GO:0019983 interleukin-9 binding: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0019983 (interleukin-9 binding) is a molecular function defined as binding to interleukin-9 (IL-9), a pleiotropic cytokine.
• IL-9 binding is mediated by the IL-9 receptor (IL-9R), a heterodimer of IL-9Rα and the common gamma chain (γc), which activates JAK/STAT signaling.
• IL-9 binding is central to Th9 cell biology, type 2 innate lymphoid cells (ILC2s), and allergic inflammation.
• Dysregulated IL-9 binding contributes to autoimmune diseases such as rheumatoid arthritis and Crohn's disease.
• IL-9 binding enhances antitumor immunity in CAR-Th9 cells, highlighting therapeutic potential.
• Research tools for IL-9 binding include knockout, knock-in, and overexpression models, as well as CRISPR screening and bioinformatics.
Description
Interleukin-9 (IL-9) is a pleiotropic cytokine produced by T helper 9 (Th9) cells, group 2 innate lymphoid cells (ILC2s), and other cell types. The biological actions of IL-9 are initiated by its binding to the IL-9 receptor (IL-9R), a heterodimeric complex composed of the IL-9 receptor alpha chain (IL-9Rα) and the common gamma chain (γc). This molecular interaction is annotated in the Gene Ontology as GO:0019983, interleukin-9 binding, defined as the binding to interleukin-9. Understanding the molecular details of IL-9 binding is essential for deciphering how IL-9 exerts its effects in immunity, inflammation, and cancer. Recent studies have shown that IL-9 binding is critical for Th9 cell differentiation and function, and its dysregulation is associated with autoimmune diseases such as rheumatoid arthritis and Crohn's disease. Moreover, IL-9 binding enhances the antitumor efficacy of CAR-Th9 cells, suggesting that targeting this interaction could improve immunotherapies. In allergic asthma, IL-9 binding to ILC2s helps maintain their transcriptional identity and promotes type 2 inflammation. Thus, GO:0019983 represents a key molecular function that bridges cytokine signaling and cellular responses in health and disease.
interleukin-9 binding At A Glance
| GO ID | GO:0019983 |
|---|---|
| GO term | interleukin-9 binding |
| Ontology | molecular_function |
| Synonym | IL-9 binding |
| Definition | Binding to interleukin-9. |
| Major function | Mediates IL-9 signal transduction by receptor binding |
| Key receptor | IL-9R (IL-9Rα/γc heterodimer) |
| Associated cells | Th9 cells, ILC2s, mast cells, CAR-T cells |
| Related diseases | Rheumatoid arthritis, Crohn's disease, allergic asthma, cancer |
What Is GO:0019983?
GO:0019983, interleukin-9 binding, is a molecular function term that describes the selective interaction of a protein or molecular complex with interleukin-9 (IL-9). This binding event is typically mediated by the IL-9 receptor (IL-9R) and is the first step in IL-9 signal transduction, leading to activation of downstream pathways such as JAK/STAT. The term encompasses both high-affinity binding to the IL-9Rα chain and the subsequent recruitment of the common gamma chain (γc) to form a functional signaling complex.
Why Is interleukin-9 binding Important in Cell Biology?
GO:0019983 is important because IL-9 binding is the initiating event for IL-9-mediated signaling, which regulates diverse immune responses, including Th9 cell differentiation, ILC2 homeostasis, and allergic inflammation. Dysregulated IL-9 binding is implicated in autoimmune diseases such as rheumatoid arthritis and Crohn's disease, where it promotes pathogenic T cell responses. Conversely, enhancing IL-9 binding in CAR-Th9 cells improves antitumor efficacy, underscoring its therapeutic potential. Therefore, studying interleukin-9 binding provides insights into basic immunology and offers targets for treating inflammatory diseases and cancer.
• IL-9 binding is essential for Th9 cell development and function, which are key drivers of allergic and autoimmune responses.
• It mediates ILC2 activation and type 2 inflammation in allergic asthma.
• Dysregulated IL-9 binding contributes to rheumatoid arthritis pathogenesis via a PU.1-IL9 positive feedback loop.
• In Crohn's disease, IL-9 binding promotes pathogenic Th9 cell generation through TL1A/DR3 signaling.
