Abstract
The paper by Groux et al sheds some light on how IL-10 (generally thought of as an immunosuppressive cytokine) may act to regulate intestinal inflammation. The authors show that repetitive antigenic stimulations in vitro of human and murine CD4+ cells in the presence of IL-10 results in the generation of a T cell subset with low proliferative capacity which secretes high levels of IL-10 and interferon γ (IFN-γ) and has immune regulatory activities both in vitro and in vivo. These cells, which the authors term T regulatory 1 cells (Tr1), exhibit a cytokine profile distinct from previously described Th1, Th2 and Th0 subsets of CD4+ T cells.