TGF-β Regulation of T Cells.

Transforming growth factor β (TGF-β) is a key cytokine regulating the development, activation, proliferation, differentiation, and death of T cells. In CD4⁺ T cells, TGF-β maintains the quiescence and controls the activation of naive T cells. While inhibiting the differentiation and function of Th1 and Th2 cells, TGF-β promotes the differentiation of Th17 and Th9 cells. TGF-β is required for the induction of Foxp3 in naive T cells and the development of regulatory T cells. TGF-β is crucial in the differentiation of tissue-resident memory CD8⁺ T cells and their retention in the tissue, whereas it suppresses effector T cell function. In addition, TGF-β also regulates the generation or function of natural killer T cells, γδ T cells, innate lymphoid cells, and gut intraepithelial lymphocytes. Here I highlight the major findings and recent advances in our understanding of TGF-β regulation of T cells and provide a personal perspective of the field.