Fig. 4: Terminal maturation of NK cells is associated with the downregulation of Eomes.

a–c Newborn C57BL/6 mice were intraperitoneally infected with 200 PFU of MCMV or mock-infected 24–36 h after birth. a On day 21 after infection, expression of Eomes and T-bet was determined by flow cytometry. b Eomes expression was analyzed on CD27⁺CD11b⁻, CD27⁻CD11b⁺, KLRG1⁺ and KLRG1⁻ NK cells from MCMV and mock-infected mice, representative histograms are shown. c Quantification of Eomes expressing CD27⁺CD11b⁻, CD27⁻CD11b⁺, KLRG1⁺ and KLRG1⁻ NK cells (n = 9 mice per group, Mann–Whitney two-tailed test). Mean values ± SD are shown. d Newborn BALB/c and 129/SvJ mice were intraperitoneally infected with 200 PFU of MCMV or mock-infected 24–36 h after birth. On day 21 after infection, mice were euthanized and the frequency of terminally differentiated, KLRG1 and Eomes expressing splenic NK cells was determined (n = 4 Mock BALB/C, n = 5 MCMV BALB/C, n = 6 Mock 129/SvJ, n = 3 MCMV 129/SvJ, Mann–Whitney two-tailed test). Mean values ± SD are shown. e Newborn C57BL/6 mice were intraperitoneally infected with 200 PFU of MCMV or mock-infected 24–36 h after birth. On days 60 and 90 after infection, mice were euthanized and the expression of KLRG1 and Eomes on NK cells was analyzed (n = 3 Mock 60 d.p.i., n = 4 MCMV 60 d.p.i., n = 4 Mock 90 d.p.i., n = 6 MCMV 90 d.p.i., Mann–Whitney two-tailed test). Mean values ± SD are shown. f–h Adult C56BL/6 mice were infected with 2 × 10⁵ PFU of WT MCMV. On day 21 p.i., the expression and frequency of CD27 and CD11b (f), KLRG1 (g) and Eomes (h) by NK cells were analyzed by flow cytometry (n = 5 Mock, n = 5 MCMV, Mann–Whitney two-tailed test). Representative histograms and mean values ± SD are shown. Statistically significant differences are indicated (P values). Source data are provided as a Source Data file.