• IL-9 binding enhances CAR-Th9 cell antitumor efficacy, offering a strategy for cancer immunotherapy.
• The interaction between IL-9 and its receptor is a potential target for therapeutic intervention in inflammatory diseases.
• IL-9 binding is conserved across species, as shown by characterization of chicken IL-9Rα.
• Studying IL-9 binding helps understand cytokine receptor sharing and signaling specificity.
• IL-9 binding is regulated by transcriptional and epigenetic mechanisms, including YTHDF2-mediated m6A modification.
• It serves as a model for studying cytokine-receptor interactions and signal transduction.
Molecular Mechanism of interleukin-9 binding
IL-9 Recognition by IL-9Rα
In simple terms: IL-9 first docks onto a specific receptor subunit called IL-9Rα.
Interleukin-9 binding begins with the specific recognition of IL-9 by the IL-9 receptor alpha chain (IL-9Rα). This interaction is mediated by the extracellular domain of IL-9Rα, which forms a high-affinity complex with IL-9. Structural studies of γc family receptors have revealed that IL-9 binding induces conformational changes that facilitate receptor heterodimerization. The binding is characterized by a nanomolar affinity and is essential for initiating downstream signaling.
Heterodimerization with the Common Gamma Chain (γc)
In simple terms: After IL-9 binds, the receptor recruits a second subunit, γc, to form a complete signaling complex.
Following IL-9 binding to IL-9Rα, the complex recruits the common gamma chain (γc, also known as CD132) to form a heterodimeric receptor. This heterodimerization is a prerequisite for signal transduction and is shared among several cytokines, including IL-2, IL-4, IL-7, IL-15, and IL-21. The assembly of the IL-9/IL-9Rα/γc ternary complex triggers activation of associated Janus kinases (JAKs), particularly JAK1 and JAK3.
Activation of JAK/STAT Signaling
In simple terms: The receptor complex activates JAK enzymes, which then phosphorylate STAT proteins to turn on specific genes.
Upon heterodimerization, JAK1 (bound to IL-9Rα) and JAK3 (bound to γc) are activated through trans-phosphorylation. Activated JAKs phosphorylate tyrosine residues on the intracellular domain of IL-9Rα, creating docking sites for STAT transcription factors, primarily STAT1, STAT3, and STAT5. Phosphorylated STATs dimerize and translocate to the nucleus, where they regulate target gene expression, including genes involved in Th9 differentiation and ILC2 function.
Regulation by Transcriptional and Epigenetic Factors
In simple terms: The amount of IL-9 and its receptor can be controlled by other proteins that turn genes on or off.
IL-9 binding is regulated at multiple levels. The transcription factor PU.1 promotes IL-9 expression in Th9 cells, creating a positive feedback loop that enhances IL-9 binding and rheumatoid arthritis development. In ILC2s, Blimp-1 and IL-9 signaling cooperate to maintain transcriptional identity and promote allergic asthma. Epigenetic regulation by YTHDF2, an m6A reader, controls Th9 programming and CAR-Th9 antitumor efficacy, affecting IL-9 production and binding. Additionally, TL1A/DR3 signaling regulates pathogenic Th9 cell generation in Crohn's disease, indirectly influencing IL-9 binding.
Cross-Species Conservation and Receptor Sharing
In simple terms: The way IL-9 binds its receptor is similar across species, and the receptor is shared with other cytokines.
IL-9 binding is conserved across species; the chicken IL-9 receptor alpha chain has been characterized and shown to share structural and functional features with its mammalian counterparts. The common gamma chain (γc) is shared among multiple cytokine receptors, and structural studies have elucidated the basis of γc family receptor sharing at the membrane level. This sharing ensures that IL-9 binding triggers specific signaling outcomes despite common subunits.
