A SIMIAN IMMUNODEFICIENCY VIRUS ENVELOPE V3 CYTOTOXIC T-LYMPHOCYTE EPITOPE IN RHESUS-MONKEYS AND ITS RESTRICTING MAJOR HISTOCOMPATIBILITY COMPLEX CLASS-I MOLECULE MAMU-A(ASTERISK)02

The use of the simian immunodeficiency virus (SIV) macaque model for a ssessing human immunodeficiency virus vaccine strategies will be facil itated by the characterization of predominant SIV cytotoxic T-lymphocy te (CTL) epitopes and their restricting major histocompatibility compl ex (MHC) class I molecules in macaque species. We now define a rhesus monkey SIVmac CTL epitope in the third hypervariable region of the env elope glycoprotein of the virus. This epitope, YNLTMKCR, contains the first two amino acids of a cysteine cysteine loop which is the SIVmac analog of the human immunodeficiency virus type 1 V3 loop. We also emp loyed one-dimensional isoelectric focusing to characterize the MHC cla ss I molecule of the rhesus monkey that binds this SIVmac envelope pep tide fragment. Cloning and sequencing the cDNAenvelope peptide fragmen t. Cloning and sequencing the cDNA encoding this rhesus monkey MHC cla ss I molecule demonstrates that it is a newly described HLA-A homolog, Mamu-A02. This viral CTL epitope and its restricting MHC class I mol ecule will facilitate the use of the SIVmac rhesus monkey model for st udies of envelope-based vaccine strategies and for exploring AIDS immu nopathogenesis.