Human IL-9
Interleukin-9 (IL-9) is a cytokine that plays important roles in immune regulation, particularly in allergic responses and T helper cell differentiation.
Human IL-9
Function
Interleukin-9 (IL-9) is a pleiotropic cytokine that belongs to the γc family of cytokines. It is primarily produced by T helper 9 (Th9) cells, regulatory T cells, and some innate lymphoid cells. IL-9 signals through the IL-9 receptor complex, which consists of the IL-9Rα chain and the common gamma chain (γc). This cytokine plays crucial roles in immune regulation, particularly in allergic diseases, autoimmunity, and anti-tumor immunity.Biological Functions
Immune System Regulation
- Th9 Cell Development: Promotes the differentiation and maintenance of Th9 cells
- Mast Cell Activation: Enhances mast cell proliferation and degranulation
- B Cell Function: Supports B cell survival and antibody production
- Regulatory T Cells: Modulates Treg cell function and IL-10 production
Disease Associations
- Allergic Diseases: Elevated in asthma, atopic dermatitis, and food allergies
- Autoimmunity: Implicated in inflammatory bowel disease and multiple sclerosis
- Cancer: Dual role as both tumor promoter and anti-tumor factor depending on context
- Parasitic Infections: Important for immunity against helminth parasites
Target Details
Protein Information
Protein Information
Organism: Homo sapiens (Human)
Gene Name: IL9
Alternative Names: T-cell growth factor P40, Cytokine P40
Protein Family: Four-helix bundle cytokines, γc family
Database References
Database References
UniProt ID: P15248
Gene ID: 3578
NCBI Reference: Q01113-1
Protein Region: Ser 41 - Pro 270
Structural Information
Structural Information
Molecular Weight: ~14 kDa (mature protein)
Structure: Four-helix bundle topology typical of γc cytokines
Key Features: Signal peptide, glycosylation sites, receptor binding domains
Receptor Complex: IL-9Rα + γc (CD132)
Expression and Regulation
Expression and Regulation
Primary Sources: Th9 cells, Tregs, ILC2s, mast cells
Expression Regulation: IL-4, TGF-β, IL-2, OX40 signaling
Tissue Distribution: Predominantly immune tissues and sites of inflammation
Half-life: Relatively short (~2-4 hours in circulation)
Research Applications
Therapeutic Development
- Allergic Diseases: Target for anti-IL-9 therapies in asthma and allergies
- Cancer Immunotherapy: Potential target for enhancing anti-tumor immunity
- Autoimmune Diseases: Therapeutic modulation in inflammatory conditions
- Regenerative Medicine: Role in tissue repair and wound healing
Biomarker Studies
- Disease Monitoring: IL-9 levels as biomarkers for allergic diseases
- Treatment Response: Monitoring therapeutic efficacy in clinical trials
- Patient Stratification: Identifying patients likely to benefit from IL-9-targeted therapies
Basic Research
- Immune Cell Biology: Understanding Th9 cell development and function
- Cytokine Networks: Studying IL-9 interactions with other immune mediators
- Disease Mechanisms: Investigating IL-9’s role in various pathological conditions
Clinical Relevance
Current Therapeutic Approaches
- Monoclonal Antibodies: Anti-IL-9 antibodies in clinical development
- Receptor Antagonists: Small molecule and protein-based IL-9R inhibitors
- Combination Therapies: IL-9 blockade combined with other immunomodulatory approaches
Diagnostic Applications
- Allergy Testing: IL-9 measurement in allergic disease diagnosis
- Immune Profiling: Part of comprehensive cytokine panels
- Research Tools: Essential for studying Th9 biology and allergic responses
IL-9 represents an emerging target in immunology research. Its dual roles in immunity make it an interesting target for both enhancing immune responses (in cancer) and suppressing them (in allergies and autoimmunity).