The DNA-binding inhibitor Id3 regulates IL-9 production in CD4+ T cells. Mus musculus

The molecular mechanisms by which signaling via transforming growth factor-β (TGF-β) and interleukin 4 (IL-4) control the differentiation of IL-9-producing CD4+ helper T cells (TH9 cells) remain incompletely understood. We found here that the DNA-binding inhibitor Id3 regulated TH9 cell differentiation, as deletion of Id3 increased IL-9 production from CD4+ T cells. Mechanistically, TGF-β1 and IL-4 downregulated Id3 expression, and this process required the kinase TAK1. A reduction in Id3 expression enhanced binding of the transcription factors E2A and GATA-3 to the Il9 promoter region, which promoted Il9 transcription. Notably, Id3’s control of TH9 differentiation regulated anti-tumor immunity in an experimental melanoma-bearing model in vivo and also in human CD4+ T cells in vitro. Thus, our study reveals a previously unrecognized TAK1–Id3–E2A–GATA-3 pathway that regulates TH9 differentiation. Overall design: Comapring of GATA3 binding after the TGF-β1 and IL-4 stimulations