleles, was used to predict CTL epitopes shown by HLA supertypes (cbs.dtu.dk/services/NetCTL/). The total number of predicted epitopes by HLA supertype (Figure 1A): HIV (78), SIV (74), and FIV (85) were tallied after analysis of the full-length integrase sequence from each virus. The predicted CTL epitopes were compared and the conserved epitopes between the viruses were identified based on aa position and same predicted HLA supertype (Figure IB): HIV-SIV (34), HIV-FIV (25), and HIV-SIV-FIV (17).

Figure 2. Possible Location of Counterpart Epitopes. HIV proteins (A, B) aligned to FIV proteins (A, B) showing four HIV epitopes (hi, h2, h3, h4) and three FIV epitopes (fl, f2, f3) with arrows indicating the location of the direct counterpart (arrow a) and indirect counterpart epitopes (arrows b, and c).

Figure 3. Comparison Between FIV RT and HIV-1 RT. CD3+CD4+ and CD3+CD8+ T-cell CFSE-proliferation (n=24) and PBMC IFNy ELISpot (n=28) responses of HIV+ subjects to overlapping FIV RT (FRT 1-21, top) and HIV-1 (HRT 1- 21, bottom) peptide pools. Results are shown as a mean value of % CFSEi_0W or spot forming unit (SFU) per 10⁶ PBMC with percentage of responders over total subjects tested (% Responder). Uninfected subjects (n=10) had negligible to no responses. Dark red box represents the highest response while boxes with lighter shades of red showing lesser responses with blue representing minimal to no responses. Thresholds are >2% for CFSE-proliferation and >70 SFU for ELISpot.

Figure 4. Comparison Between FIV p24 and HIV-1 p24. CD3+CD4+ and CD3+CD8+ T-cell CFSE-proliferation (n=24) and PBMC IFNy ELISpot (n=31) responses to overlapping FIV p24 (Fp 1-17, top) and HIV-1 p24 (Hp 1-18, bottom) peptide pools. Results are shown as a mean value of % CFSEi_0W or spot forming unit/10⁶ PBMC with (% Responder). Dark red box represents the highest response while lighter shades of red show lesser responses with blue representing minimal to no response.

Figure 5. Sequence comparison between HIV-I _LA_I reverse transcriptase (RT) (441 aa) and FIV_FC_I RT (445 aa).

Figure 6. Sequence comparison between HIV-I _LA_I RT (441 aa) and SIV_MHLZS_I (439 aa).

Figure 7. Sequence comparisons between FIV-Pet p24 (223 aa) and SIV-Delta B670 p24 (228 aa), between HIV1 HXB2 p24 (231 aa) and FIV-Pet p24 (223 aa), and between HIV1-HXB2 p24 (231 aa) and SIV-Delta B670 p24 (228 aa).

Figures 8A and 8B. Chimera HIVp24/FIV-Shizuoka infected PBMC (batch 10) with MAb reactive to both FIV p24 and HIV-1 p24 (Figure 8A). Chimera HIVp24/FIV- Shizuoka infected PBMC (batch 10) with MAb reactive to FIV gp95 (surface envelope) (Figure 8B). Chimera HIVp24/FIV-Shizuoka infected PBMC (batch 10) with isotype IgG control antibody (Figure 8C). Indirect fluorescent antibody (IFA) analysis of feline PBMC infected with chimera HIVp24/FIV-Shizuoka (subtype-D backbone) virus. Note HIV-luc_Di belongs to HIV-1 subtype B. The culture supernatant from chimera transinfected 293T cells was inoculated into uninfected feline PBMC culture, and then 2- 3 weeks later when the cells were dying co-cultured with fresh uninfected feline PBMC for 2-3 weeks before the cells were used for IFA analysis. Murine MAb reactive to both FIV p24 and HIV-1 p24 (Figure 8 A) and anti-FIV gp95 (surface envelope) MAb (Figure 8B) in combination with FITC-labeled anti-mouse IgG detect chimera HIVp24/FIV- Shizuoka virus infected PBMC (green fluorescent cell in Figures 8 A and 8B). Murine isotype IgG control antibody in combination with FITC-labeled anti-mouse IgG has no fluorescent reactivity (Figure 8C). Thus, the chimera HIVp24/FIV-Shizuoka virus is infectious to feline PBMC.

Figures 9A-9D. Indirect fluorescent antibody (IFA) analysis of feline PBMC infected with chimera HIVp24/FIV-Petaluma (subtype-A backbone) virus. Chimera HIVp24/FIV-Petaluma infected PBMC (batch 14) with MAb reactive to both FIV p24 and HIV-1 p24 (Figure 9A). Chimera HIVp24/FIV-Petaluma infected PBMC (batch 14) with anti-FIV gp95 MAb (Figure 9B). Chimera HIVp24/FIV-Petaluma infected PBMC (batch 14) with anti-FIV gp95 MAb (Figure 9C). Chimera HIVp24/FIV-Petaluma infected PBMC (batch 14) with isotype IgG control antibody (Figure 9D). The culture supernatant from chimera transinfected 293T cells was inoculated into uninfected feline PBMC culture, and then 2-3 weeks later when the cells were dying co-cultured with fresh uninfected feline PBMC for 2-3 weeks before the cells were used for IFA analysis. Murine MAb reactive to both FIV p24 and HIV-1 p24 (Figure 9 A) and anti-FIV gp95 (surface envelope) MAb (Figures 9B and 9C) in combination with FITC-labeled anti- mouse IgG detect chimera HIVp24/FIV-Shizuoka virus infected PBMC (green fluorescent cell in Figures 9A, 9B, 9C). Murine isotype IgG control antibody in combination with FITC-labeled anti-mouse IgG has no fluorescent reactivity (Figure 9D). Thus, the chimera HIVp24/FIV-Petaluma virus is infectious to feline PBMC.

Figure 10. Reactivity of MAbs to HIV-1 and FIV p24 proteins in Western blot (WB) with FIV (top) or HIV-1 (bottom) p24 substrate. FIV p24-specific MAbs HL2350 and HL2351 do not cross react to HIV-1 p24 proteins or its degraded proteins in WB and ELISA. HIV-1 p24-specific MAbs HL2309 and HL2310 do not cross react with FIV p24 proteins or its degraded proteins in WB and ELISA.

Figure 11. Reactivity of HIV-1+ human subjects: comparison between FIV RT and HIV-1 RT. CD3+CD4+ and CD3+CD8+ T-cell CFSE-proliferation (n=24) and PBMC IFNy ELISpot (n=28) responses of HIV+ subjects to overlapping FIV RT (FRT 1 - 21, top) and HIV-1 (HRT 1-21, bottom) peptide pools. Results are shown as a mean value of % CFSEi_0W or spot forming unit (SFU) per 10⁶ PBMC with percentage of responders over total subjects tested (% Responder). Uninfected subjects (n=10) had negligible to no responses. Dark red box represents the highest response while boxes with lighter shades of red showing lesser responses with blue representing minimal to no responses. Thresholds are >2% for CFSE-proliferation and >70 SFU for ELISpot.

Figure 12. Reactivity of HIV-1+ human subjects: comparison between FIV p24 and HIV-1 p24. CD3+CD4+ and CD3+CD8+ T-cell CFSE-proliferation (n=24) and PBMC ΙΚΝγ ELISpot (n=31) responses to overlapping FIV p24 (Fp 1-17, top) and HIV-1 p24 (Hp 1-18, bottom) peptide pools. Results are shown as a mean value of % CFSEi_0W or spot forming unit/10⁶ PBMC with (% Responder). Dark red box represents the highest response while lighter shades of red show lesser responses with blue representing minimal to no responses. HIV p24 sequence is longer than that of FIV. Therefore, the alignment shifts after Fp6, and Fp7 is the counterpart of Hp8 and so on.

Figure 13 A. Full aa sequence alignment of HIV-1 LAI reverse transcriptase (RT)

(441 aa) and FIV_FCi RT (445 aa) show 47.7% identity and 70.8% homology. Based on the results in Figure 11 above, four epitopic regions (HRT3/FRT3, HRT6/FRT6, HRT11/FRTl 1, HRT13/FRT13) with moderate to high reactivity to FIV RT peptide pool by either IFNy-ELISpot or CFSE-proliferation were selected for aa sequence analysis using GENESTREAM network server. Red aa sequence represents HRT peptide pool sequence, while blue aa sequence represents FRT peptide pool sequence. The aa sequence with red or blue underline are counterpart section between FIV and HIV RT proteins and are also evaluated for aa identity and homology as shown on the right. GENESTREAM network server (xylian.igh.cnrs.fr/bin/align-guess.cgi): Pearson, W.R., Wood, T., Zhang, Z., and Miller, W. (1997), Comparision of DNA sequences with protein sequences, Genomics 46: 24-36. Figure 13B. Full aa sequence alignment of HIV- I_LA_I RT (441 aa) and SIV_{MULZS I} (439 aa) show 59.6% identity and 81.9% homology. Based on the results in Figure 14 below, four epitopic regions (HRT3, HRT6, HRTl l, HRT14) with moderate to high reactivity to HIV RT peptide pool by IFNy-ELISpot were selected for aa sequence analysis using GENESTREAM network server. Red aa sequence represents HRT peptide pool sequence, while blue aa sequence represents FRT peptide pool sequence. These counterpart peptide pool regions of HIV and SIV RT proteins are also evaluated for aa identity and homology as shown on the right. The yellow highlight represents the HIV peptide pool and the macaques (immediately below the counterpart SIV sequence) reacting to the corresponding peptide pool. PBMCs from infected macaques were also tested with shorter peptides of HRT3 which are known to be CTL epitope for HIV+ humans. PBMCs from macaques R395 and R397 reacted to peptide "WRKLVDFRE" (SEQ ID NO:450) (red & counterpart blue underlined) while that of macaque R416 reacted to both overlapping peptide pool HRT3 and individual peptide "KWRKLVDFRELNKR" (SEQ ID NO: 166) in green highlight. Furthermore, PBMC of macaque R422 reacted to FIV p24 peptide "NPWNTPVFAIKK " (SEQ ID NO:61) and its SIV counterpart sequence is shown in aqua highlight. The reason why only R416 responded to overlapping peptide pool while others (R395, R397, R422) only reacted to smaller peptides are technical reasons such as smaller peptides can bind to MHC more readily than the larger peptides (l l-16mers) used for overlapping peptide pools and that other peptide(s) in the pool can decrease the responses.

Figures 14A-14B. IFNy ELISpot Responses to HIV RT (reverse transcriptase) and HIV p24 (core protein) of the Primate PBMCs. Overlapping HIV-1 p24 (Figure 14 A) and RT (Figure 14B) peptide pool analyses are shown for nine SIV-infected rhesus macaques and four pre-infection macaques. Frozen PBMC were thawed and plated at the concentration of 1.4 X 10⁵ viable cells per mL. Peptides were used at a concentration of 15 μg/mL. Each bar represents an individual primate's response in spot forming units (SFU/10⁶ PBMC) after subtraction of 2 times the media control; except for the black and red bars. The black bar represents the average response of the pre-infection responders (Av. n=3) and the red bar represents the average response of all 4 pre-infection samples (Av. total n=4). Since these cells were frozen for over 5 years, positive responses are values of >50 SFU. We believe that fresh (non-cryopreserved) cells will give higher responses to HIV p24 peptide pools (Figure 14A: Hp 1 -Hp 18) and HIV RT peptide pools (Figure 14B: Hrl-Hr21). Various mitogens (Mito.) (concanavalin A, Staphyloccocal enterotoxin A, phytohemaglutinin A) were used since these frozen cells did not always respond to mitogen.

Figure 15. HIV-1 and FIV p24 sequences and individual peptides in the peptide pools. (SEQ ID NOs:257-262,264-319,321-335,337-370).

Figure 16. FRT3 induces the secretion of multiple cytokines in the PBMC of 3/5 HIV+ individuals tested.

Figures 17A-17F. IFNy and CD8+ T cell proliferation responses of HIV- infected subjects to HIV and FIV reverse transcriptase (RT) peptide pools. The IFNy ELISpot (Figures 17A and 17B, n=32; 12 LTS, 12 ST, 8 ART+) and CD3+CD8+ T-cell proliferation (Figures 17C and 17D, n=26; 11 LTS, 7 ST, 8 ART+) responses to overlapping peptide pools of HIV RT (H1-H21; Figures 17A and 17C) and FIV RT (Fl- F21; Figures 17B and 17D) are shown. The HIV+ subjects (panel- A insert for Figures 17A-17D) consisted of long-term survivors (LTS) who have had HIV infection for over 10 years without antiretro viral therapy (ART) (LTS; black bar); subjects recently diagnosed with short-term infection without ART (ST; grey bar); and subjects on ART at various duration of infection (ART+, red bar). Each bar represents a positive response by an individual with a threshold of 70 spot forming units (SFU) per 10⁶ PBMC for ELISpot or threshold of 3% CFSElow for CD3+CD8+ T-cell proliferation. Cells from each individual were stimulated with T-cell mitogen, phytohemaglutinin A (PHA), as positive control. The HIV- control subjects (n=10) had no responses (data not shown). All responses below the positive threshold are not shown to clearly distinguish those positive values close to the threshold.

The average frequencies of IFNy and proliferation responders to HIV-1 (Figure

17E) and FIV (Figure 17F) RT peptide pools are derived from Figures 17A-17D and are shown as % responders. The solid bar for each peptide represents an average responder frequency of IFNy responses, while the grey bar represents of the CD8+ T-cell proliferation responses.

Figures 18A-18B. CD3+CD4+ T-cell proliferation responses to HIV and FIV

RT peptide pools. The CD3+CD4+ T-cell proliferation responses to overlapping peptide pools of HIV RT (H1-H21; Figure 18 A) and FIV RT (F1-F21; Figure 18B) are shown for HIV+ subjects (n=26; 1 1 LTS, 7 ST, 8 ART+). The insert in panel Figure 18A shows the bar color codes for both panels as: LTS without ART (LTS; black bar), ST without ART (ST; grey bar), and those on ART (ART+; white bar). Each bar represents a positive response by an individual with a positive threshold of 70 SFU per 10⁶ PBMC for ELISpot or 3% CFSE^l0W for CD3+CD4+ T-cell proliferation. None of the HIV- control subjects (n=10) had positive responses (data not shown). Responses below positive thresholds are not shown.

Figures 19A-19B. Persistence of IFNy and CD8+ T-cell proliferation responses to selected peptide pools. The IFNy (Figure 19A) and CD8+ T-cell proliferation (Figure 19B) responses of HIV+ subjects who responded first time (tl) and second time (t2, at least 1 year later) are shown for peptide-pool F3 (both analyses), HI 1 (both analyses), and H6 (IFNy) or F6 (T-cell proliferation). The total number of HIV+ subjects who participated is 22 subjects (Figure 19A: 9 LTS, 8 ST, 5 ART+) in IFNy study and 1 1 subjects (Figure 19B: 3 LTS, 6 ST, 2 ART+) in CD8+ T-cell proliferation study. However, the number of subjects with different clinical status differs among the peptide-pool groups since it is based on the number of responders to the peptide at the first time (tl). In addition, the IFNy responses to H6 and F3 have a third time point (t3, >2 yr). The /?-value of each peptide-pool group indicates that the results from tl are statistically different from those from t2 when p<0.5. Only CD8+ T-cell proliferation responses to F6 at tl are statistically different from those at t2. A statistical comparisons between t2 and t3 of H6 (n=5) and F3 (n=5) were /?=0.124 and /?=0.133, respectively (p- value not shown).

Figures 20A-20B. F3 peptide epitopes recognized by F3 responders. The peptide-pool F3 consists of five overlapping 13-15mer peptides spanning from amino- to carboxyl-terminal (F3-1 , F3-2, F3-3, F3-4, and F3-5). IFNy (Figure 20A; n=10; 5 LTS, 3 ST, 2 ART+) and CD8+ T-cell proliferation (Figure 20B; n=8; 3 LTS, 3 ST, 2 ART+) by cells from HIV-infected F3 responders to each of these peptides are shown along with responses to F3 pool. F3 responders consist of those subjects with long-term HIV-1 infection but not on ART (LTS; black bar); those with short-term infection and not on ART (ST; grey bar); and those on ART with various duration of infection (ART+; red bar). All responses below positive thresholds are not shown. Figures 21A-21D. Characterization of CTL-associated epitopes on H6, Hll, F3, and F6 pools. ICS analysis for perforin (Perf), granzyme A (GrzA), and granzyme B (GrzB) expression is shown for CD8+ T cells (left column) and CD4+ T cells (right column) from selected HIV+ responders of designated peptide pools (H6, n=8; Hl l, n=8; F3, n=l l; F6, n=6; and PHA, n=12) (Figures 21A-21C). The HIV+ subjects (panel-A insert for Figures 21 A-21C) consist of the following individuals: those with long-term infection without ART (LTS; black closed circle); those recently diagnosed, with short- term infection without ART (ST; grey closed circle); and those on ART with various duration of infection (ART+; open circle). The number of each clinical status group is the following for each peptide-pool group: H6 (4 LTS, 2 ST, 2 ART+), HI 1 (4 LTS, 1 ST, 3 ART+), F3 (5 LTS, 3 ST, 3 ART+), F6 (2 LTS, 2 ST, 2 ART+), and PHA (5 LTS, 3 ST, 4 ART+). Six F3-pool responders (5 LTS, 1 ART+) were tested for Perf (·), GrzA (□), and GrzB (Δ) responses to the five 13-15mer F3 peptides (Figure 2 ID). Only three subjects were the same as those from above (Figures 21A-21C), but the blood was collected at a different time-point.

Figures 22A-22B. The aa sequence identity between counterpart HIV/FIV peptide pools and between various lentiviruses. The percentage of aa identity (Figure 22A) between the sequences of each HIV (H) peptide pool and its counterpart FIV (F) peptide pool were obtained by alignment of the sequences using ebi.ac.uk/Tools/psa/emboss_needle/. Note that the highest aa identity observed is 68.7% with peptide-pools H4/F4 and the second highest is 66.7%> with peptide-pools H3/F3. In Figure 22B, the percentages shown on the right of the diagonal divider represent % aa sequence similarity and those on the left represent % aa sequence identity between the two viruses intersecting the value. The lentivirus strains compared are HIV-1HXB2 (GenBank K03455.1), FIVFCl (DQ365597.1), SIVMm251 (AAB59906.1), and CAEV (AAG48629.1).

BRIEF DESCRIPTION OF THE SEQUENCES

SEQ ID NOs:l-40 are epitopes contemplated within the scope of the invention. SEQ ID NOs:41 and 42 are chimeric polynucleotides of the present invention.

