Figure 1. The pool of virtual memory CD8⁺ T cells is decreased in IFNAR^−/− mice.

(a) Total circulating CD8⁺ T cells were analysed ex vivo for the frequency of memory CD44⁺CD62L⁺CD8⁺ T cells, virtual memory CD44⁺CD49d^lo CD8⁺ T cells (VM) and true memory CD44⁺CD49d^hi CD8⁺ T cells (TM) in WT and IFNAR^−/− mice. (b) Absolute numbers of naive, VM and TM CD8⁺ T cells in the spleens of WT and IFNAR^−/− mice. (c) Mean fluorescence intensity (MFI) of Eomes in VM CD8⁺ T cells. Representative histograms of Eomes expression in WT (blue line) and IFNAR^−/− (red line) VM CD8⁺ T cells are shown. As a control, we included staining in CD8⁺ T cells from Eomes^fl/flCD4^cre mice (plain histogram). *P<0.05, **P<0.01 and ***P<0.001, NS: not significant (non-parametric Mann–Whitney). In graphs, each dot represents an individual mouse and bars represent mean±s.e.m.