Fig. 3.

Mouse NK cells are activated by Pf-RBC via an ITAM-independent and MyD88-dependent pathway. (A and B) Freshly isolated mouse splenocytes (from WT or genetically deficient mice for the indicated molecules) were cocultured with Pf-RBC (3D7-RBC) or uninfected RBC (RBC) for 20-24 h. NK cell activation was analyzed by flow cytometry after gating on CD3^-NK1.1⁺ NK cells. Each dot represents the result from one individual mouse. Statistical analyses were done by using a one-tailed Wilcoxon signed rank test. (A Left and B) NK cell IFN-γ production was determined by intracytoplasmic staining after activation in the presence of suboptimal doses of IL-12. (A Right) CD69 expression on WT NK cell surface was assessed after indicated stimulation in the absence of exogenous cytokines (B) shows the percentage of IFN-γ-producing NK cells in the presence of 3D7-RBC (the background signals detected in the presence of uninfected RBC were subtracted).