Recombinant Human M-CSF R

Recombinant human M-CSF (macrophage colony-stimulating factor) offers substantial scientific value across multiple research applications due to its diverse biological functions and well-characterized mechanisms of action.

Key Biological Functions

M-CSF serves as a critical regulator of myeloid cell development and function. It plays an essential role in the survival, proliferation, and differentiation of hematopoietic precursor cells, particularly mononuclear phagocytes. The cytokine binds to CD14+ monocytes and promotes their survival and proliferation, making it invaluable for studies involving monocyte and macrophage biology.

Enhanced Cellular Capabilities

When applied to monocytes and macrophages, recombinant M-CSF significantly enhances multiple functional properties. The protein primes and amplifies macrophage killing of both tumor cells and microorganisms, regulates the release of cytokines and inflammatory modulators, and stimulates pinocytosis. Additionally, M-CSF enhances inducible monocyte functions including phagocytic activity, microbial killing, cytotoxicity for tumor cells, and synthesis of inflammatory cytokines such as IL-1, TNFα, and IFNγ.

Immunological Applications

In infection models, recombinant M-CSF demonstrates remarkable protective capacity. Studies show that M-CSF treatment substantially improves survival rates in hematopoietic cell transplant recipients facing lethal infections, with survival improvements from 15.3% in controls to 87.5% in treated mice against bacterial pathogens, and significant reductions in fungal tissue load. This protective effect occurs through increased myelopoiesis and enhanced donor-derived cell recovery, even with single-dose treatments.

Bone and Skeletal Research

M-CSF plays a critical regulatory role in osteoclast biology. The cytokine regulates osteoclast proliferation and differentiation, controls bone resorption, and is required for normal bone development. M-CSF induces RANKL production in mature osteoclasts, making it a potent stimulator of osteoclast resorbing activity.

Experimental Versatility

Recombinant M-CSF is suitable for diverse experimental approaches including bioassays with cell lines, whole cell culture systems, and functional assays measuring proliferation and differentiation. The availability of both standard and GMP-grade formulations allows flexibility for basic research through to more stringent applications.

Recombinant Human M-CSF R (CSF1R) can be used as a standard for quantification or calibration in ELISA assays only if the assay is specifically designed to detect and quantify the receptor protein (CSF1R), not the ligand (M-CSF). For ELISAs targeting M-CSF quantification, the standard must be recombinant M-CSF, not its receptor.

Essential context and supporting details:

• ELISA Standards Must Match the Target: In ELISA assays, the standard should be the same molecule as the analyte being measured. If your assay is designed to quantify M-CSF, you must use recombinant human M-CSF as the standard. If your assay is designed to quantify M-CSF R (CSF1R), then recombinant human M-CSF R is appropriate as the standard.

• Assay-Specific Calibration: Commercial ELISA kits for M-CSF quantification use recombinant human M-CSF, calibrated against international standards (e.g., NIBSC/WHO). Kits for CSF1R quantification use recombinant CSF1R as the standard.

• Protocol Requirements: When using recombinant proteins as standards, ensure:

  • The protein is of high purity and properly formulated (e.g., in PBS, low endotoxin).
  • The standard curve is generated using serial dilutions of the recombinant protein within the assay's detection range.
  • The recombinant standard matches the form (e.g., glycosylation, dimerization) of the native protein as closely as possible for accurate quantification.

• Limitations: Using the wrong recombinant protein (e.g., CSF1R as a standard for M-CSF quantification) will yield inaccurate results, as the antibodies in the ELISA are specific to the target analyte.

Summary Table:

Best Practices:

• Always verify the specificity of your ELISA antibodies and the intended analyte.
• Use recombinant standards that match the analyte in structure and sequence.
• Follow the kit or protocol instructions for standard preparation and calibration.

If your goal is to quantify M-CSF R (CSF1R), you may use recombinant human M-CSF R as a standard. If you intend to quantify M-CSF, you must use recombinant human M-CSF as the standard.

Recombinant Human M-CSF R (Macrophage Colony-Stimulating Factor Receptor, also known as CSF1R or CD115) has been validated in published research primarily for bioassays, cell signaling studies, and cell culture applications involving monocyte/macrophage lineage cells.

