Induction of airway hyperreactivity by IL-25 is dependent on a subset of invariant NKT cells expressing IL-17RB.

IL-25 has been shown to induce Th2 responses and airway hyperreactivity (AHR) in mice, but the mechanism of action is not understood and it is unclear which cells mediate this disease. In this study we show that the receptor for IL-25, IL-17RB, is highly expressed on a subset of naive and activated CD4(+) invariant NKT (iNKT) cells, but not on activated T cells. IL-17RB(+) iNKT cells produced large amounts of Th2 cytokines that were substantially increased by IL-25 stimulation.