Syk is required for CD45-independent, ITAM-dependent degranulation. (A-C) Enriched NK cells were incubated on plates coated with the indicated mAbs or with the indicated stimuli. Cells shown were gated on NK1.1⁺CD3⁻ cells. (A-B) Incubation was done in the presence of anti-CD107a whereby only cells that degranulate stained positively for CD107a. (A) Data are representative of 3-5 independent experiments. (B) Stimulation with PMA (25 ng/mL) and ionomycin (1 μg/mL). Data are representative of 4 independent experiments. (C) Cells were incubated with IL-12 (20 ng/mL), IL-18 (10 ng/mL), and brefeldin A, followed by intracellular staining for IFNγ. Data are representative of 3 independent experiments. (A-C) Graphs to the right show the average ± SEM of results of 3 independent experiments. The P values for significant differences between genotypes are located above each condition in each graph. NS indicates no significant differences between genotypes were found using a 2-tailed unpaired t test.