A) Percentage of NK cells that express Sca-1 in naïve B6 mice (grey fill) or B6 mice 2 days p.i. MCMV (no fill), VV (stripes), or HSV (dots). B) Fold change of the MFI of Sca-1 between NK cells from naïve B6 mice and B6 mice 2 days p.i. MCMV (no fill), VV (stripes), or HSV (dots). C) Representative histograms showing Sca-1, KLRG1, or CD69 expression on splenic NK cells from naïve B6 mice (thin line, grey fill) or from B6 mice 2 days p.i. wt MCMV (thick line, no fill). D) Percentage of NK cells that express Sca-1, KLRG1, or CD69 in naïve B6 mice (grey fill) or B6 mice 2 days p.i. MCMV (no fill). E) Fold change of the MFI of Sca-1, KLRG1, or CD69 between NK cells from naïve B6 mice and B6 mice 2 days p.i. MCMV. F) Frequency of Sca-1+ or CD69+ NK cells from wt B6 (solid outline) or IFNαβR−/− (dashed outline) mice 2 days p.i. MCMV. Composite data from 2 independent experiments each with 3–4 mice/genotype. B and E) MFI values are for the entire NK cell population. A), B), D), and E) show composite results from 2–3 independent experiments with a total of 3–5 naïve mice and 7–9 infected mice.