Negative regulation of Th17 responses.

The discovery of the Th17 lineage of T helper cells and the realization that this subset was implicated in the pathogenesis of a variety of inflammatory conditions has lead to an intense effort devoted to identifying the cytokines and transcription factors that promote their development. In contrast, less attention has been paid to understanding the cytokines that temper Th17 activity. Recent studies, however, have provided insights into the cytokines that limit these T cells. The aim of this article is to review our current understanding of the regulatory networks that limit T helper subsets and how they relate to the Th17 lineage.