Recombinant Human Interleukin 13 Receptor, Alpha 1 (IL-13 Rα1)

Recombinant Human Interleukin 13 Receptor, Alpha 1 (IL13 Rα1) is a critical tool for research focused on cytokine signaling, immune modulation, and disease mechanisms involving the IL13/IL4 pathway. Its use is particularly relevant in studies of asthma, allergy, fibrosis, and alternative macrophage activation.

Key reasons to use recombinant IL13 Rα1 in research applications:

• Dissecting IL13/IL4 Signaling Pathways: IL13 Rα1 is a core component of the type II IL4 receptor complex, which mediates signaling for both IL13 and IL4. Using recombinant IL13 Rα1 allows you to study ligandreceptor interactions, downstream signaling events (such as JAK/STAT activation), and the specific contributions of this receptor in various cell types, including airway epithelial cells, fibroblasts, smooth muscle, and most leukocytes except T lymphocytes.

• Modeling Disease Mechanisms: IL13 Rα1 is essential for mediating the effects of IL13 in models of asthma, allergy, and fibrosis. Recombinant IL13 Rα1 can be used to:

  • Investigate how IL13 drives airway hyperresponsiveness, mucus production, and tissue remodeling.
  • Study the receptor’s role in alternative macrophage activation (M2 polarization), which is important in tissue repair and fibrosis.
  • Explore the inhibition of classical macrophage activation by IL13, which is relevant for immune regulation and chronic inflammation.

• Screening and Characterizing Therapeutics: Recombinant IL13 Rα1 is valuable for:

  • Screening antibodies or small molecules that block IL13/IL13 Rα1 interactions, which is a therapeutic strategy for asthma, atopic dermatitis, and other inflammatory diseases.
  • Developing and validating ELISA or other binding assays to quantify IL13 or test the efficacy of IL13 antagonists.

• Functional and Structural Studies: Recombinant IL13 Rα1 enables:

  • Biochemical and biophysical analyses (e.g., surface plasmon resonance, crystallography) to characterize binding affinities and receptorligand complex structures.
  • Cellbased assays to assess downstream gene expression, receptor activation, and cellular responses to IL13 or IL4 stimulation.

• Genetic and Variant Analysis: Recombinant forms can be engineered to represent specific genetic variants, allowing the study of how polymorphisms in IL13 Rα1 affect signaling and disease susceptibility.

Summary of Applications:

• Mechanistic studies of cytokine signaling (IL13/IL4 pathways)
• Disease modeling (asthma, allergy, fibrosis)
• Therapeutic screening (antagonists, antibodies)
• Assay development (ELISA, binding assays)
• Structural and biophysical characterization
• Functional genomics and variant analysis

Using recombinant IL13 Rα1 provides a controlled, reproducible system to dissect the molecular and cellular roles of this receptor in health and disease, supporting both basic research and translational applications.

Recombinant Human Interleukin 13 Receptor, Alpha 1 (IL13 Rα1) can be used as a standard for quantification or calibration in ELISA assays, but only for assays specifically designed to measure IL13 Rα1, not for IL13 itself.

Key context and details:

• ELISA standards must match the analyte: In ELISA, the standard used for calibration must be the same molecule as the analyte being measured. If your assay is designed to quantify IL13 Rα1 (the receptor), then recombinant IL13 Rα1 is appropriate as a standard. If your assay is for IL13 (the cytokine/ligand), you must use recombinant IL13 as the standard.

• Assay specificity: Commercial ELISA kits for IL13 Rα1 use recombinant IL13 Rα1 as the standard to generate the calibration curve. These kits are validated to detect both natural and recombinant forms of IL13 Rα1, ensuring accurate quantification of the receptor in biological samples.

• Not interchangeable with IL13 standards: Recombinant IL13 Rα1 cannot be used as a standard in ELISAs designed to detect IL13, as the antibodies in those assays are specific for IL13, not its receptor. Similarly, recombinant IL13 cannot be used as a standard in IL13 Rα1 assays.

• Validation and calibration: For accurate quantification, the recombinant IL13 Rα1 standard should be wellcharacterized and ideally calibrated against an international reference standard if available. The standard curve should cover the expected concentration range of IL13 Rα1 in your samples.

Summary Table:

Best practices:

• Always use a standard that matches the analyte your ELISA is designed to detect.
• Confirm that your recombinant IL13 Rα1 is of high purity and properly quantified.
• Validate the standard curve in your specific assay matrix for accuracy and reproducibility.

