GO:0042011 interleukin-16 binding: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0042011 (interleukin-16 binding) is a molecular_function term defined as binding to interleukin-16 (IL-16).
• IL-16 is a PDZ domain-containing cytokine whose structure resembles a PDZ domain with an occluded peptide-binding site.
• The best-characterized IL-16 receptor interaction is with CD4; a specific CD4 domain is required for IL-16 binding and lymphocyte activation.
• IL-16 binding is implicated in T cell activation, plasma cell differentiation, inflammatory pain, atherosclerosis, cancer, and autoimmunity.
• The HTLV-1 Tax oncoprotein binds the IL-16 precursor, linking IL-16 biology to viral oncogenesis.
• IL-16 promoter induction in T lymphocytes is controlled by GA-binding protein factors with the coactivator CREB binding protein/p300.
Description
GO:0042011, interleukin-16 binding, is a Gene Ontology molecular_function term describing the selective interaction of a protein or other molecule with the cytokine interleukin-16 (IL-16). IL-16 is a pleiotropic cytokine that was originally identified as a lymphocyte chemoattractant factor and is now recognized as a key mediator of T cell activation, inflammation, and immune regulation. The structural basis of IL-16 binding has been illuminated by the observation that the IL-16 structure resembles a PDZ domain with an occluded peptide-binding site, suggesting a regulated mode of target recognition. At the receptor level, a specific CD4 domain is required for IL-16 binding and lymphocyte activation, establishing CD4 as a principal binding partner for IL-16 on T cells. Beyond CD4, the HTLV-1 Tax oncoprotein binds the precursor of IL-16, a T cell PDZ domain-containing protein, indicating that IL-16 binding interfaces extend to viral oncoproteins. Because IL-16 binding governs downstream signaling in immune and non-immune cells, researchers study this term to understand cytokine-receptor specificity, inflammatory disease mechanisms, and therapeutic targeting opportunities. Recent work shows that IL-16 promotes plasma cell differentiation, mediates inflammatory pain via glial activation, and can be cleared by a sweeping antibody for cancer and autoimmunity applications. In atherosclerosis, IL-16 upregulates tissue inhibitor of metalloproteinase 3 to promote plaque stability, further broadening the physiological reach of IL-16 binding. This article synthesizes the authoritative GO definition and verified PubMed literature to provide a research-grade overview of GO:0042011 for experimental design and therapeutic hypothesis generation.
interleukin-16 binding At A Glance
| GO ID | GO:0042011 |
|---|---|
| GO term | interleukin-16 binding |
| Ontology | molecular_function |
| Synonym | IL-16 binding |
| Definition | Binding to interleukin-16. |
| Major function | Mediates recognition of the cytokine IL-16 by receptors and other binding partners, initiating downstream immune and inflammatory signaling. |
| Key binding partner | CD4, via a specific domain required for IL-16 binding and lymphocyte activation. |
| Structural feature | IL-16 resembles a PDZ domain with an occluded peptide-binding site. |
| Viral interaction | HTLV-1 Tax oncoprotein binds the precursor of IL-16, a T cell PDZ domain-containing protein. |
| Regulatory context | IL-16 promoter induction in T lymphocytes is controlled by GA-binding protein factors with CREB binding protein/p300. |
What Is GO:0042011?
In the Gene Ontology, GO:0042011 (interleukin-16 binding) is defined as the molecular function of binding to interleukin-16. This term captures the physical interaction between a binding partner and IL-16, whether the partner is a cell-surface receptor such as CD4, a viral protein such as HTLV-1 Tax, or another intracellular or extracellular molecule. The term is classified under molecular_function and carries the synonym IL-16 binding. It does not describe downstream signaling events per se, but rather the recognition step that initiates IL-16-dependent cellular responses.
Why Is interleukin-16 binding Important in Cell Biology?
