HIV-1 ENVELOPE-SPECIFIC CD4(-HELPER CELLS FROM SIMIAN() T)HUMAN IMMUNODEFICIENCY VIRUS-INFECTED RHESUS-MONKEYS RECOGNIZE EPITOPES RESTRICTED BY MHC CLASS-II DRB1-ASTERISK-0406 AND DRB-ASTERISK-W201 MOLECULES/

The HIV-1 envelope (Env)-specific Th cell response of rhesus monkeys i nfected with nonpathogenic chimeric simian/human immunodeficiency viru ses (SHIV) was assessed at a molecular level by establishing rgp120-sp ecific CD4(+) T cell lines. Epitopes recognized by these MHC class If- restricted Th cells were identified within the second (C2), third (C3) , and fifth (C5) conserved regions of HIV-1: gp120. The epitope locate d in C2 was found to be restricted by the rhesus monkey (Macaca mulatt a) leukocyte Ag Mamu-DRB10406, and the Th cell epitope in C5 was foun d to be restricted by Mamu-DRBW201. The restriction element requireme nts of the C2 and C5 epitope-specific CD4(+) Th cells appear to be rat her stringent, because these peptide epitopes were not recognized in t he presence of other Mamu-DR expressing cell lines. The ability to ana lyze HIV-1 Env-specific CD4(+) T cell responses in SHIV-infected monke ys will enhance the utility of this model for studying AIDS pathogenes is and for assessing novel HIV-I vaccine strategies.