Fig. 2.

TGF-β promotes acetylated FOXP3 binding to chromatin. (A) ChIP was performed by using mIgG, anti-acetyl histone H3 (AcH3), and anti-FOXP3 antibodies with ten million in vitro expanded human CD4⁺CD25⁺ Treg cells treated with TGF-β at the indicated time points. The eluted genomic DNA fragment was amplified with hIL-2 promoter-specific primers. (B) Ten million serum-starved human HA-FOXP3a- and -3b-transfected Jurkat T cells were stimulated with or without 1 ng of TGF-β per million cells for indicated time periods. Equal amounts of protein from chromatin fractions were separated by SDS/PAGE, transferred to nitrocellulose, and immunoblotted with anti-acetyl lysine-specific antibody (Ac-K-103, Santa Cruz Biotechnology), followed by reprobing with anti-HA-HRP-conjugated antibody. Acetylated FOXP3a and FOXP3b proteins are indicated.