GO:0042011 is important because IL-16 binding is the first committed step in IL-16-mediated immune activation and inflammation, and dysregulation of this interaction contributes to cancer, autoimmunity, neuroinflammation, and atherosclerosis. Understanding the molecular rules of IL-16 binding enables rational design of blocking antibodies, decoy receptors, and small-molecule inhibitors, as exemplified by a sweeping antibody that efficiently clears IL-16 in cancer and autoimmunity contexts. Moreover, the CD4-dependent nature of IL-16 binding links this term directly to T cell biology and HIV-related research, since CD4 is the primary receptor for both IL-16 and HIV. The PDZ-like architecture of IL-16 further suggests that binding specificity can be modulated by occluded peptide-binding sites, offering a structural handle for therapeutic intervention.
• IL-16 binding to CD4 is required for lymphocyte activation, making GO:0042011 central to T cell immunology.
• IL-16 promotes plasma cell differentiation, linking IL-16 binding to humoral immunity and vaccine responses.
• Spinal IL-16 mediates inflammatory pain via glial activation, implicating IL-16 binding in neuroimmune pain pathways.
• IL-16 upregulates TIMP3 to promote atherosclerotic plaque stability, connecting IL-16 binding to cardiovascular protection.
• A sweeping antibody that clears IL-16 shows therapeutic potential in cancer and autoimmunity, validating IL-16 binding as a drug target.
• The HTLV-1 Tax oncoprotein binds the IL-16 precursor, linking IL-16 binding to viral oncogenesis.
• IL-16 promoter induction by GA-binding protein factors and CBP/p300 provides a transcriptional layer of regulation for IL-16 availability.
• The PDZ-like structure of IL-16 with an occluded peptide-binding site informs structure-based design of binding modulators.
• GO:0042011 supports research into cytokine-receptor specificity and off-target effects in immunotherapy.
• IL-16 binding is a tractable node for CRISPR knockout, knock-in, and overexpression studies of immune and inflammatory disease models.
Molecular Mechanism of interleukin-16 binding
CD4 recognition and lymphocyte activation
In simple terms: IL-16 grabs onto a specific part of the CD4 receptor to switch on immune cells.
A specific CD4 domain is required for interleukin-16 binding and lymphocyte activation, establishing CD4 as a principal receptor for IL-16 on T cells. This interaction initiates intracellular signaling that leads to lymphocyte activation, making the CD4-IL-16 binding event a critical checkpoint in adaptive immunity.
PDZ-like structural basis of IL-16 binding
In simple terms: IL-16 is shaped like a PDZ domain, but its peptide-binding pocket is blocked, so it binds partners in a regulated way.
The structure of interleukin 16 resembles a PDZ domain with an occluded peptide binding site, which suggests that IL-16 binding to partners is conformationally controlled rather than constitutively open. This structural feature distinguishes IL-16 from canonical PDZ proteins and provides a basis for selective binding modulation.
Viral oncoprotein interaction with the IL-16 precursor
In simple terms: A viral cancer protein from HTLV-1 can bind the precursor form of IL-16.
Binding of HTLV-1 tax oncoprotein to the precursor of interleukin-16, a T cell PDZ domain-containing protein, demonstrates that IL-16 binding interfaces are targeted by viral oncoproteins. This interaction may alter IL-16 processing or function during HTLV-1 infection and leukemogenesis.
Transcriptional regulation of IL-16 availability
In simple terms: Before IL-16 can bind, the cell must produce it, and that production is switched on by specific transcription factors.
GA-binding protein factors, in concert with the coactivator CREB binding protein/p300, control the induction of the interleukin 16 promoter in T lymphocytes. This transcriptional control determines how much IL-16 is available for binding and thus modulates the effective activity of GO:0042011.
Downstream functional consequences of IL-16 binding
In simple terms: Once IL-16 binds its partner, it can change how immune cells behave in disease.
IL-16 binding triggers functional outcomes including plasma cell differentiation, inflammatory pain via glial activation, and atherosclerotic plaque stabilization through TIMP3 upregulation. These diverse effects underscore that GO:0042011 is not merely a binding event but a gateway to context-dependent physiology and pathology.