Key Genes Involved in GO:0019983 interleukin-9 binding
The following genes and proteins are directly involved in interleukin-9 binding and its downstream signaling.
| Gene | Major Role | Research Relevance |
|---|---|---|
| IL9 | Encodes interleukin-9 cytokine | Ligand for IL-9R; central to Th9 and ILC2 biology |
| IL9R | Encodes IL-9 receptor alpha chain | High-affinity binding subunit for IL-9 |
| IL2RG | Encodes common gamma chain (γc) | Shared signaling subunit; required for IL-9 binding and signaling |
| JAK1 | Janus kinase 1 | Phosphorylates STATs downstream of IL-9R |
| JAK3 | Janus kinase 3 | Associates with γc; activated upon IL-9 binding |
| STAT1 | Signal transducer and activator of transcription 1 | Mediates IL-9-induced gene expression |
| STAT3 | Signal transducer and activator of transcription 3 | Mediates IL-9-induced gene expression |
| STAT5 | Signal transducer and activator of transcription 5 | Mediates IL-9-induced gene expression |
| PU.1 | Transcription factor | Regulates IL-9 expression; positive feedback loop in Th9 cells |
| Blimp-1 | Transcription factor | Maintains ILC2 identity; cooperates with IL-9 signaling |
| YTHDF2 | m6A reader | Regulates Th9 programming and IL-9 production |
| TL1A | TNF-like ligand 1A | Regulates pathogenic Th9 generation in Crohn's disease |
| DR3 | Death receptor 3 | Receptor for TL1A; modulates Th9 responses |
| IL-9Rα | IL-9 receptor alpha chain protein | Binds IL-9 with high affinity |
| γc | Common gamma chain protein | Heterodimerizes with IL-9Rα |
| Neuromedin U | Neuropeptide | Stimulates ILC2s and type 2 inflammation, indirectly affecting IL-9 |
| CAR | Chimeric antigen receptor | Engineered receptor in CAR-Th9 cells; enhances antitumor efficacy with IL-9 |
How Is interleukin-9 binding Regulated?
Interleukin-9 binding is regulated at multiple levels. Transcriptional regulation of IL9 and IL9R genes controls the availability of ligand and receptor. PU.1 promotes IL-9 expression in Th9 cells, creating a positive feedback loop that amplifies IL-9 binding and rheumatoid arthritis development. In ILC2s, Blimp-1 and IL-9 signaling cooperate to maintain transcriptional identity and promote allergic asthma. Epigenetic regulation by YTHDF2, an m6A reader, controls Th9 programming and CAR-Th9 antitumor efficacy, affecting IL-9 production and binding. Additionally, TL1A/DR3 signaling regulates pathogenic Th9 cell generation in Crohn's disease, indirectly influencing IL-9 binding. Post-translational modifications, such as glycosylation of IL-9Rα, may also affect binding affinity, though specific details require further study.
interleukin-9 binding and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| IL9 | Rheumatoid arthritis | Collagen-induced arthritis mouse model with IL9 knockout |
| IL9R | Allergic asthma | Ovalbumin-induced asthma model with IL9R knockout |
| TL1A/DR3 | Crohn's disease | Experimental colitis model with TL1A blockade |
| YTHDF2 | Cancer immunotherapy | CAR-Th9 cells with YTHDF2 knockout |
| PU.1 | Rheumatoid arthritis | Th9 cell-specific PU.1 knockout mice |
Rheumatoid Arthritis
In rheumatoid arthritis, a positive feedback loop involving PU.1 and IL-9 promotes Th9 cell differentiation and disease development. IL-9 binding to its receptor on Th9 cells enhances their pathogenic function, contributing to joint inflammation and destruction. Targeting IL-9 binding or its downstream signaling may offer therapeutic benefits for rheumatoid arthritis patients.
Crohn's Disease
Tumor necrosis factor-like ligand 1A (TL1A) and its receptor death receptor 3 (DR3) regulate the generation of pathogenic Th9 cells in experimental Crohn's disease. IL-9 binding to IL-9R on these cells promotes their expansion and cytokine production, exacerbating intestinal inflammation. Blocking IL-9 binding could reduce pathogenic Th9 responses in inflammatory bowel diseases.
Allergic Asthma
In allergic asthma, IL-9 binding to ILC2s, along with Blimp-1, protects the transcriptional identity of group 2 innate lymphocytes and promotes type 2 inflammation. This contributes to airway hyperresponsiveness and mucus production. Neuromedin U stimulates ILC2s and type 2 inflammation, further highlighting the role of IL-9 binding in asthma pathogenesis.
