Analysis of CD62L, CD27, KIR or NKG2A expression in relation to NK-cell proliferation and IFN-γ production. (A) FACS analysis of PBMCs stained for the indicated markers and gated on CD3⁻ CD56⁺ NK cells (left) or on CD3⁻ CD56^dim NK cells (right); 1 representative donor of 11 is shown. (B) Percentage of 2 + 3D KIR⁺ (indicated as KIR), NKG2A⁺ or CD27⁺ cells within CD56^dim CD62L⁺ or CD56^dim CD62L⁻ subsets; 26 (KIR), 22 (NKG2A), and 10 (CD27) different healthy donors are shown. **P < .01; ***P < .0001 as calculated by Wilcoxon test. (C) Ki67 expression in PB-NK cell subsets after staining for CD62L, KIR (2 + 3D KIR), NKG2A and CD27 and gating on CD56^bright or the indicated CD56^dim subsets; 7 (KIR and NKG2A) or 8 (CD27) donors plus corresponding medians are shown. (D) CD56^dim NK cells derived from HLA-Bw4 donors were sorted for NKG2A⁻ CD62L⁺ or NKG2A⁻ CD62L⁻ cells and stimulated with 50 ng/mL IL-12 + 50 ng/mL IL-18 for 24 hours, in the presence of BrefeldinA for the final 8 hours. After staining for 2D KIR and KIR3DL1 (indicated as 3DL1), IFN-γ expression was analyzed within competent 2D KIR⁻ KIR3DL1⁺ or hyporesponsive 2D KIR⁻ KIR3DL1⁻ cells. Mean ± SEM of 6 independent experiments is shown. (E) CD56^dim NK cells were sorted according to CD27 and CD62L expression and IFN-γ was analyzed after stimulation with IL-12+IL-18. Mean ± SEM of 6 independent experiments is shown. *P < .05 as calculated by Wilcoxon test.