Recombinant Human IL-19

Recombinant Human IL-19 is used in research applications to investigate its roles in immune modulation, anti-inflammatory responses, vascular protection, and disease models due to its well-characterized bioactivity and reproducibility.

Key scientific reasons to use recombinant IL-19 include:

• Immunological Studies: IL-19 is a member of the IL-10 cytokine family and is known to modulate immune responses by promoting Th2 differentiation, upregulating anti-inflammatory cytokines like IL-10, and inducing IL-6 and TNF-α production in monocytes and dendritic cells. This makes it valuable for dissecting mechanisms of immune regulation and inflammation.

• Anti-inflammatory and Protective Effects: IL-19 has demonstrated protective effects in vascular smooth muscle cells (VSMCs) by inducing heme oxygenase-1 (HO-1), reducing reactive oxygen species (ROS), and decreasing apoptosis, which are relevant for studying vascular inflammatory diseases and atheroprotection.

• Disease Modeling: Recombinant IL-19 has been shown to suppress the formation and progression of abdominal aortic aneurysms (AAA) in animal models, reduce aneurysm rupture, and improve survival, highlighting its translational potential for cardiovascular research.

• Cell Culture and Assay Standardization: Recombinant IL-19 is ideal for use as a standard in ELISA assays, a control in Western blotting, and for stimulating cells in culture to study cytokine signaling pathways and downstream effects.

• Reproducibility and Consistency: Using recombinant proteins ensures batch-to-batch consistency, defined concentration, and absence of contaminating factors, which is critical for reliable experimental outcomes and mechanistic studies.

• Mechanistic Studies: IL-19 activates the IL-20 receptor complex and STAT3 signaling, allowing researchers to probe specific signaling pathways and gene expression changes in target cells.

Typical applications include:

• Investigating cytokine signaling and immune cell differentiation.
• Modeling inflammatory and autoimmune diseases.
• Studying vascular biology and mechanisms of tissue protection.
• Standardizing immunoassays and biochemical analyses.

In summary, recombinant human IL-19 is a versatile tool for immunology, vascular biology, and inflammation research, providing a controlled means to study its biological effects and therapeutic potential.

Yes, recombinant human IL-19 can be used as a standard for quantification or calibration in ELISA assays, provided it is of high purity and its concentration is accurately determined. This is a common practice in quantitative ELISA protocols.

Key considerations and supporting details:

• Standard Curve Requirement: Quantitative ELISA assays require a standard curve generated from known concentrations of the target protein. Recombinant proteins are widely used for this purpose, especially when purified native protein is unavailable.
• Purity and Quantification: The recombinant IL-19 used as a standard should be highly purified, and its concentration must be accurately measured (e.g., by absorbance at 280 nm, BCA assay, or HPLC). Impurities or inaccurate quantification can lead to errors in sample measurement.
• Formulation: Recombinant IL-19 is often supplied lyophilized and should be reconstituted according to the manufacturer’s instructions. The diluent and matrix used for the standard curve should match the sample matrix as closely as possible to minimize matrix effects.
• Validation: If you are not using the standard provided with a commercial ELISA kit, you should validate that your recombinant IL-19 standard yields a linear, parallel standard curve within the assay’s dynamic range and that it is recognized equivalently by the assay antibodies.
• Best Practices: Prepare serial dilutions of the recombinant IL-19 to cover the expected concentration range in your samples (e.g., 0–1000 pg/mL, or as specified by your assay). Always include replicates and quality controls.

Summary Table: Recombinant Protein as ELISA Standard

References to best practices and protocols:

• "A purified protein should be used to prepare the standard curve. Otherwise, use a recombinant protein which can be semi-purified in the lab and measure the concentration with HPLC".
• "The standard or calibration curve is the element of the quantitative ELISA that will allow you to determine the concentration of your analyte in unknown samples".

