FIGURE 3.

IL-2 and Ab dependence of postvaccination NK cell responses to influenza. PBMC, collected at baseline (0) or 2 wk after vaccination, were cultured in medium alone or with H1N1 influenza virus in the presence of anti-human IL-2 (or rat IgG2a isotype control) in either complete or IgG-depleted (IgG⁻) AB serum. IFN-γ (A), CD107a (B), and CD25 (C) responses were measured among total NK cells. Data are shown for 32 individuals (17 HCMV⁻ and 15 HCMV⁺) for whom sufficient cells were available at both time points. Boxes represent medians and interquartile ranges, whiskers represent 90th percentiles, and outliers are shown by solid dots. Paired comparisons between treatments were performed using Wilcoxon signed-rank test. *p < 0.05, **p < 0.01, ***p < 0.001.