Figure 6. Alterations of CD4⁺ and CD8⁺ T cell populations in secondary lymphoid and non-lymphoid organs of middle-aged mice with (open symbols) and without (closed symbols) latent MCMV-infection.

Half of the mice were infected with 10⁷ pfu MCMV-Δ157 i.v. at the age of 8 weeks. At the age of 8 (triangles) or 13 (circles) months, blood was taken, mice were perfused and sacrificed and total numbers of naïve (CD44⁻CD62L⁺) CD8⁺ (A) and CD4⁺ (D) T cells, effector memory (Tem; CD44⁺CD62L⁻) CD8⁺ (B) and CD4⁺ (E) T cells and central memory (Tcm; CD44⁺CD62L⁺) CD8⁺ (C) and CD4⁺ (F) T cells were determined in different organs by polychromatic flow cytometry using bead calibration. Absolute numbers of T cells are given for blood, lung, spleen, cervical (cer) and inguinal (in) lymph nodes (LN). Circles indicate values of individual mice, horizontal bars correspond to the median of an experimental group. Significance was assessed by t-test (* p<0.05; ** p<0.01; *** p<0.001; ns = not significant).