Key Genes Involved in GO:0042011 interleukin-16 binding
The following genes and proteins are directly implicated in interleukin-16 binding (GO:0042011) or its functional consequences according to verified literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| IL16 | Encodes the cytokine interleukin-16, the ligand for GO:0042011 | Central to all IL-16 binding studies; target for knockout and overexpression |
| CD4 | Cell-surface receptor containing a domain required for IL-16 binding and lymphocyte activation | Key binding partner; CD4 mutants define IL-16 binding specificity |
| TIMP3 | Tissue inhibitor of metalloproteinase 3, upregulated by IL-16 to promote plaque stability | Effector of IL-16 binding in atherosclerosis |
| GABP | GA-binding protein factors controlling IL-16 promoter induction | Transcriptional regulator of IL-16 availability |
| CREBBP | CREB binding protein/p300 coactivator for IL-16 promoter induction | Epigenetic/transcriptional coactivator in T lymphocytes |
| EP300 | p300 coactivator partnering with GABP for IL-16 promoter induction | Transcriptional coactivator in T lymphocytes |
| TAX | HTLV-1 Tax oncoprotein that binds the IL-16 precursor | Viral oncoprotein linking IL-16 binding to HTLV-1 biology |
| IL16 precursor | PDZ domain-containing precursor protein that binds HTLV-1 Tax | Target for viral-host interaction studies |
| Plasma cell markers | Differentiation markers downstream of IL-16 binding | Readout for IL-16-driven plasma cell differentiation |
| Glial activation markers | Indicators of spinal IL-16-mediated glial activation | Readout for inflammatory pain models |
| Sweeping antibody target | IL-16 epitope cleared by a novel sweeping antibody | Therapeutic validation in cancer and autoimmunity |
| Atherosclerotic plaque markers | TIMP3 and plaque stability readouts | Cardiovascular model for IL-16 binding |
| T cell activation markers | CD25, CD69 and related activation markers | Functional readout of CD4-dependent IL-16 binding |
| PDZ domain proteins | Structural family resembling IL-16 fold | Comparative structural studies of binding |
| NF-kB pathway components | Downstream inflammatory signaling after IL-16 binding | Mechanistic studies of IL-16 signaling |
| Cytokine receptors | Potential additional IL-16 binding partners | Screening for novel IL-16 receptors |
How Is interleukin-16 binding Regulated?
IL-16 binding is regulated at multiple levels. Transcriptionally, GA-binding protein factors in concert with the coactivator CREB binding protein/p300 control induction of the interleukin 16 promoter in T lymphocytes, thereby determining ligand availability. Structurally, the PDZ-like fold of IL-16 with an occluded peptide-binding site suggests that binding is conformationally gated, providing a potential switch for regulated partner engagement. At the receptor level, the requirement for a specific CD4 domain indicates that CD4 expression and post-translational modifications can modulate IL-16 binding and subsequent lymphocyte activation. Additionally, viral proteins such as HTLV-1 Tax can bind the IL-16 precursor, potentially competing with or altering normal binding interactions. Finally, therapeutic clearance of IL-16 by a sweeping antibody demonstrates that extracellular IL-16 levels can be experimentally regulated to control binding availability.
interleukin-16 binding and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| IL16 | Cancer and autoimmunity | IL16 knockout and overexpression cell lines; sweeping antibody treatment |
| IL16 | Inflammatory pain | Spinal IL-16 knockdown or knockout in rodent pain models |
| IL16 | Atherosclerosis | IL16 knockout in ApoE-deficient mice; TIMP3 readout |
| IL16 | Plasma cell differentiation | IL16 knockout B cell cultures; plasma cell marker analysis |
| CD4 | T cell activation and HIV-related biology | CD4 domain mutants and knock-in cell lines |
IL-16 binding in cancer and autoimmunity
A novel sweeping antibody exhibits efficient clearance of the cancer- and autoimmunity-associated cytokine interleukin 16, demonstrating that IL-16 binding is a validated therapeutic axis in oncology and autoimmune disease. By removing IL-16 from circulation, such antibodies prevent IL-16 from engaging its binding partners, thereby dampening downstream pathogenic signaling.
IL-16 binding in inflammatory pain
Spinal interleukin-16 mediates inflammatory pain via promoting glial activation, implicating IL-16 binding in neuroimmune pain processing. Blocking IL-16 binding in the spinal cord may therefore represent a strategy for analgesic intervention.
