Figure 3

Age related T cell lymphopenia differently affects secondary lymphoid organs. (A) CD4 and CD8 T cell numbers recovered from spleen (SP), superficial (inguinal, brachial and axillary lymph nodes (sLN)) and mesenteric (mLN) lymph nodes. Numeration and FACS analyses of each secondary lymphoid organs were performed from young (Y) (n = 30), middle-aged (M) (n = 20) and old (O) (n = 12) C57BL/6 mice. (B) CD4 and CD8 T cell persistence in each secondary lymphoid organ. Age related persistence was expressed as the percentage of residual T cells recovered in either middle-aged or old mice compared to values recovered from young animals [older absolute number / young absolute number x 100]. Graphs show mean ± SEM of absolute numbers of independent experiments comparing young animals to middle-aged and/or old animals. Statistical difference between sLN and SP T cell recovery depending of age is shown (Student’s t test): ns, non-significant; *, p < 0.05; **, p < 0.01; ***, p < 0.001.