Fig. 4.

There is a decreased proportion of naïve CD4⁺ and CD8⁺ T cells and accumulation of CD4⁺ effector/memory and regulatory T cells in aged LCK^CRE Bim^fl/fl mice. Old LCK^CRE Bim^fl/fl mice have reduced proportions of a, b naïve (CD44^lowCD62L^high) CD4⁺ T cells and accumulation of effector memory (CD44^highCD62L^low) CD4⁺ T cells. c, d Old LCK^CRE Bim^fl/fl mice have reduced proportions of naïve CD8⁺ T cells but similar numbers of effector memory CD8⁺ T cells compared to WT controls. e Both WT and LCK^CRE Bim^fl/fl mice increase their percentage CD4⁺FOXP3⁺ regulatory Tregs as they age. Absolute numbers of Tregs are greater in LCK^CRE Bim^fl/fl animals compared to WT controls but their overall numbers remain relatively constant throughout their lives. Representative flow plots of f CD4⁺, CD8⁺ and g FOXP3⁺ CD4⁺ Treg populations from young mice are shown to the right of each bar graph. LCK^CRE Bim^fl/fl and WT n ≥ 4 for each age group. Data represented as means ± SEM. *p < 0.05, **p < 0.01, ***p < 0.001