IL-16 binding in atherosclerosis
Interleukin-16 upregulates tissue inhibitor of metalloproteinase 3 to promote atherosclerotic plaque stability, linking IL-16 binding to cardiovascular protection. This suggests that enhancing IL-16 binding in the vessel wall could stabilize plaques and reduce cardiovascular events.
IL-16 binding in plasma cell differentiation
IL-16 promotes plasma cell differentiation, connecting IL-16 binding to humoral immunity and antibody production. Dysregulated IL-16 binding may therefore contribute to autoimmune antibody responses.
From interleukin-16 binding-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of IL16 abolish IL-16 binding-dependent lymphocyte activation? | IL16 knockout T cell lines or primary T cells |
| Which CD4 domain residues are required for IL-16 binding? | CD4 point-mutation knock-in cell lines |
| Can IL-16 binding be blocked therapeutically in autoimmunity? | IL16 overexpression models treated with sweeping antibody |
| Does IL-16 binding promote plasma cell differentiation? | IL16 knockout and overexpression B cell models |
| Does spinal IL-16 binding drive glial activation and pain? | IL16 knockdown in spinal cord pain models |
| Does IL-16 binding stabilize atherosclerotic plaques via TIMP3? | IL16 knockout in atherosclerosis mouse models |
How to Study the interleukin-16 binding Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Surface plasmon resonance | Real-time binding affinity and kinetics | IL-16 binding to CD4 and other partners |
| Co-immunoprecipitation | Physical interaction in cell lysates | Detecting IL-16 binding complexes |
| X-ray crystallography | Three-dimensional structure of IL-16 and complexes | PDZ-like fold and occluded binding site analysis |
| Lymphocyte activation assay | T cell activation markers after IL-16 binding | CD4-dependent functional validation |
| Plasma cell differentiation assay | Plasma cell marker expression | IL-16-driven B cell differentiation |
| Glial activation assay | Glial marker upregulation in spinal cord | Inflammatory pain models |
| TIMP3 expression assay | TIMP3 protein or mRNA levels | Atherosclerotic plaque stability studies |
| Promoter reporter assay | IL-16 promoter activity | GABP and CBP/p300 regulation |
Binding assays for IL-16 interactions
Surface plasmon resonance, isothermal titration calorimetry, and co-immunoprecipitation can measure direct IL-16 binding to CD4 and other partners. These methods quantify affinity, kinetics, and stoichiometry, which are essential for characterizing GO:0042011.
Structural biology of IL-16 binding
X-ray crystallography and cryo-EM can resolve the PDZ-like fold of IL-16 and its occluded peptide-binding site, revealing how binding partners are recognized. Structural data guide mutagenesis of CD4 domains required for IL-16 binding.
Functional readouts of IL-16 binding
Lymphocyte activation assays, plasma cell differentiation markers, glial activation markers, and TIMP3 expression are functional readouts of IL-16 binding in immune, neuroimmune, and cardiovascular contexts. These readouts connect molecular binding to physiology.
Transcriptional and promoter analysis
Promoter reporter assays and chromatin immunoprecipitation can assess GA-binding protein and CBP/p300 control of IL-16 promoter induction, which determines ligand availability for binding. These methods link transcriptional regulation to GO:0042011 activity.
How CRISPR Can Be Used to Study GO:0042011 interleukin-16 binding
Knockout
CRISPR knockout of IL16 or CD4 can abolish IL-16 binding and downstream lymphocyte activation, providing causal evidence for GO:0042011 in immune responses. Knockout models are also useful to test whether IL-16 binding is required for plasma cell differentiation and inflammatory pain.
Point Mutation
Point mutations in the CD4 domain required for IL-16 binding can dissect the precise residues that mediate recognition and lymphocyte activation. Such mutants help distinguish binding-dependent from binding-independent functions of CD4.
Knock-in
Knock-in of tagged or mutant IL16 alleles enables tracking of IL-16 binding partners and localization in vivo. Tagged knock-in models can also reveal how the PDZ-like fold engages targets.
Overexpression
Overexpression of IL16 or its binding partners can amplify IL-16 binding signals to study downstream effects such as TIMP3 upregulation and plaque stability. Overexpression models are also valuable for testing sweeping antibodies that clear IL-16.
