Recombinant Human IL-1 RI

Recombinant Human IL-1 RI (Interleukin-1 Receptor Type I) is used in research applications primarily as a tool to study and modulate IL-1-mediated signaling, inflammation, and immune responses. It acts as a decoy or antagonist for IL-1, allowing researchers to dissect the role of IL-1 in various biological and pathological processes.

Key scientific applications and rationale include:

• Blocking IL-1 Activity: Recombinant IL-1 RI can bind IL-1α and IL-1β, preventing them from interacting with cell-surface receptors and thus inhibiting downstream pro-inflammatory signaling. This is crucial for studying the specific contributions of IL-1 in inflammation, autoimmunity, and tissue injury.

• Anti-inflammatory Research: By antagonizing IL-1, recombinant IL-1 RI is used to model and investigate anti-inflammatory strategies in diseases such as rheumatoid arthritis, sepsis, and other inflammatory conditions. For example, soluble recombinant IL-1 receptors have been shown to suppress synovitis and joint destruction in animal models of arthritis.

• Biomarker and Mechanistic Studies: Using recombinant IL-1 RI in assays (such as ELISA, Western blot, and bioassays) helps quantify IL-1 activity, receptor occupancy, and downstream effects, supporting mechanistic studies of cytokine signaling.

• Therapeutic Target Validation: Recombinant IL-1 RI is used in preclinical models to validate IL-1 as a therapeutic target, helping to assess the efficacy of IL-1 blockade in reducing disease severity or progression.

• Assay Development: It serves as a standard or competitor in binding assays, surface plasmon resonance, and antibody absorption protocols, enabling quantitative and qualitative analysis of IL-1 interactions.

Summary of typical research applications:

• In vitro and in vivo studies of inflammation and immune modulation
• ELISA and Western blot as a standard or competitor
• Surface plasmon resonance for binding kinetics
• Antibody absorption and neutralization assays
• Mechanistic studies of cytokine signaling pathways

In summary, recombinant human IL-1 RI is a versatile reagent for dissecting IL-1 biology, validating therapeutic strategies, and developing assays to measure IL-1 activity and inhibition in diverse research contexts.

Recombinant Human IL-1 RI can be used as a standard for quantification or calibration in ELISA assays, provided it is appropriately validated for your specific assay system. Several commercial ELISA kits and protocols use recombinant IL-1 RI as a standard to generate calibration curves for quantifying IL-1 RI in biological samples.

Key considerations and supporting details:

• Assay Compatibility: The recombinant IL-1 RI standard must be recognized by the capture and detection antibodies used in your ELISA. Most validated ELISA kits for IL-1 RI include a recombinant human IL-1 RI standard, and the assay is optimized to detect both recombinant and natural forms in parallel.
• Standard Preparation: The standard is typically supplied lyophilized and should be reconstituted and serially diluted according to the kit or protocol instructions to generate a standard curve within the assay’s dynamic range (e.g., 125–8000 pg/mL).
• Quantification Accuracy: Using a recombinant standard allows for accurate quantification of IL-1 RI in unknown samples, as long as the recombinant protein’s structure and epitopes are similar to the native protein in your samples. Parallelism between the standard curve and sample dilution curves should be confirmed to ensure accurate quantification.
• Validation: If you are developing a custom ELISA, you must validate that your recombinant IL-1 RI standard produces a standard curve that is parallel to the response of endogenous IL-1 RI in your sample matrix. This ensures that matrix effects or differences in glycosylation do not affect quantification.

Best Practices:

• Use recombinant IL-1 RI from a reliable source, ideally with a certificate of analysis confirming purity and identity.
• Always run a standard curve in each assay to account for day-to-day and plate-to-plate variability.
• Confirm that your antibodies do not discriminate between recombinant and native IL-1 RI, especially if your recombinant protein is produced in a different expression system than the native protein in your samples.

Summary Table: Use of Recombinant Human IL-1 RI as ELISA Standard

In summary: Recombinant Human IL-1 RI is suitable as a standard for ELISA quantification if validated for your assay, and this is a common practice in both commercial kits and custom assay development.

Recombinant Human IL-1 RI has been validated for several key applications in published research, including surface plasmon resonance, bioassays, ELISA (as a standard), antibody absorption, Western blot, and in vivo studies.

Validated Applications:

• Surface Plasmon Resonance (SPR): Used to study molecular interactions, such as ligand-receptor binding and antibody affinity.
• Bioassay: Employed to assess biological activity, including modulation of immune cell responsiveness and cytokine signaling.
• ELISA (Standard): Utilized as a standard protein for quantifying IL-1 or its receptor in immunoassays.
• Antibody Absorption: Applied to confirm antibody specificity by absorbing recombinant protein prior to immunodetection.
• Western Blot: Used for protein detection and quantification in cell or tissue lysates.
• In Vivo Studies: Investigated for its role in disease models, such as inflammation and autoimmune conditions.

Additional Context:

• Cellular and Tissue Localization: Recombinant IL-1 RI has been used in immunolocalization studies to map receptor distribution in tissues, such as skeletal muscle in inflammatory myopathies.
• Functional Mechanistic Studies: It has been applied to dissect IL-1 signaling pathways, receptor-ligand interactions, and the effects of receptor antagonists in various disease models.
• Therapeutic Research: Recombinant IL-1 RI has been explored in preclinical and clinical studies for its potential to modulate inflammatory responses, particularly in rheumatoid arthritis and other autoimmune diseases.

These applications demonstrate the versatility of recombinant human IL-1 RI in both basic and translational immunology research.

To reconstitute and prepare Recombinant Human IL-1 RI protein for cell culture experiments, dissolve the lyophilized protein at a concentration of 100 μg/mL in sterile PBS containing at least 0.1% human or bovine serum albumin (BSA). This carrier protein helps stabilize the recombinant protein and prevents adsorption to surfaces.

Step-by-step protocol:

• Equilibrate the vial and reconstitution buffer to room temperature before starting.
• Briefly centrifuge the vial to collect all lyophilized material at the bottom.
• Add sterile PBS with ≥0.1% BSA to achieve the desired concentration (e.g., 100 μg/mL).
• Gently mix by swirling or inverting; avoid vigorous shaking or vortexing to prevent denaturation and foaming.
• Allow the protein to dissolve for 15–30 minutes at room temperature with gentle agitation.
• Aliquot the reconstituted protein into suitable volumes to avoid repeated freeze-thaw cycles.
• Storage: After reconstitution, store aliquots at 2–8 °C for up to 1 month, or at –20 °C to –70 °C for up to 3 months under sterile conditions.

Additional notes for cell culture:

• For further dilution, use PBS or cell culture medium containing carrier protein (≥0.1% BSA or serum) to maintain stability.
• Always perform a dose-response assay to determine the optimal concentration for your specific cell type and experimental conditions.
• Avoid multiple freeze-thaw cycles, as these can reduce protein activity and stability.
• If particulates are observed, mix gently at room temperature and, if needed, at 4 °C overnight.

Summary of key points:

• Reconstitute at 100 μg/mL in sterile PBS + 0.1% BSA
• Gentle mixing, no vortexing
• Aliquot and store appropriately
• Dilute in carrier-containing buffer for cell culture

This protocol ensures the recombinant IL-1 RI protein remains stable and active for cell culture applications.