Recombinant Human IL-34

Recombinant Human IL-34 is used in research applications to study and manipulate the differentiation, proliferation, and function of monocytes, macrophages, and dendritic cells, as well as to investigate signaling pathways and disease mechanisms involving the colony-stimulating factor 1 receptor (CSF-1R).

Key scientific applications and rationale include:

• Cell Differentiation and Functional Assays: IL-34 is a potent cytokine that promotes the proliferation, survival, and differentiation of monocytes and macrophages, making it essential for in vitro studies of myeloid cell biology.
• CSF-1R Signaling Investigation: IL-34 is a ligand for CSF-1R, and its use allows for the dissection of CSF-1R-mediated signaling pathways, which are critical in immune regulation, inflammation, and tissue homeostasis.
• Neurobiology and CNS Research: IL-34 is required for the development of microglia and has neuroprotective roles, such as limiting neurotoxicity and promoting microglial accumulation in models of neurodegeneration and Alzheimer’s disease.
• Immunology and Disease Modeling: IL-34 is implicated in autoimmune, inflammatory, and metabolic diseases, as well as cancer progression and immunotherapy resistance. Recombinant IL-34 enables mechanistic studies and biomarker development for these conditions.
• Bone Marrow and Hematopoiesis: IL-34 induces colony-forming unit macrophages in bone marrow cultures, supporting research into hematopoietic development and disorders.
• Cytokine Release and Inflammatory Response: IL-34 stimulates the production of chemokines such as MCP-1 (CCL2) and pro-inflammatory cytokines, facilitating studies on immune cell recruitment and inflammation.

Best practices for using recombinant IL-34 include:

• Determining optimal concentrations via dose-response experiments for each specific application.
• Employing validated functional assays to assess biological activity, such as monocyte proliferation or cytokine induction.

In summary, recombinant human IL-34 is a versatile tool for dissecting myeloid cell biology, CSF-1R signaling, neuroimmune interactions, and disease mechanisms in both basic and translational research contexts.

You can use recombinant human IL-34 as a standard for quantification or calibration in your ELISA assays, provided that the recombinant protein is of high purity, its concentration is accurately known, and it is compatible with the antibodies and detection system used in your assay.

Key considerations and supporting details:

• Recombinant IL-34 is commonly used as a standard in commercial ELISA kits for quantifying both recombinant and natural human IL-34 in biological samples. These kits typically include a recombinant IL-34 standard, and the assay is validated for this use.
• The standard curve in ELISA must be generated with each experiment using the recombinant IL-34 standard, and sample concentrations are interpolated from this curve.
• The expression system (e.g., E. coli, HEK293, NS0) and post-translational modifications (such as glycosylation) can affect the recognition of the recombinant protein by the antibodies in your ELISA. Most commercial kits are validated with a specific recombinant IL-34 standard, and cross-reactivity with natural IL-34 is confirmed.
• Purity and formulation: The recombinant IL-34 should be highly pure (typically >95%) and free from interfering substances such as high endotoxin levels or carrier proteins, unless the ELISA protocol specifically accommodates them.
• Concentration accuracy: The concentration of your recombinant IL-34 must be precisely determined, as errors here will directly affect the accuracy of your quantification.
• Compatibility: Ensure that the recombinant IL-34 you use as a standard is recognized by the capture and detection antibodies in your ELISA. Some kits specify that only their provided standard should be used, as they have validated the assay with that specific protein.

Best practices:

• Always prepare a fresh standard curve for each assay run.
• If using a recombinant IL-34 standard not supplied with your ELISA kit, verify that it is recognized equivalently to the kit standard by running a parallel standard curve and comparing results.
• Avoid mixing standards or reagents from different kits or vendors, as this can affect assay performance and quantification accuracy.

Summary:
Recombinant human IL-34 is suitable as a standard for ELISA quantification if it is of high quality, its concentration is accurately known, and it is compatible with your assay system. Always validate your standard in the context of your specific ELISA to ensure accurate quantification.

Recombinant Human IL-34 has been validated in published research for a range of applications, primarily involving immune cell differentiation, functional assays, and disease modeling.

