PRIMARY IN-VITRO SENSITIZATION OF HUMAN T-HELPER LYMPHOCYTES BY PEPTIDES DERIVED FROM THE V3 LOOP OF HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1 (HIV-1) ENVELOPE GLYCOPROTEIN

To generate CD4+ T-helper cell lines, lymphocytes from HIV-seronegativ e subjects were primed in vitro with peptides derived from the V3 loop of HIV-1 gp120. Antigen-specific reactivity was inhibited by an anti- DR monoclonal antibody, indicating HLA-class II dependency, but peptid es could be recognized in different HLA-class II contexts. Three sites on V3(LAI) and two on V3(MN) were identified as targets of the respec tive V3(LAI)- and V3(MN)-specific lines. Recognition of V3 peptides wa s isolate-specific. The lines did not react against whole gp160, which suggests that V3 may be differently presented when used as such rathe r than as part of the entire glycoprotein. Similar results were obtain ed in chimpanzees immunized in vivo against V3(LAI).