Studies on V3-specific cross-reactive T-cell responses in chimpanzees chronically infected with HIV-1IIIB.
OBJECTIVE
In this study we used synthetic peptides corresponding to the third variable region (V3) in the envelope protein gp120 of 14 different HIV-1 strains, and tested whether V3-specific T-cell responses are HIV-1 strain-specific or broadly cross-reactive in nine chimpanzees chronically infected with HIV-1IIIB.


METHODS
Peripheral blood mononuclear cells isolated from nine HIV-infected chimpanzees and two uninfected controls were tested, by the [3H]-thymidine incorporation assay, for proliferative responses against phytohemagglutinin, control peptide and V3-loop peptides corresponding to 14 different HIV-1 strains. Serum samples collected from the chimpanzees were analyzed by enzyme-linked immunosorbent assay for antibodies against the V3 peptides.


RESULTS
Chimpanzees 100, 139 and 175 exhibited high level of proliferative response directed against the cognate V3 peptide from HIV-1IIIB and also showed cross-reactivity to V3 peptides from 13, seven and 13 of 13 other HIV-1 strains, respectively. Additionally, five out of nine chimpanzees showed cross-reactive proliferative responses to V3 peptides from at least eight different HIV-1 strains, while significant proliferation to V3 peptides from two or more HIV-1 strains was observed in seven out of nine chimpanzees. On the other hand, four out of nine chimpanzees showed antibody response directed against the cognate V3 peptide from HIV-1IIIB, and serum from only one chimpanzee (100) showed cross-reactive antibody to six different V3 peptides.


CONCLUSIONS
Overall, these studies in chimpanzees chronically infected with HIV-1IIIB indicate that with respect to the immunodominant V3 region, the virus-induced T-cell immunity is directed against a broad spectrum of HIV-1 strains.
Nehete
P N
PN
Department of Veterinary Sciences, Science Park, University of Texas MD Anderson Cancer Center, Bastrop 78602, USA.
Murthy
K K
KK
Satterfield
W C
WC
Arlinghaus
R B
RB
Sastry
K J
KJ
D000595:Amino Acid Sequence; D000818:Animals; D002455:Cell Division; D002478:Cells, Cultured; D003429:Cross Reactions; D015483:HIV Antibodies / Q000276:immunology*; D015699:HIV Envelope Protein gp120 / Q000276:immunology*; D015658:HIV Infections / Q000276:immunology*; D015497:HIV-1 / Q000276:immunology*; D007135:Immunoglobulin Variable Region / Q000737:chemistry / Q000276:immunology*; D008969:Molecular Sequence Data; D009500:Neutralization Tests; D002679:Pan troglodytes / Q000276:immunology / Q000821:virology*; D010455:Peptides / Q000138:chemical synthesis / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology
D015483:HIV Antibodies; D015699:HIV Envelope Protein gp120; D007135:Immunoglobulin Variable Region; D010455:Peptides