NK cells specifically control MCMV infection via cytotoxic effector molecules.

(A) Splenic viral titers were analyzed by qPCR following a three-day infection with WT MCMV (5000 PFU/mouse) or (B) five-day infection with WT MCMV (20000 PFU/mouse). Statistical analysis performed by comparing values from WT mice with genetically modified or antibody-treated mice. (C) Schematic of the dual-infection system depicting the starting viral mixture and two possible results: Ly49H-dependent control of WT MCMV with resulting selection of Δm157 clones vs. equivalent replication of both MCMV strains due to absence of Ly49H-dependent control of WT MCMV. (D) Splenic viral titers following a five-day infection, as in (B), with the indicated dose and strains following antibody treatment. (E-F) Splenic viral escape (Δm157) frequency determined five days after a mixed MCMV infection with WT MCMV and Δm157 (20000 PFU/mouse). NK1.1 antibody was administered where indicated 48hrs prior to infection. Data are combined from two independent experiments with individual points representing a single mouse. L = Limit of quantification. I = Input frequency (10% frequency of Δm157). ****p < .0001, ***p < .001, **p < .01, *p < .05, ns = not significant.