Fig. 4.

Expression of Bcl6 protein in DKO T cells is mTOR dependent. a Naive T cells from wt and DKO mice were cultured as described in Fig. 3 and treated with vehicle control or rapamycin (20 nM) for the final 24 h of the 3-day culture. Bcl6 expression was assessed by western blotting using nuclear extracts. Levels of IRF4 and Lamin B were evaluated as control. b Western blotting analysis of the levels of p-4E-BP in extracts from wt or DKO T cells. c Representative FACS plots for CXCR5 and PD1 on splenic CD4⁺ T cells from young (4–14-week old) wt, DKO, and BXSB-Yaa mice. F female, M male. Data are representative of two independent experiments (n = 3–4). d Representative FACS plots for BTLA and PD1 gated on CD4⁺CD44⁺ T cells from DKO or BXSB-Yaa mice. e Representative FACS histograms showing p-4E-BP levels in T_FH effector (CD4⁺BTLA^hiPD1^hiCD44⁺) and non-T_FH effector (CD4⁺BTLA⁻PD1⁻CD44⁺) cells of the indicated genotypes. Rapa rapamycin. f Western blotting analysis of the levels of Bcl6 in nuclear extracts from naive wt or DKO T cells cultured as in Fig. 3 and treated with vehicle control or the indicated doses of 4EGI-1 for the final 24 h of the 3-day culture. Levels of IRF4 and HDAC1 were evaluated as control. Data are representative of two independent experiments