FIG. 2.

SIV Nef peptide-specific cytolytic activity of PBL from an SIV-infected rhesus monkey is localized to the 25-amino-acid peptide p199. (A) PBL from monkey 24195 (an SIVmac251-infected Mamu-A*01⁻ Mamu-A*02⁺ rhesus monkey) were stimulated in vitro with a mix of the overlapping SIV Nef peptides p190 to p193, p194 to p197, or p198 to p200, as indicated, at 20 μg/ml for each peptide. On day 11 of culture, the lymphocytes were assessed as effector cells in a standard 4-h ⁵¹Cr release CTL assay. Target cells were B-LCL made from monkey 16097 (Mamu-A*01⁻ Mamu-A*02⁺) that had been incubated for 1.5 h in the indicated mix of peptides at 20 μg/ml per peptide. (B) PBL from monkey 24195 were stimulated in vitro with a mix of the overlapping SIV Nef peptides p198, p199, and p200 at 20 μg/ml each. On day 13 of culture, the lymphocytes were assessed as effector CTL as described above, using B-LCL from monkey 16097 that had been incubated overnight with 20 μg of the indicated peptide per ml.