If you are quantifying IL13 Rα1, you can use recombinant IL13 Rα1 as your standard. If you are quantifying IL13, you must use recombinant IL13 as your standard. Mixing these will result in inaccurate and nonspecific results.

Recombinant Human Interleukin 13 Receptor, Alpha 1 (IL13Rα1) has been validated in published research for several key applications, primarily in the study of immune cell differentiation, signaling, disease models, and as a potential therapeutic target or biomarker.

Validated Applications in Published Research:

• Surface Marker for Macrophage Subsets:
  IL13Rα1 is used as a surface marker to distinguish M2 macrophages from M1 macrophages. Its expression is associated with M2 polarization, and it is functionally relevant for STAT6 signaling and phagocytic activity assays in both in vitro and in vivo models.

• Functional Signaling Studies:
  Recombinant IL13Rα1 is used to reconstitute or block IL13/IL4 signaling pathways in cellbased assays, particularly to study the activation of the JAK/STAT6 pathway and the induction of alternatively activated (M2) macrophages. It is also used to dissect the requirements for receptor subunits in cytokine signaling using knockout or overexpression systems.

• Gene Expression and Pathway Analysis:
  IL13Rα1 is employed in gene expression studies to assess the induction of IL4/IL13responsive genes and to analyze downstream effects on immune modulation, such as inhibition of IFNγinduced classical macrophage activation.

• Disease Model Research:
  The receptor is validated in animal models of fibrosis, heart disease, and lung injury to study its role in tissue remodeling, repair, and inflammation. For example, IL13Rα1 has been shown to regulate myocardial homeostasis and is implicated in the pathogenesis of heart failure and pulmonary fibrosis.

• Cancer Research and Biomarker Studies:
  IL13Rα1 expression is analyzed in hematological malignancies (e.g., Hodgkin lymphoma) as a potential biomarker for disease aggressiveness and therapeutic response. It is also being explored as a therapeutic target in diffuse intrinsic pontine glioma (DIPG) and other cancers.

• Metabolic and Adipogenesis Studies:
  IL13Rα1 signaling has been validated in preadipocyte models to study its role in beige adipogenesis and metabolic programming.

Experimental Techniques Where Recombinant IL13Rα1 Is Used:

• Flow cytometry and immunophenotyping (as a cell surface marker)
• Functional cell signaling assays (e.g., STAT6 phosphorylation)
• Gene expression analysis (qPCR, RNAseq)
• In vitro and in vivo phagocytosis assays
• Animal models of disease (fibrosis, heart failure, lung injury)
• Immunohistochemistry and tissue staining (biomarker studies)

Summary Table: Key Validated Applications

These applications are supported by peerreviewed studies using recombinant IL13Rα1 in both basic and translational research contexts.

To reconstitute and prepare Recombinant Human Interleukin 13 Receptor, Alpha 1 (IL13 Rα1) protein for cell culture experiments, dissolve the lyophilized protein in 10 mM PBS (pH 7.4) to achieve a final concentration between 0.1–1.0 mg/mL. This buffer is compatible with most cell culture applications and maintains protein stability.

Stepbystep protocol:

• Centrifuge the vial briefly before opening to ensure all lyophilized material is at the bottom.
• Add sterile 10 mM PBS (pH 7.4) to the vial. For example, to prepare 1 mg/mL, add 100 μL PBS to 100 μg protein; for 0.1 mg/mL, add 1 mL PBS to 100 μg protein.
• Gently mix by pipetting up and down or by slow vortexing. Avoid vigorous agitation to prevent protein denaturation.
• Allow the protein to dissolve completely at room temperature for 10–30 minutes. Inspect visually to confirm full dissolution.
• Aliquot the solution to avoid repeated freezethaw cycles, which can degrade the protein.
• Store aliquots at −20°C or −80°C for longterm storage. For shortterm use (up to 1 month), store at 4°C.

Additional considerations:

• If your application is sensitive to endotoxin, confirm the endotoxin level is suitable for cell culture (typically <1 EU/μg).
• For functional assays, you may further dilute the reconstituted stock in cell culture medium or assay buffer as needed.
• Avoid buffers containing carrier proteins (e.g., BSA or serum) unless specifically required for your assay, as these can interfere with downstream applications.
• Always consult the productspecific Certificate of Analysis (CoA) for any manufacturerrecommended variations in reconstitution protocol.

Summary Table:

This protocol ensures optimal solubility and stability of IL13 Rα1 for cell culture experiments.