FIGURE 2.

Cellular responses in gag pDNA vaccinated macaques. (A) PBMC from rhesus macaques (n = 31) immunized with pDNA encoding the full-length SIV p57^Gag protein were analyzed by flow cytometry for Ag-specific responses targeting the complete p27^Gag (gray bars) protein or epitopes encoded by the CE (red bars). The values are plotted by decreasing p27^Gag T cell responses and sorted according to the presence (n = 18) or absence (n = 13) of CE responses. Of note, animals P516 and P517 were analyzed with a peptide pool covering p39^Gag that spans both the N terminal p19^Gag and the p27^Gag. (B) p27^Gag-specific T cell responses were evaluated for their cytotoxic potential. The frequency of granzyme B⁺ Gag-specific T cells was determined among IFN-γ–producing p27^Gag T cells comparing the subgroup of gag pDNA immunized macaques with (n = 18) and without (n = 13) CE-specific responses. The median and p values (t test) are indicated.