(A, B) KLRG1int+ and KLRG1− NK cells from C57BL/6 mice (CD45.2+) and congenic C57BL/6.SJL mice (CD45.1+), respectively, were sorted using flow cytometry to >99% purity. An equal number (1 × 105 cells) of CD45.2+Ly49H+ KLRG1int+ and CD45.1+Ly49H+ KLRG1− NK cells were mixed and adoptively transferred into Ly49H-deficient hosts (day -1) followed by MCMV infection (day 0). (A) Percentages of CD45.1+ (KLRG1− cells-derived) and CD45.1− (KLRG1int+ cells-derived) cells in the Ly49H+ NK cell population. (B) Percentages of adoptively transferred CD45.1+ (KLRG1− cells-derived) and CD45.2+ (KLRG1int+ cells-derived) Ly49H+ NK cells within the total NK cell population. (C, D) Sorted KLRG1int+ Ly49H+and KLRG1− Ly49H+ NK cells (1 × 104 of each subset) were adoptively transferred into Ly49H-deficient hosts (day -1) and infected with MCMV (day 0). Virus copy number in peripheral blood (C) and oral lavage (D) was quantitated by real-time qPCR. Data are representative of three (A, B) and two (C, D) independent experiments. Error bars show SEM (n=3 for A, B; n=3–7 for C, D). See also Figure S1.