T-bet is a key modulator of IL-23-driven pathogenic CD4+ T cell responses in the intestine

How transcription factor T-bet and Th17 cells contribute to colitis remains incompletely understood. Here the authors identify T-bet as a negative regulator of IL-23R pathway activation and show that T-bet deficient T cells drive colitogenic Th17 responses dependent on the cytokines IL-17A and IL-22.