In summary: As long as your recombinant human IL-19 is pure, accurately quantified, and validated for use in your specific ELISA system, it is suitable as a standard for quantification or calibration. Always ensure the standard curve generated is reliable and reproducible within your assay conditions.

Recombinant Human IL-19 has been validated for several key applications in published research, primarily in immunological, vascular, and cell biology studies.

Validated Applications:

• ELISA Standard: Used as a quantitative standard in enzyme-linked immunosorbent assays to measure IL-19 levels in biological samples.
• Western Blot Control: Serves as a positive control for detecting IL-19 protein in Western blot assays.
• Cell Culture Studies: Applied to investigate IL-19’s biological effects on various cell types, including immune cells and vascular cells.

Functional and Disease Model Applications:

• Autoimmune Disease Models: Recombinant IL-19 has been used to suppress experimental autoimmune encephalomyelitis (EAE), a mouse model of multiple sclerosis, by inhibiting macrophage antigen presentation and Th17 cell expansion. This demonstrates its role in modulating immune responses and inflammation.
• Vascular Disease Models: It has been validated in studies suppressing the formation and progression of experimental abdominal aortic aneurysms (AAAs) in mice. IL-19 treatment attenuated elastin and smooth muscle destruction, leukocyte infiltration, neoangiogenesis, and matrix metalloproteinase expression.
• Inflammatory Disease Research: IL-19 is implicated in the study of diseases such as asthma, atopic dermatitis, psoriasis, and rheumatoid arthritis, where it modulates Th2-skewed immune responses.

Additional Laboratory Applications:

• Immunohistochemistry and Immunofluorescence: Used for tissue localization and quantification of IL-19 in research settings.
• Flow Cytometry: Applied to analyze IL-19’s effects on immune cell populations.
• Immunoprecipitation: Used to isolate and study IL-19 protein interactions.

Summary Table:

Key Insights:

• Recombinant Human IL-19 is widely used as a standard and control in immunoassays and protein detection methods.
• It is functionally validated in disease models, especially for its immunomodulatory and vascular protective effects.
• Its use extends to diverse laboratory techniques for studying cytokine biology and immune regulation.

If you require protocols or specific experimental details for any application, please specify the intended use.

To reconstitute and prepare Recombinant Human IL-19 protein for cell culture experiments, follow these best-practice steps:

• Centrifuge the vial briefly before opening to ensure all lyophilized protein is at the bottom.
• Reconstitute the protein in sterile PBS (phosphate-buffered saline). Common reconstitution concentrations are 100 μg/mL or 500 μg/mL, depending on the specific product and experimental requirements.
• Gently pipette the buffer down the sides of the vial to dissolve the protein completely. Avoid vigorous mixing or vortexing, as this can denature the protein.
• Allow the solution to sit at room temperature for several minutes to ensure full dissolution.
• If the protein is not supplied with a carrier protein (such as BSA), consider adding 0.1% BSA or another carrier (e.g., 10% FBS, 5% HSA) to the buffer to stabilize the protein, especially for storage or when preparing working dilutions.
• Aliquot the reconstituted protein to avoid repeated freeze-thaw cycles. Store aliquots at –20°C to –80°C for long-term storage.
• For short-term use, store at 2–8°C for up to one week.

Summary protocol:

1. Centrifuge vial briefly.
2. Add sterile PBS (e.g., 100 μg/mL or 500 μg/mL).
3. Gently pipette to dissolve; do not vortex.
4. Let stand at room temperature for several minutes.
5. Aliquot and store appropriately.

Additional notes:

• Always consult the product-specific Certificate of Analysis or datasheet for precise instructions, as formulations and recommended concentrations may vary.
• Use sterile technique throughout to prevent contamination.
• For cell culture, dilute the reconstituted stock to the desired working concentration in culture medium immediately before use, ideally with a carrier protein to minimize adsorption and loss.

These steps will help ensure the biological activity and stability of recombinant IL-19 for your cell culture experiments.