The development and in vivo function of T helper 9 cells

Abstract

The specialized cytokine secretion profiles of T helper (TH) cells are the basis for a focused and efficient immune response. On the 20th anniversary of the first descriptions of cytokine signals that act to differentiate interleukin-9 (IL-9)-secreting T cells, this review focuses on the extracellular signals and transcription factors that promote the development of what we now term TH9 cells, which are characterized by the production of this cytokine. We summarize our current understanding of the contribution of TH9 cells to both effective immunity and immunopathological disease and propose that TH9 cells could be targeted for the treatment of allergic and autoimmune disease.