IL9

Interleukin 9 (IL9), also known as P40 or HP40, encoded by IL9 gene, is a cytokine belonging to the group of interleukins. It can activate JAK1 and JAK3 tyrosine kinases and different signal transducer and activator (STAT) proteins (STAT1, STAT3, and STAT5) through interleukin 9 receptor (IL9R). These proteins are involved in intracellular signal transduction, controlling cell growth, differentiation, and apoptosis. In vitro, IL9 stimulate proliferation of activated T cells to accelerate the immunoglobulin production in B cells. Moreover, IL9 also facilitate proliferation and differentiation of mast cells and hematopoietic progenitors. These suggest that IL9 is related to immune regulation.
Numerous studies have been shown that IL9 is associated with the progression of various diseases, including Vogt-Koyanagi-Harada disease, primary biliary cirrhosis, immune thrombocytopenia, atopic dermatitis, inflammatory bowel diseases, allergic disorders, and asthma. It has been shown that the patients with ulcerative colitis present the higher IL9 levels than the control person and the IL9 levels correspond with endoscopic inflammation. In addition, IL-9, as an established proinflammatory cytokine, might promote the inflammatory response via increasing the production of IL-17 in VKH disease.
Gene ID: 3578
UniProt ID: P15248