SEQ ID NOs:43 and 44 are chimeric polypeptides encoded by a chimeric polynucleotide of the invention. SEQ ID NOs:45-450 are epitopes contemplated within the scope of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The subject invention concerns methods and materials for providing an immune response in an animal or person against an immunodeficiency virus, such as HIV, SIV, or FIV. In one embodiment, a method of the invention comprises administering one or more antigens and/or immunogens to the person or animal wherein the antigen or immunogen comprises one or more epitopes evolutionarily conserved between different immunodeficiency viruses. In one embodiment, the epitope is one that is conserved between HIV and SIV, or between HIV and FIV. In another embodiment, the epitope is one that is conserved between HIV, SIV, and FIV. In one embodiment, where a human is administered the antigen and/or immunogen, the antigen or immunogen is from an FIV or HIV, and the epitope is evolutionarily conserved between HIV and FIV. In one embodiment, where the animal is a feline animal, the antigen and/or immunogen is from an HIV or FIV, and the epitope is evolutionarily conserved between HIV and FIV. In one embodiment of a method of the present invention, the epitope is a T-cell epitope. In a specific embodiment, the T-cell epitope is a cytotoxic T lymphocyte (CTL) and T-helper (Th) epitope. Antigens and immunogens of the invention can be peptides and/or proteins that comprise one or more evolutionarily conserved epitopes of the invention.

Examples of epitopes contemplated within the scope of the invention include peptides or proteins having the amino acid sequence shown in any of SEQ ID NOs: l-40 or in any of SEQ ID NOs:51-450, or in any of the examples, figures or tables of the subject application, or an immunogenic fragment or variant of the amino acid sequence. In a specific embodiment, a peptide or protein of the invention comprises the amino acid sequence shown in any of SEQ ID NOs:61, 62, 63, 64, 65, 163, 164, 165, 166, 167, 431, 432, 438, 442, and 443. In one embodiment, a plurality of peptides and/or proteins comprising an epitope of the invention are administered to the person or animal. For example, in one embodiment, two or more peptides or proteins comprising the amino acid sequence of any of SEQ ID NOs:61, 62, 63, 64, 65, 163, 164, 165, 166, 167, 431, 432, 438, 442, or 443 are administered. For example, a first peptide comprising SEQ ID NO:61 and a second peptide comprising SEQ ID NO: 63 can be administered. In another embodiment, a peptide or protein comprising two or more epitopes of the present invention is administered to the person or animal. In one embodiment, a peptide or protein comprising two or more amino acid sequences shown in any of SEQ ID NOs:61, 62, 63, 64, 65, 163, 164, 165, 166, 167, 431, 432, 438, 442, or 443 is administered to the person or animal. In a specific embodiment, a peptide or protein comprising the amino acid sequence of SEQ ID NO:63 is administered to the person or animal. In yet another embodiment, a peptide or protein utilized in the present invention comprises an amino acid sequence shown in any of SEQ ID NO: 10, SEQ ID NO: 21, SEQ ID NO:22, or SEQ ID NO:23. In a further embodiment, a peptide or protein utilized in the present invention comprises an amino acid sequence shown in any of SEQ ID NOs:176, 177, 178, 179, 214, 215, 216, 217, or 218.

In one embodiment, the immune response induced by a method of the present invention is a CTL-associated immune response. In a specific embodiment, the immune response induced by a method of the present invention comprises CD4+ and/or CD8+ T cell responses. In one embodiment, the immune response is a protective immune response that provides protection from infection by an immunodeficiency virus. In a specific embodiment, the immune response provides the person or animal with protection from infection by HIV or FIV. In one embodiment, the person or animal receiving the antigen or immunogen is already infected with an immunodeficiency virus. In another embodiment, the person or animal is not infected with an immunodeficiency virus prior to administration of the antigen or immunogen.

The subject invention also concerns chimeric polynucleotides and polypeptides that comprise sequences from more than one immunodeficiency virus. In one embodiment, a chimera of the invention comprises sequences of HIV and FIV. In a specific embodiment, a chimera of the invention is a chimeric Gag protein wherein matrix (MA) and nucleocapsid (NC) sequences are from FIV and wherein the core or capsid (CA) (p24) sequences are from an HIV. In an exemplified embodiment, a chimera polynucleotide comprises the sequence shown in SEQ ID NO:41 or SEQ ID NO:42. In a further exemplified embodiment, a chimera polypeptide comprises the sequence shown in SEQ ID NO:43 or SEQ ID NO:44. The subject invention contemplates that HIV proteins can be substituted for corresponding FIV proteins in other chimeric polynucleotides and polypeptides of the invention. For example, HIV pol sequences can be substituted into corresponding FIV pol sequences. The subject invention also concerns methods for determining whether an animal, such as a feline animal, has been vaccinated against FIV with an FIV vaccine of the present invention, or is infected by FIV or has been infected by FIV. In one embodiment, a biological sample, such as a blood or serum sample, is obtained from a feline animal, and the sample is assayed to determine whether the animal has antibodies that bind specifically to HIV antigens. In a specific embodiment, if an animal is vaccinated with a chimeric polynucleotide or polypeptide of the present invention wherein p24 of FIV is replaced with p24 of HIV, then antibodies specific for the HIV p24 will be present in the animal and can be detected. If an animal has been infected with FIV, then that animal will not have antibodies that bind to certain HIV p24 epitopes. Epitopes of an HIV protein that are only recognized by HIV antibodies and that are not recognized by FIV antibodies can be used in the subject invention.

The subject invention also concerns evolutionarily conserved epitopes of immunodeficiency viruses. In one embodiment, the epitope is one that is conserved between HIV and SIV, or between HIV and FIV. In another embodiment, the epitope is one that is conserved between HIV, SIV, and FIV. In one embodiment, the epitope is a T-cell epitope. In a specific embodiment, the T-cell epitope is a cytotoxic T lymphocyte (CTL) and T-helper (Th) epitope. In one embodiment, the epitopes are from a viral integrase protein. In another embodiment, the epitopes are from a viral reverse transcriptase protein. In a further embodiment, the epitopes are from a viral core or capsid (p24) protein. Antigens and immunogens of the invention can be peptides and/or proteins that comprise one or more evolutionarily conserved epitopes of the invention. Examples of epitopes contemplated within the scope of the invention include peptides or proteins having the amino acid sequence shown in SEQ ID NOs: 1-40 or in any of SEQ ID NOs:51-450, or in any of the examples, figures or tables of the subject application, or an immunogenic fragment or variant of the amino acid sequence. In a specific embodiment, a peptide or protein of the invention comprises the amino acid sequence shown in any of SEQ ID NOs:61, 62, 63, 64, 65, 163, 164, 165, 166, 167, 431, 432, 438, 442, and 443. In another embodiment, a peptide or protein of the invention can comprise two or more amino acid sequences of any of SEQ ID NOs:61, 62, 63, 64, 65, 163, 164, 165, 166, 167, 431, 432, 438, 442, and/or 443. In a specific embodiment, a peptide or protein comprises the amino acid sequence of SEQ ID NO: 63. In yet another embodiment, a peptide or protein of the present invention comprises an amino acid sequence shown in any of SEQ ID NO: 10, SEQ ID NO: 21, SEQ ID NO:22, or SEQ ID NO:23. In a further embodiment, a peptide or protein of the present invention comprises an amino acid sequence shown in any of SEQ ID NOs: 176, 177, 178, 179, 214, 215, 216, 217, or 218. The subject invention also concerns polynucleotides encoding the amino acid sequence of epitopes of the invention.

The subject invention also concerns vaccines comprising one or more antigens and/or immunogens that comprise evolutionarily conserved epitopes of the present invention. The vaccine or immunogenic compositions of the subject invention also encompass recombinant viral vector-based constructs that may comprise a nucleic acid encoding a peptide or protein comprising an evolutionarily conserved epitope of the present invention or encoding a chimeric polypeptide of the present invention. Examples of epitopes contemplated within the scope of the invention include peptides or proteins having the amino acid sequence shown in SEQ ID NOs: l-40 or in any of SEQ ID NOs:51-450, or in any of the examples, figures or tables of the subject application, or an immunogenic fragment or variant of the amino acid sequence. In a specific embodiment, a peptide or protein of the invention comprises the amino acid sequence shown in any of SEQ ID NOs:61, 62, 63, 64, 65, 163, 164, 165, 166, 167, 431, 432, 438, 442, and 443. In another embodiment, a peptide or protein of the invention can comprise two or more amino acid sequences of any of SEQ ID NOs:61, 62, 63, 64, 65, 163, 164, 165, 166, 167, 431, 432, 438, 442, and/or 443. In a specific embodiment, a peptide or protein comprises the amino acid sequence of SEQ ID NO: 63. In yet another embodiment, a peptide or protein of the present invention comprises an amino acid sequence shown in any of SEQ ID NO: 10, SEQ ID NO: 21, SEQ ID NO:22, or SEQ ID NO:23. In a further embodiment, a peptide or protein of the present invention comprises an amino acid sequence shown in any of SEQ ID NOs: 176, 177, 178, 179, 214, 215, 216, 217, or 218. In an exemplified embodiment, a chimera polynucleotide comprises the sequence shown in SEQ ID NO:41 or SEQ ID NO:42. In a further exemplified embodiment, a chimera polypeptide comprises the sequence shown in SEQ ID NO:43 or SEQ ID NO:44. Any suitable viral vector that can be used to prepare a recombinant vector/virus construct is contemplated for use with the subject invention. For example, viral vectors derived from adenovirus, avipox, herpesvirus, vaccinia, canarypox, entomopox, swinepox, West Nile virus and others known in the art can be used with the compositions and methods of the present invention. Recombinant polynucleotide vectors that encode and express components can be constructed using standard genetic engineering techniques known in the art. In addition, the various vaccine compositions described herein can be used separately and in combination with each other. For example, primary immunizations of an animal may use recombinant vector-based constructs, having single or multiple strain components, followed by secondary boosts with vaccine compositions comprising inactivated virus or inactivated virus-infected cell lines. Other immunization protocols with the vaccine compositions of the invention are apparent to persons skilled in the art and are contemplated within the scope of the present invention.

The subject invention also concerns compositions comprising epitopes and/or chimeric polypeptides of the invention, or polynucleotides encoding them. In one embodiment, a composition of the invention comprises a pharmaceutically or biologically acceptable carrier, diluent, and/or adjuvant.

The subject invention also concerns antibodies that bind to HIV, SIV, and/or FIV epitopes. In one embodiment, an antibody of the invention binds specifically to an HIV protein, e.g., an HIV p24 protein. In another embodiment, an antibody of the invention binds specifically to an FIV protein, e.g., an HIV p24 protein. In a further embodiment, an antibody of the invention binds specifically to both an HIV and an FIV protein, i.e., the antibody cross-reacts with an epitope that is present on both an HIV and an FIV protein, such as a p24 protein. Table 1 shows monoclonal antibodies of the present invention and their reactivity with HIV p24 and FIV p24.

Table 1.

isotype/light

Monoclonal ID clone number antigen chain cross-reactivity**

HL 2309 2B3-1F6 HIV-1 UCD-1 p24 IgGl / kappa NO***

HL 2310 2B3-2A4 HIV-1 UCD-1 p24 IgGl / kappa NO***

HL 2311 2B4-1B6 HIV-1 UCD-1 p24 IgGl / kappa NO***

HL 2312 2B4-1E8 HIV-1 UCD-1 p24 IgGl / kappa NO***

HL 2335 4C3 HIV-1 UCD-1 p24 IgG2b / kappa NO***

HL 2336 5G2 HIV-1 UCD-1 p24 IgM / kappa YES

HL 2322 9D6 FIV Petaluma p24 IgGl / kappa YES isotype/light

Monoclonal ID clone number antigen chain cross-reactivity**

HL 2323 7A3 FIV Petaluma p24 IgGl / kappa NO***

HL 2324 2G12 FIV Petaluma p24 IgGl / kappa YES

HL 2348 9A12-2A3 FIV Petaluma p24 IgGl / kappa YES

HL 2349 9A12-2C2 FIV Petaluma p24 IgGl / kappa YES

HL 2350 8B2-1E1 FIV Petaluma p24 IgGl / kappa NO***

HL 2351 8B2-2A1 FIV Petaluma p24 IgGl / kappa NO***

* All mouse monoclonal antibodies (MAbs) to HIV-1 p24 are positive by ELISA and Weternblot to HIV-1 p24. Similarly, all MAbs to FIV p24 are positive by ELISA and WB to FIV p24.

** Cross-reactivity denotes reactivity of anti-HIV-1 p24 MAbs to FIV p24 and vice versa. *** These MAbs differentiate between HIV- p24 and FIV p24 when used in right combinations.

The subject invention also concerns expression constructs comprising one or more polynucleotides of the invention. Expression constructs of the invention will also generally include regulatory elements that are functional in the intended host cell in which the expression construct is to be expressed. Thus, a person of ordinary skill in the art can select regulatory elements for use in, for example, bacterial host cells, yeast host cells, plant host cells, insect host cells, mammalian host cells, and human host cells. Regulatory elements include promoters, transcription termination sequences, translation termination sequences, enhancers, and polyadenylation elements. As used herein, the term "expression construct" refers to a combination of nucleic acid sequences that provides for transcription of an operably linked nucleic acid sequence. As used herein, the term "operably linked" refers to a juxtaposition of the components described wherein the components are in a relationship that permits them to function in their intended manner. In general, operably linked components are in contiguous relation.

An expression construct of the invention can comprise a promoter sequence operably linked to a polynucleotide sequence encoding a peptide of the invention. Promoters can be incorporated into a polynucleotide using standard techniques known in the art. Multiple copies of promoters or multiple promoters can be used in an expression construct of the invention. In a preferred embodiment, a promoter can be positioned about the same distance from the transcription start site as it is from the transcription start site in its natural genetic environment. Some variation in this distance is permitted without substantial decrease in promoter activity. A transcription start site is typically included in the expression construct.

For expression in animal cells, an expression construct of the invention can comprise suitable promoters that can drive transcription of the polynucleotide sequence. If the cells are mammalian cells, then promoters such as, for example, actin promoter, metallothionein promoter, NF-kappaB promoter, EGR promoter, SRE promoter, IL-2 promoter, NFAT promoter, osteocalcin promoter, SV40 early promoter and SV40 late promoter, Lck promoter, BMP5 promoter, TRP-1 promoter, murine mammary tumor virus long terminal repeat promoter, STAT promoter, or an immunoglobulin promoter can be used in the expression construct.

Expression constructs of the invention may optionally contain a transcription termination sequence, a translation termination sequence, signal peptide sequence, and/or enhancer elements. Transcription termination regions can typically be obtained from the 3' untranslated region of a eukaryotic or viral gene sequence. Transcription termination sequences can be positioned downstream of a coding sequence to provide for efficient termination. Signal peptides are a group of short amino terminal sequences that encode information responsible for the relocation of an operably linked peptide to a wide range of post-translational cellular destinations, ranging from a specific organelle compartment to sites of protein action and the extracellular environment. Targeting a peptide to an intended cellular and/or extracellular destination through the use of operably linked signal peptide sequence is contemplated for use with the immunogens of the invention. Chemical enhancers are cis-acting elements that increase gene transcription and can also be included in the expression construct. Chemical enhancer elements are known in the art, and include, but are not limited to, the cytomegalovirus (CMV) early promoter enhancer element and the SV40 enhancer element. DNA sequences which direct polyadenylation of the mRNA encoded by the structural gene can also be included in the expression construct.

Unique restriction enzyme sites can be included at the 5' and 3' ends of the expression construct to allow for insertion into a polynucleotide vector. As used herein, the term "vector" refers to any genetic element, including for example, plasmids, cosmids, chromosomes, phage, virus, and the like, which is capable of replication when associated with proper control elements and which can transfer polynucleotide sequences between cells. Vectors contain a nucleotide sequence that permits the vector to replicate in a selected host cell. A number of vectors are available for expression and/or cloning, and include, but are not limited to, pBR322, pUC series, Ml 3 series, and pBLUESCRIPT vectors (Stratagene, La Jolla, CA).

Polynucleotides, vectors, and expression constructs of the invention can be introduced in vivo via lipofection (DNA transfection via liposomes prepared from synthetic cationic lipids) (Feigner et ah, 1987). Synthetic cationic lipids (LIPOFECTIN, Invitrogen Corp., La Jolla, CA) can be used to prepare liposomes to encapsulate a polynucleotide, vector, or expression construct of the invention. A polynucleotide, vector, or expression construct of the invention can also be introduced as naked DNA using methods known in the art, such as transfection, microinjection, electroporation, calcium phosphate precipitation, and by biolistic methods.

As used herein, the terms "nucleic acid" and "polynucleotide sequence" refer to a deoxyribonucleotide or ribonucleotide polymer in either single- or double-stranded form, and unless otherwise limited, would encompass known analogs of natural nucleotides that can function in a similar manner as naturally-occurring nucleotides. The polynucleotide sequences include both the DNA strand sequence that is transcribed into RNA and the RNA sequence that is translated into protein. The polynucleotide sequences include both full-length sequences as well as shorter sequences derived from the full-length sequences. It is understood that a particular polynucleotide sequence includes the degenerate codons of the native sequence or sequences which may be introduced to provide codon preference in a specific host cell. The polynucleotide sequences falling within the scope of the subject invention further include sequences which specifically hybridize with the exemplified sequences. The polynucleotide includes both the sense and antisense strands as either individual strands or in the duplex.

The methods of the present invention contemplate a primary immunization with an antigen, immunogen, peptide, polypeptide, polynucleotide, and/or composition of the invention. Subsequent or secondary immunizations are also contemplated within the scope of the subject methods. The antigen, immunogen, peptide, polypeptide, polynucleotide, and/or composition used for secondary immunizations can be the same as or vary from that used for primary immunization. For example, primary immunizations of an animal may use recombinant vector-based HIV, FIV, or SIV constructs, having single or multiple strain components, followed by secondary boosts with compositions comprising HIV-, FIV-, or SIV-infected cell lines, or HIV, FIV, or SIV polypeptides, or cell free HIV or SIV virus, also having single or multiple strain components. Primary immunizations can also use an HIV, FIV, and/or SIV DNA vaccine. In one embodiment, a recombinant vector construct is used for the primary immunization, whereas a protein, or protein plus recombinant vector construct, subunit vaccine composition is used for secondary boosts. Other immunization protocols with the vaccine compositions of the invention are apparent to persons skilled in the art and are contemplated within the scope of the present invention.

The antibodies can be polyclonal or monoclonal in form. The antibodies can be derived from any animal capable of producing antibodies to the epitopes, and include, for example, human, ape, monkey, mouse, rat, goat, sheep, pig, cow, and feline animals. Also contemplated within the scope of the invention are non-human antibodies that have been "humanized" using standard procedures known in the art, such as those described in U.S. Patent Nos. 5,530,101; 5,585,089; 5,693,762; 6,180,370; and 6,407,213.

An antibody that is contemplated for use in the present invention can be in any of a variety of forms, including a whole immunoglobulin, an antibody fragment such as Fv, Fab, and similar fragments, as well as a single chain antibody that includes the variable domain complementarity determining regions (CDR), and similar forms, all of which fall under the broad term "antibody," as used herein.

