Recombinant Rat IL-18

Recombinant Rat IL-18 is used in research applications to study immune modulation, inflammation, and disease mechanisms due to its potent ability to induce pro-inflammatory cytokines and regulate T helper cell responses.

Key scientific reasons to use Recombinant Rat IL-18:

• Immunomodulation: IL-18 is a critical cytokine that enhances production of interferon-gamma (IFN-γ), driving Th1 polarization and activating both T cells and NK cells. This makes it essential for investigating immune responses in rat models, especially those involving infection, autoimmunity, or tumor immunity.

• Disease Modeling: Recombinant rat IL-18 is widely used in animal models of chronic inflammatory diseases (e.g., rheumatoid arthritis, Crohn’s disease, psoriasis) to dissect its role in disease progression and immune regulation. Studies show that IL-18 administration can modulate the severity and incidence of arthritis, alter antibody production, and influence cytokine profiles in vivo.

• Mechanistic Studies: IL-18’s ability to induce TNF, IL-1, Fas ligand, and chemokines allows researchers to explore pathways of inflammation, cell death, and immune cell recruitment. It also selectively enhances FasL-mediated cytotoxicity, relevant for studies on immune cell-mediated cytotoxicity.

• Neuroimmune Research: IL-18 signaling has been implicated in neuroimmune interactions, such as in the central amygdala, affecting synaptic transmission and potentially contributing to models of stress and neuropsychiatric disorders.

• Cancer Immunology: IL-18 is instrumental in anti-tumor immunity by activating T and NK cells, and recombinant forms are used to evaluate its therapeutic potential and mechanisms in preclinical cancer models.

Typical applications include:

• In vitro stimulation of rat immune cells to assess cytokine production and cell activation.
• In vivo administration in rat models to study disease mechanisms, immune modulation, and therapeutic interventions.
• Use as a standard in immunoassays (e.g., ELISA) for quantifying IL-18 or related immune responses.

Summary of best practices:

• Select recombinant rat IL-18 for experiments requiring species-specific cytokine activity.
• Use appropriate dosing based on published protocols, as effects can be dose-dependent and bimodal (e.g., low doses may enhance inflammation, high doses may suppress it).
• Validate biological activity in your system, as recombinant proteins may differ in stability and potency depending on production methods.

In conclusion, recombinant rat IL-18 is a versatile tool for dissecting immune mechanisms, modeling inflammatory and autoimmune diseases, and exploring therapeutic strategies in rat-based research systems.

Yes, recombinant rat IL-18 can be used as a standard for quantification or calibration in ELISA assays designed to measure rat IL-18 concentrations.

Most commercial rat IL-18 ELISA kits use recombinant rat IL-18 as their standard protein to generate the calibration curve. These kits are validated to ensure that both natural and recombinant rat IL-18 are recognized equivalently by the capture and detection antibodies, allowing accurate quantification in biological samples. The standard curve generated with recombinant IL-18 enables you to interpolate the concentration of IL-18 in your unknown samples.

Key considerations for using recombinant rat IL-18 as a standard:

• Ensure the recombinant protein matches the immunogen sequence and structure recognized by the antibodies in your ELISA (e.g., full-length mature IL-18, correct amino acid sequence).
• Confirm that your ELISA kit or protocol is validated for both natural and recombinant forms of IL-18.
• Prepare the standard dilutions in the same buffer or matrix as your samples to minimize matrix effects and ensure accurate quantification.
• Follow the recommended protocol for standard preparation, including proper reconstitution, dilution, and handling to maintain protein integrity and reproducibility.

Best practices:

• Use duplicate or triplicate wells for each standard concentration to ensure precision.
• Include internal controls to verify assay performance and consistency across runs.
• Validate the linearity and parallelism of the standard curve with your sample matrix if possible.

In summary, recombinant rat IL-18 is widely accepted and routinely used as a standard for ELISA quantification, provided the assay is validated for this application and the recombinant protein is properly prepared and matched to the assay requirements.

Recombinant Rat IL-18 has been validated for several applications in published research, primarily in the context of immunology, inflammation, and disease modeling.

Key validated applications include:

• Bioassays and Functional Studies: Recombinant rat IL-18 is widely used to stimulate immune cells (such as T cells and NK cells) to assess cytokine production, particularly interferon-gamma (IFN-γ), in vitro and in vivo. Its biological activity is often confirmed by its ability to induce IFN-γ secretion from lymphocytes.

• ELISA and Immunoassays: It serves as a standard or analyte in enzyme-linked immunosorbent assays (ELISA) and other immunoassays to quantify IL-18 or to validate antibody specificity. Published protocols describe its use in sandwich ELISA formats for detection and quantification of IL-18.

• Western Blotting: Recombinant rat IL-18 is used as a positive control or standard in Western blotting to detect IL-18 protein and validate antibody specificity.

• SDS-PAGE: It is used for protein characterization and purity assessment by SDS-PAGE, confirming molecular weight and integrity.

• In Vivo Animal Models: Recombinant rat IL-18 has been administered to animal models to study its role in immune modulation, inflammation, and disease, including models of chronic inflammatory diseases (e.g., rheumatoid arthritis, Crohn’s disease, psoriasis), cancer immunotherapy, and neuroinflammation. Studies have used it to investigate cytokine signaling, immune cell activation, and therapeutic interventions.

• Pathway Analysis: It is used to probe signaling pathways such as cytokine-cytokine receptor interaction, NOD-like receptor signaling, and responses to infectious diseases (e.g., malaria, tuberculosis, influenza).

Summary Table of Validated Applications

Additional Notes:

• Recombinant rat IL-18 is fully biologically active and is often compared to standards in dose-dependent assays.
• It is used in both basic and preclinical research, including target discovery and lead validation.
• Its role as a pro-inflammatory cytokine makes it a valuable tool for studying immune responses and potential therapeutic interventions in various disease models.

If you require details on a specific application or protocol, please specify the context (e.g., cell type, disease model, assay format).

To reconstitute and prepare Recombinant Rat IL-18 protein for cell culture experiments, briefly centrifuge the vial before opening, then reconstitute the lyophilized protein in sterile distilled water to a concentration of 0.1–0.5 mg/mL (100–500 μg/mL). Avoid vortexing or vigorous pipetting to prevent protein denaturation.

Step-by-step protocol:

• Centrifuge the vial briefly to collect all lyophilized material at the bottom.
• Add sterile distilled water to achieve a final concentration of 0.1–0.5 mg/mL (e.g., add 1 mL to 0.1 mg for 0.1 mg/mL).
• Gently mix by slow pipetting or gentle inversion. Do not vortex or pipette up and down vigorously.
• For cell culture use, further dilute the reconstituted stock into your desired cell culture medium or buffer. If needed, add a carrier protein such as 0.1% BSA or 5% HSA to stabilize the protein, especially for long-term storage or low-concentration applications.
• Aliquot the reconstituted protein to avoid repeated freeze-thaw cycles, which can degrade the protein.
• Storage: Store reconstituted aliquots at –20°C or lower for long-term use. For short-term use (up to one week), store at 4°C.

Additional notes:

• If your application is sensitive to endotoxins, confirm the endotoxin level is suitable for cell culture (typically <0.1 ng/μg is acceptable for most applications).
• For working concentrations in cell culture, typical final concentrations range from 1–100 ng/mL, but optimize based on your specific assay and cell type.

Summary Table:

This protocol ensures the protein remains stable and bioactive for your cell culture experiments.