Recombinant Human IL-2

Recombinant Human IL-2 is widely used in research applications because it is a potent cytokine that regulates immune cell proliferation, differentiation, and function, making it essential for studies involving T cells, NK cells, B cells, and immune modulation.

Key scientific reasons to use recombinant human IL-2 in research include:

• T Cell Expansion and Activation: IL-2 is critical for the proliferation and activation of CD4+ and CD8+ T cells, which is fundamental for immunological assays, adoptive cell therapies, and CAR-T cell manufacturing workflows.
• NK and B Cell Stimulation: IL-2 also promotes the growth and functional activity of natural killer (NK) cells and B cells, supporting research in innate and adaptive immunity.
• Regulatory T Cell Development: IL-2 is essential for the development, survival, and function of regulatory T cells (Tregs), which are crucial for immune tolerance and studies of autoimmune diseases.
• Cancer Immunotherapy Research: Recombinant IL-2 has been pivotal in developing immunotherapies, especially for metastatic melanoma and renal cell carcinoma, and is used to expand tumor-infiltrating lymphocytes for adoptive cell transfer studies.
• Autoimmunity and Immune Modulation: Low-dose IL-2 is being investigated for its ability to selectively expand Tregs and modulate immune responses in autoimmune and inflammatory disease models.
• Reproducibility and Purity: Recombinant production ensures high purity, low endotoxin levels, and batch-to-batch consistency, which are critical for reliable experimental outcomes.

Additional considerations:

• Validated Bioactivity: Recombinant IL-2 is biologically active and validated in cell-based assays, ensuring its effectiveness in experimental protocols.
• Scalability and Supply: Recombinant systems allow for scalable production, supporting large-scale experiments and clinical-grade cell manufacturing.

In summary, recombinant human IL-2 is indispensable for immunological research due to its central role in immune cell biology, therapeutic development, and experimental reproducibility.

Yes, recombinant human IL-2 can be used as a standard for quantification or calibration in ELISA assays. Multiple sources confirm that recombinant human IL-2 is specifically designed and validated for this purpose. Here are the key points:

• Recombinant human IL-2 is commonly used as a standard in sandwich ELISA assays for the quantitative determination of IL-2 in samples such as cell culture supernatants, serum, and plasma.
• The protein is suitable for generating a standard curve, typically through serial dilutions (e.g., doubling dilutions from 2000 pg/mL down to 15 pg/mL or similar ranges depending on the kit).
• The assay will recognize both natural and recombinant human IL-2, ensuring accurate quantification.
• It is recommended to reconstitute the standard according to the manufacturer's instructions and to generate a fresh standard curve for each assay to ensure accuracy.
• The immunoassay is often calibrated against international reference standards (e.g., NIBSC 86/504) to ensure consistency and comparability across different laboratories and kits.

In summary, recombinant human IL-2 is an appropriate and widely used standard for calibrating and quantifying IL-2 levels in ELISA assays.

Recombinant Human IL-2 has been validated for a broad range of applications in published research, primarily in immunology, cell therapy, and cancer immunotherapy.

Key validated applications include:

• Immune cell activation and proliferation: IL-2 is widely used to activate and expand T cells (both CD4⁺ and CD8⁺), regulatory T cells (Tregs), and natural killer (NK) cells in vitro and in vivo.
• Cell culture and expansion protocols: Recombinant IL-2 is a standard supplement for the expansion of T cells and NK cells in cell culture, including protocols for adoptive cell therapy and CAR T cell manufacturing.
• Cancer immunotherapy: High-dose recombinant IL-2 is FDA-approved for metastatic melanoma and renal cell carcinoma, where it boosts anti-tumor immune responses. It is also used in combination with immune checkpoint inhibitors and cancer vaccines.
• Autoimmune disease research: Low-dose IL-2 is being investigated for selective expansion of Tregs to restore immune balance in conditions such as lupus and type 1 diabetes.
• Transplantation tolerance: Modified forms of recombinant IL-2 have been validated for expanding Tregs to promote tolerance and prolong allograft survival in transplantation models.
• Bioassays and functional assays: IL-2 is used as a positive control and stimulant in various immunological bioassays, including cytokine detection and quantification.
• Hematopoietic stem and progenitor cell research: IL-2 supports the expansion and maintenance of certain stem and progenitor cell populations.
• Chronic infection models: IL-2 has been studied for enhancing immune cell recovery and function in chronic infections such as HIV and hepatitis C.

Additional validated uses:

• Screening and release assays for cell therapy products.
• Differentiation studies for immune cell subsets.
• Combination protocols with other cytokines (e.g., IL-15) to increase cell viability and proliferation.

These applications are supported by extensive published research and clinical studies, demonstrating recombinant human IL-2’s central role in immunological assays, cell therapy development, and translational medicine.

To reconstitute and prepare Recombinant Human IL-2 protein for cell culture experiments, dissolve the lyophilized protein in sterile 100 mM acetic acid or sterile distilled water to a concentration of at least 100 μg/mL, optionally including 0.1% carrier protein (such as human or bovine serum albumin) to enhance stability.

Step-by-step protocol:

1. Preparation:

   • Briefly centrifuge the vial to collect the powder at the bottom before opening.
   • Perform all steps under aseptic conditions in a biosafety cabinet.

2. Reconstitution:

   • Add sterile 100 mM acetic acid (preferred for maximum solubility and activity) or sterile distilled/deionized water to achieve a final concentration of 100 μg/mL or higher.
   • If using water, use the solution within 24 hours and store at 2–8 °C.
   • For improved stability, add at least 0.1% carrier protein (e.g., human or bovine serum albumin) to the reconstitution buffer.
   • Gently swirl or tap the vial to dissolve; do not vortex, as vigorous agitation may reduce biological activity.

3. Aliquoting and Storage:

   • Once fully dissolved, aliquot the solution into working volumes to avoid repeated freeze-thaw cycles.
   • Store aliquots at ≤ –20 °C for long-term storage. Avoid frost-free freezers.
   • For short-term use (up to 1 week), store at 2–8 °C.

4. Dilution for Cell Culture:

   • Make further dilutions in cell culture medium or buffer containing serum or 0.1% BSA/HSA to minimize protein loss due to adsorption.
   • The optimal working concentration depends on your specific assay and cell type; titrate as needed.

Additional notes:

• If using a carrier-free formulation, reconstitute in 100 mM acetic acid only.
• Some protocols recommend reconstitution in 10 mM HCl at 0.1 mg/mL as an alternative.
• Avoid filtering the reconstituted IL-2 unless absolutely necessary, as the protein is typically provided sterile and filtration may cause loss of material.

Summary of key points:

• Reconstitution buffer: 100 mM acetic acid (preferred) or sterile water.
• Concentration: ≥100 μg/mL.
• Carrier protein: 0.1% BSA or HSA recommended for stability.
• Mixing: Gentle swirling, no vortexing.
• Storage: Aliquot and freeze at ≤ –20 °C; short-term at 2–8 °C.
• Dilution: Use cell culture medium with serum or BSA/HSA.

These steps will ensure that your recombinant human IL-2 is optimally prepared for cell culture applications.