TGFβ signalling in control of T-cell-mediated self-reactivity

In the immune system, transforming growth factor-beta (TGF beta) affects multiple cell lineages by either promoting or opposing their differentiation, survival and proliferation. Understanding the cellular mechanisms of TGF beta-mediated regulation is complicated due to a broad distribution of TGF beta receptors on the surface of different immune-cell types. Recent studies using in vivo genetic approaches revealed a critical role for TGF beta signalling in T cells in restraining fatal autoimmune lesions. Here, we review recent advances in our understanding of a role for TGF beta signalling in the regulation of T-cell differentiation in the thymus and in the periphery, with a particular emphasis on TGF beta-mediated control of self-reactive T cells.