mMCV infection induces Ccl3 regardless of NK cell subsets. (A–D) CCL3-EASER mice were infected i.v. with mCMV and analyzed by flow cytometry 16 h after infection. Ccl3-protein expression of liver NK cells was analyzed by flow cytometry according to Venus⁺ signal, after 4 h of in vitro stimulation in the presence of monensin and brefeldin A. NK cells were defined considering the following markers: NK1.1⁺CD3⁻DX5⁺CD49_a⁻CXCR₆⁻. Analysis of Ccl3 protein expression was performed in naive and mCMV-infected CCL3-EASER mice. In every case, on the left: representative contour plots of subsets analyzed; on the right: pie charts indicating the frequency of Venus expression from total NK cells. NK cells were subdivided according to: (A) NK cell status of maturation based on the expression of CD11b and CD27 markers; (B) expression of Ly49H and -D activation receptors; (C) expression of KLRG1 receptor; and (D) production of IFNg and Granzyme B (GrzB). Data are presented as mean (in C as mean ± SD) and it is representative of two independent experiments (n = 5 per group). Unpaired nonparametric Mann–Whitney U-test was used: n.s., not significant; *P < 0.05.