Recombinant Human IL-13 Rα2

Recombinant Human IL-13 Rα2 is valuable in research applications primarily because it serves as a key tool for studying cancer biology, immunotherapy, and receptor signaling due to its selective expression and functional roles in tumor progression and immune modulation.

Key scientific applications and rationale:

• Cancer Targeting and Therapy Development:
  IL-13 Rα2 is overexpressed in various cancers (e.g., glioblastoma, colorectal, ovarian, pancreatic), but is rarely found in healthy tissues, making it an attractive target for developing tumor-specific therapies such as CAR T cells, antibody-drug conjugates, and peptide inhibitors. Recombinant IL-13 Rα2 enables in vitro assays to validate binding specificity, cytotoxicity, and therapeutic efficacy of candidate molecules.

• Mechanistic Studies of Tumor Progression:
  Recombinant IL-13 Rα2 allows researchers to dissect its role in tumor proliferation, invasion, metastasis, and immune escape. Recent evidence shows IL-13 can signal through IL-13 Rα2, influencing pathways such as PI3K/AKT, FAK, and Src, which are critical for cancer cell survival and migration. Using recombinant protein, you can study downstream signaling events and identify potential inhibitors.

• Immunomodulation and Decoy Receptor Function:
  IL-13 Rα2 was initially considered a decoy receptor, but it is now known to actively modulate immune responses and fibrosis. Recombinant IL-13 Rα2 can be used to investigate its effects on cytokine signaling, immune cell recruitment, and tumor microenvironment modulation.

• Biomarker and Diagnostic Research:
  The soluble form of IL-13 Rα2 may serve as a surrogate marker for disease monitoring in cancers such as ovarian cancer. Recombinant protein is essential for developing and validating assays (e.g., ELISA) to quantify IL-13 Rα2 in biological samples.

• Drug Screening and Functional Assays:
  Recombinant IL-13 Rα2 is used in binding assays, competition studies, and screening for small molecule or peptide modulators that block or enhance its activity, facilitating the discovery of new therapeutic agents.

Best practices for use:

• Employ recombinant IL-13 Rα2 in cell-based assays to confirm specificity and functional effects of candidate drugs or antibodies.
• Use in biochemical assays to study receptor-ligand interactions and downstream signaling.
• Integrate into animal models to evaluate therapeutic efficacy and safety of IL-13 Rα2-targeted interventions.

In summary, recombinant human IL-13 Rα2 is a critical reagent for advancing research in cancer immunotherapy, receptor biology, and biomarker development due to its selective expression, functional significance in tumor progression, and utility in mechanistic and translational studies.

Recombinant Human IL-13 Rα2 can be used as a standard for quantification or calibration in ELISA assays specifically designed to measure IL-13 Rα2, provided the assay is validated for both natural and recombinant forms.

Most commercial ELISA kits for IL-13 Rα2 are designed to quantify both natural and recombinant human IL-13 Rα2 in biological samples, such as serum, plasma, or cell culture medium. These kits typically use recombinant IL-13 Rα2 as the calibration standard, allowing for accurate quantification of the analyte in unknown samples. The standard curve generated from recombinant protein enables the calculation of sample concentrations by comparison to known amounts of the standard.

Key considerations for use:

• Assay specificity: The ELISA must be validated to recognize both natural and recombinant IL-13 Rα2, ensuring that the recombinant standard is appropriate for calibration.
• Protein purity and integrity: The recombinant IL-13 Rα2 used as a standard should be of high purity (typically >90%) and properly characterized (e.g., by SDS-PAGE, SEC-MALS).
• Standard preparation: Follow the kit or assay protocol for reconstitution, dilution, and storage of the recombinant standard to maintain accuracy and reproducibility.
• Validation: If developing a custom ELISA, validate the assay for linearity, accuracy, precision, and parallelism using the recombinant standard and relevant biological matrices.

Limitations:

• The recombinant standard should match the form of IL-13 Rα2 present in your samples (e.g., glycosylation status, tag presence) to avoid matrix effects or quantification errors.
• Do not use recombinant IL-13 Rα2 as a standard for quantifying IL-13 itself; IL-13 and IL-13 Rα2 are distinct proteins and require their own specific standards.

Summary of best practices:

• Use recombinant human IL-13 Rα2 as a standard only in ELISA assays validated for IL-13 Rα2 quantification.
• Ensure the standard is well-characterized and matches the assay requirements.
• Do not substitute IL-13 Rα2 for IL-13 standards in IL-13 quantification assays.

If you are using a commercial ELISA kit for IL-13 Rα2, consult the kit manual for specific instructions regarding standard preparation and calibration. If developing your own assay, rigorous validation using the recombinant standard is essential for reliable quantification.