Key validated applications include:

• Differentiation of monocytes, macrophages, and dendritic cells: IL-34 is widely used in vitro to induce the differentiation of human monocytes into macrophages and dendritic cells, as well as for the generation of microglia from human induced pluripotent stem cells (iPSCs).

• Functional bioassays: IL-34 is used to stimulate proliferation, survival, and functional responses in human peripheral blood monocytes and macrophages, including the induction of cytokine production such as MCP-1 (CCL2).

• Colony-forming unit-macrophage (CFU-M) assays: IL-34 promotes the formation of CFU-M in human bone marrow cultures, supporting its role in myeloid lineage development.

• Disease modeling and mechanistic studies:

  • Graft-versus-host disease (GVHD): Recombinant IL-34 has been shown to mitigate GVHD severity in mouse models by reprogramming macrophages to a less inflammatory phenotype.
  • Acute myeloid leukemia (AML): IL-34 administration in mouse models suppresses leukemia development and promotes differentiation of leukemic cells.
  • Neuroinflammation and neurodegeneration: IL-34 is used to generate microglia-like cells for studies on neuroinflammation, fibromyalgia, and tau-associated neurodegeneration.
  • Cancer research: IL-34 is implicated in tumor progression, therapeutic resistance, and the regulation of tumor-associated macrophages.
  • Viral infection: IL-34 has been shown to inhibit hepatitis B virus replication in vitro and in vivo.
  • Autoimmune and inflammatory disease models: IL-34-induced macrophages are studied for their immunosuppressive properties and potential in anti-inflammatory and anti-fibrotic therapies.

• Signaling studies: IL-34 is used to investigate CSF1R (colony-stimulating factor 1 receptor) signaling pathways and downstream effects such as ERK1/2 phosphorylation in monocytes.

• Developmental biology: IL-34 is essential for the development of Langerhans cells and microglia, and is used in studies of bone marrow and central nervous system development.

• Immunomodulation and cell-cell interaction studies: IL-34 has been used to study its effects on T cell polarization (e.g., switching memory T cells into Th17 cells) and antibody-dependent cellular cytotoxicity (ADCC) and phagocytosis (ADCP) by monocytes and macrophages.

These applications are supported by both primary research articles and product validation data, demonstrating the broad utility of recombinant human IL-34 in immunology, cell biology, and disease research.

To reconstitute and prepare Recombinant Human IL-34 protein for cell culture experiments, dissolve the lyophilized protein at a concentration of 100 μg/mL in sterile PBS (phosphate-buffered saline) containing at least 0.1% human or bovine serum albumin (HSA/BSA) if the product contains a carrier, or in sterile PBS alone if it is carrier-free.

Step-by-step protocol:

• Centrifuge the vial briefly before opening to ensure all lyophilized material is at the bottom.
• Add sterile PBS (pH 7.2–7.4) to achieve the desired concentration (commonly 100 μg/mL).
  • For proteins supplied with a carrier (BSA/HSA), include at least 0.1% carrier protein in the PBS.
  • For carrier-free proteins, use only sterile PBS.
• Gently swirl or tap the vial to mix. Avoid vigorous shaking or vortexing, which can denature the protein.
• Allow the protein to dissolve at room temperature for 15–30 minutes with gentle agitation.
• Aliquot the reconstituted protein to avoid repeated freeze-thaw cycles.
• Storage after reconstitution:
  • Store aliquots at –20 °C to –80 °C for long-term use (up to 6 months).
  • For short-term use, store at 2–8 °C for up to 1 week.
• Avoid repeated freeze-thaw cycles to maintain protein activity.

Additional notes:

• The working concentration for cell culture applications (e.g., monocyte proliferation, microglia differentiation) typically ranges from 0.5–100 ng/mL, depending on the assay and cell type.
• Always consult the product’s Certificate of Analysis (CoA) for any lot-specific instructions.

Summary Table:

Key points:

• Use sterile technique throughout.
• Include carrier protein if recommended for stability.
• Avoid vigorous mixing and repeated freeze-thaw cycles.

These steps will ensure optimal solubility and biological activity of recombinant human IL-34 for cell culture experiments.