The term "antibody fragment" refers to a portion of a full-length antibody, generally the antigen binding or variable region. Examples of antibody fragments include Fab, Fab', F(ab')₂ and Fv fragments. Papain digestion of antibodies produces two identical antigen binding fragments, called the Fab fragment, each with a single antigen binding site, and a residual "Fc" fragment, so-called for its ability to crystallize readily. Pepsin treatment of an antibody yields an F(ab')₂ fragment that has two antigen binding fragments, which are capable of cross-linking antigen, and a residual other fragment (which is termed pFc'). Additional fragments can include diabodies, linear antibodies, single-chain antibody molecules, and multispecific antibodies formed from antibody fragments. As used herein, "antigen binding fragment" with respect to antibodies, refers to, for example, Fv, F(ab) and F(ab')₂ fragments. Antibody fragments can retain an ability to selectively bind with the antigen or analyte are contemplated within the scope of the invention and include:

(1) Fab is the fragment of an antibody that contains a monovalent antigen-binding fragment of an antibody molecule. A Fab fragment can be produced by digestion of whole antibody with the enzyme papain to yield an intact light chain and a portion of one heavy chain.

(2) Fab' is the fragment of an antibody molecule can be obtained by treating whole antibody with pepsin, followed by reduction, to yield an intact light chain and a portion of the heavy chain. Two Fab' fragments are obtained per antibody molecule. Fab' fragments differ from Fab fragments by the addition of a few residues at the carboxyl terminus of the heavy chain CHI domain including one or more cysteines from the antibody hinge region.

(3) (Fab')₂ is the fragment of an antibody that can be obtained by treating whole antibody with the enzyme pepsin without subsequent reduction. F(ab')₂ is a dimer of two Fab' fragments held together by two disulfide bonds.

(4) Fv is the minimum antibody fragment that contains a complete antigen recognition and binding site. This region consists of a dimer of one heavy and one light chain variable domain in a tight, non-covalent association (V_H-V_L dimer). It is in this configuration that the three CDRs of each variable domain interact to define an antigen- binding site on the surface of the V_H-V_L dimer. Collectively, the six CDRs confer antigen-binding specificity to the antibody. However, even a single variable domain (or half of an Fv comprising only three CDRs specific for an antigen) has the ability to recognize and bind antigen, although at a lower affinity than the entire binding site.

(5) Single chain antibody ("SCA"), defined as a genetically engineered molecule containing the variable region of the light chain (V_L), the variable region of the heavy chain (V_H), linked by a suitable polypeptide linker as a genetically fused single chain molecule. Such single chain antibodies are also referred to as "single-chain Fv" or "sFv" antibody fragments. Generally, the Fv polypeptide further comprises a polypeptide linker between the V_H and V_L domains that enables the sFv to form the desired structure for antigen binding. For a review of sFv fragments, see Pluckthun in The Pharmacology of Monoclonal Antibodies, vol. 113, Rosenburg and Moore eds. Springer- Verlag, N.Y., pp. 269 315 (1994). Antibodies within the scope of the invention can be of any isotype, including IgG, IgA, IgE, IgD, and IgM. IgG isotype antibodies can be further subdivided into IgGl, IgG2, IgG3, and IgG4 subtypes. IgA antibodies can be further subdivided into IgAl and IgA2 subtypes.

Antibodies to be used in the subject invention can be genus or species specific to a target cell. Antibodies of the invention can be prepared using standard techniques known in the art. Antibodies useful in the invention can be polyclonal or monoclonal antibodies. Monoclonal antibodies can be prepared using standard methods known in the art (Kohler et al, 1975).

The subject invention also concerns hybridomas that produce monoclonal antibodies of the present invention.

Peptide and/or polypeptide antigens and immunogens of the present invention can also be provided in the form of a multiple antigenic peptide (MAP) construct, with or without lypophylic attachment to each peptide string. The preparation of MAP constructs has been described in Tarn (1988). MAP constructs utilize a core matrix of lysine residues onto which multiple copies of an immunogen are synthesized (Posnett et ah, 1988). Multiple MAP constructs, each containing the same or different immunogens, can be prepared and administered in a vaccine composition in accordance with methods of the present invention. In one embodiment, a MAP construct is provided with and/or administered with one or more adjuvants.

Natural, recombinant or synthetic polypeptides of immunodeficiency viral proteins, and peptide fragments thereof, can also be used as vaccine compositions according to the subject methods. Procedures for preparing FIV, SIV, and HIV polypeptides are well known in the art. For example, FIV, SIV, and HIV polypeptides can be synthesized using solid-phase synthesis methods (Merrifield, 1963). FIV, SIV, and HIV polypeptides can also be produced using recombinant DNA techniques wherein a polynucleotide molecule encoding an FIV, SIV, or HIV protein or peptide is expressed in a host cell, such as bacteria, yeast, or mammalian cell lines, and the expressed protein purified using standard techniques of the art.

According to the methods of the subject invention, the antigenic and immunogenic compositions described herein are administered to susceptible hosts in an effective amount and manner to induce protective immunity against subsequent challenge or infection of the host by FIV, SIV, or HIV. The immunogens are typically administered parenterally, by injection, for example, either subcutaneously, intradermally, intraperitoneally, or intramuscularly, or by oral or nasal administration, or any combination of such routes of administration. Usually, the immunogens are administered to a host animal at least two times, with an interval of one or more weeks between each administration. However, other regimens for the initial and booster administrations of the immunogens are contemplated, and may depend on the judgment of the practitioner and the particular host animal being treated.

Antigens and immunogens that can be used in accordance with the present invention can be provided with a pharmaceutically-acceptable carrier or diluent. Compounds and compositions useful in the subject invention can be formulated according to known methods for preparing pharmaceutically useful compositions. Formulations are described in detail in a number of sources which are well known and readily available to those skilled in the art. For example, Remington 's Pharmaceutical Science by E.W. Martin, Easton Pennsylvania, Mack Publishing Company, 19^th ed., 1995, describes formulations which can be used in connection with the subject invention. In general, the compositions of the subject invention will be formulated such that an effective amount of an antigen or immunogen is combined with a suitable carrier in order to facilitate effective administration of the composition. The compositions used in the present methods can also be in a variety of forms. These include, for example, solid, semi-solid, and liquid dosage forms, such as tablets, pills, powders, liquid solutions or suspension, suppositories, injectable and infusible solutions, and sprays. The preferred form depends on the intended mode of administration and therapeutic application. The compositions also preferably include conventional pharmaceutically acceptable carriers and diluents which are known to those skilled in the art. Examples of carriers or diluents for use with the subject peptidomimetics include, but are not limited to, water, saline, oils including mineral oil, ethanol, dimethyl sulfoxide, gelatin, cyclodextrans, magnesium stearate, dextrose, cellulose, sugars, calcium carbonate, glycerol, alumina, starch, and equivalent carriers and diluents, or mixtures of any of these. Formulations of an immunogen of the invention can also comprise suspension agents, protectants, lubricants, buffers, preservatives, and stabilizers. To provide for the administration of such dosages for the desired therapeutic treatment, pharmaceutical compositions of the invention will advantageously comprise between about 0.1% and 45%, and especially, 1 and 15% by weight of the antigen, antigens, immunogen or immunogens based on the weight of the total composition including carrier or diluent.

The immunogenic compositions of the subject invention can be prepared by procedures well known in the art. For example, the antigens or immunogens are typically prepared as injectables, e.g., liquid solutions or suspensions. The antigens or immunogens are administered in a manner that is compatible with dosage formulation, and in such amount as will be therapeutically effective and immunogenic in the recipient. The optimal dosages and administration patterns for a particular antigen or immunogen formulation can be readily determined by a person skilled in the art.

Virus and cells in an antigenic or immunogenic formulation may be inactivated or attenuated using methods known in the art. The amount of cell- free whole or partial virus in a vaccine dose will usually be in the range from about 0.1 mg to about 5 mg, and more usually being from about 0.2 mg to about 2 mg. The dosage for formulations comprising virus-infected cell lines will usually contain from about 10⁶ to about 10⁸ cells per dose, and more usually from about 5 x 10⁶ to about 7.5 x 10⁷ cells per dose. The amount of protein or peptide immunogen in a dose for a feline animal can vary from about 0.1 μg to 10000 μg, or about 1 μg to 5000 μg, or about 10 μg to 1000 μg, or about 25 μg to 750 μg, or about 50 μg to 500 μg, or 100 μg to 250 μg, depending upon the size, age, etc., of the animal receiving the dose.

In one embodiment, an antigen or immunogen of the invention is provided with one or more adjuvants that increase the person or animal's immune response against the antigen or immunogen. Antigens and immunogens of the invention can be provided with and/or administered with any suitable adjuvant or adjuvants known in the art. In one embodiment, the adjuvant is one that helps induce a strong cellular immune response. Adjuvants that can be used in the antigen and immunogen formulations of the invention include threonyl muramyl dipeptide (MDP) (Byars et ah, 1987), Ribi adjuvant system components (Corixa Corp., Seattle, WA) including the cell wall skeleton (CWS) component, Freund's complete, and Freund's incomplete adjuvants, bacterial lipopolysaccharide (LPS), such as from E. coli, or a combination thereof. A variety of other adjuvants suitable for use with the methods and vaccines of the subject invention, such as alum, aluminum hydroxide, and saponin are well known in the art and are contemplated for use with the subject invention. Cytokines (γ-IFN, GM-CSF, CSF, etc.) and lymphokines and interleukins (IL-1, IL-2, IL-3, IL-4, IL-5, IL-6, IL-7, IL-8. IL-9, IL- 10, IL-11, IL-12, IL-13, IL-14, IL-15, IL-16, IL-17, IL-18, IL-19, IL-20, IL-21, and IL- 22) have also been used as adjuvants and/or supplements to vaccine compositions and are contemplated within the scope of the present invention. One or more different cytokines and lymphokines can be included in a composition comprising an antigen or immunogen of the invention. In one embodiment, an antigen or immunogen of the invention is administered to an animal in combination with the lymphokine interleukin-12 (IL-12) in combination with another adjuvant. Also specifically contemplated within the scope of the invention is the use of the lymphokine interleukin-18 (IL-18) as part of an adjuvant composition. In one embodiment, an adjuvant composition used with the subject invention comprises a combination of IL-12 and IL-15, or IL-15 and IL-18, or IL-12 and IL-18, or IL-12, IL-15, and IL-18. The cytokine selected is of a species that has biological activity in the animal receiving the antigen or immunogen. For example, if the animal is a cat, then the cytokine can be a human cytokine or a feline cytokine, e.g., feline IL-12, feline IL-15, feline IL-18, etc.

Abbreviations of FIV strains used herein are shown below:

Strain (subtype) Abbreviation Strain (subtype) Abbreviation

Petaluma (A) FIVpet PPR (A) FIVpp_R

Dixon (A) FIV_Dlx FranceWo FIV_Fra

UK8 (A) FIVU 8 Netherlands FIVNet

Bangston (B) FIVBang USILbrny03B (B) FIVusio3

Aomori-1 (B) FIVAoml TM2 (B) FIVTM2

Aomori-2 (B) FIVAom2 USCKlgri02B (B) FIVusco2

FC1 (B) FIVFCI Yokohama (B) FIV_Yok

Shizuoka (D) FIV_Shl USMAsboy03B (B) FIVuSMA03

Dutchl l3 (A) FIVDutll3 USTXmtex03B (B) FIVUSTO3

Dutchl9K (A) FIVoutl9 USMCglwd03B (B) FIVuSMC03

UK2 (A) FIVUK2 CABCpbar03C (C) FIVcAB03

SwissZ2 (A) FIVswiZ2 CABCpbar07C (C) FIVcAB07

Sendai-1 (A) FlVsenl CABCpady02C (C) FIVcAB02

Sendai-2 (B) FIV_Sen2 Fukuoka (D) FlVpuku Strain (subtype) Abbreviation Strain (subtype) Abbreviation

USCAzepyOlA (A) FIV

USCAhnkyl 1 A (A) FIVuscii

USC Art- 1 OA (A) FIVuscio

USCAlemyOl (A) FIV

USCAsam-01A (A) FIV

Antigens and immunogens of the invention are typically administered parenterally, by injection, for example, either subcutaneously, intradermally, intraperitoneally, or intramuscularly. Other suitable modes of administration include oral or nasal administration. Usually, the antigens and immunogens are administered to a human or animal at least two times, with an interval of one or more weeks between each administration. However, other regimens for the initial and booster administrations of the antigens and immunogens are contemplated, and may depend on the judgment of the practitioner and the patient being treated.

Antigenic and immunogenic compositions of the subject invention can be prepared by procedures well known in the art. For example, the antigens and immunogens are typically prepared as injectables, e.g., liquid solutions or suspensions. The antigens and immunogens are administered in a manner that is compatible with dosage formulation, and in such amount as will be therapeutically effective and immunogenic in the recipient. The optimal dosages and administration patterns for a particular antigen and immunogen formulation can be readily determined by a person skilled in the art.

Antigens and immunogens that can be used in accordance with the present invention can be provided with a pharmaceutically-acceptable carrier or diluent. In one embodiment, an antigen or immunogen of the invention is provided with one or more adjuvants that increase the human or animal's immune response against the antigen or immunogen. Antigens and immunogens of the invention can be provided with and/or administered with any suitable adjuvant or adjuvants known in the art.

The antigenic or immunogenic peptides contemplated in the subject invention include the specific peptides exemplified herein as well as equivalent peptides which may be, for example, somewhat longer or shorter than the peptides exemplified herein. For example, using the teachings provided herein, a person skilled in the art could readily make peptides having from 1 to about 15 or more amino acids added to, or 1 to 10 amino acids removed from, either or both ends of the disclosed peptides using standard techniques known in the art. Any added amino acids can be different or the same as the corresponding amino acids of the full-length protein from which the peptide is derived. The skilled artisan, having the benefit of the teachings disclosed in the subject application, could easily determine whether a longer or shorter peptide retained the immunogenic activity of the specific peptides exemplified herein.

Substitution of amino acids other than those specifically exemplified or naturally present in a peptide of the invention are also contemplated within the scope of the present invention. For example, non-natural amino acids can be substituted for the amino acids of a peptide, so long as the peptide having the substituted amino acids retains substantially the same immunogenic activity as the peptide in which amino acids have not been substituted. Examples of non-natural amino acids include, but are not limited to, ornithine, citrulline, hydroxyproline, homoserine, phenylglycine, taurine, iodotyrosine, 2,4-diaminobutyric acid, a-amino isobutyric acid, 4-aminobutyric acid, 2-amino butyric acid, γ-amino butyric acid, ε-amino hexanoic acid, 6-amino hexanoic acid, 2-amino isobutyric acid, 3-amino propionic acid, norleucine, norvaline, sarcosine, homocitrulline, cysteic acid, τ-butylglycine, τ-butylalanine, phenylglycine, cyclohexylalanine, β-alanine, fluoro-amino acids, designer amino acids such as β-methyl amino acids, C-methyl amino acids, N-methyl amino acids, and amino acid analogues in general. Non-natural amino acids also include amino acids having derivatized side groups. Furthermore, any of the amino acids in the protein can be of the D (dextrorotary) form or L (levorotary) form.

Amino acids can be generally categorized in the following classes: non-polar, uncharged polar, basic, and acidic. Conservative substitutions whereby a peptide of the present invention having an amino acid of one class is replaced with another amino acid of the same class fall within the scope of the subject invention so long as the peptide having the substitution still retains substantially the same immunogenic activity as the peptide that does not have the substitution. Table 2 below provides a listing of examples of amino acids belonging to each class. Table 2.

Class of Amino Acid Examples of Amino Acids

Nonpolar Ala, Val, Leu, lie, Pro, Met, Phe, Trp

Uncharged Polar Gly, Ser, Thr, Cys, Tyr, Asn, Gin

Acidic Asp, Glu

Basic Lys, Arg, His

Polynucleotides encoding a specifically exemplified peptide or chimeric polypeptide of the invention, or a shorter or longer peptide or chimeric polypeptide, or a peptide having one or more amino acid substitutions in the sequence are contemplated within the scope of the present invention. The subject invention also concerns variants of the polynucleotides of the present invention that encode a peptide of the invention. Variant sequences include those sequences wherein one or more nucleotides of the sequence have been substituted, deleted, and/or inserted. The nucleotides that can be substituted for natural nucleotides of DNA have a base moiety that can include, but is not limited to, inosine, 5-fluorouracil, 5-bromouracil, hypoxanthine, 1-methylguanine, 5- methylcytosine, and tritylated bases. The sugar moiety of the nucleotide in a sequence can also be modified and includes, but is not limited to, arabinose, xylulose, and hexose. In addition, the adenine, cytosine, guanine, thymine, and uracil bases of the nucleotides can be modified with acetyl, methyl, and/or thio groups. Sequences containing nucleotide substitutions, deletions, and/or insertions can be prepared and tested using standard techniques known in the art.

Fragments and variants of a peptide or a chimeric polypeptide of the present invention can be generated as described herein and tested for the presence of immunogenic activity using standard techniques known in the art.

Polynucleotides, peptides, and chimeric polypeptides contemplated within the scope of the subject invention can also be defined in terms of more particular identity and/or similarity ranges with those sequences of the invention specifically exemplified herein. The sequence identity will typically be greater than 60%, preferably greater than 75%, more preferably greater than 80%, even more preferably greater than 90%, and can be greater than 95%. The identity and/or similarity of a sequence can be 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, or 99% as compared to a sequence exemplified herein. Unless otherwise specified, as used herein percent sequence identity and/or similarity of two sequences can be determined using the algorithm of Karlin and Altschul (1990), modified as in Karlin and Altschul (1993). Such an algorithm is incorporated into the NBLAST and XBLAST programs of Altschul et al. (1990). BLAST searches can be performed with the NBLAST program, score = 100, wordlength = 12, to obtain sequences with the desired percent sequence identity. To obtain gapped alignments for comparison purposes, Gapped BLAST can be used as described in Altschul et al. (1997). When utilizing BLAST and Gapped BLAST programs, the default parameters of the respective programs (NBLAST and XBLAST) can be used. See Worldwide Website: ncbi.nlm.nih.gov.

Factors affecting the preferred dosage regimen may include, for example, the age, weight, sex, diet, activity, lung size, and condition of the subject; the route of administration; the efficacy, safety, and duration-of-immunity profiles of the particular vaccine used; whether a delivery system is used; and whether the vaccine is administered as part of a drug and/or vaccine combination. Thus, the dosage actually employed can vary for specific animals, and, therefore, can deviate from the typical dosages set forth above. Determining such dosage adjustments is generally within the skill of those in the art using conventional means. It should further be noted that live attenuated viruses are generally self-propagating; thus, the specific amount of such a virus administered is not necessarily critical.

