FIG. 5.

Mechanisms for IFN-γ production by NK cells. A) Intracellular flow cytometry staining for IFN-γ and surface markers in IL-2 (100 U) and IL-12 (5 U)-stimulated whole blood (100,000 gated lymphocytes); 4.9% of the NKp46-positive cells produced IFN-γ. B) IFN-γ production in IL-2-activated NK cell cultures after stimulation with IL-2 and different levels of IL-12 with or without neutralization by anti-IL-12. C) Production of IFN-γ by NK cells stimulated with supernatant from antigen-stimulated adherent cells. Supernatants from antigen-stimulated adherent cells were diluted 1:10 and incubated with or without anti-IL-12 for 1 hour before addition of NK cells. The amount of IFN-γ was measured by ELISA after 24 h of incubation.