IL-17A
IL-17A (interleukin 17A, also known as IL-17, CTLA8 or IL17) is a secreted proinflammatory effector cytokine of the innate and adaptive immune systems. It drives neutrophil recruitment, antimicrobial defence and the maintenance of epithelial barriers. Browse Assay Genie's current range of IL-17A research reagents below, or read on for the biology behind the target.
IL-17A is an effector cytokine that connects T cell-mediated adaptive immunity with the acute inflammatory response, helping to clear extracellular bacteria and fungi. It signals through the IL17RA-IL17RC heterodimeric receptor complex, which recruits the adapter TRAF3IP2. This leads to TRAF6-mediated activation of NF-kappa-B and MAP kinase pathways and to transcription of cytokines, chemokines, antimicrobial peptides and matrix metalloproteinases. It can also stimulate IL-6 and cyclooxygenase-2 expression and enhance nitric oxide production.
As a signature cytokine of T-helper 17 (Th17) cells, IL-17A mainly induces neutrophil activation and recruitment to sites of infection and inflammation. In airway epithelium it promotes neutrophil chemotaxis by inducing CXCL1 and CXCL5. It is also produced by a subset of gamma-delta T cells, invariant natural killer cells and group 3 innate lymphoid cells. In synergy with IL-17F, it drives production of the beta-defensins DEFB1, DEFB103A and DEFB104A by mucosal epithelial cells. In secondary lymphoid organs it contributes to germinal centre formation by shaping B cell responses to CXCL12 and CXCL13. It also helps maintain epithelial barrier integrity, including through OCLN localisation and tight junction biogenesis, and it contributes to antiviral defence, including against West Nile virus and influenza A virus.
The IL17A gene belongs to the IL-17 family, and the protein is a member of the Interleukins group. The gene was originally named for cytotoxic T-lymphocyte-associated serine esterase 8, hence the alias CTLA8. High IL-17A levels are associated with chronic inflammatory diseases such as rheumatoid arthritis, psoriasis and multiple sclerosis, and the cytokine has been implicated in infectious disease, autoimmunity, cancer and SARS-CoV-2-related lung inflammation.
IL-17A is a signature effector cytokine of Th17 cells, linking adaptive T cell responses to acute inflammation.
High IL-17A levels are associated with rheumatoid arthritis, psoriasis and multiple sclerosis, making it a focus of chronic inflammation research.
IL-17A supports epithelial barrier integrity and induces antimicrobial peptides and neutrophil recruitment against bacterial and fungal pathogens.
IL-17A contributes to host responses to West Nile virus and influenza A, and to inflammation in SARS-CoV-2 lung damage.
IL-17A is a secreted effector cytokine that signals through the IL17RA-IL17RC receptor complex to activate NF-kappa-B and MAP kinase pathways. It induces chemokines, antimicrobial peptides and matrix metalloproteinases, recruiting neutrophils and supporting defence against extracellular bacteria and fungi.
IL-17A is also called IL-17, CTLA8 and IL17. The HGNC symbol is IL17A, and the previous name was interleukin 17 (cytotoxic T-lymphocyte-associated serine esterase 8). It is the founding member of the IL-17 family, which includes IL-17B, IL-17C, IL-17D and IL-17F.
High IL-17A levels are associated with rheumatoid arthritis, psoriasis and multiple sclerosis. Orthologues exist in mouse and rat, both named Il17a, so the cytokine can be studied in rodent models; check the datasheet of any product for its validated reactivity.
Other IL-17 family members, Th17-associated interleukins and inflammatory cytokines with products at Assay Genie.
Gene and protein annotations from HGNC, NCBI Gene and UniProt Q16552; product specifications from Assay Genie datasheets.