Key validated applications in published research include:

• Bioassays: Recombinant Human M-CSF R is widely used in bioassays to study ligand-receptor interactions, particularly the binding and signaling of M-CSF and IL-34, which are its physiological ligands. These assays often measure downstream effects such as receptor phosphorylation, activation of signaling pathways, and functional cellular responses like proliferation, survival, and differentiation of monocytes and macrophages.

• Cell Signaling Studies: The receptor is used to investigate the molecular mechanisms of M-CSF-induced signal transduction, including receptor dimerization, tyrosine phosphorylation, and recruitment of intracellular signaling proteins that regulate cell proliferation, survival, and cytoskeletal reorganization.

• Cell Culture and Differentiation: Recombinant M-CSF R has been applied in cell culture systems to support the differentiation and maintenance of macrophages, microglia, and osteoclasts from precursor cells. It is also used to model disease processes and study the effects of M-CSF/CSF1R signaling in various cell types, including stem cell-derived macrophages and tissue-resident macrophages.

• Disease Modeling and Therapeutic Research: The M-CSF/CSF1R axis is a target in preclinical models of cancer, rheumatoid arthritis, neurodegenerative diseases, and inflammatory conditions. Recombinant M-CSF R is used to validate the effects of inhibitors, antibodies, or other modulators of this pathway in vitro and in vivo.

• Protein-Protein Interaction and Binding Assays: The recombinant receptor is used in binding assays to characterize interactions with ligands (M-CSF, IL-34) and to screen for potential therapeutic inhibitors or antibodies that block receptor function.

Representative published research applications:

• Analysis of macrophage and microglia development and function in co-culture and organotypic models.
• Investigation of CSF1R signaling in cancer, including tumor-associated macrophage biology and tumor microenvironment studies.
• Studies of inflammatory and neurodegenerative disease mechanisms, including the role of CSF1R in microglial proliferation and activation.
• Validation of CSF1R as a therapeutic target using recombinant protein in preclinical models.

Summary Table:

References:

• : Bioassay, cell signaling, and protein interaction applications
• : Cell culture, macrophage differentiation, and disease modeling
• : Disease modeling, therapeutic research, and neurobiology
• : Binding assays, cell differentiation, and proliferation studies

If you need protocols or more specific examples from the literature, please specify the cell type or disease model of interest.

To reconstitute and prepare Recombinant Human M-CSF R protein for cell culture experiments, follow these technical steps:

• Centrifuge the vial briefly before opening to ensure all lyophilized powder is at the bottom.

• Reconstitute the protein in a suitable sterile buffer. Common options include:

  • Sterile water at a concentration of 0.1–1.0 mg/mL.
  • Sterile PBS (pH 7.2–7.4), optionally supplemented with 0.1% carrier protein such as endotoxin-free recombinant human serum albumin (HSA) or bovine serum albumin (BSA).
  • 20 mM Tris-HCl, pH 8.0 is also recommended for carrier-free formulations.

• Mix gently by swirling or tapping the vial. Do not vortex as this may denature the protein.

• Allow the protein to dissolve completely (typically 5–10 minutes at room temperature).

Aliquoting and Storage:

• If not used immediately, aliquot the reconstituted solution to avoid repeated freeze-thaw cycles.
• For long-term storage, add a carrier protein (e.g., 0.1% HSA or BSA) to stabilize the protein.
• Store aliquots at –20°C to –80°C.

Preparation for Cell Culture:

• Before use, dilute the stock solution to the desired working concentration in cell culture medium. Typical working concentrations for bioassays range from 0.5–1.5 ng/mL for cell proliferation assays, but optimal concentrations should be empirically determined for your specific application.
• Ensure all solutions are sterile and endotoxin-free to prevent adverse effects on cell cultures.

Summary Table: Reconstitution Options

Best Practices:

• Always consult the specific product datasheet or Certificate of Analysis for buffer recommendations and concentration ranges.
• Use endotoxin-free reagents and sterile technique throughout preparation.
• Avoid repeated freeze-thaw cycles by aliquoting stock solutions.

These protocols ensure optimal protein stability and bioactivity for cell culture applications.