IL17A Gene (Interleukin 17A): Function, Pathways, and Clinical Significance
A key pro-inflammatory cytokine gene involved in autoimmune diseases, host defense, and cancer.
Gene Information Card
| Symbol | IL17A |
|---|---|
| Full Name | Interleukin 17A |
| Gene Type | protein-coding |
| Chromosomal Location | 6p12.2 |
| NCBI Gene ID | 3605 ncbi.nlm.nih.gov/gene/3605 |
| Ensembl ID | ENSG00000112115 |
| UniProt ID | Q16552 |
| OMIM ID | 603149 |
| HGNC ID | 5981 |
| Aliases | CTLA8, IL-17, IL-17A, ILA17 |
Description
IL17A encodes a pro-inflammatory cytokine that is a potent mediator of delayed-type reactions. It is produced by activated T cells, particularly Th17 cells, and stimulates the production of other cytokines, chemokines, and matrix metalloproteinases in various cell types (e.g., fibroblasts, endothelial cells, epithelial cells). IL17A plays a critical role in host defense against extracellular bacteria and fungi, but its dysregulation is linked to autoimmune and inflammatory diseases.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Psoriasis | IL17A promotes keratinocyte hyperproliferation and inflammation; IL-17 inhibitors are effective. | ClinVar, OMIM, literature |
| Rheumatoid Arthritis | IL17A induces synovial fibroblast activation, osteoclastogenesis, and joint inflammation. | OMIM, literature |
| Ankylosing Spondylitis | IL17A contributes to inflammation and bone remodeling; anti-IL17 therapy is approved. | OMIM, literature |
| Inflammatory Bowel Disease (Crohn's disease, ulcerative colitis) | IL17A is elevated in inflamed mucosa; however, IL-17 blockade showed mixed results, indicating complex role. | ClinVar, literature |
| Multiple Sclerosis | IL17A is implicated in neuroinflammation and blood-brain barrier disruption. | OMIM, literature |
| Asthma | IL17A contributes to neutrophilic airway inflammation and steroid resistance. | OMIM, literature |
| Cancer (e.g., colorectal, lung) | IL17A can promote tumor angiogenesis and inflammation; effects are context-dependent. | COSMIC, literature |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Lymph node | 0.0 | Not detected |
| Spleen | 0.0 | Not detected |
| Bone marrow | 0.0 | Not detected |
| Appendix | 0.0 | Not detected |
| Lung | 0.0 | Not detected |
| Skin | 0.0 | Not detected |
| Small intestine | 0.0 | Not detected |
| Colon | 0.0 | Not detected |
| Kidney | 0.0 | Not detected |
| Liver | 0.0 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| Th17 cells (primary) | Not available | High expression upon activation |
| Gamma-delta T cells | Not available | High expression upon activation |
| NKT cells | Not available | Moderate expression upon activation |
| Mast cells | Not available | Low expression |
| Neutrophils | Not available | Low expression (some studies) |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| rs2275913 (G-197A) | SNP (promoter) | Allele frequency varies (A allele ~30-40% in Europeans) | May affect IL17A transcription; associated with susceptibility to certain autoimmune diseases and cancers. |
| rs3819024 (A/G) | SNP (intronic) | Allele frequency varies | Potential association with inflammatory diseases; functional impact unclear. |
| rs4711998 (A/G) | SNP (intronic) | Allele frequency varies | Linked to asthma and atopic dermatitis in some studies. |
| Somatic mutations in cancer | Missense, etc. | Rare (<1%) | Not well-characterized; potential impact on cytokine function or secretion. |
Mutation functional classification
Loss of Function (LOF)
Rare loss-of-function mutations in IL17A or its receptor lead to chronic mucocutaneous candidiasis (CMC) due to impaired antifungal immunity. These are typically inherited in an autosomal recessive manner (e.g., IL17RA mutations, but IL17A mutations are extremely rare).
Gain of Function (GOF)
No clear gain-of-function mutations have been reported for IL17A. Overexpression is often due to regulatory dysregulation rather than coding mutations.
Dominant Negative (DN)
Dominant-negative mutations have not been described for IL17A itself; however, dominant-negative mutations in IL17F (a related cytokine) can cause CMC, but IL17A is not known to have such variants.
View complete mutation data：
Gene Ontology (GO)
| • cytokine activity | • interleukin-17 receptor binding |
| • extracellular space | • immune response |
| • inflammatory response | • positive regulation of tumor necrosis factor production |
| • positive regulation of interleukin-6 production | • positive regulation of NF-kappaB transcription factor activity |
| • positive regulation of cell proliferation | • defense response to fungus |
| • defense response to Gram-positive bacterium |
Pathways
• IL-17 signaling pathway (KEGG hsa04657)
• Cytokine-cytokine receptor interaction (KEGG hsa04060)
• Th17 cell differentiation (KEGG hsa04659)
• Inflammatory bowel disease (KEGG hsa05321)
• Rheumatoid arthritis (KEGG hsa05323)
• Allograft rejection (KEGG hsa05330)
• Graft-versus-host disease (KEGG hsa05332)
• Chagas disease (KEGG hsa05142)
• Tuberculosis (KEGG hsa05152)
• Amoebiasis (KEGG hsa05146)
Protein Summary
IL17A is a 155-amino acid protein (with a 23-aa signal peptide) that forms a homodimer. It is a cysteine-knot cytokine that binds to the IL-17 receptor complex (IL17RA/IL17RC). The protein is secreted and acts on a wide range of cell types to induce pro-inflammatory gene expression. It is a key effector of Th17 cells and is a major therapeutic target in autoimmune diseases.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| IL17A Knockout HEK293 Cell Line | EDJ-KQ959 | Human | 3605 | Details Get a Quote |
| IL17A Knockout HeLa Cell Line | EDJ-KQ53655 | Human | 3605 | Details Get a Quote |
| IL17A Knockout A-549 Cell Line | EDJ-KQ62129 | Human | 3605 | Details Get a Quote |
| IL17A Knockout HCT 116 Cell Line | EDJ-KQ70619 | Human | 3605 | Details Get a Quote |
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