Fig 2. Inhibition of PD-1 in vivo increased the regulatory capacity of BWF₁ CD4⁺T_reg in different spleen cell subsets.

(A) Apoptosis in PD1^loCD4⁺T_reg was significantly less compared to PD1^hiCD4⁺T_reg, whether or not cultures contained T_h and B cells (p < 0.05, unpaired student t-test). (B) PD1^loCD4⁺T_reg were viable and were increased in numbers compared to PD1^hiCD4⁺T_reg (p < 0.05, unpaired student t-test). (C) PD1^loCD4⁺T_reg induced more apoptosis in CD19⁺ B cells than did PD1^hiCD4⁺T_reg. (D) Numbers of viable B cells were decreased in cultures containing PD1^loCD4⁺T_reg compared to those with PD1^hiCD4⁺T_reg (p < 0.05, unpaired student t-test). (E) PD1^loCD4⁺T_reg induced more apoptosis in CD4⁺CD25-T cells than did PD1^hiCD4⁺T_reg. (F) PD1^loCD4⁺T_reg suppressed proliferation of CD4⁺CD25-syngeneic T cells as detected by CFSE (Fig. 2C, 2E, 2F, p < 0.001, one-way ANOVA). *p < 0.05, **p < 0.01, ***p < 0.001 (Tukey's test). Data are representative of 2 individual experiments, n = 6 mice per group in each experiment.