Figure 5.

Butyrate regulates T cells by inhibiting HDAC8. (A) Naïve CD4⁺ T cells were cultured under T_H17-polarizing conditions for 1 day, and the messenger RNA (mRNA) level of each subtype of histone deacetylases was measured. Dotted line indicates the expression of conditions that did not stimulate anything. (B) EL4 cells were stimulated with butyrate, anti-CD3, and IL-6; immunoprecipitated with an anti-ERRα antibody; and immunoblotted using anti-acetyl lysine and anti-ERRα antibodies. (C) Naïve CD4⁺ T cells were cultured under T_H17-polarizing conditions with 500 µM butyrate for 3 days, and CPTIA and NR1D1 expression was visualized by confocal microscopy. Relative bar charts are shown in the right panel. ***p < 0.001. (D) One day after induction of T_H17 cells, the mRNA levels of CPTIA and NR1D1 were measured. (E) Naïve CD4⁺ T cells were isolated from splenocytes and cultured with butyrate, etomoxir, or SR8278 under T_H17 differentiation conditions for 3 days, and the T_H17 and T_reg cell populations were analyzed by flow cytometry. *p < 0.05.