Figure 5.

Foxo1 is required for naive T cell survival. (a) CD4⁺ and CD8⁺ cells in peripheral blood of 8- to 12-week-old mice, as assessed by flow cytometry. Results are representative of n = 5 littermate controls and n = 9 Cd4Cre mice analyzed in two independent experiments. (b) Purified lymph node T cells were mixed at a 1:1 ratio based on the number of CD8⁺CD44^lo cells and transferred into C57BL/6 CD45.1⁺ hosts (2 × 10⁶ total CD8⁺CD44^lo cells). Donor cell recovery was analyzed before injection (Mix.) and at the indicated time points (CD45.2⁺-gated CD45.1⁺ versus CD45.1⁻ cells). LN, lymph node. Representative results from two independent experiments with n ≥ 3 mice per group and per time point (initial difference in CD4⁺CD44^lo proportion comes from a modification of the CD4:CD8 ratio in Foxo1^f/f-Cd4Cre mice). (c) T and B cell recovery in mixed bone chimeras 8 weeks after reconstitution (mean ± s.e.m. of n = 3 mice per group). (d) Quantification of Bcl-2 expression in CD44^lo T cells from 8- to 12-week-old mice (mean ± s.e.m.). Data represent n = 9 littermate controls and n = 12 Cd4Cre mice analyzed in two independent experiments (***, P < 0.0001).