Cancer Immunotherapy
Loss of YTHDF2 enhances Th9 programming and CAR-Th9 cell antitumor efficacy, partly through increased IL-9 production and binding. IL-9 binding in the tumor microenvironment promotes cytotoxic T cell responses and tumor rejection. Thus, modulating IL-9 binding could improve adoptive cell therapies for cancer.
From interleukin-9 binding-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does IL-9 binding promote Th9 differentiation? | IL9R knockout mice or CRISPR knockout in Th9 cells |
| What is the affinity of IL-9 for IL-9Rα? | Surface plasmon resonance with recombinant proteins |
| How does IL-9 binding affect ILC2 function? | IL9R conditional knockout in ILC2s |
| Can IL-9 binding be targeted to treat asthma? | Humanized mouse model with IL-9R blockade |
| Does IL-9 binding enhance CAR-T efficacy? | CAR-Th9 cells with IL-9 overexpression |
| What is the role of m6A in IL-9 binding? | YTHDF2 knockout mice and Th9 cells |
How to Study the interleukin-9 binding Process
| Method | What It Measures | Typical Application |
|---|---|---|
| CRISPR knockout screening | Gene essentiality for IL-9 binding | Identify novel regulators of IL-9 signaling |
| Surface plasmon resonance | Binding affinity and kinetics | Characterize IL-9/IL-9R interaction |
| Flow cytometry | Cell surface IL-9 binding | Assess IL-9R expression and function |
| Phospho-STAT Western blot | JAK/STAT activation | Measure downstream signaling |
| RNA sequencing | Transcriptional changes | Identify IL-9 target genes |
| Bioinformatics pathway analysis | Enriched pathways | Interpret RNA-seq data |
| Immunoprecipitation | Protein-protein interactions | Detect IL-9/IL-9R complexes |
| ELISA | Cytokine production | Quantify IL-9 secretion |
CRISPR Knockout Screening
Genome-wide CRISPR knockout screens can identify genes essential for IL-9 binding and signaling. For example, knocking out IL9R or IL2RG abolishes IL-9 binding and downstream STAT phosphorylation, which can be measured by flow cytometry or Western blot. Such screens have revealed regulators of Th9 differentiation and ILC2 function.
Surface Plasmon Resonance (SPR)
SPR measures the binding affinity and kinetics between IL-9 and its receptor. Recombinant IL-9Rα extracellular domain can be immobilized on a sensor chip, and IL-9 injected to determine KD values. This method has been used to characterize γc family receptor sharing.
Flow Cytometry and Phospho-STAT Analysis
Flow cytometry can detect IL-9 binding to cell surface receptors using fluorescently labeled IL-9. Phospho-STAT staining allows quantification of downstream signaling activation upon IL-9 binding. This method is useful for assessing IL-9 responsiveness in primary cells and cell lines.
RNA Sequencing and Bioinformatics
RNA-seq of cells stimulated with IL-9 can identify transcriptional programs activated by IL-9 binding. Bioinformatics analyses, such as Gene Ontology enrichment and pathway analysis, can reveal downstream targets and regulatory networks. Integration with CRISPR screening data can pinpoint key regulators of IL-9 binding.
How CRISPR Can Be Used to Study GO:0019983 interleukin-9 binding
Knockout
CRISPR knockout of IL9R or IL2RG completely abolishes IL-9 binding and downstream signaling, providing a clean background to study the function of this interaction. Knockout models have been used to demonstrate the role of IL-9 binding in Th9 differentiation and ILC2 function. EDITGENE offers custom IL9R knockout cell lines and mice to accelerate research.
Point Mutation
Point mutations in IL9R or IL2RG can be introduced to dissect binding interfaces and signaling motifs. For example, mutating specific tyrosine residues in IL-9Rα can prevent STAT docking without affecting IL-9 binding, allowing separation of binding from signaling. Such models are valuable for understanding structure-function relationships.
Knock-in
Knock-in of tagged IL-9Rα (e.g., HA or GFP) enables visualization and purification of the receptor complex. Knock-in of reporter genes under the IL9 promoter allows tracking of IL-9-producing cells. These models facilitate studies of IL-9 binding dynamics in vivo.
Overexpression
Overexpression of IL-9 or IL-9Rα can enhance IL-9 binding and signaling, mimicking pathological conditions. For instance, overexpression of IL-9 in CAR-Th9 cells boosts antitumor efficacy. Overexpression models are useful for gain-of-function studies and drug screening.
