A role for BATF3 in T _H9 differentiation and T cell driven mucosal pathologies

Abstract

T helper 9 (T _H9) cells are important for the development of inflammatory and allergic diseases. The T _H9 transcriptional network converge signals from cytokines and antigen presentation but is incompletely understood. Here, we identified TL1A, a member of the TNF superfamily, as strong inducer of mouse and human T _H9 differentiation. Mechanistically, TL1A induced the expression of the transcription factors BATF and BATF3 and facilitated their binding to the Il9 promoter leading to enhanced secretion of IL-9. BATF- and BATF3-deficiencies impaired IL-9 secretion under T _H9 and T _H9-TL1A polarizing conditions. In vivo, using a T cell transfer model we demonstrated that TL1A promoted IL-9-dependent, T _H9 cell-induced intestinal and lung inflammation. Neutralizing IL-9 antibodies attenuated TL1A-driven mucosal inflammation. Batf3 ^−/− T _H9-TL1A cells induced reduced inflammation and cytokine expression in vivo compared to WT cells. Our results demonstrate that TL1A promotes T _H9 cell differentiation and function and define a role of BATF3 in T cell driven mucosal inflammation.