Effect of the PI-3K inhibitor LY294002 on IFN-γ production by monokine-activated primary human NK cells. Enriched primary NK cells were first incubated (45 minutes, 37°C) in medium containing either dimethyl sulfoxide (DMSO) vehicle control or the indicated concentration of LY294002, followed by an additional 18 hours of incubation in the presence of IL-12 (10 ng/mL), IL-18 (100 ng/mL), and/or IL-15 (100 ng/mL). Cell pellets were then collected for quantification of IFN-γ transcript by real-time RT-PCR (A-B), and supernatants were collected and quantified for IFN-γ protein production by ELISA (C-D). This experiment is representative of 4 experiments performed with similar results. Error bars indicate ± SEM.