Il9

Function

Multifunctional cytokine secreted mainly by T-helper 2 lymphocytes and also mast cells or NKT cells that plays important roles in the immune response against parasites (PubMed:11070175, PubMed:19433802). Affects intestinal epithelial permeability and adaptive immunity (PubMed:12704113). In addition, induces the differentiation of specific T-cell subsets such as IL-17 producing helper T-cells (TH17) and also proliferation and differentiation of mast cells (PubMed:11070175, PubMed:19433802). Mechanistically, exerts its biological effects through a receptor composed of IL9R subunit and a signal transducing subunit IL2RG (PubMed:2145361, PubMed:7718508). Receptor stimulation results in the rapid activation of JAK1 and JAK3 kinase activities leading to STAT1, STAT3 and STAT5-mediated transcriptional programs (PubMed:10464327). Induction of differentiation genes seems to be mediated by STAT1 alone, while protection of cells from apoptosis depends on STAT3 and STAT5 (PubMed:10464327).

Sequence Similarities

Belongs to the IL-7/IL-9 family.

Cellular localization

• Secreted

Alternative names

Interleukin-9, IL-9, Cytokine P40, T-cell growth factor P40, Il9

Database links

swissprot:P15247 entrezGene:16198

Other research areas

• Immuno-oncology