The effector function of HIV-specific CD8⁺ T cells is enhanced by IL-15.

(A) Representative flow cytometry from 1 HIV-infected individual showing IFNγ production by unstimulated PBMCs, treated with IL-15, Gag-specific peptide, or Gag-specific peptide + IL-15 for 6 hours, respectively. Gag-tetramer stain shown in plot on the left. FACS plots depict lymphocytes gated by FSC and SSC. MFI, mean fluorescence intensity. (B) Cytotoxicity by purified CD8⁺ T cells from HIV-infected individuals ± IL-15 against HIV-peptide–loaded targets in 6 hours direct ex vivo cytotoxicity assay (n = 8). An effector-to-target ratio of 50:1 is shown. Horizontal lines depict means. The P values were calculated by using Student t test for paired samples.