Fig 4. Reduction of proinflammatory cytokine and autoAb production in co-cultures with syngeneic CD4⁺CD25^- T_h and B cells.

PD1^loCD4⁺T_reg added to cultures were induced by adding anti-PD-1 Ab in vitro to CD4⁺CD25⁺ T cells from unmanipulated mice. CD4⁺T_reg from 22 week-old unmanipulated BWF₁ mice (PD1^hi CD4⁺T_reg) were treated with anti-PD-1 Ab at 75 μg/ml for 24 hours to generate PD1^loCD4⁺T_reg, followed by washing with PBS, then cocultured for 48 hours with T_h and B cells from unmanipulated syngeneic mice. PD1^lo CD4⁺T_reg decreased the production of (A) IFN-γ, (B) IL-6, (C) IL-10, (D) anti-DNA and (E) IgG (Fig. 4A-E, p < 0.001, one-way ANOVA). PD1^hiCD4⁺T_reg and B cells alone from these mice were used as controls. * p < 0.05, ** p < 0.01, *** p < 0.001 (Tukey's test). Data are representative of 3 individual experiments, n = 5 mice per group in each experiment.