Increased MCMV viral loads upon depletion of licensed Ly49 subsets based on donor MHC-I in allo-HSCT. Livers of mice that underwent allogeneic HSCT 10 days prior to infection and depleted of various NK subsets were compared in terms of viral load 7 days postinfection in (A) B10 (H-2^b) and (B) B10.D2 (H-2^d) host mice using real-time–polymerase chain reaction for MCMV IE1 gene sequences. (C) CB6F1 mice that are a cross between C57BL/6 (H-2^b) and Balb/c (H-2^d) mice were used as donors in an HSCT for C57BL/6 (H-2^b) host mice, and livers were harvested 7 days postinfection for viral load determination. (D) Allo-HSCT was performed on B10 host mice, mice were infected 17 days post-HSCT, and livers were harvested 7 days postinfection for viral load determination. Mice were given 300 μg of rat/mouse IgG, anti-NK1.1, anti-Ly49G2, or anti-Ly49C/I 2 days prior to infection. Data are representative of 2 to 3 experiments with 4 mice per group. Error bars represent the standard error of the mean. Statistical analysis was performed using 1-way ANOVA and Tukey posttest. *P < .05.