It is contemplated that the vaccine may be administered to the patient a single time; or, alternatively, two or more times over days, weeks, months, or years. In some embodiments, the vaccine is administered at least two times. In some such embodiments, for example, the vaccine is administered twice, with the second dose (e.g., the booster) being administered at least about 2 weeks after the first. In some embodiments, the vaccine is administered twice, with the second dose being administered no greater than 8 weeks after the first. In some embodiments, the second dose is administered at from about 2 weeks to about 4 years after the first dose, from about 2 to about 8 weeks after the first dose, or from about 3 to about 4 weeks after the first dose. In some embodiments, the second dose is administered about 4 weeks after the first dose. In the above embodiments, the first and subsequent dosages may vary, such as, for example, in amount and/or form. Often, however, the dosages are the same as to amount and form. When only a single dose is administered, the amount of vaccine in that dose alone generally comprises a therapeutically effective amount of the vaccine. When, however, more than one dose is administered, the amounts of vaccine in those doses together may constitute a therapeutically effective amount.

In some embodiments, the vaccine is administered before the recipient is infected with virus. In such embodiments, the vaccine may, for example, be administered to prevent, reduce the risk of, or delay the onset of one or more (typically two or more) clinical symptoms.

In some embodiments, the vaccine is administered after the recipient is infected with influenza. In such embodiments, the vaccine may, for example, ameliorate, suppress, or eradicate the virus or one or more (typically two or more) clinical symptoms.

It is contemplated that the vaccine may be administered via the feline patient's drinking water and/or food. It is further contemplated that the vaccine may be administered in the form of a treat or toy.

"Parenteral administration" includes subcutaneous injections, submucosal injections, intravenous injections, intramuscular injections, intrasternal injections, transcutaneous injections, and infusion. Injectable preparations (e.g., sterile injectable aqueous or oleaginous suspensions) can be formulated according to the known art using suitable excipients, such as vehicles, solvents, dispersing, wetting agents, emulsifying agents, and/or suspending agents. These typically include, for example, water, saline, dextrose, glycerol, ethanol, corn oil, cottonseed oil, peanut oil, sesame oil, benzyl alcohol, benzyl alcohol, 1 ,3-butanediol, Ringer's solution, isotonic sodium chloride solution, bland fixed oils (e.g., synthetic mono- or diglycerides), fatty acids (e.g., oleic acid), dimethyl acetamide, surfactants (e.g., ionic and non-ionic detergents), propylene glycol, and/or polyethylene glycols. Excipients also may include small amounts of other auxiliary substances, such as pH buffering agents.

The vaccine may include one or more excipients that enhance a patient's immune response (which may include an antibody response, cellular response, or both), thereby increasing the effectiveness of the vaccine. Use of such excipients (or "adjuvants") may be particularly beneficial when using an inactivated vaccine. The adjuvant(s) may be a substance that has a direct (e.g., cytokine or Bacille Calmette-Guerin ("BCG")) or indirect effect (liposomes) on cells of the patient's immune system. Examples of often suitable adjuvants include oils (e.g., mineral oils), metallic salts (e.g., aluminum hydroxide or aluminum phosphate), bacterial components (e.g., bacterial liposaccharides, Freund's adjuvants, and/or MDP), plant components (e.g., Quil A), and/or one or more substances that have a carrier effect (e.g., bentonite, latex particles, liposomes, and/or Quil A, ISCOM). It should be recognized that this invention encompasses both vaccines that comprise an adjuvant(s), as well as vaccines that do not comprise any adjuvant.

It is contemplated that the vaccine may be freeze-dried (or otherwise reduced in liquid volume) for storage, and then reconstituted in a liquid before or at the time of administration. Such reconstitution may be achieved using, for example, vaccine-grade water.

The present invention further comprises kits that are suitable for use in performing the methods described above. The kit comprises a dosage form comprising a vaccine described above. The kit also comprises at least one additional component, and, typically, instructions for using the vaccine with the additional component(s). The additional component(s) may, for example, be one or more additional ingredients (such as, for example, one or more of the excipients discussed above, food, and/or a treat) that can be mixed with the vaccine before or during administration. The additional component(s) may alternatively (or additionally) comprise one or more apparatuses for administering the vaccine to the patient. Such an apparatus may be, for example, a syringe, inhaler, nebulizer, pipette, forceps, or any medically acceptable delivery vehicle. In some embodiments, the apparatus is suitable for subcutaneous administration of the vaccine. In some embodiments, the apparatus is suitable for intranasal administration of the vaccine.

Other excipients and modes of administration known in the pharmaceutical or biologies arts also may be used.

The subject invention also concerns a method for selecting antigens and/or immunogens for use in a vaccine against an immunodeficiency virus, such as HIV or FIV, wherein the method comprises comparing the amino acid sequences of a target protein from two or more immunodeficiency viruses and identifying evolutionarily conserved epitopes of the target protein, wherein one or more of the identified epitopes are selected for use as an antigen or immunogen in the vaccine.

All patents, patent applications, provisional applications, and publications referred to or cited herein are incorporated by reference in their entirety, including all figures and tables, to the extent they are not inconsistent with the explicit teachings of this specification.

Following are examples that illustrate procedures for practicing the invention. These examples should not be construed as limiting. All percentages are by weight and all solvent mixture proportions are by volume unless otherwise noted.

Example 1— Selection of HIV immunogens and conserved epitopes

Careful design of vaccine immunogens for protection against a wide number of HIV variants will be required to deal with the large antigenic diversity. Conserved viral antigens, subtype-matched antigens, consensus antigens, variants of single antigens and multiple antigens have all been used alone or in combination (Li et al. (2007); Korber et al. (2009)). Table 7 shows a few examples for each of the strategies. CTL responses have been shown to preferentially target the conserved regions over the more variable ones (Cao et al. (1997)), and these responses have been associated with better HIV disease outcomes or no disease manifestation (Kiepiela et al. (2007); Rowland- Jones et al. (1998); Johnson et al. (1991)).

The most conserved regions of HIV, especially those conserved across subtypes (Korber et al. (2009)) or among lentiviruses (Yamamoto et al. (2010)), may be the best targets of the immune system for inducing vaccine protection. Some of these regions may be protective and are less likely to mutate because they hold a functional or structural importance to the virus species (possibly to the genus); a mutation would induce impairment to viral fitness (Santra et al. (2010); Barouch et al. (2010)). This possibility makes the identification of conserved epitopes an important aspect of immunogen selection in vaccine design. One means of including these conserved regions is to construct polyvalent mosaic proteins as vaccine immunogens; thus far, preclinical evaluations of the mosaic vaccine have demonstrated great potential for broad T-cell responses, across subtypes (Korber et al. (2009); Smith (2004); Wang et al. (2009)). A method of selecting highly conserved regions is to identify those with the lowest entropy, which is the lowest variability at each aa position. Based on this concept, the most conserved HIV proteins have been shown to be (in order of lowest variability): integrase (IN), core capsid (Gag-p24), reverse transcriptase (RT), and protease (PR) (Table 3) (Yusim et al. (2002)). They were followed by Vpr, Vif, matrix (Gag-pl7), Nef, Rev, and the surface envelope (SU-Env). Tat and Vpu have the highest variability (Table 3). This observation suggests that the selection of conserved vaccine epitopes should be done first from IN, Gag-p24, RT, and PR.

While Jenner may not have considered functional conservation when developing his smallpox vaccine, he can be considered to have been the first developer of a vaccine that was based on conserved features between two different viral species (Jenner (1798)). In a similar fashion, comparisons with other lentiviruses could help identify highly conserved epitopes that are required for viral function and survival. FIV is a lentivirus that is only distantly related to HIV-1, but may still be relevant to the evolutionary conserved approach of vaccine development because of the shared similarities between the HIV and FIV viruses in terms of aa sequence, structure, and pathogenesis (Yamamoto et al. (2007)). A comparison of the aa composition of proteins between HIV-1 and FIV demonstrates the following percentages of identity/homology: RT, 47/72; IN, 37/65; Gag- p24, 32/63; nucleocapsid (Gag-p7), 30/54; PR, 24/48; Gag-pl7, 20/50; SU-Env, 19/43; transmembrane envelope (TM-Env) 18/42 (Yamamoto et al. (2010)) (Table 3). The three most conserved proteins are also those that have the lowest entropy calculation, as shown in Table 3 (Yusim et al. (2002)). Hence, the IN, RT, and Gag-p24 proteins appear to be excellent targets for identifying evolutionary conserved regions that may also contain conserved T-cell epitopes.

Table 3. HIV-1/FIV proteins.

a The average Shannon entropy score is the average value of variability of a given protein at each aa position, calculated by using many aligned sequences. The approximate values shown are derived from the figure of HIV-1 (group M) protein variability from Yusim et al (Yusim et al. (2002))), where the proteins are presented from lowest to highest variability. Lower scores represent lower variability and therefore higher aa conservation. ^b The percentage of aa identity and homology between HIV and FIV proteins are shown, with the three most conserved HIV and FIV proteins bolded.

† (Yusim et al. (2002))

% (Yamamoto et al. (2010))

Example 2— Identification of evolutionary conserved HIV CTL epitopes: Use of FIV proteins

Immunoninformatics has become an integral part in the design of new vaccines with great promise of rapid and effective vaccine discovery (Ardito et al. (2011); Moss et al. (2011); De Groot et al. (2008)). A number of tools and databases are now available online including HLA class-I and -II binding predictions (Los Alamos National Laboratory. HIV molecular immunology database: Best-defined CTL/CD8⁺ Epitope Summary: (www.hiv.lanl.gov/content/immunology/tables/optimal_ctl_ summary.html); Yongqun et al. (2010)), and a number of tools that are useful for the prediction of CTL epitopes (Table 4). In one study performed by our group, NetCTL-1.2 was used to identify CTL epitopes on the integrase sequences of HIV, SIV and FIV (Figure 1A). For the twelve HLA supertypes shown in Figure 1, a large number of CTL epitopes were predicted on each integrase sequence regardless of the virus: HIV with 78 epitopes, SIV with 74 epitopes, and FIV with 85 epitopes. Some of these were conserved between HIV and SIV (34 epitopes), as well as between HIV and FIV (25 epitopes) (Figure IB). A smaller number (17 epitopes) was conserved among all three viruses, reducing the target epitopes to the expected most evolutionary conserved.

Table 4. CTL-epitope prediction tools.

† Bhasin et al. (2004)

% Larsen et al. (2007)

§ Stranzl et al. (2010) Thirteen HIV CTL epitopes termed best-defined CTL epitopes have been identified empirically on HIV integrase by different laboratories and compiled on the Los Alamos National Laboratory (LANL) website (Table 5). In this regard, based on observations using SIV and FIV, an evolutionary conserved HIV CTL epitope can be defined as a CTL epitope with a direct or indirect SIV and/or FIV CTL counterpart (Figure 2). Using the direct counterpart approach (Figure 2, arrow a), three of these epitopes are predicted to be CTL epitopes conserved between HIV, SIV, and FIV and one was shown to be an indirect FIV counterpart (Table 6). They share the same HLA binding and CTL supertype predictions (Larsen et al. (2007); Lundegaard et al. (2008)). The evolutionary conserved (Figure 2, arrow c). An indirect counterpart to an HIV epitope (bolded in Table 6), located upstream on FIV integrase, has higher aa identity and homology than the direct counterpart (Figure 2, arrow b). This indirect FIV counterpart has the same binding alleles and predicted CTL supertype as the HIV epitope. Table 5. Best defined CTL epitopes on HIV integrase^a.

(hiv.lanl.gov/content/immunology/tables/optimal_ctl_summary.html) which was last updated on 2009-08-31. The best defined CTL epitopes or "A list" represent the epitopes whose specific HLA class I allele has been demonstrated with strong certainty and are judged to be at their optimal length.

Table 6. HIV-1 integrase CTL epitopes and direct FIV counterparts.

^a The HIV epitope sequences are from the LANL list of the best defined CTL epitopes for HIV integrase. The SIV counterpart sequences are derived from LANL SIVmm239 and the FIV counterpart sequences are derived from GenBank (ABD 16378) after aa alignment with HXB2 sequence.

b The identity (iden.) and homology (horn.) values were obtained using EMBOSS Stretcher - Pairwise Sequence Alignment (www.ebi.ac.uk/Tools/psa/emboss_stretcher/). ^c MHC binding for HIV, SIV and FIV counterpart epitopes were predicted using the Immune Epitope Database (IEDB) MHC class I binding prediction tool (http://tools.immuneepitope.org/analyze/html/mhc_binding.html).

The matching binding alleles are shown along with their binding affinity values (nM) which are derived from the Artificial Neural Network (ANN) analysis, where lower values represent higher binding affinity and potential for CD8⁺ T-cell activity. The total numbers of binding alleles with affinity below 500 nM are shown in parenthesis next to the supertypes.

d HIV epitope with non-matching SIV and FIV (direct counterparts) is in italics and the bolded FIV epitope is an indirect counterpart with matching alleles to the HIV epitope.

The predicted results of SIV sequences can be explained by the high aa identity between HIV and SIV as SIV is more closely related to HIV than FIV. However, despite the relatively lower aa identity between HIV and FIV, FIV counterpart epitopes still appear to be potentially effective HIV antigens (see Table 6), most likely due to the slightly higher aa homology observed between the two viruses. This finding indicates that both SIV and FIV epitopes could induce CTL responses in human PBMCs. Therefore, conserved SIV and FIV integrase peptides can be used as immunogens in vitro to compare and identify conserved immune responses generated by the PBMCs of HIV⁺ individuals.

Table 7. Phase I and Ila clinical trials of HIV CTL multi-epitope vaccine.

^a All trials are phase I clinical trials except for the bolded trial numbers which are phase Ila (with subjects not at risks of HIV infection); International AIDS Vaccine Initiative (IAVI); HIV Vaccine Trials Network (HVTN); Agence National de Recherche sur le SIDA (ANRS).

b United Kingdom (UK); South Africa (SA); United States of America (USA).

c Prime (p); boost (b); day (d); month (mo); modified vaccinia Ankara (MVA); multi- epitope peptide {MEP); granulocyte macrophage colony stimulating factor (GM-CSF). 'Nine of the 18 volunteers from IAVI-001 who were primed with HIVA-DNA agreed to receive a boost 9-14 months later.

d Intramuscular immunization (i.m.); intradermal immunization (i.d.); subcutaneous immunization (s.c).

e MHC class I molecules can accommodate CTL epitopes of 8 to 11 aa in length [137]. The p24/pl7 represents 73% of the Gag and contains both CTL and T-helper epitopes. The pan-DR T-helper epitope is a 13-mer that binds to all common HLA-DR alleles. Each of the four peptides in the MEP vaccine is made up of both TH and CTL epitopes; T helper (TH).

f The HIV subtypes used in the vaccine. ^Consensus sequence. ^jThe CTL epitopes are present in 50-90% of HIV isolates from the different subtypes.

g Percentage of vaccinees with detected IFNy ELISpot responses to the CTL epitopes.

The responses were detected at different time points, before or after the end of the immunization schedule for the IAVI studies; after the last immunization for HVTN 064; and after the 2^nd or 3rd vaccination (single time point) for HVTN 056.

k Cultured ELISpot assay results.

h Reference (REF).

Example 3— Monoclonal Antibodies to HIV-1 and FIV Recombinant p24 Antibodies

Monoclonal antibodies (MAbs) to HIV-1 p24 and FIV p24 were produced by immunizing mice with recombinant HIV-1 p24 and recombinant FIV p24, respectively (Table 8). Two of seven MAbs to HIV-1 p24 (HL2309 and HL2310) were only reactive to HIV-1 p24, while remaining five MAbs were reactive to both HIV-1 and FIV p24 proteins. Two of six MAbs to FIV p24 (HL2350 and HL2351) were only reactive to FIV p24, while remaining four MAbs were reactive to both HIV-1 and FIV p24 proteins. Based on Western blot (WB) and ELISA results (Fig. 8), the epitopes recognized by HIV- 1 p24-specific MAbs HL2309 and HL2310 are specific for HIV-1 and are not likely to be specific for FIV. Hence, such HIV-1 -specific epitopes can be used in Western blot or ELISA to detect HIV-1 p24 specific antibodies in chimera HIV-1 p24/FIV backbone vaccine (hereon called chimera HIV/FIV vaccine) immunized cats but such Western blot or ELISA should not react with antibodies from FIV-infected cats since HL2309 and HL2310 epitopes are specific for HIV-1 and not for FIV. Using the same concept, the epitopes recognized by FIV p24-specific MAbs HL2350 and HL2351 are specific for FIV and are not likely to be specific for HIV-1. Therefore, HL2350 and HL2351 epitopes can be used in WB or ELISA to detect antibodies from FIV-infected cats but should not react to antibodies from cats immunized with chimera HIV/FIV vaccine. HL2309, HL2310, HL2350, and HL2351 epitope peptides can be used in WB or ELISA based assays to differentiate chimera HIV/FIV vaccinated cats from FIV-infected cats.

Table 8. ELISA Reactivity of Monoclonal Antibodies to HIV-1UCD-I p24 and FIV_PET p24

* All mouse monoclonal antibodies (MAbs) to HIV-1 p24 are positive by ELISA and Western blot to HIV-1 p24. Similarly, all MAbs to FIV p24 are positive by ELISA and WB to FIV p24.

** Cross-reactivity denotes reactivity of anti-HIV-1 p24 MAbs to FIV p24 and vice versa. Example 4

See Figures 11 and 12. To investigate evolutionarily conserved CTL epitopes using FIV peptides, the individual 11-16-mer peptides in the pools with high responses such as FRT3/HRT3, FRT11/HRT11, FP9/HplO, and Fpl4/Hpl5 are being tested with PBMCs from the peptide-pool responders. IFNy and CD3+CD8+ T-cell proliferation responses to FIV RT peptide FRT3-3 ("K KDSTKWRKLVDFR" (SEQ ID NO:165), 15mer) are highly conserved among HIV+ subjects and no normal (HIV-negative) individuals responded. Since FRT3 induced perforin response in PBMCs from HIV+ subjects, FRT3-3 should have excellent probability in inducing CTL responses detected by perforin.

HUMAN PBMC ASSAYS STIMULANTS:

HIV-1 p24 (Hp 1 -Hp 18) & FIV p24 (Fpl-Fpl7) peptide pools were 3-4 overlapping peptides of 11-15 aa long per pool, while HIV-1 RT (HRT1-HRT21) & FIV RT (FRT1-FRT21) peptide pools 3-5 overlapping peptides of 11-15 aajong per pool. These peptides had an overlap of 9 aa spanning the entire length of the proteins.

IFNy-ELISpot

1.0xl0⁵-2.0xl0⁵ PBMCs were stimulated with peptides (15 μg peptide/well) in

ELISpot plates for 18 hours in AIMS V medium (at 10% normal human serum). The spots were counted with an ELISpot reader and adjusted to spot forming units (SFU) per 10⁶ cells.

Positive reactivity was defined at >70 SFU/10⁶ cells after subtracting the background derived from non-specific peptide control or media control, and the average of 3 HIV-1 negative controls (<30 SFU/10⁶ cells).

