CD4(-LYMPHOCYTE LINES DEVELOPED FROM HIV-1-SEROPOSITIVE PATIENTS RECOGNIZE DIFFERENT EPITOPES WITHIN THE V3 LOOP() T)

To define the epitopes present within the V3 loop sequence recognized by five HIV-1 envelope-specific T-cell lines, a panel of V3 LAI peptid es bearing sequential truncations from both the N- and C-terminus was synthesized and tested for their ability to induce proliferation. Each individual T-cell line had a different pattern of response against th e truncated V3 peptides, demonstrating the presence of a cluster of CD 4(+) T-cell epitopes within the V3 loop. To assess the ability of thes e envelope-specific T-cell lines to recognize and proliferate in respo nse to V3 loops of different viral strains, they were tested against a panel of heterologous V3 loop peptides derived from different viral g enotypes within and outside of HIV-1 clade B. There was no proliferati ve response against heterologous V3 loops by any of the lines, demonst rating that recognition of the V3 epitopes is highly strain specific. One of the defined epitopes was shown to elicit a cytotoxic response a s well, suggesting the multifaceted role that the CD4(+) T cell might play in HIV-1 disease.