Recombinant Human Galectin-1

Recombinant human galectin-1 (rHsGal-1) is a valuable research tool with diverse applications spanning immunology, cell biology, and therapeutic development. Here are the key reasons to incorporate it into your research:

Immunomodulatory Properties

Recombinant galectin-1 exhibits potent immunosuppressive and anti-inflammatory effects that make it particularly useful for studying immune regulation. The protein selectively controls T cell survival by inducing apoptosis of activated Th1 and Th17 cells while promoting Th2 cell survival, allowing you to investigate differential immune responses in your experimental systems. Additionally, it contributes to negative selection of developing T cells and supports regulatory T cell function, making it ideal for studying immune tolerance mechanisms.

Anti-inflammatory Applications

The protein effectively inhibits leukocyte migration and extravasation in inflammatory settings. At optimal concentrations (approximately 0.3 μg), recombinant galectin-1 inhibits polymorphonuclear leukocyte (PMN) chemotaxis and transmigration across endothelial barriers, providing a tool for investigating leukocyte-endothelial interactions. This makes it particularly valuable for acute and chronic inflammation models, including arthritis and inflammatory disease research.

Cell-Cell and Cell-Matrix Interaction Studies

Galectin-1 modulates cell-cell and cell-matrix interactions, promoting either cell attachment or detachment depending on the cell type and developmental stage. This versatility enables investigation of adhesion mechanisms, cell signaling, and developmental processes in various biological contexts.

Therapeutic Development Research

The protein serves as a foundation for developing novel therapeutics. Research demonstrates potential applications in treating inflammatory and autoimmune diseases, muscular dystrophies, and cancer immunotherapy. Its role in immune evasion by tumor cells also makes it valuable for cancer biology research and immunotherapy development.

Established Bioassay Applications

Recombinant galectin-1 is well-characterized for multiple bioassay formats, including red blood cell agglutination assays (ED₅₀ < 5.0 µg/ml) and T-cell death assays. These standardized applications provide reliable readouts for functional studies and screening experiments.

Pregnancy and Immune Tolerance Research

The protein plays a critical role in creating immune tolerance during pregnancy, making it essential for studying fetal immune privilege and maternal-fetal immunological interactions.

When using recombinant galectin-1, maintain protein integrity by avoiding repeated freeze-thaw cycles and verify bioactivity through appropriate controls, such as heat-inactivation or neutralizing antiserum, to confirm specificity of observed effects.

Yes, recombinant human Galectin-1 can be used as a standard for quantification or calibration in ELISA assays, provided it is of appropriate purity and correctly formulated for this purpose. Multiple validated ELISA kits and protocols use recombinant human Galectin-1 as the standard to generate calibration curves for quantifying Galectin-1 in biological samples.

Key considerations and supporting details:

• ELISA Standard Use: Commercially available ELISA kits for human Galectin-1 routinely use recombinant human Galectin-1, often expressed in E. coli, as the standard for generating calibration curves. These standards are validated to ensure that the assay can accurately quantify both recombinant and native Galectin-1 in samples.

• Parallelism and Accuracy: Studies and kit documentation show that standard curves generated with recombinant Galectin-1 are parallel to those obtained with native Galectin-1, indicating that the recombinant protein is suitable for accurate quantification.

• Formulation Requirements: The recombinant protein should be of high purity, free from interfering substances (such as high levels of endotoxin or carrier proteins unless specifically required), and reconstituted or diluted in the same buffer as your samples to ensure consistency and accuracy in quantification.

• Validation: If you are developing your own ELISA or using a kit not originally validated with your specific recombinant standard, it is best practice to confirm that your standard produces a linear, parallel standard curve and that recovery and precision are within acceptable ranges.

• Intended Use: Ensure the recombinant Galectin-1 you use is labeled or validated for use as an ELISA standard. Some recombinant proteins are formulated for bioassays or cell culture and may not be suitable for calibration in immunoassays unless specifically tested for this application.

Summary Table: Recombinant Galectin-1 as ELISA Standard

Best Practices:

• Use the same diluent for standards and samples.
• Validate parallelism and recovery if using a new recombinant standard.
• Avoid repeated freeze-thaw cycles to maintain protein integrity.

Conclusion:
Recombinant human Galectin-1 is widely accepted and validated as a standard for ELISA quantification, provided it meets purity and formulation requirements and is validated for this use in your specific assay context.