CFSE-PROLIFERATION

2xl0⁵-5xl0⁵ CFSE labeled PBMCs were incubated with 15-20μg of peptides in 600 of RPMI media with 10% FBS for 5 days at 37°C (5% C0₂). After harvesting, they were labeled with allophycocyanin (APC), APC-H7, and Pacific Blue labeled monoclonal antibodies (MAb) to human CD3, CD4, and CD8, respectively and analyzed for T-cell proliferation by flow cytometry using BD LSRII (BD Biosciences). The proliferating CD4 or CD8 T cell populations were defined from the CD3 cell population as either CD3⁺CD8⁺ or CD3⁺CD4⁺T cells (mutually exclusive) with low CFSE (CFSE^l0W) staining. INTRACELLULAR STAINING (ICS)

Briefly, lxl0⁶ PBMCs (freshly isolated) are stimulated with 20 μg of peptides for 6 hours in a total volume of 200 in a 96-well plate in presence of Golgi transport inhibitor (37°C, 5% C0₂). The cells are processed as previously described (Horton et al. (2007)). Cells were stained with the LIVE/DEAD® fixable yellow dye (Invitrogen, Eugene, OR). The monoclonal antibodies fluorochome-conjugated to human cytokines used are: APC-H7 to CD3 (clone SK7); BD Horizon V450 to CD4 (clone RPA-T4); Qdot to CD 8 (clone 3B5); PE-cy7 to IFN-γ (clone 4S.B3); APC to IL-2 (clone MQ1-17H12) PerCP to perforin (clone B-D48); Alexa F1.700 to granzyme-B (clone GB11) and PE to granzyme-A (clone CB9). The flow cytometry data is collected using BD LSRII and analyzed with the F AC S DIVA software .

POPULATION OF STUDY

HIV-1 positive adult males and females were evaluated for IFNy ELISpot (n=28 for p24 & n=31 for RT), CD3⁺CD4⁺ T-cell CSFE-proliferation (n=24), and CD3⁺CD8⁺ T- cell CFSE-proliferation (n=24) responses to overlapping HIV-1 p24, HIV-1 RT, FIV p24, or FIV RT peptide pools. A total of 10 normal healthy (HIV-1 negative) males and females were used as uninfected control group. All patients have signed an approved IRB consent form. Figures 14A-14B. IFNy ELISpot Responses to HIV RT (reverse transcriptase) and HIV p24 (core protein) of the Primate PBMCs.

Overlapping HIV-1 p24 (Figure 14 A) and RT (Figure 14B) peptide pool analyses are shown for nine SIV-infected rhesus macaques and four pre-infection macaques.

Frozen PBMC were thawed and plated at the concentration of 1.4 X 10⁵ viable cells per mL. Peptides were used at a concentration of 15 μg/mL. Each bar represents an individual primate's response in spot forming units (SFU/10⁶ PBMC) after subtraction of 2 times the media control; except for the black and red bars. The black bar represents the average response of the pre-infection responders (Av. n=3) and the red bar represents the average response of all 4 pre-infection samples (Av. total n=4). Since these cells were frozen for over 5 years, positive responses are values of >50 SFU. We believe that fresh (non- cryopreserved) cells will give higher responses to HIV p24 peptide pools (Figure 14A: Hpl-Hpl8) and HIV RT peptide pools (Figure 14B: Hrl-Hr21). Various mitogens (Mito.) (concanavalin A, Staphyloccocal enterotoxin A, phytohemaglutinin A) were used since these frozen cells did not always respond to mitogen.

Note that only two infected macaques responded to Hp 15 while three pre- infection macaques also responded. Similarly three infected macaques responded to Hrl 1 (i.e., HRT11) while three pre-infection macaques also responded. These results suggest that the PBMC from uninfected macaques recognize these Hp 15 and Hrl 1. Consequently the epitopes to these peptide pools are cross-reacting with epitopes already present in the uninfected macaques. In contrast three infected macaques are responding to Hr6 and two infected macaques are responding to Hrl4 (i.e., HRT14), but the uninfected macaques do not respond to these peptide epitopes, indicating that recognition of these peptide pools are due to SIV infection. The PBMCs from HIV+ subjects respond robustly to Hr6 and Hrl4 but those of uninfected subjects did not. Thus, Hr6 (i.e., HRT6) and Hrl4 may be conserved between HIV and SIV, and is currently being evaluated for the presence of conserved CTL epitopes.

NOTE that in the text we call individual peptides in the pool according to the order below. In the case of FRT2, individual peptide FRT2-3 is the same as Peptide 8 (VERLELEGKVKRA (SEQ ID NO:51)) or the third one listed under Pool FRT2. FIV-FC 1 RT ( 12- 17-mer) with RNASE in bold.

Pool FRT1

1) AQISEKIPIVKVRMK (SEQ ID NO:52)

2) IPIVKVRMKDPTQGPQV (SEQ ID NO:53)

3) KDPTQGPQVKQWPL (SEQ ID NO: 54)

4) GPQVKQWPLSNEKI (SEQ ID NO: 55)

5) KQWPLSNEKIEAL (SEQ ID NO: 56)

Pool FRT2

6) LSNEKIEALTDIVER (SEQ ID NO:57)

7) EALTDIVERLELEGK (SEQ ID NO: 58)

8) VERLELEGKVKRA = FRT2-3 (SEQ ID NO: 51)

9) ELEGKVKRADPNNPW (SEQ ID NO: 59)

10) KRADPNNPWN PVFA (SEQ ID NO: 60) Pool FRT3

11) NPWNTPVFAIKKK (SEQ ID NO: 61)

12) TPVFAIKKKSGKWRM (SEQ ID NO: 62)

13) KKKSGKWRMLIDFRV (SEQ ID NO: 63)

14) WRMLIDFRVLNKL (SEQ ID NO: 64)

15) IDFRVLNKLTDKGA (SEQ ID NO: 65)

Pool FRT4

16) LNKLTDKGAEVQLGL (SEQ ID NO: 66)

17) KGAEVQLGLPHPAGL (SEQ ID NO: 67)

18) LGLPHPAGLKMRKQV (SEQ ID NO: 68)

19) AGLKMRKQVTVLDI (SEQ ID NO: 69)

Pool FRT5

20) RKQV VLDIGDAYF (SEQ ID NO: 70)

21) VLDIGDAYFTIPL (SEQ ID NO:71)

22) GDAYFTIPLDPDYA (SEQ ID NO:72)

23) TIPLDPDYAPYTAF (SEQ ID NO:73)

Pool FRT6

24) PDYAPYTAFTLPRK (SEQ ID NO:74)

25) YTAFTLPRKNNA (SEQ ID NO: 75)

26) FTLPRKNNAGPGRRY (SEQ ID NO: 76)

27) NNAGPGRRYVWCSL (SEQ ID NO:77)

Pool FRT7

28) GRRYVWCSLPQGWVL (SEQ ID NO: 78)

29) CSLPQGWVLSPLIY (SEQ ID NO:79)

30) GWVLSPLIYQSTL (SEQ ID NO: 80) 31) SPLIYQSTLDNIL (SEQ ID NO:81)

Pool FRT8

32) YQSTLDNILQPFIR (SEQ ID NO: 82)

33) DNILQPFIRQNPEL (SEQ ID NO: 83) 34) PFIRQNPELDIYQYM (SEQ ID NO: 84)

35) PELDIYQYMDDIYI (SEQ ID NO: 85)

36) YQYMDDIYIGSDLNK (SEQ ID NO: 86)

Pool FRT9

37) IYIGSDLNKKEHKQK (SEQ ID NO: 87)

38) LNKKEHKQKVEELRK (SEQ ID NO: 88)

39) KQKVEELRKLLLWW (SEQ ID NO: 89)

40) ELRKLLLWWGFETPEDK (SEQ ID NO: 90)

41) WGFETPEDKLQEEPPY (SEQ ID NO: 91)

Pool FRT10

42) DKLQEEPPYKWMGY (SEQ ID NO: 92)

43) EPPYKWMGYELHPL (SEQ ID NO: 93)

44) WMGYELHPLTWS I (SEQ ID NO: 94) 45) ELHPLTWSIQQKQL (SEQ ID NO: 95)

46) TWSIQQKQLEIPER (SEQ ID NO: 96)

Pool FRT1 1

47) IQQKQLEIPERPTL (SEQ ID NO: 97) 48) LEIPERPTLNELQKL (SEQ ID NO: 98)

49) PTLNELQKLVGKINW (SEQ ID NO: 99)

50) LQKLVGKINWASQTI (SEQ ID NO: 100)

51) KINWASQTIPDLSIK (SEQ ID NO: 101) Pool FRT12

52) SQTIPDLSIKELTT (SEQ ID NO: 102

53) LSIKELTTMMRGDQR (SEQ ID NO: 103

54) TTMMRGDQRLDSIR (SEQ ID NO: 1 04)

55) GDQRLDSIREWTTEA (SEQ ID NO: 105

56) SIREWTTEAKKEVQK (SEQ ID NO: 106

Pool FRT13

57) TEAKKEVQKAKEAI (SEQ ID NO:l 07)

58) EVQKAKEAIETQAQL (SEQ ID NO: 108

59) EAIETQAQLKYY (SEQ ID NO : 109 )

60) ETQAQLKYYDPSREL (SEQ ID NO: 110

61) KYYDPSRELYAKLSL (SEQ ID NO: 111

Pool FRT14

62) RELYAKLSLVGPHQI (SEQ ID NO: 112

63) LSLVGPHQICYQVYH (SEQ ID NO: 113

64) HQICYQVYHKNPEHV (SEQ ID NO: 114

65) VYHKNPEHVLWYGKM (SEQ ID NO: 115

66) EHVLWYGKMNRQKKK (SEQ ID NO: 116

Pool FRT15

67) GKMNRQKKKAENTCDI (SEQ ID NC : 11

68) KKAENTCDIALRACY (SEQ ID NO: 118

69) CDIALRACYKIR (SEQ ID NO : 119 )

70) ALRACYKIREESIIR (SEQ ID NO: 120

71) KIREESIIRIGKEPI (SEQ ID NO: 121

Pool FRT16

72) IIRIGKEPIYEIPA (SEQ ID NO:122)

73) KEPIYEI PASREAW (SEQ ID NO:123)

74) EIPASREAWESNLIR (SEQ ID NO: 124

75) EAWESNLIRSPYLKA (SEQ ID NO: 125

76) LIRSPYLKAPPPEV (SEQ ID NO:126)

Pool FRT17

77) YLKAPPPEVEFIHAA (SEQ ID NO: 127

78) PEVEFIHAALNIKRA (SEQ ID NO: 128

79) HAALNIKRALSMI (SEQ ID NO: 129)

80) NIKRALSMIQDTPIL (SEQ ID NO: 130

81) SMIQDTPILGAETWY (SEQ ID NO: 131

82) PILGAETWYIDGGRK (SEQ ID NO: 132

Pool FRT18

83) TWYIDGGRKQGKAAR (SEQ ID NO: 133)

84) GRKQGKAARAAYW (SEQ ID NO: 134)

85) GKAARAAYWTDTGKW (SEQ ID NO: 135)

86) AYWTDTGKWQYMEI (SEQ ID NO: 136)

87) TGKWQVMEIEGSNQK (SEQ ID NO: 137)

Pool FRT19

88) MEIEGSNQKAEVQAL (SEQ ID NO: 138)

89) NQKAEVQALLLALQA (SEQ ID NO: 139)

90) VQALLLALQAGPEEM (SEQ ID NO: 140) 91) ALQAGPEEMNII (SEQ ID NO: 141)

92) AGPEEMNIITDSQYI (SEQ ID NO: 142)

Pool FRT20

93) NIITDSQYILNII (SEQ ID NO: 143) 94) DSQYILNIITQQPDL (SEQ ID NO: 144)

95) NIITQQPDLMEGLW (SEQ ID NO: 145)

96) TQQPDLMEGLWQEVL (SEQ ID NO: 146)

97) MEGLWQEVLEEMEKK (SEQ ID NO: 147)

Pool FRT21

98) EVLEEMEKKIAIFI (SEQ ID NO: 148)

99) MEKKIAIFIDWVPGH (SEQ ID NO: 149)

100) IFIDWVPGHKGI (SEQ ID NO: 150)

101) DWVPGHKGIPGNEEV (SEQ ID NO: 151)

102) KGIPGNEEVDKLCQTM (SEQ ID NO: 152)

Subtype-B HIV-l-UCDl RT (11-16-mer) with RNAse in bold.

Pool HRT1

1) PISPIETVPVKLK (SEQ ID NO: 153)

2) IETVPVKLKPGM (SEQ ID NO: 154)

3) VPVKLKPGMDGPKVK (SEQ ID NO:155)

4) PGMDGPKVKQWPL (SEQ ID NO: 156)

5) GPKVKQWPLTEEKIK (SEQ ID NO:157)

Pool HRT2

6) WPLTEEKIKALIEI (SEQ ID NO:158)

7) EKIKALIEICTEMEK (SEQ ID NO:159)

8) IEICTEMEKEGKISK (SEQ ID NO:160)

9) MEKEGKISKIGPENPY (SEQ ID NO: 161

10) SKIGPENPYNTPVFA (SEQ ID NO:162)

Pool HRT3

11) NPYNTPVFAIKKK (SEQ ID NO: 163)

12) TPVFAIKKKDSTKWR (SEQ ID NO:164)

13) KKKDSTKWRKLVDFR (SEQ ID NO:165)

14) KWRKLVDFRELNKR (SEQ ID NO:166)

15) VDFRELNKRTQDFW (SEQ ID NO:167)

Pool HRT4

16) LNKRTQDFWEVQLGI (SEQ ID NO:168)

17) DFWEVQLGIPHPAGL (SEQ ID NO:169)

18) LGIPHPAGLKKKKSV (SEQ ID NO:170)

19) AGLKKKKSVTVLDV (SEQ ID NO:171)

Pool HRT5

20) KKSVTVLDVGDAYF (SEQ ID NO:172)

21) VLDVGDAYFSVPLDK (SEQ ID NO:173)

22) AYFSVPLDKDFRKY (SEQ ID NO:174)

23) PLDKDFRKYTAF I (SEQ ID NO:175)

Pool HRT6

24) FRKYTAFTIPSI (SEQ ID NO: 176)

25) FTIPSTNNETPGIRY (SEQ ID NO:177)

26) NNETPGIRYQYNVL (SEQ ID NO:178)

27) GIRYQYNVLPQGWK (SEQ ID NO:179)

Pool HRT7

28) YNVLPQGWKGSPAIF (SEQ ID NO:180)

29) GWKGSPAIFQSSMTK (SEQ ID NO:181)

30) AIFQSSMTKILEPFR (SEQ ID NO:182)

3 D MTKILEPFRKQNPDI (SEQ ID NO:183) Pool HRT8

32) PFRKQNPDIVIYQYM (SEQ ID NO: 1 84

33) PDIVIYQYMDDLYV (SEQ ID NO:l 8 5)

34) YQYMDDLYVGSDLEI (SEQ ID NO: 1 86

35) LYVGSDLEIGQHRTK (SEQ ID NO: 1 87

36) LEIGQHRTKIEELR (SEQ ID NO:l 8 8)

Pool HRT9

37) HRTKIEELRQHLLRW (SEQ ID NO: 189)

38) ELRQHLLRWGFTTPDK (SEQ ID NO: 190)

39) RWGFTTPDKKHQK (SEQ ID NO: 191)

40) TTPDKKHQKEPPFLW (SEQ ID NO: 192)

41) HQKEPPFLWMGYELH (SEQ ID NO: 193)

Pool HRT10

42) FLWMGYELHPDKWTV (SEQ ID NO:194

43) ELHPDKWTVQPIML (SEQ ID NO:195)

44) KWTVQPIMLPEKDSW (SEQ ID NO:196

45) IMLPEKDSWTVNDI (SEQ ID NO:197)

46) KDSWTVNDIQKLVGK (SEQ ID NO:198

Pool HRT1 1

47) NDIQKLVGKLNWA (SEQ ID NO: 199)

48) KLVGKLNWASQIYA (SEQ ID NO:200)

49) LNWASQIYAGIKVR (SEQ ID NO:201)

50) SQIYAGIKVRQLCKL (SEQ ID NO:202

51) IKVRQLCKLLRGAKA (SEQ ID NO:203

Pool HRT12

52) CKLLRGAKALTEVI (SEQ ID NO:204)

53) GAKALTEVI PLTKEA (SEQ ID NO:205

54) EVIPLTKEAELELA (SEQ ID NO:206)

55) TKEAELELAENREIL (SEQ ID NO:207

56) ELAENREILKEPVH (SEQ ID NO:208)

Pool HRT13

57) REILKEPVHGVYY (SEQ ID NO: 209)

58) KEPVHGVYYDPSKDL (SEQ ID NO:210

59) VYYDPSKDLIAEIQK (SEQ ID NO:211

60) KDLIAEIQKQGQGQW (SEQ ID NO:212

61) IQKQGQGQWTYQIY (SEQ ID NO:213)

Pool HRT14

62) GQGQWTYQIYQEPFK (SEQ ID NO:214

63) YQIYQEPFKNLKTGK (SEQ ID NO:215

64) PFKNLKTGKYARMR (SEQ ID NO:216)

65) KTGKYARMRGAH (SEQ ID NO: 217)

66) KYARMRGAHTNDVK (SEQ ID NO:218)

Pool HRT15

67) RGAHTNDVKQLTEAV (SEQ ID NO:219

68) DVKQLTEAVQKIV (SEQ ID NO: 220)

69) LTEAVQKIVTESIVI (SEQ ID NO:221

70) KIVTESIVIWGKTPK (SEQ ID NO:222

71) IVIWGKTPKFKLPI (SEQ ID NO:223)

Pool HRT16

72) KTPKFKLPIQKETW (SEQ ID NO:224) 73) KLPIQKETWEAWW (SEQ ID NO: 225)

74) IQKETWEAWWTEYW (SEQ ID NO:226)

75) WEAWWTEYWQATWI (SEQ ID NO: 227)

76) TEYWQATWI PEWELV (SEQ ID NO: 228)

Pool HRT17

77) TWIPEWELVNTPPLV (SEQ ID NO:229)

78) ELVNTPPLVKLWYQL (SEQ ID NO: 230)

79) PLVKLWYQLEKEPI (SEQ ID NO:231)

80) WYQLEKEPIEGAETF (SEQ ID NO:232)

81) EPIEGAETFYVDGAA (SEQ ID NO:233)

82) ETFYVDGAANRETKL (SEQ ID NO:234)

Pool HRT18

83) GAANRETKLGKAGYV (SEQ ID NO: 235)

84) TKLGKAGYVTNRGR (SEQ ID NO: 236)

85) AGYVTNRGRQKWPL (SEQ ID NO: 237)

86) RGRQKWPLTDA (SEQ ID NO: 238)

87) RQKWPLTDATNQK (SEQ ID NO: 239)

Pool HRT19

88) PLTDATNQKTELEAI (SEQ ID NO: 240)

89) NQKTELEAIHLAL (SEQ ID NO: 241)

90) ELEAIHLALQDSGL (SEQ ID NO: 242)

91) HLALQDSGLEVNIV (SEQ ID NO: 243)

92) DSGLEVNIVTDSQYA (SEQ ID NO: 244)

Pool HRT20

93) NIVTDSQYALGIIQA (SEQ ID NO: 245)

94) SQYALGIIQAQPDK (SEQ ID NO: 246)

95) GIIQAQPDKSESELV (SEQ ID NO: 247)

96) PDKSESELVSQII (SEQ ID NO: 248)

97) ESELVSQIIEQLIKK (SEQ ID NO: 249)

Pool HRT21

98) SQIIEQLIKKEKVYL (SEQ ID NO: 250)

99) LIKKEKVYLAWVPAH (SEQ ID NO:251)

100) VYLAWVPAHKGI (SEQ ID NO:252)

101) AWVPAHKGIGGNEQV (SEQ ID NO: 253)

102) KGIGGNEQVDKLV (SEQ ID NO:254)

103) GNEQVDKLVSSGIRK (SEQ ID NO: 255)

104) KLVSSGIRKVL (SEQ ID NO: 256)

NOTE that in the text we call individual peptides in the pool according to the order below each pool. In the case of Fp3, individual peptide FRT3-3 is the same as Peptide 10 (VQLWFTAFSANL) (SEQ ID NO:257) or the third one listed under Pool Fp3.

