Figure 2

Naïve and effector/memory CD4 and CD8 absolute numbers in secondary lymphoid organs during ageing. Numeration and FACS analyses were performed on spleen and lymph nodes from young, middle-aged and old C57BL/6 mice as described in Figure 1. (A, B) Absolute numbers of naïve (A) and effector/memory (B) CD4 and CD8 T cells recovered in secondary lymphoid organs. (C) Thymocyte numbers. Numerations were performed on young (n = 10 to 30), middle-aged (n = 10 to 20) and old (n = 10 to 12) C57BL/6 mice. For each experiment, comparison of young animals to middle-aged and/or old animals was simultaneously performed. Cumulative results show the mean ± SEM of absolute numbers. Statistical significance (Student’s t test) is shown: ns, non-significant; *, p < 0.05; **, p < 0.01; ***, p < 0.001.