FIG 4.

HIV-1-specific CD8⁺ T-cell polyfunctionality. Polyfunctionality, understood as simultaneous multiple production of IFN-γ, TNF-α, and IL-2 per T cell, was studied only for subjects categorized as responders. The T-cell response was defined as the frequency of cells (>0.05% after background subtraction of the unstimulated condition) with detectable IFN-γ, TNF-α, and/or IL-2 intracellular cytokine production after stimulation. Due to the low number of Gag-specific CD4⁺ T-cell responders in TC, polyfunctionality analysis was not applicable. (A) Pie charts show polyfunctional distribution of HIV-1-specific CD8⁺ TD CD57⁺ T cells with up to three functional responses to Gag stimulation; IFN-γ, TNF-α, and IL-2 production in the polyfunctional distribution is shown in arcs. Pestle and Spice were used for analysis. (B) Percentages of Gag-specific CD8⁺ T cells expressing the activation profile, CD38⁺, and the maturation profile, CD45RA⁻ CD27⁺ CD57⁻; only significant differences are shown. (C to E) Polyfunctionality index of Gag-specific total CD8⁺ T cells. Values from PC and preloss time points of follow-up (–T2 and –T1) in TC are based on the proportions of cells expressing combinations of IFN-γ, TNF-α, and IL-2 (three functions) (C), plus CD107a (four functions) (D), and plus perforin (five functions) (E). Single and double production of CD107a and perforin were excluded from the analyses. Differences between groups were determined by the Mann-Whitney U test.