FIV p24 Overlapping Peptides (subtype-A FIV-Bangston backbone with subtype-B FIV- FC1 (tubes 47-51))

Pool Fp1

1) PIQTVNGAPQYVAL (SEQ ID NO: 258)

2) TVNGAPQYVALDPKM (SEQ ID NO: 259)

3) APQYVALDPKMVSIF (SEQ ID NO: 260)

4) VALDPKMVSIFMEKA (SEQ ID NO: 261)

Pool Fp2

5) PKMVSIFMEKAREGL (SEQ ID NO: 262) 6) SIFMEKAREGLGGEEV (SEQ ID NO: 263)

7) KAREGLGGEEVQLWF (SEQ ID NO: 265)

Pool Fp3

8) GLGGEEVQLWFTAF (SEQ ID NO: 266)

9) GEEVQLWFTAFSANL (SEQ ID NO: 267)

10) VQLWFTAFSANL =Fp3-3 (SEQ ID NO: 257)

11) LWFTAFSANLTPTDM (SEQ ID NO: 268)

Pool Fp4

12) AFSANLTPTDMATLI (SEQ ID NO: 269)

13) NLTPTDMATLIMAA (SEQ ID NO:270)

14) PTDMATLIMAAPGCA (SEQ ID NO:271)

Pool Fp5

15) ATLIMAAPGCAADK (SEQ ID NO:272)

16) IMAAPGCAADKEIL (SEQ ID NO: 273)

17) APGCAADKEILDESL (SEQ ID NO:274)

Pool Fp6

18) AADKEILDESLKQL (SEQ ID NO:275)

19) KEILDESLKQLTAEY (SEQ ID NO:276)

20) DESLKQLTAEYDRTH (SEQ ID NO: 277)

21) KQLTAEYDRTHPPDGPR (SEQ ID NO: 278)

Pool Fp7

22) YDRTHPPDGPRPLPY (SEQ ID NO: 279)

23) HPPDGPRPLPYFTAA (SEQ ID NO:280)

24) GPRPLPYFTAAEIM (SEQ ID NO:281)

25) PLPYFTAAEIMGIGL (SEQ ID NO:282)

Pool Fp8

26) FTAAEIMGIGLTQEQQA (SEQ ID NO: 283)

27) MGIGLTQEQQAEARF (SEQ ID NO:284)

28) LTQEQQAEARFAPAR (SEQ ID NO: 285)

Pool Fp9

29) EQQAEARFAPARM (SEQ ID NO: 286)

30) AEARFAPARMQCRAW (SEQ ID NO: 287)

31) FAPARMQCRAWYLEA (SEQ ID NO: 288)

Pool Fp10

32) RMQCRAWYLEALGKL (SEQ ID NO: 289)

33) RAWYLEALGKLAAIK (SEQ ID NO: 290)

34) LEALGKLAAIKAK (SEQ ID NO: 291)

Pool Fp1 1

35) ALGKLAAIKAKSPRA (SEQ ID NO:292)

36) LAAIKAKSPRAVQLR (SEQ ID NO:293)

37) KAKSPRAVQLRQGAK (SEQ ID NO: 294)

Pool Fp12

38) PRAVQLRQGAKEDY (SEQ ID NO: 295)

39) VQLRQGAKEDYSSFI (SEQ ID NO:296)

40) RQGAKEDYSSFIDRL (SEQ ID NO: 297)

Pool Fp13

41) KEDYSSFIDRLFAQI (SEQ ID NO:298)

42) DRLFAQIDQEQNTA (SEQ ID NO:299)

43) FAQIDQEQNTAEVKL (SEQ ID NO:300)

Pool Fp14

44) DQEQNTAEVKLYLK (SEQ ID NO: 301)

45) EQNTAEVKLYLKQSL (SEQ ID NO: 302)

46) AEVKLYLKQSLSIA (SEQ ID NO:303)

47) KLYLKQSLSIANA (SEQ ID NO:304)

Pool Fp15

48) YLKQSLSIANANPDCK (SEQ ID NO: 305)

49) LSIANANPDCKRAM (SEQ ID NO: 306)

50) ANANPDCKRAMSHLK (SEQ ID NO: 307)

Pool Fp16 51) PDCKRAMSHLKPESTL (SEQ ID NO: 308)

52) AMSHLKPESTLEEKL (SEQ ID NO: 309)

53) LKPESTLEEKLRA (SEQ ID NO: 310)

Pool Fp17

54) PESTLEEKLRACQEV (SEQ ID NO:311)

55) LEEKLRACQEVGSPGY (SEQ ID NO:312)

56) RACQEVGSPGYKMQLL (SEQ ID NO: 313)

Consensus Subtype-B HIV-1 p24 Overlapping Peptides

Pool HD1

1) PIVQNLQGQMVHQAI (SEQ ID NO: :314

2) NLQGQMVHQAISPRT (SEQ ID NO: :315

3) QMVHQAISPRTLNAW (SEQ ID NO: :316

4) QAISPRTLNAWVKVV (SEQ ID NO: :317

Pool HD2

5) PRTLNAWVKVVEEKA (SEQ ID NO: :318

6) NAWVKVVEEKAFSPE (SEQ ID NO: :319

7) KVVEEKAFSPEVIPM (SEQ ID NO: :320

Pool HD3

8) EKAFSPEVIPMFSAL (SEQ ID NO: :322

9) SPEVIPMFSALSEGA (SEQ ID NO: :323

10) IPMFSALSEGATPQD (SEQ ID NO: :324

Pool HD4

11) SALSEGATPQDLNTM (SEQ ID NO: :325

12) EGATPQDLNTMLNTV (SEQ ID NO: :326

13) PQDLNTMLNTVGGHQ (SEQ ID NO: :327

Pool HD5

14) NTMLNTVGGHQAAMQ (SEQ ID NO: :328

15 ) N VGGHQAAMQMLKE (SEQ ID NO: :329

16) GHQAAMQMLKE INE (SEQ ID NO: :330

Pool HD6

17) AMQMLKE INEEAAE (SEQ ID NO: :331

18) LKETINEEAAEWDRL (SEQ ID NO: :332

19) INEEAAEWDRLHPVH (SEQ ID NO: :333

Pool HD7

20 ) AAEWDRLHPVHAGPI (SEQ ID NO: :334

21) DRLHPVHAGPIAPGQ (SEQ ID NO: :335

22) PVHAGPIAPGQMREP (SEQ ID NO: :336

Pool HD8

23) GPIAPGQMREPRGSD (SEQ ID NO: :338

24) PGQMREPRGSDIAGT (SEQ ID NO: :339

25) REPRGSDIAGTTSTL (SEQ ID NO: :340

Pool HD9

26) GSDIAGTTSTLQEQI (SEQ ID NO: :341

27) AGTTSTLQEQIGWMT (SEQ ID NO: :342

28) STLQEQIGWMTNNPP (SEQ ID NO: :343

Pool HD10

29) EQIGWMTNNPPIPVG (SEQ ID NO: :344

30) WMTNNPPIPVGEIYK (SEQ ID NO: :345

31) NPPIPVGEIYKRWII (SEQ ID NO: :345

Pool HD1 1

32) PVGEIYKRWI ILGLN (SEQ ID NO: :347

33) IYKRWI ILGLNKIVR (SEQ ID NO: :348

34) WIILGLNKIVRMYSP (SEQ ID NO: :349

Pool HD12

35) GLNKIVRMYSPTSIL (SEQ ID NO: :350

36) IVRMYSPTSILDIRQ (SEQ ID NO: :351

37) YSPTSILDIRQGPKE (SEQ ID NO: :352

Pool HD13

38) SILDIRQGPKEPFRD (SEQ ID NO: :353

39) IRQGPKEPFRDYVDR (SEQ ID NO: :354

40) PKEPFRDYVDRFYKT (SEQ ID NO: :355

Pool HD14

41 ) FRDYVDRFYKTLRAE (SEQ ID NO: :356 42 ) VDRFYKTLRAEQASQ (SEQ ID NO::357

43 ) YKTLRAEQASQEVK (SEQ ID NO: :358

Pool HD15

44 ) RAEQASQEVK WMTE (SEQ ID NO: :359

45) ASQEVK WMTETLLV (SEQ ID NO: :360

46 ) VK WMTETLLVQNAN (SEQ ID NO: :361

Pool HD16

47) MTETLLVQNANPDCK (SEQ ID NO: :362

48) LLVQNANPDCK ILK (SEQ ID NO: :363

49) NANPDCK ILKALGP (SEQ ID NO: :364

Pool HD17

50) DCK ILKALGPAATL (SEQ ID NO: :365

51) ILKALGPAATLEEMM (SEQ ID NO: :366

52) LGPAATLEEMMTACQ (SEQ ID NO: :367

Pool HD18

53) ATLEEMMTACQGVGG (SEQ ID NO: :368

54) EMMTACQGVGGPGHK (SEQ ID NO: :369

55 ) ACQGVGGPGHKARVL (SEQ ID NO: :370

PEPTIDES FOR MAPPING MAB EPITOPES

Antibody FIV p24 Peptides (FB=Bangston; FC=FC1 ; FCS= only "PDCK" changed to FC1

Code Peptide sequence (aa- ■mer)

FBI) PIQTVNGAPQYVALDPKMVSIFMEKAREGL (30) (SEQ ID NO: :371

FB2) QYVALDPKMVSIFMEKAREGLGGEEVQL (28) (SEQ ID NO: :372

FC2) EVQLWFTAFSANLTPTDMATLIMAAP (26) (SEQ ID NO: :373

FB3) TLIMAAPGCAADKEILDESLKQLTAEYDR (29) (SEQ ID NO: :374

FB4) SLKQLTAEYDRTHPPDGPRPLPYFTAAEIM (30) (SEQ ID NO: :375

FB5) PLPYFTAAEIMGIGLTQEQQAEARFAPARM (30) (SEQ ID NO: :376

FB6) EQQAEARFAPARMQCRAWYLEALGKLAAIK (30) (SEQ ID NO: :377

FB7) LEALGKLAAIKAKSPRAVQLRQGAKEDY (28) (SEQ ID NO: :378

FB8) VQLRQGAKEDYSSFIDRLFAQIDQEQNTA (29) (SEQ ID NO: :379

FB9) FAQIDQEQNTAEVKLYLKQSLSIANANA (28) (SEQ ID NO: :380

FB10) KQSLSIANANAECKKAMSHLKPESTLEEKL (30) (SEQ ID NO: :381

FB11) LKPESTLEEKLRACQEVGSPGYKMQLL (28) (SEQ ID NO: :382

FCS12) ι FAQIDQEQNTAEVKLYLKQSLSIANANPDCK (31) (SEQ ID NO: :383

FCS13) ι LSIANANPDCKRAMSHLKPESTLEEKLRA (29) (SEQ ID NO: :384

FIV-Bang p24 (SO-mer)

Code Peptide sequence (aa-mer\ [Hydrophlicity]

FBOl) PIQTVNGAPQYVALDPKMVSIFMEKAREGL (30) -0.02] (SEQ ID NO:371

FB02) PQYVALDPKMVSIFMEKAREGLGGEEVQ (28) -0 , .30] (SEQ ID NO :385)

FB03) IFMEKAREGLGGEEVQLWFTAFSANLTPTD (30) -0 , .12] (SEQ ID NO :386)

FB04) KAREGLGGEEVQLWFTAFSANLTPTDMA (28) -0 , .20] (SEQ ID NO :387)

FC05) NLTSTDMATLIMSAPGCAADKEILDETLKQ (30) -0 , .03] FC1 i [SEQ ID NO:3?

FB06) TLIMAAPGCAADKEILDESLKQLTAEYDRT (30) -0 , .18] (SEQ ID NO :389)

FB07) AAPGCAADKEILDESLKQLTAEYDRTHPPD (30) -0 , .83] (SEQ ID NO :390)

FB08) CAADKEILDESLKQLTAEYDRTHPPDAPRP (30) -1 , .08] (SEQ ID NO :391)

FB09) SLKQLTAEYDRTHPPDAPRPLPYFTAAEIM (30) -0 , .64] (SEQ ID NO :392)

FBO10) ι RTHPPDAPRPLPYFTAAEIMGIGLTQEQQA (30) -0 , .56] (SEQ ID NO :393)

FBOll) ι LPYFTAAEIMGIGLTQEQQAEARFAPARMQ (30) -0 , .11] (SEQ ID NO :394)

FB012) ι GIGLTQEQQAEARFAPARMQCRAWYLEALG (30) -0 , .33] (SEQ ID NO :395)

FB013) ι EARFAPARMQCRAWYLEALGKLAAIKAKSP (30) -0 , .16] (SEQ ID NO :396)

FB014) ι CRAWYLEALGKLAAIKAKSPRAVQLRQGAK (30) -0 , .20] (SEQ ID NO :397)

FB015) ι KLAAIKAKSPRAVQLRQGAKEDYSSFIDRL (30) -0 , .53] (SEQ ID NO :398)

FB016) ι RAVQLRQGAKEDYSSFIDRLFAQIDQEQNT (30) -0 , .94] (SEQ ID NO :399) FB017) EDYSSFIDRLFAQIDQEQNTAEVKLYLKQS (30) [-0 76] (SEQ ID NO 400

FB018) FAQIDQEQNTAEVKLYLKQSLSIANANAEC (30) [-0 37] (SEQ ID NO 401

FB019) AEVKLYLKQSLSIANANAECKKAMSHLKPE (30) [-0 39] (SEQ ID NO 402

FBO20) LSIANANAECKKAMSHLKPESTLEEKLRAC (30) [-0 45] (SEQ ID NO 403

FB021) KKAMSHLKPESTLEEKLRACQEVGSPGYKM (30) [-0 92] (SEQ ID NO 404

FB022) STLEEKLRACQEVGSPGYKMQLL (23) [-0 44] (SEQ ID NO 405

HIV-1 -UCD1 p24 (22-30-mer)

HBl) PWQNLQGQMVHQPISPRTLNAWVKWEEK (30) [-0 .34] (SEQ ID NO: 406)

HB2) QMVHQPISPRTLNAWVKWEEKAFSPEVIP (30) [-0 .13] (SEQ ID NO: 407)

HB3) KWEEKAFSPEVIPMFTALSEGATPQDLNT (30) [-0 .12] (SEQ ID NO: 408)

HB4) SPEVIPMFTALSEGATPQDLNTMLNTVGGH (30) [-0 .00] (SEQ ID NO: 409)

HB5) TALSEGATPQDLNTMLNTVGGHQAAMQMLK (30) [-0 .19] (SEQ ID NO: 410)

HB6) DLNTMLNTVGGHQAAMQMLKETINEEAAEW (30) [-0 .43] (SEQ ID NO: 411)

HB7) GHQAAMQMLKETINEEAAEWDRLHPVHAGP (30) [- 0.75] (SEQ ID NC :412

HB8) ETINEEAAEWDRLHPVHAGPIAPDQMREPR (30) [- 1.12] (SEQ ID NC :413

HB9) DRLHPVHAGPIAPDQMREPRGSDIAGITST (30) [- 0.64] (SEQ ID NC :414

HB10) IAPDQMREPRGSDIAGITSTLQEQIGWMTN (30) [-0 .56] (SEQ ID NO: 415)

HB11) GSDIAGITSTLQEQIGWMTNNPPIPVGEIY (30) [-0 .09] (SEQ ID NO: 416)

HB12) LQEQIGWMTNNPPIPVGEIYKRWI ILGLNK (30) [-0 .22] (SEQ ID NO: 417)

HB13) MTNNPPIPVGEIYKRWI ILGLNKIVRMYSP (30) [-0 .02] (SEQ ID NO: 418)

HB14) KRWI ILGLNKIVRMYSP SILDIRQGPKEP (30) [-0 .31] (SEQ ID NO: 419)

HB15) IVRMYSPTSILDIRQGPKEPFRDYVDRFYK (30) [-0 .72] (SEQ ID NO: 420)

HB16) ETINEEAAEWDRLHPVHAGPIAPDQMREPR (30) [-1 .12] (SEQ ID NO: 413)

HB17) DRLHPVHAGPIAPDQMREPRGSDIAGITST (30) [-0 .64] (SEQ ID NO: 414)

HB18) IAPDQMREPRGSDIAGITSTLQEQIGWMTN (30) [-0 .56] (SEQ ID NO: 415)

HB19) GSDIAGITSTLQEQIGWMTNNPPIPVGEIY (30) [-0 .09] (SEQ ID NO: 416)

HB20) LQEQIGWMTNNPPIPVGEIYKRWI ILGLNK (30) [-0 .22] (SEQ ID NO: 417)

HB21) MTNNPPIPVGEIYKRWI ILGLNKIVRMYSP (30) [-0 .02] (SEQ ID NO: 418)

HB22) KRWI ILGLNKIVRMYSPTSILDIRQGPKEP (30) [-0 .31] (SEQ ID NO: 419)

HB23) IVRMYSPTSILDIRQGPKEPFRDYVDRFYK (30) [-0 .72] (SEQ ID NO: 420)

HB24) LDIRQGPKEPFRDYVDRFYKTLRAEQASQD (30) [-1 .32] (SEQ ID NO: 421)

HB25) FRDYVDRFYKTLRAEQASQDVKNWMTETLL (30) [-0 .83] (SEQ ID NO: 422)

HB26) TLRAEQASQDVKNWMTETLLVQNANPDCKT (30) [-0 .79] (SEQ ID NO: 423)

HB27) VKNWMTETLLVQNANPDCKTILKALGPAAT (30) [-0 .01] (SEQ ID NO: 424)

HB28) VQNANPDCKTILKALGPAATLEEMMTACQG (30) [-0 .02] (SEQ ID NO: 425)

HB29) TLEEMMTACQGVGGPGHKARVL (22) [-0 .04] (SEQ ID NO: 426)

MATERIALS AND METHODS FOR EXAMPLES 5-11

Study population. Blood from HIV-1 infected subjects was obtained from the

University of California at San Francisco (UCSF), the University of South Florida in Tampa, and the University of Florida Center for HIV/AIDS Research, Education and Service (UF CARES) in Jacksonville. These subjects are distributed into three groups according to the length of infection and the anti-retroviral therapy (ART) status (Table 9). The HIV-infected (HIV+) subjects consist of long-term survivors (LTS) who have been infected for more than 10 years and remain healthy without antiretro viral therapy (LTS/ART-); subjects with short-term infection without ART (ST/ ART-) and subjects on ART for various amounts of time (ART+). T-cell counts and HIV-1 RNA levels were performed by clinical laboratories at UCSF Medical Center and UF Shands Medical Center (Gainesville, FL). Bloods from HIV seronegative (HIV-) samples were obtained from LifeSouth Community Blood Centers (Gainesville, FL) or randomly selected volunteers at UF. The blood collections were performed according to the policy and protocol approved by the Institutional Review Boards at UF and UCSF and processed in 2-30 hours after collection.

