Figure 2. Mamu-A1*007:01 restricts both the Pol_782-789 YL8 and Vpr_45-55 NL11 epitopes.

721.221 cells, which do not express endogenous classical MHC class I molecules, were either stably or transiently transfected with the alleles shown. By W6/32 staining, MHC expression level was between 2% and 24%, at least 50% of cells had receptor on the surface. The transfectants were pulsed with either the 15-mer peptides used to raise the specific CD8⁺ T cell lines, no peptide (data not shown), or an A1*002:01-restricted irrelevant peptide. Peptide-pulsed cells were used in either ICS or ELISPOT assays with peptide-specific CD8⁺ T cell lines specific for a) a Pol-derived 15-mer peptide containing YL8 or b) a Vpr-derived 15-mer peptide containing NL11. Both cell lines were cultured from animal r97113; autologous BLCLs from this animal were used to check the specificity of the cell line. Peptide-pulsed 721.221 cells were used as a negative control. P/I refers to PMA and ionomycin, which are used as a positive control for inducing cytokine secretion.