How EDITGENE Supports interleukin-16 binding Research
Researchers studying interleukin-16 binding-related genes often need to determine whether a candidate gene is causally involved in IL-16 recognition, signaling, or disease progression. EDITGENE provides end-to-end CRISPR services to generate precisely engineered cell models that answer these questions with publication-grade rigor.
Contact EDITGENE today to design your custom CRISPR model for interleukin-16 binding research.
Frequently Asked Questions About interleukin-16 binding
What is GO:0042011?
GO:0042011 is the Gene Ontology molecular_function term for interleukin-16 binding, defined as binding to interleukin-16.
What is interleukin-16 binding?
Interleukin-16 binding is the physical interaction between the cytokine IL-16 and a binding partner such as CD4, initiating downstream immune signaling.
What genes are involved in interleukin-16 binding?
Key genes include IL16, CD4, TIMP3, GABP, CREBBP, EP300, and the HTLV-1 Tax gene.
Which receptor binds interleukin-16?
A specific CD4 domain is required for interleukin-16 binding and lymphocyte activation, making CD4 a principal receptor.
What is the structure of interleukin-16?
Interleukin-16 resembles a PDZ domain with an occluded peptide binding site.
How is interleukin-16 binding regulated?
IL-16 promoter induction is controlled by GA-binding protein factors with CREB binding protein/p300, and binding may be conformationally gated by the PDZ-like fold.
What diseases are linked to interleukin-16 binding?
IL-16 binding is linked to cancer, autoimmunity, inflammatory pain, atherosclerosis, and plasma cell differentiation.
Can interleukin-16 be targeted therapeutically?
Yes, a novel sweeping antibody efficiently clears IL-16 in cancer and autoimmunity models.
How do I study interleukin-16 binding in the lab?
Use binding assays such as surface plasmon resonance, co-immunoprecipitation, structural biology, and functional readouts like lymphocyte activation and TIMP3 expression.
What CRISPR models are available for IL-16 binding research?
Knockout, point-mutation, knock-in, and overexpression models can be generated for IL16, CD4, and related pathway genes.
Conclusion
GO:0042011 (interleukin-16 binding) is a molecular_function term that captures the essential recognition step between IL-16 and its partners, most notably CD4. The PDZ-like structure of IL-16 with an occluded peptide-binding site provides a structural framework for understanding binding specificity and regulation. Functionally, IL-16 binding drives lymphocyte activation, plasma cell differentiation, inflammatory pain, and atherosclerotic plaque stability, while also being targeted by viral oncoproteins and therapeutic antibodies. Continued research using CRISPR knockout, point-mutation, knock-in, and overexpression models will clarify how IL-16 binding can be modulated for therapeutic benefit in cancer, autoimmunity, and cardiovascular disease.
References
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- 2. Zhu X et al.. 2024. Spinal interleukin-16 mediates inflammatory pain via promoting glial activation.. Int Immunopharmacol 127:111411 PMID: 38113689
- 3. Baker JM et al.. 2025. A novel sweeping antibody exhibits efficient clearance of the cancer- and autoimmunity-associated cytokine interleukin 16.. bioRxiv PMID: 40766633
- 4. He H et al.. 2026. Interleukin-16 upregulates tissue inhibitor of metalloproteinase 3 to promote atherosclerotic plaque stability.. J Transl Med 24(1):232 PMID: 41555435
- 5. Liu Y et al.. 1999. Identification of a CD4 domain required for interleukin-16 binding and lymphocyte activation.. J Biol Chem 274(33):23387-95 PMID: 10438516
- 6. Mühlhahn P et al.. 1998. Structure of interleukin 16 resembles a PDZ domain with an occluded peptide binding site.. Nat Struct Biol 5(8):682-6 PMID: 9699630
- 7. Wilson KC et al.. 2003. Binding of HTLV-1 tax oncoprotein to the precursor of interleukin-16, a T cell PDZ domain-containing protein.. Virology 306(1):60-7 PMID: 12620798
- 8. Bannert N et al.. 1999. GA-binding protein factors, in concert with the coactivator CREB binding protein/p300, control the induction of the interleukin 16 promoter in T lymphocytes.. Proc Natl Acad Sci U S A 96(4):1541-6 PMID: 9990060