RT overlapping peptides. Overlapping peptides of subtype-B HIV-lUCDl and subtype-B FIVFCl RT proteins and selected peptides for epitope mapping were produced initially by SynPep (Dublin, CA) and later by RS Synthesis LLC (Louisville, KY) with similar findings. Four to five consecutive peptides (11-16 aa long with 8-10 aa overlap) were grouped into 21 pools: H1-H21 for HIV and counterparts F1-F21 for FIV. In addition, 9mer and 15-16mer peptides with modified sequences were also synthesized by RS Synthesis LLC and used for peptide epitope mapping as shown in Table 10.

ELISpot assays. Enzyme-linked immunosorbent spot assays (ELISpot) for IFNy (R&D Systems, Minneapolis, MN) were performed with AIM V medium containing 5% heat-inactivated (56°C, 30 min) human serum as previously described (Abbott et al. (2012)). The PBMC from HIV+ subjects were stimulated with either peptide pool (4-5 consecutive peptides per pool at 5 μg per peptide) or individual peptide (15 μg/well). The peptides were 11-16 aa in length with 8-10 aa overlap. The results were analyzed with an ELISpot reader (MVS Pacific LLC, Minneapolis, MN) and adjusted to spot forming units (SFU) per 10⁶ cells, after subtraction of the average medium control for each subject. The PBMC from HIV+ subjects were stimulated with T-cell mitogen, phytohemaglutinin A (PHA, 5 μg/mL), as positive control. At a positive threshold of 70 SFU, HIV- subjects had no substantial IFNy responses (>50 SFU) to HIV and FIV peptide pools.

Flow cytometry (FACS) for carboxyfluoresein diacetate succinimide ester (CFSE)-proliferation and intracellular cytotoxin staining (ICS). The CFSE- proliferation analysis was performed on PBMC according to the manufacturer's protocol (Invitrogen, Carlsbad, CA) and processed as previously described (Lichterfeld et al. (2004)). Modifications consisted of using 2.0-5.0xl0⁵ CFSE-labeled cells stimulated for 5 days (37°C, 5% CO²) with 30 μg/well of total peptides in a pool (15 μg/well for individual peptide, Table 10) or 5 μ§/ητΙ. PHA in AIM V medium containing 25 μ§/ι Ι. of gentamycin and 10% heat-inactivated human serum. Subsequently these cells were harvested and labeled with the LIVE/DEAD fixable yellow dye (Invitrogen) and then treated 5 min with anti-CD 16/CD32 antibody (Biolegend, San Diego, CA) for blocking non-specific binding before phenotype-specific antibodies. The following antibodies were used for the CFSE-proliferation analysis: anti-CD4 APC, anti-CD3 APC-H7, and anti- CD8 Pacific Blue (BD Biosciences, San Jose, CA).

The ICS analysis (Horton et al. (2007)) involved stimulating 0.5-1.0xl0⁶ freshly isolated PBMC for 6 h with the same peptide stimulant and culture conditions as the proliferation analysis in the presence of 1 μg/mL of Golgi transport inhibitor and monensin followed by labeling with LIVE/DEAD fixable yellow dye and then treatment with anti-CD 16/CD32 antibody and T-cell phenotypic antibodies. The cells were subsequently fixed and permeabilized with Cytofix/Cytoperm solution (BD Biosciences) before reaction with anti-cytotoxin antibodies. The antibodies consisted of anti-CD3 APC-H7, anti-CD4 BD Horizon V450, and anti-CD8 FITC followed by anti-GrzB Alexa 700 and anti-GrzA PE (all from BD Biosciences), and anti-perforin PerCP {Abeam, Boston, MA).

In both analyses, 1.0-2.0xl0⁴ cells were fixed in phosphate -buffered saline (PBS) containing 2% paraformaldehyde and analyzed on BD LSRII using FACSDIVA Software (BD Biosciences), with a positive threshold of 3% CFSE^low for CFSE-proliferation and 1%) T cells expressing cytotoxin for ICS. The final value for each subject was derived after subtraction of the subject's medium control and the average value of peptide- stimulated cells from uninfected control subjects.

Statistics. Paired Student t-test with two-tailed distribution (SigmaPlot version 11.0, San Jose, CA) was used to evaluate the statistical differences between the results from two time points in Figure 19. These results were considered statistically different when /?<0.05.

Example 5— Screening for IFNy-inducing epitopes on HIV-1 and FIV RT

As a first step towards identifying the CTL-associated reactive sites on HIV-1 and FIV RT proteins, the PBMC from HIV+ subjects and HIV- subjects were screened by ELISpot analysis for IFNy responses to overlapping RT peptide pools of HIV-1 and FIV. NK cells, CD3+CD4+ T-helper cells, CD3+CD4+ CTLs, and CD3+CD8+ CTLs generally produce IFNy responses to viral peptides (Abbas et al. (2010); Soghoian et al. (2012)). In this study, many HIV-1 pools induced IFNy responses of high magnitudes above the threshold level (>70 SFU) with the PBMC from HIV+ subjects (Figure 17 A) but none with the PBMC from HIV- subjects (data not shown). Therefore, the viral specificity of the IFNy responses is associated with HIV-1 infection. The average responder frequency for all 21 pools was 25% (range, 4-54%) (Figure 17E). Of all HIV peptide pools screened, pool Hl l induced the highest and the most frequent IFNy responses.

Compared to the HIV peptide-pool responses, the magnitude and the frequency of the IFNy responses to the FIV peptide pools were much lower in the PBMC from HIV+ subjects (Figures 17B and 17F). The average responder frequency for all 21 pools was 17%) (range, 4-69%>) (Figure 17F). A noticeable exception was observed with pool F3 which induced the highest and the most frequent cellular responses among the FIV pools (Figures 17B and 17F). PBMC from only five subjects (SF08, J08, J02, J09, TP01) responded to a counterpart pool H3 (grouped data only, Figure 17 A), and remarkably PBMC from four of these subjects responded to both F3 and H3 (grouped data only, Figures 17A and 17B). As expected, the PBMC of HIV- subjects had no IFNy responses to the FIV pools (data not shown). Overall, HIV pools induced much higher and more frequent IFNy responses than the FIV counterparts except for pool F3. However, only a few HIV and FIV counterparts were detected by the same individual (4-5 responders detected both: H3/F3, H6/F6, H7/F7, HI 1/Fl 1, H13/F13).

The immune responses observed were present in all three clinical groups (LTS/ART-, ST/ ART-, ART+). In addition these groups were not statistically different in terms of cell counts. However, it is noteworthy that 4 of 5 responders to pool H3 are in the ST group which may indicate that this response has been lost in the LTS and ART+ group, possibly due to HIV infection.

Example 6— Screening for T-cell proliferation epitopes on HIV-1 and FIV RTs

The presence of strong T-cell proliferation responses to HIV antigen(s) has been associated with lower viral load and better disease outcome in HIV+ individuals (McKinnon et al. (2012)). In the current studies, CD3+CD4+ T cells (hereon CD4+ T cells) from HIV+ subjects (Figures 18A and 18B) had fewer proliferation responses than CD3+CD8+ T cells (CD8+ T cells) to both HIV and FIV pools (Figures 17C and 17D). The CD4+ T cells from only 5 of 26 HIV+ subjects responded to at least one HIV pool, whereas 9 of 26 HIV+ subjects responded to at least one FIV pool (Figures 18A and 18B). In contrast, the CD8+ T cells from 17 of 26 HIV+ subjects responded to the HIV pools, and 22 of 26 subjects responded to the FIV pools (Figures 17C and 17D).

The most striking result was the high magnitude and the high frequency of CD 8+ T-cell proliferation to the FIV pools in comparison to HIV pools (Figures 17C and 17D). Furthermore, the average responder frequency to all FIV pools was 17% (range, 0-54%>) (Figure 17F), which is higher than the average of 10%> (range, 0-24%>) observed with the HIV pools (Figure 17E). Only one of the HIV pools (HI 1) had a responder frequency of >20%> (Figure 17E), while the responder frequencies to the six FIV pools (F3, F6, F7, Fl l, F15, F21) were >20% (Figure 17E). In addition, only a few HIV and FIV counterparts were detected by the same subject (2-4 responders detected both: H3/F3, H6/F6, H14/F14, H15/F15, H17/F17, H19/F19), but 43% (23 of 53) of the total positive proliferation responses to the HIV-1 pools were also positive to FIV counterparts.

The above results support the view that the CD8+ T-cell proliferative responses to FIV pools are more robust or possibly more intact than those to HIV pools. This finding is clearly opposite from the results of the IFNy studies where the IFNy responses were stronger against the HIV pools than the FIV pools (Figures 17A and 17B). These conflicting findings may be partially attributed to the difference in the cell types used (PBMC versus CD8+ T cells). Moreover, 12 of 15 responders showing CD8+ T-cell proliferation to the F3 pool also had robust IFNy responses to the F3 pool (Figures 17B and 17D). These findings indicate that these subjects recognize peptide epitope(s) that induce both responses.

Example 7— The persistence of IFNy and proliferation responses to selected HIV and FIV peptide pools

Due to the ability of HIV to quickly escape from immunological pressure (Leslie et al. (2004); Troyer et al. (2009)), the PBMC from IFNy responders (Figures 17A and 17B) were retested at least one year later for IFNy responses to peptide pools H6, Hl l, and F3. The majority of the individuals tested retained positive IFNy responses at the second time -point to H6 (8 of 11 responders) and to F3 (11 of 14 responders) but fewer to Hl l (5 of 14 responders) (Figures 19A). The cells from a few subjects were retested against H6 and F3 for a third time-point and demonstrated the persistence of the IFNy responses to the F3 pool (4 of 5) but to a lesser extent to the H6 pool (2 of 4) after 3 years (Figure 19A). More importantly, the persistence of the IFNy responses to the F3 pool demonstrated the reproducibility of this activity even though no IFNy responses were observed to the HIV-counterpart H3 by those who were tested after 2 years (Table 10, top for H3-3 peptide).

The CD4+ and CD8+ T-cell proliferation responses did not correlate with the IFNy responses in general as only a low frequency of CD4+ T responses were observed. However, more CD4+ T-cell responses were observed in the production of cytotoxins. The lack of correlation between IFNy ELISpot and CD8+ T-cell proliferation responses has been described before, with p24 proteins. In this case, the majority of responses (64%) were IFNy+/proliferation- and only 30% of the responses were IFNy+/proliferation+ (Richmond et al. (2011)). Furthermore, the use of PBMC in the IFNy analysis may have contributed to the lack of correlation between IFNy and T-cell proliferation responses. Cells such as NK cells in PBMC are known to be high producer of IFNy (Caligiuri (2008)) and could have also given the IFNy responses.

In addition, the CD8+ T-cell proliferation responses to F3 pool (7 of 9 responders) persisted but not to Hl l pool (2 of 5) and F6 pool (1 of 4) (Figure 19B). Overall, these results suggest a major loss of Hl l-specific IFNy and proliferation responses with maintenance of reactions to the F3 pool. Due to the strong persistent proliferation and IFNy responses to the F3 pool, subsequent studies focused on the F3 peptide pool and its five individual peptide/epitopes.

Example 8— Identifying the peptide epitope(s) on F3 region that induces IFNy and CD8+ T-cell proliferation responses

The finding that 69%> and 58% of the HIV+ subjects responded to pool F3 with IFNy production and CD8+ T-cell proliferation respectively (Figures 17E and 17F) suggested the potential that the F3 region contains multiple epitopes. The F3 peptide pool has five overlapping peptides of 13-15mers (F3-1, F3-2, F3-3, F3-4, F3-5). All ten F3 responders tested 1-2 years later had IFNy responses to the F3-3 peptide, and one individual each had low IFNy responses to individual peptides F3-1 and F3-4 (Figure 20 A). Furthermore, 4 of 22 F3 responders had IFNy responses to the counterpart pool H3 in the first year (Figure 17 A), but all three of the H3 responders tested on or after the second year lost IFNy responses to H3 and had no reactivity to any of the individual 13- 15mer H3 peptides (Table 10, top; 0/3 IFNy response to H3-3). As expected, all ten HIV- control subjects had no IFNy responses to individual peptides of both pools F3 and H3 (data not shown).

Remarkably, the majority of IFNy responses observed to pool F3 were specific for the F3-3 peptide, and the highest responder frequency of CD8+ T-cell proliferation was observed with F3-3 (5 of 8) as well; slightly lower reactions were noted with F3-2, F3-4, and F3-5 (3 of 8 each) (Figure 20B). F3-3 is therefore the predominant FIV RT peptide that gives both IFNy and T-cell proliferation responses.

Example 9— Characterization of CTL-associated activities induced by the F3 pool and F3-3 peptide

One of the most important CMI activities needed to control HIV infection is potent cytotoxicity (Betts et al. (1999)). Both CD4+ CTLs and CD8+ CTLs against HIV- 1 have been detected in HIV+ subjects (McDermott et al. (2012)) and in HIV- individuals immunized with a candidate HIV-1 vaccine (de Souza et al. (2012)). Although activities to H6, HI 1, and F6 pools were demonstrated, our focus was on CTL-associated activities to F3 pool (Figures 21A-21C) and its five individual peptides (Figure 21D). 100% (11 of 11) of the F3 responders expressed at least one cytotoxin (GrzA, GrzB, or perforin) in their CD4+ or CD8+ T cells similar to the 100% (8 of 8) of HI 1 responders but higher than the 75%> (6 of 8) of H6 responders and 50%> (3 of 6) of F6 responders. Hence, CTL- associated epitope(s) present on F3 and Hl l were recognized by all the subjects tested. These findings suggest that multiple CTL epitopes may reside on each of these regions.

This study showed that all five individual F3 peptides induced GrzA, GrzB, and/or perforin in the CD4+ and/or CD8+ T cells of at least one or more HIV+ subjects tested (Figure 2 ID). Based on this finding, different CTL-associated epitopes appear to be present within all five of the individual F3 peptides (data not shown).

Example 10— CMI epitopes at H3-3 and F3-3 are conserved among lentiviruses According to LANL QuickAlign analysis, the H3 pool makes up a stretch of aa that is highly conserved among lentiviruses as it is identical to 47% of the HIV-1 RTs and 7% of the SIV RTs (hiv.lanl.gov/content/sequence/QUICK_ALIGN/QuickAlign.html). AA sequence analysis of all HIV and FIV counterpart pairs determined that H3/F3 had the second highest aa identity of 66.7%> (Figure 22 A). Furthermore, aa sequence analysis of the individual 13-15mer peptides shows high aa sequence identity and similarity between HIV and FIV (Figure 22B). The HIV and FIV pair with the highest similarity was shown in order of the highest to the lowest: H3-1/F3-1 (92%), H3-2/F3-2 (81%), H3- 3/F3-3 (75%), H3-4/F3-4 (71%), and H3-5/F3-5 (71%). Considerable similarities in sequences were observed when the H3 and F3 13-15mer peptides were compared to SIV and CAEV counterpart sequences. Based on aa sequence similarity, both the H3/F3 peptide-pool regions and their counterpart individual peptides are evolutionarily conserved (Figures 22A and 22B).

Due to the consistently higher CMI responses to F3-3 than to the other four individual F3 peptides (Figure 20), subsequent studies focused on F3-3 and its HIV- counterpart H3-3. According to LANL QuickAlign analysis, H3-3 has an 83% and 35% aa identity with various HIV-1 and SIV sequences, respectively. H3-3 and F3-3 peptides have 69%o identity and 75% similarity with two gaps (Figure 22B; Table 10, top). Even with such sequence similarity, IFNy and CD8+ T-cell proliferation responses greatly differed between these peptides (Table 10).

F3-3 differs from the H3-3 used in the current study (row 1 versus row 2, Table 10) by lacking one aa (Asp on position 4 of H3-3) and having four aa differences at the F3-3 positions 5, 9, 11, and 15. The combination of a D4 deletion and three changes at K10, V12, and E16 of H3-3 with aa identical to F3-3 resulted in IFNy responses approaching F3-3 (Table 10, F3-3m6). The addition of D4 to F3-3 (16mer) (F3-3m2) also resulted in IFNy responses approaching F3-3, whereas the removal of V16 from F3-3m2, giving 15mer F3-3ml, caused a major loss in IFNy responses and also a modest loss in CD 8+ T-cell proliferation responses. Furthermore, a single aa change at F3-3 positions 9 (M9→K9; F3-3m5), 11 (I11→V11; F3-3m3), or 15 (V15→E15; CAEV & MVV peptide) caused major losses in both IFNy and CD8+ T-cell proliferation responses. Note that none of the modifications of H3-3 and the peptides tested in Table 10, induced IFNy or T-cell proliferation responses in the PBMC or the T cells from HIV- control subjects (data not shown).

Peptide F3-3 has high degrees of aa identity to those of ungulate lentiviruses (93%, caprine arthritis-encephalitis virus [CAEV] and Maedi-Visna virus [MVV]) (Table 10). Thus, the F3-3 sequence is greatly conserved among lentiviruses. In this regard, the ungulate peptide counterpart of F3-3, induced IFNy responses in the PBMC from 1 of 9 F3-3 responders tested (Table 10, top). The above results demonstrate that the F3-3 sequence contains evolutionarily-conserved epitope(s) that induces persistent CMI responses, including strong CTL-associated activity, even when the responses to the counterpart H3-3 are lost.

Example 11

In these studies, the CMI responses by the HIV+ subjects to FIV and HIV RT peptides or peptide pools resulted in three major observations: First, the CD8+ T-cell proliferation responses to FIV pools were more robust with higher frequency of responders than those induced by the HIV pools (Figures 17E and 17F). This observation was unexpected since higher levels of IFNy responses were observed with HIV pools than with FIV pools. These proliferation responses to the FIV pools, especially to F3, persisted over a longer time period than those to the HIV pools tested (Figure 19B). Thus, the few aa differences between these viruses may be sufficient for the CD 8+ T cells to recognize the F3 but not the H3 peptides. In fact, three aa substitutions in the H3-3 aa sequence (V10→I10; K12→M12; E16→V16) with aa identical to F3-3 led to immunological responses more consistent with that of F3-3 (Table 10). This observation clearly supports our finding that only a few aa changes can substantially alter the responses to a peptide epitope.

