FIGURE 5.

NK cell responses of HCMV⁺ donors with or without the characteristic CD56^dimCD57⁺NKG2C⁺ expansion. PBMCs were cultured in vitro for 18 h with medium alone, LCC, killed whole-cell pertussis (Per), inactivated whole H1N1 influenza virus (H1N1), Per + LCC, H1N1 + LCC, or HCC. Donors were stratified into HCMV⁻ (−), HCMV⁺ without expansion of CD56^dimCD57⁺NKG2C⁺ cells (+), and HCMV⁺ with expansion of CD56^dimCD57⁺NKG2C⁺ cells (++). Responses are expressed as the percentage of total NK cells expressing CD25 (A), coexpressing CD25/IFN-γ (B), or expressing CD107a (C). CD57-defined (D–F) or CD57/NKG2C-defined subsets (G–I) were analyzed for responses to pertussis with LCC for CD25 (D and G), CD25/IFN-γ (E and H), and CD107a (F and I). Data were analyzed in Prism using one-tailed Mann–Whitney U tests to compare responses between HCMV⁺ donors and either HCMV⁻ donors or HCMV⁺⁺ donors. ANOVA for linear trend (from − to + to ++) was also performed for each functional readout. Each data point represents one donor, n = 152, except for H1N1 and H1N1 + LCC where n = 52. Bar graphs denote medians. ****p ≤ 0.0001, ***p < 0.001, **p < 0.01, *p < 0.05.