T cell responses against a pool of HIV-1 Gag peptides.

(A) IFN-γ expression by unstimulated CD4+ and CD8+ T cells, or after SEB and HIV-1 Gag peptides stimulus. (B) Comparison of the polyfunctional profiles of Gag-specific responses in CD4+ T cells from both MSM groups. The slices of the pies correspond to the proportions of Gag-specific CD4+ T cells expressing 1 (grey), 2 (light blue), 3 (dark blue), or 4 (red) functions, until n simultaneous parameters (n + 1 dimensions) are calculated using the Boolean gating; the results are presented as mean. In the permutation analysis conducted in the SPICE platform, only data higher than 0.1% were included (after background subtraction). (C) INDEX of polyfunctionality (pINDEX) of CD4+ and CD8+ T cells from both MSM groups based on the proportions of cells producing intracellular combinations of Granzyme B, MIP1-β, TNF-α, and IFN-γ; the pINDEX was calculated with Funky Cells software [31]; the comparison was performed with the Mann–Whitney U-test. For all the panels: high-risk group n = 16, low-risk group n = 44.