Recombinant Human GM-CSF

Recombinant Human Granulocyte-Macrophage Colony-Stimulating Factor (rHuGM-CSF) is a highly valuable tool for research applications due to its broad immunomodulatory and hematopoietic effects. Here are the key reasons to use rHuGM-CSF in your research:

1. Enhances Immune Cell Function

• rHuGM-CSF activates and enhances the function of multiple immune cells, including monocytes, macrophages, dendritic cells, and neutrophils.
• It increases antigen presentation by upregulating expression of HLA-DR, CD86, and class II MHC molecules on antigen-presenting cells.
• rHuGM-CSF boosts phagocytosis, cytotoxicity, oxidative metabolism, and Fc-dependent phagocytosis in monocytes and macrophages.
• It enhances dendritic cell maturation, proliferation, and migration, which are critical for adaptive immune responses.

2. Promotes Hematopoietic Recovery

• rHuGM-CSF stimulates the proliferation and differentiation of hematopoietic progenitor cells, leading to increased production of granulocytes, monocytes, and macrophages.
• It is widely used in studies of hematopoietic recovery after chemotherapy or bone marrow transplantation.

3. Supports Cancer Immunotherapy Research

• rHuGM-CSF promotes anti-tumor immune responses by activating monocytes/macrophages and enhancing dendritic cell differentiation.
• It is used as an adjuvant in cancer vaccine development and in combination with immune checkpoint inhibitors to improve therapeutic outcomes.
• rHuGM-CSF can be used to generate GM-CSF-transfected tumor cell vaccines for immunotherapy studies.

4. Modulates Inflammatory and Autoimmune Responses

• rHuGM-CSF induces a Th1-biased immune response and can be used to study inflammatory and autoimmune disease mechanisms.
• It has been investigated in models of rheumatoid arthritis, multiple sclerosis, and other autoimmune conditions.
• rHuGM-CSF can also suppress certain autoimmune diseases in animal models, making it a versatile tool for immunology research.

5. Improves Host Defense and Infection Models

• rHuGM-CSF enhances host defense mechanisms by increasing the number and function of phagocytes.
• It is used in studies of infection, particularly in immunocompromised models, to investigate the role of GM-CSF in pathogen clearance.

6. High Biological Activity and Reproducibility

• Recombinant human GM-CSF is available in highly purified, research-grade forms with high biological activity and batch-to-batch consistency, ensuring reliable and reproducible experimental results.

7. Broad Research Applications

• rHuGM-CSF is used in studies of hematopoiesis, immunology, cancer, autoimmune diseases, infection, and wound healing.
• It is also being explored for potential roles in neurodegenerative diseases and metabolic disorders.

In summary, rHuGM-CSF is a powerful and versatile cytokine for research applications, offering robust effects on immune cell function, hematopoiesis, and disease modeling. Its use can provide critical insights into immune regulation, cancer immunotherapy, and the pathogenesis of various diseases.

Yes, recombinant human GM-CSF can be used as a standard for quantification and calibration in ELISA assays. This is a well-established practice in research applications.

Suitability as ELISA Standards

Recombinant human GM-CSF proteins are specifically designed and validated for use as ELISA standards. The recombinant protein is typically produced in E. coli expression systems and is calibrated against recognized international reference standards, such as the WHO International Standard (NIBSC code: 88/646). This calibration ensures traceability and consistency across different assays and laboratories.

Key Considerations for Use

Carrier Protein Requirements

When using recombinant GM-CSF as an ELISA standard, carrier protein concentrations of 5–10 mg/mL are recommended. This is particularly important for maintaining protein stability and preventing non-specific binding to assay surfaces. Animal-free formulations are also available if your research requires non-animal-derived reagents.

Validation with Natural GM-CSF

An important advantage of recombinant standards is their compatibility with natural GM-CSF detection. Studies have demonstrated that results obtained using natural human GM-CSF show linear curves that are parallel to standard curves generated using recombinant GM-CSF standards. This indicates that recombinant standards can reliably determine relative mass values for natural GM-CSF, making them suitable for quantifying both recombinant and endogenous GM-CSF in biological samples.

