Recombinant Human VCAM-1 is widely used in research because it enables precise investigation of cell adhesion, migration, and inflammatory processes, particularly those involving leukocyte-endothelial interactions and vascular biology.

VCAM-1 (Vascular Cell Adhesion Molecule-1) is an immunoglobulin-like adhesion molecule expressed on activated endothelial cells. It mediates the adhesion and transmigration of leukocytes (such as lymphocytes, monocytes, eosinophils, and basophils) through binding to integrins like VLA-4 (α4β1) and α4β7 on leukocytes. This interaction is central to immune surveillance, inflammation, and the pathogenesis of diseases such as atherosclerosis, rheumatoid arthritis, and certain cancers.

Key research applications include:

• Modeling leukocyte-endothelial interactions: Recombinant VCAM-1 allows controlled in vitro studies of how immune cells adhere to and migrate across the endothelium, which is critical for understanding inflammation and immune cell trafficking.
• Disease modeling: VCAM-1 is implicated in atherosclerosis, cancer metastasis, and chronic inflammatory diseases. Using recombinant VCAM-1 helps dissect its role in these pathologies and test therapeutic interventions.
• Cell adhesion and migration assays: Immobilized recombinant VCAM-1 is used to quantify the adhesive properties of leukocytes or tumor cells, supporting studies on cell signaling, migration, and drug screening.
• Biomarker quantification and ELISA standards: Soluble VCAM-1 levels in biological fluids are used as biomarkers for inflammation and cardiovascular risk. Recombinant VCAM-1 serves as a standard in ELISA and other immunoassays.
• Immunological and biochemical assays: It is used as a positive control or capture reagent in Western blotting, immunoprecipitation, and flow cytometry.

Advantages of using recombinant protein:

• Consistency and purity: Recombinant VCAM-1 provides a defined, reproducible reagent with high purity, minimizing variability compared to native sources.
• Functional validation: Many recombinant VCAM-1 preparations are validated for biological activity, such as supporting leukocyte adhesion, ensuring experimental reliability.

In summary, recombinant human VCAM-1 is a versatile tool for studying vascular biology, inflammation, immune cell trafficking, and related disease mechanisms, as well as for developing and validating therapeutic strategies targeting these pathways.

Yes, you can use recombinant human VCAM-1 as a standard for quantification or calibration in your ELISA assays, provided that the recombinant protein matches the form of VCAM-1 detected by your assay (e.g., soluble, full-length, or specific isoform). Many commercial ELISA kits for human VCAM-1 are designed to recognize both endogenous and recombinant forms of the protein, and several manufacturers explicitly state that their kits can be used with recombinant VCAM-1 for standard curve generation.

For example:

• The ScienCell Human VCAM-1 ELISA Kit uses recombinant human VCAM-1 as the standard.
• Abcam and Medix Biochemica ELISA kits recognize both natural and recombinant human VCAM-1.
• It is important to validate the compatibility of your specific recombinant VCAM-1 with your ELISA system, especially if the protein has been produced in a different expression system (e.g., CHO, HEK, E. coli) or has post-translational modifications that may affect antibody binding.

Best practices:

• Always use a freshly prepared standard curve for each ELISA run.
• Ensure the recombinant VCAM-1 is properly diluted in a matrix similar to your samples to minimize matrix effects.
• Confirm the linearity and recovery of the standard in your assay conditions.

In summary, recombinant human VCAM-1 is suitable for use as a standard in ELISA assays, but assay-specific validation is recommended to ensure accurate quantification.

Validated Applications of Recombinant Human VCAM-1

Recombinant human VCAM-1 has been validated across a diverse range of research applications, spanning basic immunology, cell biology, developmental biology, and translational disease modeling.

