interleukin-9

Interleukin-9 (IL-9) is a pleiotropic cytokine belonging to the common gamma-chain (γc) family, primarily produced by Th9 cells, but also by Th2, Th17, and regulatory T cells. Traditionally, IL-9 signaling was understood to occur through a heterodimeric receptor complex consisting of the IL-9 receptor alpha (IL-9Rα) and the common gamma chain (γc), primarily in hematopoietic cells. However, recent research has identified a novel "type II" IL-9 receptor complex in airway epithelial cells, composed of IL-9Rα and the IL-13 receptor alpha 1 (IL-13Rα1) subunit. This signaling pathway activates STAT3 and induces the expression of chemokines such as CXCL3, which promotes the recruitment of CXCR2+ immune cells and contributes to airway inflammation and asthma pathogenesis. While IL-9 is a target for antagonistic therapies in respiratory disease, recombinant IL-9 is also investigated in preclinical oncology for its potential to stimulate mast cells and enhance anti-tumor immunity.

Other names

IL-9IL9IL 9P40P-40P 40T-cell growth factor P40