Recombinant Human IL-20

Recombinant Human IL-20 is used in research applications to study its roles in immune regulation, inflammation, tissue homeostasis, and disease pathogenesis, particularly in autoimmune and inflammatory conditions.

IL-20 is a member of the IL-10 cytokine family and is produced by various immune cells and epithelial cells. It signals primarily through the JAK/STAT3 pathway, influencing both innate and adaptive immune responses. Key research applications include:

• Autoimmune and Inflammatory Disease Models: IL-20 is implicated in the pathogenesis of diseases such as psoriasis, rheumatoid arthritis, and inflammatory bowel disease. It can mediate both pro- and anti-inflammatory effects, making it valuable for dissecting mechanisms of chronic inflammation and immune cell regulation.
• Cell Signaling Studies: Recombinant IL-20 is used to activate specific receptor complexes (IL-20Rα/IL-20Rβ or IL-22Rα/IL-20Rβ) in engineered cell lines, enabling the study of downstream signaling events, such as STAT3 activation.
• Tissue Regeneration and Wound Healing: IL-20 promotes keratinocyte proliferation and differentiation, as well as endothelial cell tube formation, suggesting roles in skin biology, vascular remodeling, and tissue repair.
• Hematopoiesis: It induces proliferation of multipotential hematopoietic progenitor cells, supporting research into blood cell development and immune system function.
• Host Defense and Epithelial Crosstalk: IL-20 facilitates communication between immune and epithelial cells, contributing to host defense and tissue homeostasis.

Using recombinant IL-20 allows for controlled, reproducible stimulation of target cells and pathways, enabling mechanistic studies, antibody screening, and therapeutic target validation. Its unique and overlapping functions with other IL-20 subfamily cytokines (IL-19, IL-22, IL-24) make it essential for comparative studies in cytokine biology.

In summary, recombinant human IL-20 is a versatile tool for investigating immune modulation, inflammatory processes, tissue regeneration, and disease mechanisms in both basic and translational research.

Yes, recombinant human IL-20 can be used as a standard for quantification and calibration in ELISA assays. This is actually a primary application for recombinant IL-20 proteins in immunoassay development.

Suitability as ELISA Standard

Recombinant human IL-20 expressed in E. coli has been validated for use as an ELISA standard and has demonstrated accurate quantitation of both recombinant and naturally occurring IL-20. The recombinant protein produces standard curves that are linear and parallel to those obtained with natural human IL-20, confirming its reliability for calibration purposes.

Recommended Formulation

When selecting recombinant IL-20 for use as an ELISA standard, choose the formulation that includes carrier proteins such as bovine serum albumin (BSA). This formulation is specifically recommended for use in cell or tissue culture applications and as ELISA standards, as the carrier protein helps stabilize the recombinant protein and improves its performance in assay conditions.

Important Consideration

It is critical to note that recombinant proteins designated for ELISA standardization should not be used for bioassay applications, as they are not tested for those purposes. Ensure your recombinant IL-20 is specifically validated and intended for use as an ELISA standard rather than for functional bioassays.

Storage Requirements

After reconstitution, store your recombinant IL-20 standard at -20°C or preferably at -80°C. This ensures long-term stability and maintains the integrity of your calibration standard across multiple assay runs.

Recombinant Human IL-20 has been validated in published research primarily for the following applications:

• In vitro bioactivity assays: Recombinant human IL-20 is commonly used to assess its biological activity, such as its ability to bind to the IL-20 receptor beta (IL-20Rβ) in a dose-dependent manner, and to stimulate downstream signaling pathways like STAT3 in responsive cell types.
• Cell culture studies: It is used to study its effects on various cell types, particularly keratinocytes, to investigate its role in skin inflammation and regulation of cell proliferation.
• Mechanistic studies: Recombinant IL-20 is employed to elucidate its signaling mechanisms, especially its involvement in the STAT3 pathway and its impact on inflammatory responses in tissues such as skin and potentially in cancer models.
• Receptor binding assays: The protein is used in binding assays to characterize its interaction with IL-20 receptor complexes, which is essential for understanding its biological specificity and potency.

Key details from published research and product documentation:

• Bioassay validation: Recombinant human IL-20 has been validated for use in bioassays, where its activity is measured by its ability to bind IL-20Rβ and induce cellular responses.
• Keratinocyte proliferation and skin inflammation: Studies have used recombinant IL-20 to demonstrate its regulatory effects on keratinocyte growth during inflammatory conditions, highlighting its relevance in dermatological research.
• STAT3 signaling: Its role in activating STAT3 signaling has been validated, which is a critical pathway in mediating inflammatory and proliferative responses in target cells.
• Cancer research: IL-20 and its receptor have been implicated in tumor biology, such as in colorectal cancer, where IL-20RA expression is associated with disease progression, suggesting use in mechanistic cancer studies.

Notably, while recombinant human IL-20 is widely used for in vitro and mechanistic studies, there is no evidence from the provided results that it has been validated for in vivo therapeutic applications in humans; rather, clinical studies have focused on anti–IL-20 monoclonal antibodies, not the recombinant cytokine itself.

Summary of validated applications:

• In vitro bioactivity and receptor binding assays
• Cell signaling and mechanistic studies (e.g., STAT3 activation)
• Cell culture models of inflammation and proliferation (especially keratinocytes)
• Research on cytokine function in cancer and inflammatory diseases

If you require protocols or more specific experimental details for any of these applications, please specify the context or cell type of interest.

To reconstitute and prepare Recombinant Human IL-20 protein for cell culture experiments, first review the product-specific Certificate of Analysis (CoA) for any unique instructions. The following protocol summarizes best practices based on current scientific standards:

1. Preparation Before Reconstitution

• Briefly centrifuge the vial to ensure all lyophilized powder is at the bottom.
• Allow the vial to equilibrate to room temperature before opening to prevent condensation.

2. Reconstitution

• Add sterile deionized water or sterile PBS (phosphate-buffered saline) to achieve a final concentration of 0.1–1.0 mg/mL (typical working range).
• For enhanced stability and to prevent adsorption to plastic, include a carrier protein such as 0.1% BSA (bovine serum albumin) or 0.1% HSA (human serum albumin) in the buffer.
• Gently pipette the buffer down the side of the vial and mix by gentle swirling or inversion. Avoid vigorous shaking or vortexing to prevent protein denaturation.

3. Dissolution and Inspection

• Allow the protein to dissolve at room temperature for 15–30 minutes with gentle agitation.
• Inspect for complete dissolution. If particulates remain, gently mix at room temperature for up to 2–3 hours or overnight at 4°C.

4. Aliquoting and Storage

• Aliquot the reconstituted protein into small volumes to avoid repeated freeze-thaw cycles.
• For short-term storage (up to 1 week), keep at 2–8°C.
• For long-term storage, freeze aliquots at –20°C to –80°C. Addition of carrier protein and/or 5–50% glycerol is recommended for stability.
• Avoid storing diluted protein without carrier protein, as this can lead to loss of activity due to adsorption or degradation.

5. Working Solution Preparation

• Before use in cell culture, dilute the stock solution to the desired working concentration using sterile culture medium or buffer containing carrier protein.
• If using in serum-free culture or in vivo, avoid animal-derived carrier proteins and consider using trehalose as a stabilizer.

Summary Table: Key Steps and Conditions

Critical Notes:

• Always use sterile technique throughout to avoid contamination.
• Consult the product CoA for any specific reconstitution volume or buffer recommendations, as protein formulations may vary.
• Avoid repeated freeze-thaw cycles by aliquoting.

This protocol ensures maximum stability and bioactivity of recombinant IL-20 for cell culture applications.