Cell Adhesion and Leukocyte Interaction Studies

The primary validated application involves studying cell adhesion mechanisms. Recombinant human VCAM-1 effectively supports the adhesion of multiple leukocyte populations, including lymphocytes, monocytes, eosinophils, and basophils, through binding to leukocyte integrins VLA-4 (α4β1) and α4β7. When immobilized at 10 μg/mL, the protein demonstrates robust biological activity, with approximately 85–95% of U937 human histiocytic lymphoma cells adhering after 1 hour incubation at room temperature. This functionality has been applied to investigate eosinophil transmigration in the presence of VCAM-1 and to study monocyte migration in confining channels.

Inflammatory and Vascular Biology Research

Recombinant VCAM-1 has been validated for investigating inflammatory processes and endothelial cell activation. The protein has been used to study VCAM-1-mediated endothelial cell responses, particularly in the context of pro-inflammatory cytokine stimulation such as TNF-α. Research has demonstrated that recombinant human VCAM-1 treatment induces significant molecular changes in hepatic stellate cells, including induction of YAP1 and its target genes such as connective tissue growth factor (CTGF) and ankyrin repeat domain protein 1 (ANKRD1). These applications extend to modeling liver fibrosis and understanding VCAM-1's role as a modulator of liver sinusoidal endothelial cell capillarization.

Hematopoietic and Stem Cell Differentiation

A particularly significant validated application involves hematopoietic differentiation from pluripotent stem cells. Recombinant VCAM-1, when combined with DLL4, markedly enhances the production of hematopoietic progenitors with T cell potential from human pluripotent stem cells (hPSCs), increasing downstream T cell progenitor output by more than 80-fold. This synergistic effect demonstrates VCAM-1's cooperative role in enhancing Notch signaling during endothelial-to-hematopoietic transition.

Bioassay and Immunological Applications

The protein has been validated for use in multiple bioassay formats, including ELISA standards, Western blotting, immunoprecipitation, and mass cytometry applications. These applications support both qualitative and quantitative analysis of VCAM-1 interactions and expression patterns in various biological systems.

Disease Modeling and Therapeutic Development

Recombinant VCAM-1 has been validated in disease modeling contexts, particularly for investigating inflammatory bowel disease, atherosclerosis, and cancer metastasis. The protein's functional involvement in cancer cell metastasis and its role in facilitating adhesive cell-to-cell attachments through integrin binding have positioned it as a valuable tool for understanding VCAM-1-mediated pathological processes.

To reconstitute and prepare Recombinant Human VCAM-1 protein for cell culture experiments, follow these best-practice steps:

1. Centrifuge the vial briefly before opening to ensure all lyophilized protein is at the bottom and to prevent loss of material when opening.

2. Add sterile, deionized water to reconstitute. A typical concentration is 1 mg/mL; do not reconstitute to less than 100 μg/mL unless specifically required for your application.

3. Gently mix by swirling or inverting the vial. Avoid vortexing or vigorous pipetting, as this can denature the protein.

4. Allow the protein to dissolve at room temperature for 10–15 minutes.

5. Aliquot the reconstituted solution to minimize freeze-thaw cycles. Store aliquots at 2–8 °C for up to 1 week, or at –20 °C or below for longer-term storage (up to 3 months at –20 °C to –80 °C).

6. For cell culture applications:

   • If coating plates, dilute the reconstituted VCAM-1 to the desired working concentration (e.g., 10 μg/mL in PBS for cell adhesion assays).
   • Incubate the coated plates at room temperature for 1–2 hours or overnight at 4 °C, then wash to remove unbound protein before adding cells.
   • For soluble applications, dilute the protein in cell culture medium or buffer as required for your experiment.

Additional notes:

• Avoid repeated freeze-thaw cycles, as these can reduce protein activity.
• Confirm biological activity (e.g., via cell adhesion assay) if required for your application.
• If the protein is supplied with additives (e.g., PBS, sorbitol, calcium, magnesium), check compatibility with your downstream application.

Summary Table: Key Steps for VCAM-1 Reconstitution

These steps ensure optimal solubility and activity of recombinant VCAM-1 for cell culture experiments.