IL17A
IL17A
Overview
IL17A encodes interleukin-17A, a proinflammatory cytokine produced primarily by Th17 cells and other adaptive immune populations. It is a central mediator of mucosal immunity and host defense, but it is also strongly implicated in chronic inflammatory and autoimmune disease. IL-17A acts by promoting the expression of downstream inflammatory mediators, chemokines, and tissue-remodeling factors, thereby amplifying immune-cell recruitment and local inflammation. In recent biomedical literature, IL-17A is repeatedly discussed alongside IFNG, interleukin-6, tumor necrosis factor alpha, nuclear factor kappa B, and related pathways that shape inflammatory signaling.
Clinically, IL-17A is an important biomarker and therapeutic target. Neutralization of IL-17A, alone or together with IL-17F, has been used in inflammatory diseases such as plaque psoriasis, and IL-17A signaling is also being investigated in inflammatory bowel disease, autoimmune hepatitis, arthritis, uveitis, kidney injury, melanoma brain metastases, infectious disease responses, and fibrosis. Because IL-17A sits at the intersection of protective immunity and pathogenic inflammation, it is frequently studied both as a readout of immune activation and as a mechanistic driver of disease.
Focus of Latest Publications
IL-17A has emerged as a key proinflammatory cytokine with substantial therapeutic potential across multiple disease contexts. Bimekizumab, a dual interleukin-17A and IL-17F inhibitor, demonstrated high efficacy and favorable long-term drug survival over 2 years in real-world treatment of moderate-to-severe plaque psoriasis. Secukinumab, a selective IL-17A inhibitor, is being evaluated as additional therapy for giant cell arteritis, a condition where many patients experience glucocorticoid-related toxicity or disease relapse. These monoclonal antibody approaches confirm the clinical relevance of targeting IL-17A in inflammatory and systemic diseases.
IL-17A plays a critical role in neuroinflammatory pathways and immune-mediated thrombosis. In a rat model of cerebral ischemia-reperfusion injury, suppression of IL-17A significantly improved neurological function and reduced infarct volume through modulation of the IL-17A/mitogen-activated protein kinase/NF-κB signaling pathway. In experimental autoimmune encephalomyelitis, an adaptive cellular source of IL-17A and IL-17F was absolutely required for disease induction; loss of IL-17A/F signaling eliminated an IL-23 receptor-driven pathogenic signature in T helper 17 cells. Furthermore, proteomic studies in cancer patients identified IL-17A-driven endothelial activation as a mechanistic link to thrombotic risk; administration of anti-IL-17A antibodies to CD200R1-deficient mice normalized thrombosis markers in vivo, suggesting IL-17A inhibition as a therapeutic strategy to reduce cancer-associated venous thromboembolism.
IL-17A has emerged as both a biomarker and therapeutic target in cancer immunotherapy. In melanoma brain metastases, codelivery of anti-IL-17 and anti-CD73 antibodies via a nose-to-brain delivery platform enhanced anti-tumor immunity by promoting CD8+ T cell activation, proinflammatory macrophage polarization, and reducing regulatory T cell infiltration. In high-risk bladder cancer treated with Bacillus Calmette-Guérin vaccine, IL-17 along with IL-21 and IL-26 were identified as predictive of therapeutic response, with responders characterized by increased Th17-like Th1 cells expressing these proinflammatory cytokines. In patients receiving checkpoint blockade immunotherapy, autoantibodies targeting IL-17 pathway proteins were associated with improved therapeutic response when antibodies possessed neutralizing activity.
IL-17A represents a systemic inflammatory biomarker with broad clinical associations. Serum IL-17A is elevated in periodontitis patients independent of systemic comorbidities, suggesting IL-17A dysregulation links oral inflammation to systemic inflammaging. In diabetic patients, elevated aqueous humor IL-17 levels correlated with diabetes-related ocular complications and microvascular inflammation. In cultured skin fibroblasts exposed to a pro-inflammatory cytokine cocktail including IL-17A, mitochondrial dysfunction and inflammatory metabolic reprogramming were induced; treatment with plant-derived nanovesicles suppressed these IL-17A-associated inflammatory effects and restored mitochondrial respiration. Sex-specific determinants of circulating IL-17A have been identified, with inflammatory mechanisms predominating in males and a potassium-linked metabolic axis in females, indicating that sex influences IL-17A regulation and may have implications for disease susceptibility, biomarker interpretation, and treatment response.