Figure 4: Mll1 is required for production of IL-21.

shRNA⁺ SMARTA (A-B, E) or gRNA⁺ Cas9^Tg SMARTA (C-D) CD4 T cells were transferred into C57BL/6 mice. 6 days after infection with LCMV-Arm, splenocytes were restimulated with LCMV gp_66–77 peptide. Expression of IL-21 (A) and CD40L (B) in SMARTA CD4 T cells or T_FH and T_H1 SMARTA CD4 T cells (E). Expression of IL-21 (C) and CD40L (D) in Cas9^Tg SMARTA CD4 T cells. (F) shRNA⁺ CD4 T cells were cultured in T_H1 conditions. Expression of IL-21 in shRNA⁺ CD4 T cells restimulated with anti-CD3. (G) gRNA⁺ Cas9^Tg SMARTA CD4 T cells were cultured in T_H1 conditions. Expression of IL-21 in gRNA⁺ Cas9^Tg SMARTA CD4 T cells restimulated with anti-CD3. Data shown are from one experiment representative of 5 (A-B, E), 3 (C-D) or 2 (F-G) independent experiments with 3–4 mice per group. *p ≤ 0.05, **p ≤ 0.01, ***p ≤ 0.001, ****p ≤ 0.0001 (unpaired two-tailed Student’s t-test).