TGFβ in T cell biology and tumor immunity: Angel or devil?

The evolutionally conserved transforming growth factor beta (TGF beta) affects multiple cell types in the immune system by either stimulating or inhibiting their differentiation and function. Studies using transgenic mice with ablation of TGF beta or its receptor have revealed the biological significance of TGF beta signaling in the control of T cells. However, it is now clear that TGF beta is more than an immunosuppressive cytokine. Disruption of TGF beta signaling pathway also leads to impaired generation of certain T cell populations. Therefore, in the normal physiological state, TGF beta actively maintains T cell homeostasis and regulates T cell function. However, in the tumor microenvironment, TGF beta creates an immunosuppressive milieu that inhibits antitumor immunity. Here, we review recent advances in our understanding of the roles of TGF beta in the regulation of T cells and tumor immunity. Published by Elsevier Ltd.