NK cells from mice latently infected with MuHV-4 have increased capacity to produce IFN-γ protein. Peritoneal cells from latently infected or control (naive or mock-infected) mice were stained immediately after harvest (No Cx) or after culture ex vivo with phosphate-buffered saline (PBS), IL-12 plus IL-15, or plate-bound antibodies against NK1.1 (Anti-NK1.1). (A) Representative flow cytometric density plots showing IFN-γ expression in NK cells. (B) Pooled data from 10 mice per group showing the mean ± SD percentage of NK cells that express IFN-γ. These data are representative of 3 independent experiments with 10 mice per group per experiment. *P <.001 (MuHV-4 vs control).