Recombinant Mouse I-TAC (CXCL11)

Recombinant Mouse I-TAC (CXCL11) is used in research applications to study immune cell migration, inflammatory responses, and chemokine signaling, particularly involving the CXCR3 receptor. It is especially valuable for dissecting the roles of chemokines in mouse models, where endogenous CXCL11 expression may be absent or altered due to genetic mutations in common strains like C57BL/6.

Key reasons to use recombinant Mouse I-TAC (CXCL11) in research:

• Chemotaxis Studies: CXCL11 is a potent chemoattractant for activated T cells, especially Th1 cells and NK cells, via the CXCR3 receptor. It enables precise in vitro and in vivo assays of immune cell migration, which is critical for understanding immune surveillance, inflammation, and tissue infiltration.
• CXCR3 Ligand Specificity: CXCL11 binds CXCR3 with higher affinity than other ligands (CXCL9/MIG and CXCL10/IP-10), allowing for detailed studies of receptor-ligand interactions and downstream signaling.
• Modeling Inflammatory and Autoimmune Diseases: CXCL11 is upregulated in response to interferon and during inflammatory conditions, making it relevant for modeling diseases such as multiple sclerosis, neuroinflammation, and autoimmune disorders. Its role in T cell recruitment is particularly important in these contexts.
• Functional Assays: Recombinant CXCL11 is validated for use in bioassays, including chemotaxis assays, receptor binding studies, and as a standard in ELISA for quantifying CXCL11 in biological samples.
• Overcoming Genetic Limitations in Mouse Models: Many laboratory mouse strains (e.g., C57BL/6) have a non-functional CXCL11 gene due to a premature stop codon, so recombinant protein is essential for restoring or mimicking CXCL11 function in these models.
• Pathway Analysis: CXCL11 is integral to chemotaxis and inflammatory signaling pathways, providing a tool to dissect these processes in immune and non-immune cells.

Additional considerations:

• Recombinant CXCL11 is often used in studies of T cell migration in the central nervous system, tumor microenvironment, and sites of infection or injury.
• It can be used to compare the effects of different CXCR3 ligands or to test the impact of CXCR3 antagonists in functional assays.
• The protein is typically supplied carrier-free or with stabilizers, depending on the application (e.g., cell culture, ELISA standard).

In summary, recombinant Mouse I-TAC (CXCL11) is a critical reagent for immunological research, enabling controlled, reproducible studies of chemokine-driven cell migration and immune responses in mouse systems where endogenous CXCL11 may be absent or difficult to manipulate.

Yes, recombinant Mouse I-TAC (CXCL11) protein can be used as a standard for quantification or calibration in ELISA assays, provided it is of high purity and properly validated for this application.

Supporting details:

• Intended Use: Recombinant Mouse CXCL11 is commonly used as an ELISA standard, as indicated by multiple sources specifying its application for ELISA calibration and quantification. For example, one supplier notes: "Mouse CXCL11 applications are for cell culture, ELISA standard, and Western Blot Control".
• ELISA Kit Standards: Commercial Mouse CXCL11 ELISA kits use recombinant CXCL11 as the standard to generate calibration curves for quantification in biological samples. These kits typically include a recombinant protein standard, and the assay is validated to ensure that both natural and recombinant forms are detected equivalently.
• Purity and Validation: The recombinant protein should be of high purity (typically >95% by SDS-PAGE) and ideally carrier-free if you require precise mass-based quantification. It is important to confirm that the recombinant standard is compatible with your specific ELISA system and that it produces a standard curve with appropriate sensitivity and linearity.
• Best Practices: Always reconstitute and store the recombinant standard according to the manufacturer’s instructions to maintain stability and activity. Prepare serial dilutions in the same matrix as your samples (e.g., assay buffer or sample diluent) to minimize matrix effects.

Additional considerations:

• Source and Form: Ensure the recombinant CXCL11 matches the species and isoform recognized by your ELISA antibodies. Most commercial kits and recombinant proteins are produced in E. coli and are non-glycosylated, which is generally suitable for ELISA calibration.
• Carrier Proteins: If using a carrier-free recombinant protein, handle with care to avoid adsorption losses at low concentrations. Some protocols recommend adding a small amount of BSA or other inert protein to minimize this risk.
• Validation: If you are developing your own ELISA or using a non-kit system, validate that your recombinant standard yields a parallel standard curve to native CXCL11 in your sample matrix.

