Figure 1.

Butyrate and propionate enhances FOXP3 expression in CD4+ T cells differentiated into Tregs. Naïve CD4+ T cells (CD62L+CD44low) were sorted from spleens of FOXP3 GFP mice and cultured in 96-well flat bottom plates with plate bound anti-CD3 (2 μg/ml) and soluble anti-CD28 (0.5 μg/ml) in the presence of Treg (TGF-β 2 ng/ml and IL-2 10 ng/ml) differentiation condition for 4 days. Butyrate and propionate (250 μM) were added in the culture at day 0. At day 4, cells were restimulated with with PMA (50 ng/ml), ionomycin (500 ng/ml), and brefeldin A (5 μg/ml) for 4 h at 37°C and 5% CO₂, and analyzed by flow cytometry (A). The frequencies of FOXP3+ and/or IL-9+ CD4+ T cells (B) and FOXP3+ and/or IL-10+ CD4+ T cells (C) are represented by bar graphs. Data are shown as mean ± S.D. Linear regression, Two-way ANOVA and Tukey's multiple comparison test were used for statistical analysis. NS, not significant.