Defective control of LCMV infection in NK cytotoxic-deficient mice.Rag2^−/−Il2rg^−/− and Rag2^−/− mice were reconstituted with BM from Prf1^−/− and control B6 donors. T^Prf1−NK^Prf1− (open bars), T^Prf1−NK^Prf1+ (gray bars), and T^Prf1+NK^Prf1+ mice (black bars) were infected with 200 PFU of LCMV-WE. A total of 14 days after infection, LCMV titers in the liver were determined. Data (mean ± SEM) are representative of 3 independent experiments. Statistical analysis was performed using Student t test. **P < .01.