The robust CD8+ T-cell responses by the HIV+ subjects to FIV peptide pools suggest that these peptide regions contain evolutionarily-conserved epitopes. Importantly, 23 of 53 (43%) total positive CD 8+ T-cell proliferation responses and 40 of 166 (23%>) total positive IFNy responses to HIV pools were also positive for their counterpart FIV pools (Figure 17). This observation suggests that the T-cell response measured by CD8+T-cell proliferation (43%) was more successful at screening for evolutionarily conserved peptide epitopes than by the IFNy response (23%). The second observation was the profound and persistent ΙΚΝγ and CD8+ T-cell proliferation responses to pool F3 which had more responders than to any HIV pool (Figure 19). The pool F3 induced IFNy responses in the PBMC from a large number (69%) of HIV+ subjects and CD8+ T-cell proliferation responses in a substantial number (58%) of these subjects. These results suggest the presence of multiple CD8+ T-cell epitopes in the F3 region. One to three F3 responders had IFNy or CD8+ T-cell proliferation responses to F3-1 and F3-4, and both peptide epitopes induced CTL- associated activities (Figure 21). In fact, the LANL database shows three CTL-associated epitopes (NTPVFAIK , NK9 (SEQ ID NO:427); NTPVFAIKK , NK10 (SEQ ID NO:428); and KLVDFRELNK, KK10 (SEQ ID NO:429)) on the counterpart H3. The NK9 and NK10 sequences are identical between FIV and HIV-1 and are found at the carboxy-end of both 13mer peptides F3-1 and H3-1. F3-1 only differs from H3-1 by having tryptophan (W3) instead of tyrosine (Y3) at position 3. This finding suggests that this single aa difference resulted in the CD8+ T-cell proliferation response to F3-1 but not to H3-1. In the case of KK10, this epitope resides on H3-4 and differs by three aa from its direct counterpart on F3-4 (mLiDFRvLNK (MK10) (SEQ ID NO:430); different aa indicated in lower case).

The third major observation was the robust IFNy (100%, all ten F3 responders tested) and CD8+ T-cell proliferation (62%, 5 of 8) responses to the 15mer peptide F3-3 (Figure 20). These unusually high frequencies of responders to the F3-3 epitope raised a question as to whether more than one CMI epitope resides on F3-3. In this regard, current studies, using modified epitopes, identified three CMI epitopes on F3-3, which were not previously described in LANL: KK SGKWRMLIDFRV (KV15) (SEQ ID NO:63), WRMLIDFRV (WV9) (SEQ ID NO:431), and KWRMLIDFR (KR9) (SEQ ID NO:432) (Table 10, bottom). The largest of these epitopes (F3-3; KV15) induce cytotoxin expression, and thus, one or more of them most likely are CTL-associated epitopes. These epitopes are closely related in sequence and evolution to ungulate lentiviruses (Table 10, top). Therefore, these findings indicate that the F3-3 epitopes are also evolutionarily conserved.

The unique example of pools F3/H3 (Figure 22) highlights the existence of evolutionarily conserved HIV RT epitope region that is less immunogenic than its FIV RT counterpart sequence based on pools F3/H3 and peptide F3-3/H3-3 analyses. The selection pressure against HIV in humans may explain the lack of responses against the HIV sequence; the same pressure may not exist in cats against FIV. The use of FIV approach shows that F3-3 region may be a great target for T-cell responses in an HIV vaccine, since both IFNy and proliferation responses to peptide F3-3 by HIV+ subjects indicate that they have previously encountered such sequence or its variant. The approach of using FIV to identify conserved regions for an HIV vaccine is a tool that compliments most approaches for developing a T-cell-based vaccine as in mosaic vaccines (Corey et al. (2010); Barouch et al. (2010); Santra et al. (2012)). Computational analyses identify potential conserved epitopes that are later tested for relevant biological activity. These analyses have been used to select conserved HIV/FIV sequences such as the one described for HIV/FIV integrase (Sanou et al. (2012)). The current FIV approach simultaneously compares both HIV/FIV epitope sequences and immunological responses.

This cross-recognition of the F3-3 epitope(s) by the HIV+ subjects demonstrates the polyfunctionality of the T-cell subsets tested. Three patterns with either PBMC or T cells were observed: 1) IFNy production by PBMC (IFNy/PBMC), CD8+ T-cell proliferation, and CD4+ or CD8+ (CD4+/CD8+) T-cell cytotoxin expression; 2) IFNy/PBMC and CD4+/CD8+ T-cell cytotoxin expression; and 3) CD8+ T-cell proliferation and CD4+/CD8+ T-cell cytotoxin expression. These observations are important since polyfunctional T-cell epitopes are likely to be associated with an effective HIV vaccine (McDermott et al. (2012); Betts et al. (2006)). Although current studies have had minimal focus on CD4+ T-cell responses, 2 of 3 F3 responders showing CD4+ T-cell proliferation also had expressed CD8+ T-cell responses to F3-3 (Figure 17D and Figure 18B). Moreover, the CD4+ T cells from substantial numbers of F3 responders had CTL- associated cytotoxin activities in response to pool F3 (Figure 21). A vaccine is generally administered to HIV-na^'ive subjects with normal CD4+ T-cell immunity. Therefore, the importance of the CD4+ T-cell responses to F3-3 should be considered when identifying CTL-associated epitopes for an HIV vaccine. The vaccine epitopes that induce both anti- HIV CD8+ and CD4+ T responses are likely to be needed for effective vaccine protection. These studies using FIV RT peptide pools suggest that evolutionarily- conserved immunologic epitopes could be important for an effective HIV vaccine.

Table 9. Population Characteristics

Table 9 Footnote

a HIV+ subjects from UF at Jacksonville (J), UCSF (SF), and University of South Florida at Tampa (TP); normal blood from blood bank (NB); normal blood from UF (N).

b Number of years of HIV infection or in months (mo).

c Virus load shown as copies/mL; undetectable at either <50 or <75.

d Subject started ART during the study.

e NA: not available. See Materials and Methods for other abbreviations.

Table 10. Variation of H3-3/F3-3 aa sequences and immunological responses

Table 10 footnotes:

a Genbank numbers as follows: HIV-1 H3-3 (K03455.1); FIV F3-3 (DQ365597.1); HIV-1 (C) (FJ595343); HIV-1 (A,B,C,D, 01 AE) (AJ313415, HM035584, HQ012309, HQ586068, HE590997); SIVcpz-i¾ (ACM63211); CAEV (AAG48629.1); MVV (CAC44543); HERV-K (ABA28284).

b Lower case letter aa different from FIV F3-3. Many HIV-1 strains have glutamate (E) immediately after the carboxyl end of H3-3.

c Used only responders from Figures 17-19; range of IFNy responses in SFU [range]; positive responses over total tested (positive/total).

d Small total participant numbers due to the use of only the F3 or H3 responders who are still positive during the second or third time-point. Only cells from H3 responders were used to test peptide H3-3; while cells from F3 responders were used to test other peptides. ^e Only 16mer sequences.

Replacing VI 5 with El 5 in modifications F3-3m3 to F3-3m6 resulted in almost total loss of both IFNy and proliferation responses.

g Six modifications of 15-16mer F3-3 sequences (F3-3ml to F3-3m6) with aa present on

H3-3.

^J Sequence designation shown in parenthesis with the first and the last aa followed by the number of aa.

FIV RT Peptide-Pool F3

NPWNTPVFAIKK SGKWRMLIDFRVVLNKLTDKGA (SEQ ID NO:443)

NPYNTPVFAIKKKDSTKWPvKLVDFRELNKRTQDFW (SEQ ID NO:23)

HIV RT Peptide-Pool H3

FIV RT peptides for Pool F3 :

F3-1 : NPWNTPVFAIKK (13 aa) (SEQ ID NO:61)

F3-2: TPVFAIK KSGKWRM (15) (SEQ ID NO:62)

F3-3: K KSGKWRMLIDFRV (15) (SEQ ID NO:63)

F3-4: WRMLIDFRVLNKL (13) (SEQ ID NO:64)

F3-5: IDFRVLNKLTDKGA (14) (SEQ ID NO:65)

HIV-1 RT peptides for Pool H3:

H3-1 : NPYNTPVFAIKK (13) (SEQ ID NO: 163)

H3-2: TPVFAIKKKDSTKWR (15) (SEQ ID NO: 164)

H3-3: KKKDSTKWRKLVDFR (15) (SEQ ID NO: 165)

H3-4: KWRKLVDFRELNKR (14) (SEQ ID NO: 166)

H3-5: VDFRELNKRTQDFW (14) (SEQ ID NO: 167) Combine sequence of Pool F6 immediately below:

PDYAPYTAFTLPRKNNAGPGRRYVWCSL (SEQ ID NO:444)

FRKYTAFTIPSTNNETPGIRYQYNVLPQGWK (SEQ ID NO:445) Combined sequence of Pool H6 immediately above:

Peptides in pool F6

F6-1 : PDYAPYTAFTLPRK (14) (SEQ ID NO:74)

F6-2: YTAFTLPRKNNA (12) (SEQ ID NO:75)

F6-3: FTLPRKNNAGPGRRY (15) (SEQ ID NO:76)

F6-4: NNAGPGRRYVWCSL (14) (SEQ ID NO:77)

Peptides in pool H6

H6-1 : FRKYTAFTIPSI (12) (SEQ ID NO: 176)

H6-2: FTIPSTNNETPGIRY (15) (SEQ ID NO: 177)

H6-3: NNETPGIRYQYNVL (14) (SEQ ID NO: 178)

H6-4: GIRYQYNVLPQGWK (14) (SEQ ID NO:179)

Combine sequence of Pool F7 immediately below:

GRRYVWCSLPQGWVLSPLIYQSTLDNIL (SEQ ID NO:446)

YNVLPQGWKGSPAIFQSSMTKILEPFRKQNPDI (SEQ ID NO:447) Combined sequence of Pool H7 immediately above:

Peptides in pool F7

F7-1 : GRRYVWCSLPQGWVL (15) (SEQ ID NO:78)

F7-2: CSLPQGWVLSPLIY (14) (SEQ ID NO:79)

F7-3: GWVLSPLIYQSTL (13) (SEQ ID NO:80)

F7-4: SPLIYQSTLDNIL (13) (SEQ ID NO:81) Peptides in pool H7

H7-1 : YNVLPQGWKGSPAIF (15) (SEQ ID NO: 180)

H7-2: GWKGSPAIFQSSMTK (15) (SEQ ID NO: 181)

H7-3: AIFQSSMTKILEPFR (15) (SEQ ID NO: 182)

H7-4: MTKILEPFRKQNPDI (15) (SEQ ID NO: 183)

Combine sequence of Pool F15 immediately below:

GKMNRQKKKAENTCDIALRACYKIREESIIRIGKEPI (SEQ ID NO:448) RGAHTNDVKQLTEAVQKIVTESIVIWGKTPKFKLPI (SEQ ID NO:449) Combined sequence of Pool HI 5 immediately above:

Peptides for pool F15

F15-1 : GKMNRQK KAENTCDI (16) (SEQ ID NO:117)

F15-2: KKAENTCDIALRACY (15) (SEQ ID NO: 118)

F15-3: CDIALRACYKIR (12) (SEQ ID NO: 119)

F15-4: ALRACYKIREESIIR (15) (SEQ ID NO: 120)

F15-5 : KIREESIIRIGKEPI (15) (SEQ ID NO: 121) Peptides for pool HI 5

H15-1 : RGAHTNDVKQLTEAV (15) (SEQ ID NO:219)

H15-2: DVKQLTEAVQKIV (13) (SEQ ID NO:220)

H15-3: LTEAVQKIVTESIVI (15) (SEQ ID NO:221)

H15-4: KIVTESIVIWGKTPK (15) (SEQ ID NO:222)

H15-5: IVIWGKTPKFKLPI (14) (SEQ ID NO:223)

It should be understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes in light thereof will be suggested to persons skilled in the art and are to be included within the spirit and purview of this application and the scope of the appended claims. In addition, any elements or limitations of any invention or embodiment thereof disclosed herein can be combined with any and/or all other elements or limitations (individually or in any combination) or any other invention or embodiment thereof disclosed herein, and all such combinations are contemplated with the scope of the invention without limitation thereto.

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Claims

CLAIMS I claim:

1. A method for inducing an immune response in a person or animal against an immunodeficiency virus, comprising administering one or more antigens and/or immunogens to the person or animal, wherein said one or more antigens and/or immunogens comprise one or more evolutionarily conserved epitopes, wherein said epitopes are conserved between two or more different immunodeficiency viruses.

2. The method according to claim 1, wherein said epitopes are conserved between HIV and FIV.

3. The method according to claim 1, wherein said epitopes are conserved between HIV, SIV, and FIV.

4. The method according to any preceding claim, wherein said epitope is a T-cell epitope.

5. The method according to claim 1, wherein said epitope comprises the amino acid sequence of any of SEQ ID NOs:l-40 or any of SEQ ID NOs:51-450, or in any of the examples, figures or tables of the subject application.

6. The method according to claim 1, wherein said epitope comprises the amino acid sequence of any of SEQ ID NOs:61, 62, 63, 64, 65, 163, 164, 165, 166, 167, 431, 432, 438, 442, or 443.

7. The method according to claim 1, wherein said antigens and/or immunogens are peptides or proteins, and wherein two or more peptides or proteins comprising the amino acid sequence of any of SEQ ID NOs:61, 62, 63, 64, 65, 163, 164, 165, 166, 167, 431, 432, 438, 442, or 443 are administered to the person or animal.

8. The method according to claim 1, wherein said antigens and/or immunogens are peptides or proteins, and wherein said peptides or proteins comprise two or more amino acid sequences of any of SEQ ID NOs:61, 62, 63, 64, 65, 163, 164, 165, 166, 167, 431, 432, 438, 442, and/or 443.

9. The method according to claim 1, wherein said epitope comprises the amino acid sequence of any of SEQ ID NOs: 10, 21, 22, or 23.

10. The method according to claim 1, wherein said epitope comprises the amino acid sequence of any of SEQ ID NOs: 176, 177, 178, 179, 214, 215, 216, 217, or 218.

11. The method according to claim 1, wherein said induced immune response is a CTL-associated immune response.

12. The method according to claim 1, wherein said induced immune response comprises a CD4+ and/or CD8+ T cell response.

13. The method according to claim 1, wherein a person is administered said one or more antigens and/or immunogens that are from an HIV and/or FIV.

14. The method according to claim 1, wherein the animal is a feline animal and is administered said one or more antigens and/or immunogens that are from an FIV and/or HIV.

15. A chimeric polypeptide comprising sequences of more than one immunodeficiency virus polypeptides.

16. The chimeric polypeptide according to claim 15, wherein said polypeptide comprises matrix and nucleocapsid sequences of FIV and core or capsid sequence of HIV.

17. The chimeric polypeptide according to claim 15, wherein said polypeptide comprises the amino acid sequence of SEQ ID NO:43 or SEQ ID NO:44.

18. A polynucleotide that encodes a chimeric polypeptide of any of claims 15-17.

19. The chimeric polynucleotide according to claim 18, wherein said polynucleotide comprises the nucleotide sequence of SEQ ID NO:41 or SEQ ID NO:42.

20. An antibody that binds specifically to an FIV protein or epitope and does not bind to an HIV protein or epitope.

21. An antibody that binds specifically to an HIV protein or epitope and does not bind to an FIV protein or epitope.

22. An antibody that binds to an FIV protein or epitope and also binds to the corresponding HIV protein or epitope.

23. An antibody that binds to a peptide comprising an FIV or HIV epitope, wherein said epitope comprises an amino acid sequence of any of SEQ ID NOs:l-40 or any of SEQ ID NOs:51-450, or in any of the examples, figures, or tables of the subject application.

24. The antibody according to any of claims 20-23, wherein said antibody is a monoclonal antibody.

25. A composition comprising:

i) one or more epitopes evolutionarily conserved between different immunodeficiency viruses; and/or

ii) one or more polynucleotides that encode said one or more evolutionarily conserved epitopes; and/or

iii) one or more chimeric polypeptides that comprise sequences from more than one immunodeficiency virus; and/or

iv) one or more chimeric polynucleotides that encode a chimeric polypeptide that comprises sequences from more than one immunodeficiency virus.

26. The composition according to claim 25, wherein said epitopes comprise an amino acid sequence of any of SEQ ID NOs: l-40 or any of SEQ ID NOs:51-450, or in any of the examples, figures or tables of the subject application.

27. The composition according to claim 25, wherein said polypeptides comprise the sequence shown in SEQ ID NO:43 or SEQ ID NO:44.

28. The composition according to claim 25, wherein said polynucleotide comprises the sequence shown in SEQ ID NO:41 or SEQ ID NO:42.

29. The composition according to claim 25, wherein said epitope comprises the amino acid sequence of any of SEQ ID NOs:61, 62, 63, 64, 65, 163, 164, 165, 166, 167, 431, 432, 438, 442, or 443.

30. The composition according to claim 25, wherein said composition comprises two or more peptides, wherein said two or more peptides comprise, independently, the amino acid sequence of any of SEQ ID NOs:61, 62, 63, 64, 65, 163, 164, 165, 166, 167, 431, 432, 438, 442, or 443.

31. The composition according to claim 25, wherein said composition comprises a peptide or protein that comprises two or more amino acid sequences of any of SEQ ID NOs:61, 62, 63, 64, 65, 163, 164, 165, 166, 167, 431, 432, 438, 442, and/or 443.

32. The composition according to claim 25, wherein said epitope comprises the amino acid sequence of any of SEQ ID NOs: 10, 21, 22, or 23.

33. The composition according to claim 25, wherein said epitope comprises the amino acid sequence of any of SEQ ID NOs: 176, 177, 178, 179, 214, 215, 216, 217, or 218.

34. The composition according to claim 25, wherein said composition further comprises a pharmaceutically acceptable carrier or diluent.

35. A vaccine that comprises a composition of any of claims 25 to 34.

36. A method for determining whether a feline animal has been vaccinated against FIV, said method comprising assaying a biological sample from a feline animal for the presence of an antibody that binds specifically to an HIV antigen and does not bind to an FIV antigen, wherein the presence of said antibody is indicative of vaccination against FIV infection.

37. A method for selecting antigens and/or immunogens for use in a vaccine against an immunodeficiency virus, wherein the method comprises comparing the amino acid sequences of a target protein from two or more immunodeficiency viruses and identifying evolutionarily conserved epitopes of the target protein, wherein one or more of the identified epitopes are selected for use as an antigen or immunogen in the vaccine.

38. The method according to claim 37, wherein said immunodeficiency virus is HIV or FIV.