HIV-specific CD8⁺ T cells from ECs express higher amounts of perforin and Grz B than CPs after short-term stimulation. (A) Representative flow cytometric plots showing perforin, Grz B, Grz A, and granulysin versus IFN-γ from ECs (top row) and CPs (bottom row). Percentages represent the proportion of IFN-γ–expressing cells that were either positive or negative for each cytolytic protein. The determination of gate placement was aided by consideration of cytolytic protein expression, which is often low or absent, within CD19⁺ B cells or CD4⁺ T cells. (B-C) Relative contribution of perforin, Grz B, Grz A, and granulysin to Gag-specific (B) and Nef-specific (C) CD8⁺ T-cell responses, as identified by staining for IFN-γ, TNFα, or CD107a, is shown among all ECs, CPs, and HAART subjects. For each cytolytic molecule, statistical analysis was carried out using 1-way ANOVA tests (nonparametric; Kruskal-Wallis) followed by a Dunn test for multiple comparisons. *P < .05; **P < .01. Bars represent the means and error bars indicate SDs.