Recombinant Human IL-11

Recombinant Human IL-11 (rhIL-11) is widely used in research applications for its roles in hematopoiesis, tissue protection, immune modulation, and regenerative processes. Its primary scientific value lies in its ability to stimulate platelet production, modulate inflammation, and influence epithelial and stromal cell biology.

Key scientific applications and rationale for using rhIL-11:

• Hematopoietic Effects:
  rhIL-11 stimulates the proliferation and maturation of hematopoietic stem cells and megakaryocytic progenitors, leading to increased platelet production. This property is crucial for studies on thrombopoiesis and bone marrow biology. It has been clinically validated for treating chemotherapy-induced thrombocytopenia, demonstrating its efficacy in increasing platelet counts in both animal models and humans.

• Tissue Protection and Regeneration:
  In preclinical models, rhIL-11 has shown protective effects against tissue injury and promoted regeneration in organs such as the liver, lung, kidney, and colon. It can reduce inflammation, limit fibrosis, and enhance recovery after injury, making it valuable for studies on organ repair and disease models involving epithelial or stromal damage.

• Immune Modulation:
  rhIL-11 modulates immune responses by acting on monocytes and other immune cells, influencing cytokine production and inflammatory pathways. It has been shown to reduce inflammatory responses and promote mucosal healing, particularly in models of mucositis and inflammatory bowel disease.

• Cell Culture and Differentiation Studies:
  Recombinant human IL-11 is optimized for use in cell culture systems, differentiation protocols, and functional assays, supporting research in stem cell biology, immunology, and regenerative medicine.

• Vascular Biology and Angiogenesis:
  rhIL-11 enhances mobilization of CD34⁺/VEGFR2⁺ mononuclear cells, augments collateral vessel growth, and improves perfusion in ischemic models, making it useful for studies on vascular remodeling and peripheral vascular disease.

Best practices for research use:

• Employ rhIL-11 in controlled in vitro and in vivo experiments to study its effects on cell proliferation, differentiation, and tissue repair.
• Use appropriate concentrations and dosing regimens based on published protocols for your specific cell type or animal model.
• Consider species specificity, as human IL-11 may have different effects in murine models due to cross-species interactions.

Limitations and considerations:

• Recent research has revealed that IL-11 may also contribute to fibrosis and maladaptive inflammatory responses in certain contexts, and its effects can be species-specific.
• The use of rhIL-11 should be carefully interpreted, especially in translational studies, as its biological effects may differ between human and animal systems.

Summary of scientific rationale:
Use recombinant human IL-11 in your research to investigate mechanisms of hematopoiesis, tissue protection, immune modulation, and vascular biology, while being mindful of its context-dependent effects and species specificity.

Yes, recombinant human IL-11 can be used as a standard for quantification or calibration in ELISA assays, provided it is of high purity, properly quantified, and compatible with your assay system. This is a common practice in commercial and custom ELISA development.

Supporting details:

• Commercial ELISA kits for human IL-11 routinely use recombinant human IL-11 as the standard for generating calibration curves. These standards are typically expressed in systems such as Sf21 insect cells or E. coli, and are carefully quantified and validated for use in the assay.
• Assay validation: Data from commercial kits show that recombinant IL-11 produces standard curves that are parallel to those generated with natural human IL-11, indicating equivalent immunoreactivity and suitability for quantification. This parallelism is essential for accurate quantification of endogenous IL-11 in biological samples.
• Calibration and traceability: Some kits calibrate their recombinant IL-11 standard against international reference materials (e.g., NIBSC/WHO IL-11 Reference Reagent 92/788), allowing for conversion between units if needed.
• Best practices:
  • Ensure the recombinant IL-11 is highly purified and its concentration is accurately determined (e.g., by absorbance at 280 nm or amino acid analysis).
  • Use the same diluent for standards and samples to minimize matrix effects.
  • Confirm that your ELISA antibodies recognize both recombinant and native IL-11 with similar affinity (most commercial sandwich ELISAs are designed this way).
  • Prepare a serial dilution of the recombinant standard to generate a standard curve covering the expected range of your samples.

Limitations and considerations:

• If your recombinant IL-11 is not from a validated source or lacks proper quantification, results may be less reliable.
• For regulatory or diagnostic applications, use of a standard traceable to an international reference is recommended.
• Recombinant proteins intended for ELISA calibration are not always suitable for bioassays or functional studies unless specifically validated for those purposes.

