Fig. 1: Immaturity of murine NK cells during the postnatal period.
a Splenic NK cells were sorted on post-natal days (PND) 7, 14, 21 and 60. Following RNASeq differential expression analysis, k-means clustering was performed on the set of differentially expressed genes (padj < 0.01) between PND 60 and PND 7 using a predetermined value of k = 4. Genes in identified clusters (CL1 to CL4) were then subjected to enrichment analysis, and the five most significant gene ontology (GO) terms were listed next to each cluster (n = 4 mice per time point). b At indicated time points, NK cell expression of Ki67 was determined using flow cytometry (n = 3 mice per time point, Two-tailed Student’s t test). c RNASeq heatmap showing the expression of Klra family genes encoding the surface NK cell receptors on PND 7, 14, 21 and 60. K-means clustering was performed using a predetermined value of k = 2. Graphs illustrating log2FC and negative log10padj values for the differences in expression levels on PND 60 versus PND 7 for each gene are shown to the right of the heatmap (NS = non-significant, S = Significant). d At indicated time points, NK cell expression of Ly49H, Ly49A and Ly49I was determined using flow cytometry (n = 4 PND 7, n = 5 PND 14 and PND 21, n = 3 PND 60, One-way ANOVA test). e Mice were infected at indicated time points, and the proportion of mice in each group was depleted of NK cells (αNK1.1). Viral doses used for infection were: 200 PFU for PND 1, 30 000 PFU for PND 7, and 50 000 PFU for PND 14. Virus titers were determined in the spleen 4 days post-infection (n = 10 PND 1 and PND 14, n = 12 PND 7 MCMV, n = 13 PND 7 MCMV + αNK1.1; pooled data of N = 2, Mann–Whitney two-tailed test). Statistically significant differences are indicated (P values). Source data are provided as a Source Data file.