How EDITGENE Supports interleukin-9 binding Research
Researchers studying interleukin-9 binding-related genes often need to determine whether a candidate gene is causally involved in IL-9 signaling, immune cell function, or disease pathogenesis. EDITGENE provides comprehensive CRISPR-based services to generate precisely engineered cell models and animal models, enabling rigorous functional validation of genes associated with GO:0019983.
Contact EDITGENE today to design your custom CRISPR model for interleukin-9 binding research.
Frequently Asked Questions About interleukin-9 binding
What is interleukin-9 binding?
Interleukin-9 binding (GO:0019983) is a molecular function defined as the binding to interleukin-9 (IL-9), a cytokine involved in immune regulation.
What genes are involved in interleukin-9 binding?
Key genes include IL9 (encoding IL-9), IL9R (IL-9 receptor alpha chain), and IL2RG (common gamma chain), as well as downstream JAK and STAT genes.
What is the GO ID for interleukin-9 binding?
The Gene Ontology ID for interleukin-9 binding is GO:0019983.
How does interleukin-9 binding activate signaling?
IL-9 binding to IL-9Rα induces heterodimerization with γc, activating JAK1/JAK3 and STAT transcription factors.
Which cells express the interleukin-9 receptor?
IL-9R is expressed on Th9 cells, ILC2s, mast cells, and some CAR-T cells, among others.
What diseases are associated with interleukin-9 binding?
Dysregulated IL-9 binding is linked to rheumatoid arthritis, Crohn's disease, allergic asthma, and cancer.
How can I study interleukin-9 binding in the lab?
Common methods include CRISPR knockout, surface plasmon resonance, flow cytometry, and phospho-STAT analysis.
What is the role of IL-9 binding in asthma?
IL-9 binding to ILC2s helps maintain their identity and promotes type 2 inflammation in allergic asthma.
Can interleukin-9 binding be targeted for therapy?
Yes, blocking IL-9 binding is a potential strategy for treating autoimmune diseases, while enhancing it may boost antitumor immunity.
What CRISPR models are available for interleukin-9 binding research?
EDITGENE offers knockout, point mutation, knock-in, and overexpression models for genes involved in IL-9 binding.
Conclusion
Interleukin-9 binding (GO:0019983) is a fundamental molecular function that initiates IL-9 signaling, influencing Th9 differentiation, ILC2 function, and immune responses in health and disease. Its dysregulation contributes to autoimmune diseases and allergic asthma, while its enhancement can improve cancer immunotherapy. Understanding the molecular details of IL-9 binding provides opportunities for therapeutic intervention. EDITGENE's comprehensive CRISPR services enable researchers to dissect the genetic and molecular mechanisms of IL-9 binding with precision.
References
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- 2. Klose CSN et al.. 2017. The neuropeptide neuromedin U stimulates innate lymphoid cells and type 2 inflammation.. Nature 549(7671):282-286 PMID: 28869965
- 3. He S et al.. 2023. Characterization of chicken interleukin-9 receptor alpha chain.. Poult Sci 102(10):102965 PMID: 37562135
- 4. Cai T et al.. 2023. Structural basis of γ chain family receptor sharing at the membrane level.. Science 381(6657):569-576 PMID: 37535730
- 5. Lin H et al.. 2015. Expression and regulation of interleukin-9 in chronic rhinosinusitis.. Am J Rhinol Allergy 29(1):e18-23 PMID: 25590309
- 6. Xiao S et al.. 2025. Loss of YTHDF2 enhances Th9 programming and CAR-Th9 cell antitumor efficacy.. Nat Immunol 26(9):1501-1515 PMID: 40826275
- 7. Menghini P et al.. 2025. Tumor Necrosis Factor-Like Ligand 1A/Death Receptor 3 Signaling Regulates the Generation of Pathogenic T Helper 9 Cells in Experimental Crohn's Disease.. Gastroenterology 169(5):892-908 PMID: 40204100
- 8. Zheng Y et al.. 2026. IL-9 and Blimp-1 protect the transcriptional identity of group 2 innate lymphocytes in allergic asthma.. Nat Immunol 27(6):1197-1211 PMID: 42032301
