FIG. 6.

SIV Nef peptide-specific cytolytic activity of PBL from an SIV-infected rhesus monkey is mediated by CD8⁺ T lymphocytes and restricted by Mamu-A*02. (A) PBL from monkey 19242 (a SHIV-infected Mamu-A*01⁻ Mamu-A*02⁺ rhesus monkey) were stimulated in vitro with 0.1 μg/ml of the SIV Nef 9-amino-acid peptide p199RY. On day 13 of culture, the lymphocytes were sorted for CD8 expression, and then CD8-enriched (97% CD3⁺ CD8⁺ CD4⁻) and CD8-depleted (5% CD3⁺ CD8⁺ CD4⁻) populations were assessed as effector cells in a standard 4-h ⁵¹Cr-release CTL assay. Target cells were autologous B-LCL that had been incubated for 1.5 h with 1 μg/ml p199RY or SIV gag p11c, as a negative control. (B) PBL from monkey 26795 (a SHIV-infected Mamu-A*01⁻ Mamu-A*02⁺ rhesus monkey) were stimulated in vitro with 1 μg/ml p199RY. On day 14 of culture, the lymphocytes were assessed as effector cells in a standard 4-h ⁵¹Cr release CTL assay. Target cells were either the MHC class I-deficient human B-LCL C1R or a transfectant expressing Mamu-A*02 that had been incubated for 1.5 h with 1 μg/ml p199RY or SIV gag p11c, as a negative control.