Summary Table: Use of Recombinant Human IL-11 as ELISA Standard

In summary: If your recombinant human IL-11 meets these criteria, it is appropriate to use as a standard for quantification or calibration in your ELISA assays.

Recombinant Human IL-11 has been validated for a broad range of applications in published research, spanning both basic and translational studies. Key validated applications include:

• Cell-based bioassays: Used to stimulate proliferation and differentiation of various cell types, such as hematopoietic stem cells, megakaryocytic progenitors, and plasmacytoma cell lines. It is also used to assess the biological activity of IL-11 in vitro, including T and B cell growth and survival.
• ELISA and quantification standards: Employed as a standard for the detection and quantification of IL-11 in immunoassays.
• Screening and release assays: Utilized for screening antibodies or small molecules that block IL-11 signaling, including therapeutic monoclonal antibodies targeting IL-11 or its receptor.
• Western blot, immunofluorescence, and immunohistochemistry: Validated as a target antigen for antibody validation in western blot (WB), immunofluorescence (IF), and immunohistochemistry (IHC) applications.
• In vivo studies: Used in animal models to study its effects on hematopoiesis, thrombopoiesis, mucosal protection, fibrosis, and aging.
• Clinical and preclinical therapeutic studies: Applied in clinical research for the prevention and treatment of chemotherapy- or radiotherapy-induced oral mucositis (OM), especially in patients with acute leukemia, where it has shown efficacy in reducing severity, pain, and healing time of OM.
• Functional studies in disease models: Investigated for its roles in fibrosis (pulmonary, cardiac, hepatic), cancer biology (tumor microenvironment modulation), inflammatory diseases (e.g., inflammatory bowel disease, rheumatoid arthritis), and as a therapeutic target in these contexts.

Summary Table of Validated Applications

Additional Notes:

• IL-11 is also used in studies of T cell polarization (Th2 bias), B cell IgG production, osteoclast activity, and endothelial protection.
• In clinical settings, recombinant human IL-11 has been approved for improving platelet recovery after chemotherapy-induced thrombocytopenia and has shown benefit in mucosal protection and anti-inflammatory applications.
• Research continues to expand into its role as a therapeutic target in fibrotic and oncologic diseases.

These applications are supported by both preclinical and clinical research, with protocols and validation methods detailed in the cited literature.

To reconstitute and prepare Recombinant Human IL-11 protein for cell culture experiments, dissolve the lyophilized protein in a sterile buffer, typically sterile distilled water or phosphate-buffered saline (PBS), at a recommended concentration, then dilute as needed for your assay.

General Protocol for Reconstitution and Preparation:

• Briefly centrifuge the vial before opening to ensure all material is at the bottom.
• Add sterile distilled water or PBS:
  • For carrier-free preparations, reconstitute in sterile distilled water at concentrations ranging from 0.1 mg/mL to 1.0 mg/mL.
  • Alternatively, reconstitute in sterile PBS (pH 7.4), optionally supplemented with 0.1% endotoxin-free recombinant human serum albumin (HSA) or bovine serum albumin (BSA) to enhance stability, especially for dilute working solutions.
• Gently mix by swirling or tapping the vial. Avoid vigorous vortexing to prevent protein denaturation.
• Allow the protein to dissolve fully. Some preparations may dissolve slowly; let the solution stand at room temperature for several minutes and mix gently until fully dissolved.
• Dilute the stock solution in cell culture medium or buffer to the desired working concentration for your experiment. Typical working concentrations for cell stimulation range from 0.02 ng/mL to 50 ng/mL, depending on cell type and assay sensitivity.
• Avoid repeated freeze-thaw cycles. Aliquot the reconstituted protein and store at -20°C or -80°C for long-term use.

Example Preparation Table:

Additional Notes:

• If the protein appears as a film, ensure thorough mixing after adding buffer.
• For sensitive cell types or low endotoxin requirements, use endotoxin-free reagents and buffers.
• Always consult the specific Certificate of Analysis (CoA) or product datasheet for your batch for optimal reconstitution conditions.

This protocol ensures maximum protein stability and bioactivity for cell culture applications. Adjust concentrations and buffers according to your experimental design and cell type requirements.