Differentiation and Characterization of Tr1 Cells.

Regulatory T cell-mediated suppression serves as a pivotal mechanism of negative regulation of immune-mediated inflammation. Type 1 regulatory T cells (Tr1 cells) are an important subset of CD4+ T cells that prevent excessive inflammatory responses and maintain immune tolerance. The anti-inflammatory role of Tr1 cells is mediated in part by their production of interleukin 10 (IL-10), which dampens the function of both antigen-presenting cells and antigen-specific effector T cells. Additionally, Tr1 cells can kill effector and myeloid cells through the perforin-granzyme B pathway. Adoptive transfer of in vitro differentiated Tr1 cells can be used to suppress autoimmune tissue inflammation in vivo. This unit describes the in vitro stimulation of naïve murine CD4+ T cells using IL-27 to generate IL-10-producing Tr1 cells.