Figure 6. Chronic stimulation through NKp30 or NKG2D preferentially induces inhibitory checkpoint receptor expression on adaptive NK cells.

CD3/CD19-depleted PBMCs from HCMV-seropositive donors were cultured for 7 days with 10 ng/ml IL-15 and either IgG2b isotype Ab, anti-NKG2A/C Ab, anti-NKG2C Ab, anti-NKp30 Ab or anti-NKG2D Ab. (A) Summary data of the frequencies of CD3^–CD56⁺NKG2C⁺ NK cells in each condition. (B) Summary data of the percentages and MFIs of CD45RO, LAG-3, and PD-1 on CD3^–CD56⁺NKG2C^– and CD3^–CD56⁺NKG2C⁺ NK cells in each condition (n = 5). Results are from 2 independent experiments. *P ≤ 0.05 and **P ≤ 0.01, by t test. P values of multiple group comparisons (A, each group vs. IgG isotype Ab; B, within the NKG2C^– NK cell groups and within the NKG2C⁺ NK cell groups) were adjusted using the Hommel method.