Defective cytokine secretion by p110δ-deficient NK cells. Purified NK cells were cultured for 1 week in IL-2, and thereafter stimulated, in the presence of IL-2 with anti-NK1.1, CD16, Ly49D, and NKG2D mAbs, or IL-12 for 48 hours. Secreted IFN-γ, TNF-α, and GM-CSF proteins were measured by ELISA. (A) Cytokines secreted by p110γ-deficient () and WT NK cells (●). Data points represent individual samples pooled from 2 independent experiments for IFN-γ (n = 6), and 1 experiment for TNF-α and GM-CSF (n = 3). Bars indicate the mean values of each group. (B) Cytokines secreted by p110δ-deficient (□) and WT NK cells (●). Data points represent individual samples pooled from 2 independent experiments for IFN-γ (n = 6), and 3 independent experiments for TNF-α and GM-CSF (n = 9). Bars indicate the mean values of each group.