In summary, recombinant Mouse I-TAC (CXCL11) is widely accepted and validated as a standard for ELISA quantification, provided it is of high quality and compatible with your assay system.

Recombinant Mouse I-TAC (CXCL11) has been validated in published research for several key applications, primarily in studies of immune cell chemotaxis, macrophage polarization, fibrosis models, and autoimmune disease models.

Validated Applications in Published Research:

• Macrophage Polarization and Fibrosis Models:
  Recombinant CXCL11 has been used to reprogram M2-biased macrophages toward an M1 phenotype, both in vitro and in vivo, particularly in the context of pulmonary fibrosis. In a bleomycin-induced murine model, intravenous administration of recombinant CXCL11 reduced fibrosis by shifting macrophage polarization, as assessed by immunostaining and flow cytometry for M1/M2 markers.

• Bioassays for Chemotactic Activity:
  CXCL11 is widely used in functional bioassays to assess its chemotactic effects on immune cells, especially T cells and NK cells, via its high-affinity binding to the CXCR3 receptor. These assays typically involve measuring cell migration in response to recombinant CXCL11.

• Autoimmune and Neuroinflammatory Disease Models:
  Recombinant CXCL11 (including fusion proteins) has been administered in mouse models of experimental autoimmune encephalomyelitis (EAE) to study its immunomodulatory effects, such as reducing effector T cell accumulation at sites of inflammation and suppressing disease relapse.

• ELISA and Immunoassays:
  Recombinant CXCL11 is used as a standard or control in ELISA kits and other immunoassays to quantify endogenous CXCL11 levels in biological samples.

• In Vitro Functional Assays:
  Studies have used recombinant CXCL11 to investigate signaling pathway activation (e.g., pERK, pAKT, p65) in macrophages and other immune cells, as well as to assess its effects on cell phenotype and cytokine production.

Additional Context:

• T Cell Chemotaxis:
  CXCL11 is a potent chemoattractant for IL-2-activated T lymphocytes and plays a role in T cell migration during IFN-dominated immune responses.

• Antagonist Activity:
  CXCL11 has been shown to act as an antagonist for CCR5, inhibiting the binding of other chemokines and modulating immune cell trafficking.

• Tissue Expression and Inflammation:
  Mouse CXCL11 is induced in multiple tissues during inflammatory conditions such as endotoxemia, with highest expression in lung, heart, small intestine, and kidney.

Summary Table of Validated Applications

These applications are supported by both primary research articles and product validation data from multiple sources.

To reconstitute and prepare Recombinant Mouse I-TAC (CXCL11) protein for cell culture experiments, follow these best-practice steps:

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

2. Reconstitution:

   • Add sterile distilled water or sterile PBS to the vial. For optimal protein stability and to minimize adsorption, include 0.1% BSA (bovine serum albumin) in the buffer.
   • Typical reconstitution concentrations are 0.1–1.0 mg/mL. For most cell culture applications, a starting concentration of 100 μg/mL in sterile PBS with 0.1% BSA is commonly used.
   • Gently pipette the solution down the sides of the vial to dissolve the protein. Do not vortex; mix by gentle inversion or pipetting.

3. Aliquoting and Storage:

   • Once fully dissolved, aliquot the stock solution into small volumes to avoid repeated freeze-thaw cycles.
   • Store aliquots at ≤ –20°C for long-term storage. For short-term use (up to 1 month), store at 2–8°C.

4. Working Solution Preparation:

   • Prepare further dilutions in cell culture medium or appropriate buffered solutions immediately before use.
   • If using for cell stimulation, ensure the final working concentration matches your experimental design (commonly in the range of 10–100 ng/mL for chemotaxis or signaling assays, but optimize as needed).

5. General Handling Notes:

   • Avoid repeated freeze-thaw cycles, as this can degrade the protein.
   • If the protein is supplied without carrier protein (BSA), adding 0.1% BSA during reconstitution and storage is strongly recommended to prevent loss due to adsorption.

Summary Table: Key Steps for Recombinant Mouse I-TAC (CXCL11) Reconstitution

References:

If you have specific experimental requirements (e.g., serum-free conditions, endotoxin sensitivity), ensure your buffer and handling protocols are compatible with your assay. Always consult the product datasheet for any lot-specific instructions.