Recombinant Human IL-13 Rα2 has been validated for several key applications in published research, primarily in the context of cancer biology and immunotherapy.

Validated Applications:

• Cancer Immunotherapy Research:
  Recombinant IL-13 Rα2 is widely used as a target antigen for the development and validation of chimeric antigen receptor (CAR) T cells, especially for glioblastoma and other solid tumors overexpressing IL-13 Rα2. Studies have used recombinant IL-13 Rα2 to assess CAR T cell specificity, cytotoxicity, cytokine secretion, and proliferation in vitro and in vivo.

• Functional Assays:
  Recombinant IL-13 Rα2 is employed in cell-based assays to study its role as a decoy receptor, its ability to bind and internalize IL-13, and its impact on downstream signaling pathways such as FAK, PI3K/AKT, and Src. These assays include migration, invasion, and proliferation studies in cancer cell lines.

• Binding and Affinity Studies:
  The protein is used in biochemical assays to characterize IL-13 binding affinity and selectivity, often in comparison to IL-13 Rα1. These studies inform the design of engineered IL-13 variants and muteins for improved therapeutic targeting.

• Immunotoxin and Vaccine Development:
  Recombinant IL-13 Rα2 serves as a target for immunotoxin conjugates and peptide-based cancer vaccines. It is used to validate antigen recognition and efficacy in preclinical and clinical models.

• Antibody Validation:
  Recombinant IL-13 Rα2 is used as a positive control in antibody-based applications such as Western blotting, flow cytometry, immunocytochemistry, and immunohistochemistry to confirm specificity and binding.

Supporting Details:

• Preclinical Models:
  Recombinant IL-13 Rα2 has been used to generate engineered cell lines with varying expression levels for in vitro cytotoxicity and cytokine release assays, as well as in patient-derived xenograft mouse models to evaluate therapeutic efficacy.

• Signaling Pathway Analysis:
  Studies have used recombinant IL-13 Rα2 to dissect its signaling capacity, demonstrating its involvement in tumor proliferation and metastasis through specific intracellular pathways.

• Therapeutic Target Validation:
  The protein is central to validating IL-13 Rα2 as a therapeutic target in diffuse intrinsic pontine glioma, angiosarcoma, metastatic colorectal cancer, and other malignancies.

Summary Table of Applications

Note:
Most published research utilizes recombinant IL-13 Rα2 in the context of cancer biology, immunotherapy, and receptor-ligand interaction studies. Applications outside these areas are less commonly reported in the literature.

To reconstitute and prepare Recombinant Human IL-13 Rα2 protein for cell culture experiments, follow these general steps, adapting as needed based on the specific formulation and instructions provided with your protein:

1. Centrifuge the vial before opening to ensure all lyophilized protein is at the bottom.

2. Check the formulation:

   • If the protein is lyophilized from a buffer (e.g., PBS, Tris/glycine, or with trehalose), use the recommended buffer for reconstitution if specified.
   • If no buffer is specified, sterile PBS (pH 7.2–7.4) or sterile distilled water is commonly used.

3. Reconstitution concentration:

   • A typical starting concentration is 100 μg/mL in sterile PBS or as specified in the product datasheet.
   • Do not exceed 1 mg/mL to avoid solubility issues.

4. Reconstitution procedure:

   • Add the appropriate volume of buffer or water gently down the side of the vial.
   • Do not vortex or mix vigorously; gently pipette up and down or swirl to dissolve.
   • Allow the solution to sit at room temperature for several minutes to ensure complete dissolution.

5. Carrier protein (optional but recommended for stability):

   • For long-term storage or to prevent adsorption, add a carrier protein such as 0.1% BSA or 5% trehalose.
   • Aliquot the reconstituted protein to avoid repeated freeze-thaw cycles.

6. Storage:

   • Store aliquots at –20°C to –80°C for long-term use.
   • Avoid repeated freeze-thaw cycles, which can degrade the protein.

7. Sterility:

   • Ensure all solutions and materials are sterile to prevent contamination in cell culture applications.

8. Quality check (optional):

   • Confirm protein integrity by SDS-PAGE if needed.

Example protocol for a lyophilized IL-13 Rα2 protein (from PBS/trehalose):

• Centrifuge vial briefly.
• Add sterile PBS to achieve 100 μg/mL.
• Gently pipette to dissolve; do not vortex.
• Aliquot and store at –80°C.
• Add 0.1% BSA if storing for more than a few days.

Always consult the product’s Certificate of Analysis (CoA) or datasheet for any specific instructions, as formulations and recommended buffers may vary between preparations.

If your protein is supplied in a different buffer (e.g., Tris/glycine or with specific stabilizers), use the buffer recommended by the manufacturer for reconstitution. If in doubt, sterile PBS is generally safe for most cell culture applications unless otherwise specified.