Recombinant Human CXCL11

Recombinant Human CXCL11 is used in research applications to study immune cell recruitment, macrophage polarization, tissue regeneration, and tumor immunity due to its potent chemotactic and immunomodulatory properties.

Key scientific reasons to use recombinant human CXCL11 include:

• Immune Cell Recruitment: CXCL11 is a strong chemoattractant for activated T lymphocytes (especially Th1 cells) and natural killer (NK) cells, making it valuable for studying immune cell trafficking, inflammation, and immune surveillance.

• Macrophage Polarization and Fibrosis Research: CXCL11 can reprogram M2 (pro-fibrotic, immunosuppressive) macrophages to the M1 (pro-inflammatory, anti-tumor) phenotype. This property is crucial for investigating mechanisms of tissue fibrosis, such as in pulmonary fibrosis models, and for exploring therapeutic strategies that target macrophage plasticity.

• Tumor Immunology and Microenvironment: CXCL11 influences the tumor microenvironment by recruiting anti-tumor immune cells and repolarizing macrophages, which can suppress tumor growth and enhance anti-tumor immunity. It is also studied as a potential biomarker and therapeutic target in various cancers.

• Cytokine and Chemokine Signaling: CXCL11 is upregulated by interferons and can stimulate IFN-γ expression in immune cells, providing a model for studying cytokine networks and immune activation.

• Angiogenesis and Tissue Remodeling: CXCL11 has non-chemotactic functions, such as inhibiting angiogenesis, which is relevant for research on tissue remodeling, wound healing, and cancer biology.

• Bioassays and Functional Studies: Recombinant CXCL11 is used in in vitro and in vivo assays to dissect its effects on cell migration, signaling pathways (e.g., ERK, AKT, NF-κB), and gene expression in various cell types.

• Therapeutic Development: Its ability to modulate immune responses and fibrosis makes recombinant CXCL11 a candidate for preclinical studies on immune therapies, anti-fibrotic agents, and cancer immunotherapies.

In summary, recombinant human CXCL11 is a versatile tool for dissecting immune mechanisms, modeling disease processes, and evaluating therapeutic interventions in immunology, oncology, and regenerative medicine.

Recombinant human CXCL11 can be used as a standard for quantification or calibration in ELISA assays, provided it is properly validated for your specific assay system. Most commercial ELISA kits for CXCL11 use recombinant human CXCL11 as the standard, and these kits are designed to quantify both recombinant and natural forms of the protein.

Key considerations and supporting details:

• Parallelism and Validation: Commercial ELISA kits demonstrate that standard curves generated with recombinant CXCL11 are parallel to those obtained with natural CXCL11 in biological samples, indicating that recombinant protein is suitable for calibration. This parallelism is essential for accurate quantification.

• Assay Compatibility: Ensure that the recombinant CXCL11 you use as a standard is of high purity, correctly folded, and biologically active, as impurities or misfolded protein can affect assay accuracy. The recombinant standard should be prepared and diluted according to the protocol of your specific ELISA kit.

• Matrix Effects: Some kits report no significant matrix effects when using recombinant CXCL11 as a standard in serum, plasma, or cell culture supernatants, supporting its use for quantification in these sample types.

• Standard Preparation: Follow the ELISA kit instructions for reconstituting and diluting the recombinant standard. For example, lyophilized recombinant CXCL11 is typically reconstituted in a defined volume of diluent to create a stock solution, which is then serially diluted to generate the standard curve.

• Documentation: Always refer to the product insert or protocol for your specific ELISA kit to ensure compatibility and correct preparation of the recombinant standard.

Summary Table: Use of Recombinant CXCL11 as ELISA Standard

In summary: You can use recombinant human CXCL11 as a standard for ELISA quantification, provided it is validated for your assay and prepared according to the kit protocol. Always confirm parallelism and absence of matrix effects for your specific application.

Recombinant Human CXCL11 has been validated in published research for several key applications, primarily in studies of immune cell modulation, fibrosis, cancer, and autoimmune disease models.

Validated Applications in Published Research:

• Macrophage Polarization and Fibrosis Models:
  Recombinant CXCL11 has been used to reprogram M2-biased macrophages to the M1 phenotype, thereby reducing fibrosis in vivo (e.g., bleomycin-induced pulmonary fibrosis in mice). This application involves both in vitro macrophage culture assays and in vivo animal models, with evaluation by immunostaining, secretome analysis, and histological assessment.

• Tumor Microenvironment and Cancer Immunology:
  CXCL11 has been applied in studies investigating its role in immune cell infiltration within the tumor microenvironment, particularly its ability to recruit and activate macrophages and T cells. Functional assays and xenograft models have been used to assess its impact on tumor growth and immune cell polarization.

• Autoimmune Disease Models:
  Recombinant CXCL11 has been administered in experimental autoimmune encephalomyelitis (EAE) mouse models to suppress disease symptoms and modulate T cell accumulation at sites of inflammation. This involves in vivo administration and subsequent immunological and histopathological analysis.

• Functional Assays and Chemotaxis:
  CXCL11 is widely used in in vitro functional assays to study chemotactic activity, particularly its ability to attract activated T lymphocytes and NK cells. These assays typically involve migration chambers or transwell systems.

• ELISA and Immunoassays:
  Recombinant CXCL11 is validated as a standard or analyte in ELISA-based quantification of chemokine levels in biological samples.

• Bioassays for Signal Transduction:
  Studies have used recombinant CXCL11 to investigate downstream signaling pathways (e.g., ERK, AKT, NF-κB) in immune cells, often via Western blotting or flow cytometry.

Additional Context:

• CXCL11 has also been used in research on post-translational modifications (e.g., citrullination), proteolytic processing, and receptor binding studies, often employing recombinant protein in cell-based assays.
• Mass cytometry (CyTOF), spatial biology, and vaccine development are emerging applications where recombinant CXCL11 is used as a tool for immune profiling and functional studies.

Summary Table of Validated Applications

These applications are supported by peer-reviewed publications and are widely used in immunology, cell biology, and translational research.

To reconstitute and prepare Recombinant Human CXCL11 for cell culture experiments, dissolve the lyophilized protein at 100 μg/mL in sterile PBS containing at least 0.1% human or bovine serum albumin (BSA or HSA). This carrier protein helps stabilize CXCL11 and prevents adsorption to plasticware, which is especially important for low-concentration or long-term storage.

Step-by-step protocol:

1. Centrifuge the vial briefly before opening to ensure all lyophilized material is at the bottom.
2. Add sterile PBS (phosphate-buffered saline) with at least 0.1% BSA or HSA to achieve a final concentration of 100 μg/mL.
   • For carrier-free formulations, you may use sterile PBS alone, but adding a carrier protein is recommended for stability, especially if you plan to store aliquots.
3. Gently mix by pipetting up and down or swirling. Do not vortex, as this can denature the protein.
4. Allow the protein to fully dissolve at room temperature for several minutes.
5. Aliquot the reconstituted protein to avoid repeated freeze-thaw cycles, which can reduce activity.
6. Storage:
   • Short-term (up to 1 week): 2–8 °C.
   • Long-term: –20 °C or –70 °C, ideally with carrier protein present.
   • Avoid repeated freeze-thaw cycles.

Additional notes:

• For cell culture experiments, always use sterile technique.
• If you require lower working concentrations, dilute the stock further in cell culture medium or PBS with 0.1% BSA/HSA immediately before use.
• For bioassays, confirm the activity of your preparation using a chemotaxis or signaling assay if possible.

Summary Table:

This protocol ensures protein stability and bioactivity for cell culture applications.