Tregs

Abstract

Regulatory T cells (Tregs) are a subtype of T cells with immune suppressive function and play a key role in immune self-tolerance. Its immune inhibitory function has been implicated as the important mechanism of immune evasion and immune tolerance of human cancers. Tregs suppress antitumor immune responses through soluble factor-mediated as well as cell surface molecule-dependent inhibition of T cells and antigen-presenting cells. A significant increase in Treg numbers in the peripheral blood and in the tumor microenvironment has been associated with poor prognosis in various solid tumors. Better understanding of the roles of Tregs in tumor immunity has provided the rationale for the development of therapeutic modalities targeting immunosuppressive effects of Tregs. A number of therapeutic approaches have been proposed including the depletion of Treg by targeting Treg surface markers or with chemotherapeutic agents, the blockade of Treg suppressive function through inhibition of Treg receptors, and the inhibition of Treg induction and trafficking.