Fig. S3.

PD-1–deficient Treg cells showed increased CTLA-4 expression and suppressive activity in vivo. (A) The number of CD4⁺, CD8⁺, CD44⁺CD4⁺, and CD44⁺CD8⁺ T cells in LNs from indicated mice as in Fig. 3C. (B) FACS analysis of FoxP3 and CTLA-4 expression gated on CD4⁺ T cells from the SPL and LNs of 2-mo-old PD-1 WT or PD-1 KO mice on the C57BL/6 background. Numbers in plots indicate percentage of cells in each gate. Data are representative of 3 to ∼6 mice per group. Bars represent the means (±SEM). *P < 0.05, **P < 0.01, ***P < 0.001; ns, not significant.