Typical Performance Characteristics

Recombinant GM-CSF standards enable ELISA assays to achieve sensitivity levels typically less than 10 pg/mL, with standard curve ranges around 10–250 pg/mL, though some assays achieve wider detection ranges. The specific activity of recombinant human GM-CSF is typically greater than 1.0 × 10⁷ IU/mg, providing reliable quantification across physiologically relevant concentration ranges.

Recombinant human GM-CSF has been validated for a diverse range of applications spanning both research and clinical settings.

Research and Analytical Applications

In laboratory research, recombinant GM-CSF has been validated for Functional Assay, ELISA, Western Blot, Immunohistochemistry, Blocking Assay, and Immunoprecipitation. These applications enable researchers to study the protein's biological activity, detect its presence in samples, visualize its localization in tissues, and investigate its interactions with other molecules.

Cell Culture and Differentiation Studies

The protein is extensively used in cell culture and differentiation studies. Specifically, it has been validated for dendritic cell generation and differentiation, as well as for culturing specialized cell types such as microglia derived from human induced pluripotent stem cells. These applications leverage GM-CSF's well-characterized ability to promote proliferation and differentiation of hematopoietic progenitors and the generation of neutrophils, eosinophils, and macrophages.

Cell Proliferation Studies

Recombinant GM-CSF has been validated for cell proliferation assays, allowing researchers to quantify its mitogenic effects on target cell populations.

Therapeutic and Clinical Applications

Beyond research applications, recombinant GM-CSF has demonstrated clinical efficacy in multiple therapeutic contexts. These include myeloid reconstitution after bone marrow and blood transplantation, acceleration of neutrophil recovery following chemotherapy for acute myeloid leukemia, and treatment of severe myelosuppression. Emerging applications under investigation include its use as a vaccine adjuvant, immunotherapy for malignancies, and treatment of infections in immunosuppressed populations. Additionally, research has validated its use in wound healing and burn treatment, as well as potential applications in neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease.

To reconstitute and prepare Recombinant Human GM-CSF protein for cell culture experiments, briefly centrifuge the lyophilized vial before opening, then add sterile water or buffer to achieve a concentration between 0.1–1.0 mg/mL. Gently mix without vortexing, and if needed, add carrier protein such as 0.1% human or bovine serum albumin (HSA/BSA) to improve stability and prevent adsorption to surfaces.

Step-by-step protocol:

• Centrifuge the vial briefly (10–30 seconds) to collect all powder at the bottom before opening.
• Reconstitute with sterile water or sterile PBS (pH 7.2–7.4), typically to a final concentration of 0.1–1.0 mg/mL. Common starting concentrations are 0.1 mg/mL or 0.2 mg/mL.
• For improved stability, especially for long-term storage or low-concentration working solutions, add 0.1% endotoxin-free HSA or BSA.
• Gently swirl or tap the vial to dissolve. Do not vortex or mix vigorously, as this may denature the protein.
• Allow several minutes for complete dissolution. If solubility issues arise, incubate at 4°C overnight.
• For cell culture, further dilute the stock solution in cell culture medium or buffer as required for your assay.
• Aliquot the reconstituted stock to avoid repeated freeze-thaw cycles, which can degrade the protein.
• Store aliquots at -20°C or colder for long-term storage, or at 2–8°C for short-term use (up to 1 month).

Additional notes:

• Do not exceed 1 mg/mL during reconstitution to avoid solubility issues.
• Confirm protein recovery by SDS-PAGE if necessary.
• Always consult the specific product’s Certificate of Analysis or datasheet for buffer recommendations and handling instructions, as formulations may vary.

Summary Table:

This protocol ensures optimal activity and stability of recombinant GM-CSF for cell culture applications.