Recombinant Human Galectin-1 has been validated for a broad range of applications in published research, primarily in immunology, cell biology, and cancer studies. Key validated applications include:

• Induction of apoptosis in T cells and immune modulation: Recombinant Galectin-1 is widely used in T-cell death assays to study its ability to induce apoptosis in activated T cells, particularly Th1 and Th17 subsets, and to promote immune tolerance by modulating dendritic cell differentiation and regulatory T cell function.
• Bioassays for cell adhesion, migration, and cell-matrix interactions: It is used to investigate cell-matrix interactions, cell attachment/detachment, and modulation of cell proliferation, especially in the context of tumorigenesis and immune cell trafficking.
• Agglutination assays: Recombinant Galectin-1 can agglutinate human red blood cells, and this property is used in hemagglutination assays to assess its carbohydrate-binding activity.
• Cancer research and tumor immunology: It is employed to study tumor immune evasion, tumor progression, and as a target for diagnostic imaging and therapeutic monitoring, especially in aggressive cancers such as triple-negative breast cancer.
• Bioactivity and functional studies: Used in various bioassays to assess its immunosuppressive, anti-inflammatory, and pro-apoptotic activities in different cell types, including B lymphocytes, neutrophils, and stem cells.
• Surface plasmon resonance (SPR) and binding studies: Recombinant Galectin-1 is used as a ligand in SPR assays to characterize its interactions with glycan ligands and other proteins.
• Western blot control and HPLC/SDS-PAGE standards: It serves as a positive control in Western blotting and as a standard in HPLC and SDS-PAGE for protein characterization.
• Nanoparticle conjugation and drug delivery research: Galectin-1 has been conjugated to nanoparticles to explore its potential in targeted drug delivery and immunomodulation in autoimmune and chronic inflammatory disorders.

Additional validated uses:

• Stem cell biology: Studying its role in stem cell differentiation and adhesion.
• HIV infection models: Investigating its modulatory effects on HIV-1 infection in macrophages.
• Fibrosis models: Assessing its involvement in TGF-β1-induced fibrosis via Smad2 signaling.

These applications are supported by both primary research articles and product validation data, demonstrating the protein's versatility in experimental immunology, oncology, cell biology, and translational research.

To reconstitute and prepare Recombinant Human Galectin-1 protein for cell culture experiments, follow these general best practices based on manufacturer recommendations and scientific protocols:

1. Reconstitution

• Centrifuge the lyophilized protein vial briefly (e.g., 3,000 rpm for 5 minutes) before opening to ensure all powder is at the bottom.
• Reconstitute the protein in sterile, high-purity water (e.g., 18 MΩ-cm H₂O) or sterile PBS, depending on the manufacturer’s instructions. Typical concentrations are 100 µg/mL to 1 mg/mL.
  • For example:
    • Some recommend not less than 100 µg/mL in sterile water or PBS.
    • Others suggest 0.1–1.0 mg/mL in sterile water or aqueous buffer.
• If the protein is sensitive to aggregation or loss of activity, consider adding 0.1% BSA (bovine serum albumin) or carrier protein to the reconstitution buffer.
• Gently swirl or pipette up and down to dissolve the protein; avoid vigorous shaking to prevent denaturation.

2. Aliquoting and Storage

• Aliquot the reconstituted protein into small volumes to avoid repeated freeze-thaw cycles.
• Store at –80°C for long-term stability. Use a manual defrost freezer if possible.

3. Sterilization

• For cell culture applications, sterilize the protein solution by filtration through a 0.22 µm filter in a clean bench or biosafety cabinet.

4. Buffer Exchange (Optional)

• If necessary, use an ultrafiltration device to concentrate or exchange the buffer to match your cell culture medium (e.g., PBS or serum-free medium).

5. Quality Control

• Check protein concentration using UV spectroscopy (A280) or a protein assay.
• For sensitive cell culture experiments, test for endotoxin (LPS) contamination using a Limulus amebocyte lysate (LAL) assay, especially if the protein was produced in E. coli.

6. Application in Cell Culture

• Dilute the reconstituted protein to the desired working concentration in your cell culture medium.
• Typical working concentrations for bioassays range from 10 ng/mL to 10 µg/mL, depending on the experiment.

Example Protocol Summary:

1. Centrifuge vial briefly.
2. Reconstitute in sterile water or PBS to 100 µg/mL–1 mg/mL.
3. Add 0.1% BSA if recommended.
4. Gently mix until fully dissolved.
5. Filter sterilize (0.22 µm).
6. Aliquot and store at –80°C.
7. Dilute to working concentration in cell culture medium before use.

Always refer to the specific product datasheet for exact instructions, as formulations and recommendations may vary between suppliers.