The many lives of IL-9: a question of survival?
Although the cytokine interleukin 9 (IL-9) was discovered decades ago, it remains one of the most enigmatic cytokines identified so far, in particular because its functional activities remain far from clear. Breakthroughs made through the use of IL-9 reporter mice have allowed the identification of cell types that produce IL-9 in vivo and, contrary to expectations based on previous results obtained in vitro, it is not T cells but instead a previously unknown type of innate lymphoid cell, called the 'ILC2 cell', that is the main cell type that expresses IL-9 in vivo. In this perspective, we put forward a hypothesis about the potential biological functions of IL-9 in the immune system and beyond.
Division of Molecular Immunology, Medical Research Council National Institute for Medical Research, London, UK.
Christoph
C
Wilhelm
Jan-Eric
JE
Turner
Jacques
J
Van Snick
Brigitta
B
Stockinger
D000818:Animals; D002470:Cell Survival / Q000276:immunology; D006801:Humans; D016906:Interleukin-9 / Q000276:immunology*; D051379:Mice; D018418:Th2 Cells / Q000276:immunology*
D016906:Interleukin-9