Editors' ChoiceEVOLUTION

Outfoxing Immune Excess

Sci. Signal.  17 Nov 2009:
Vol. 2, Issue 97, pp. ec373
DOI: 10.1126/scisignal.297ec373

Immune responses are kept in check by Foxp3-expressing CD4+-regulatory T cells (Tregs) through a variety of mechanisms. Expression of specific transcription factors directs Treg responses into distinct T helper cell lineages; however, the transcription factors that regulate particular helper lineages have not been completely characterized. Chaudhry et al. show that the transcription factor Stat3, which is required for the initial differentiation of TH17-effector T cells, is also required for Treg cell–mediated suppression of TH17-mediated immune responses. Mice carrying a Treg cell–specific deletion in Stat3 succumb to an intestinal inflammatory disease driven by uncontrolled TH17 responses. Thus, different classes of immune responses can result from the expression of helper lineage–specific transcription factors.

A. Chaudhry, D. Rudra, P. Treuting, R. M. Samstein, Y. Liang, A. Kas, A. Y. Rudensky, CD4+ regulatory T cells control TH17 responses in a Stat3-dependent manner. Science 326, 986–991 (2009). [Abstract] [Full Text]