IL17A
The protein encoded by this gene is a proinflammatory cytokine produced by activated T cells. This cytokine regulates the activities of NF-kappaB and mitogen-activated protein kinases. This cytokine can stimulate the expression of IL6 and cyclooxygenase-2 (PTGS2/COX-2), as well as enhance the production of nitric oxide (NO). High levels of this cytokine are associated with several chronic inflammatory diseases including rheumatoid arthritis, psoriasis and multiple sclerosis. [provided by RefSeq, Jul 2008]
Function
Effector cytokine of innate and adaptive immune system involved in antimicrobial host defense and maintenance of tissue integrity (PubMed:24120361).
Signals via IL17RA-IL17RC heterodimeric receptor complex, triggering homotypic interaction of IL17RA and IL17RC chains with TRAF3IP2 adapter. This leads to downstream TRAF6-mediated activation of NF-kappa-B and MAPkinase pathways ultimately resulting in transcriptional activation of cytokines, chemokines, antimicrobial peptides and matrix metalloproteinases, with potential strong immune inflammation (PubMed:19825828, PubMed:21350122, PubMed:17911633, PubMed:18684971, PubMed:8676080, PubMed:24120361).
Plays an important role in connecting T cell-mediated adaptive immunity and acute inflammatory response to destroy extracellular bacteria and fungi. As a signature effector cytokine of T-helper 17 cells (Th17), primarily induces neutrophil activation and recruitment at infection and inflammatory sites (By similarity).
In airway epithelium, mediates neutrophil chemotaxis via induction of CXCL1 and CXCL5 chemokines (By similarity).
In secondary lymphoid organs, contributes to germinal center formation by regulating the chemotactic response of B cells to CXCL12 and CXCL13, enhancing retention of B cells within the germinal centers, B cell somatic hypermutation rate and selection toward plasma cells (By similarity).
Effector cytokine of a subset of gamma-delta T cells that functions as part of an inflammatory circuit downstream IL1B, TLR2 and IL23A-IL12B to promote neutrophil recruitment for efficient bacterial clearance (By similarity).
Effector cytokine of innate immune cells including invariant natural killer cell (iNKT) and group 3 innate lymphoid cells that mediate initial neutrophilic inflammation (By similarity).
Involved in the maintenance of the integrity of epithelial barriers during homeostasis and pathogen infection (PubMed:21350122).
Upon acute injury, has a direct role in epithelial barrier formation by regulating OCLN localization and tight junction biogenesis (By similarity).
As part of the mucosal immune response induced by commensal bacteria, enhances host's ability to resist pathogenic bacterial and fungal infections by promoting neutrophil recruitment and antimicrobial peptides release (By similarity).
In synergy with IL17F, mediates the production of antimicrobial beta-defensins DEFB1, DEFB103A, and DEFB104A by mucosal epithelial cells, limiting the entry of microbes through the epithelial barriers (By similarity).
Involved in antiviral host defense through various mechanisms (By similarity).
Enhances immunity against West Nile virus by promoting T cell cytotoxicity (By similarity).
May play a beneficial role in influenza A virus (H5N1) infection by enhancing B cell recruitment and immune response in the lung (By similarity).
Contributes to influenza A virus (H1N1) clearance by driving the differentiation of B-1a B cells, providing for production of virus-specific IgM antibodies at first line of host defense (By similarity).
Biological Process
Adaptive immune response Source: UniProtKB-KW
Apoptotic process Source: ProtInc
Cell-cell signaling Source: ProtInc
Cell death Source: ProtInc
Cellular response to interleukin-1 Source: Ensembl
Defense response to fungus Source: Ensembl
Defense response to Gram-negative bacterium Source: Ensembl
Defense response to Gram-positive bacterium Source: Ensembl
Fibroblast activation Source: BHF-UCL
Granulocyte migration Source: Ensembl
Immune response Source: ProtInc
Inflammatory response Source: UniProtKB-KW
Innate immune response Source: UniProtKB-KW
Interleukin-17-mediated signaling pathway Source: UniProtKB
Intestinal epithelial structure maintenance Source: Ensembl
Notch signaling pathway Source: Ensembl
Positive regulation of antimicrobial peptide production Source: Ensembl
Positive regulation of bicellular tight junction assembly Source: Ensembl
Positive regulation of chemokine (C-X-C motif) ligand 1 production Source: UniProtKB
Positive regulation of cytokine production involved in inflammatory response Source: ARUK-UCL
Positive regulation of interleukin-12 production Source: ARUK-UCL
Positive regulation of interleukin-16 production Source: ARUK-UCL
Positive regulation of interleukin-1 beta production Source: ARUK-UCL
Positive regulation of interleukin-23 production Source: BHF-UCL
Positive regulation of interleukin-6 production Source: UniProtKB
Positive regulation of osteoclast differentiation Source: BHF-UCL
Positive regulation of transcription by RNA polymerase II Source: MGI
Positive regulation of tumor necrosis factor production Source: ARUK-UCL