Hu Recom IL-2 (CHO Expr.), 100 µg

A monomeric cytokine originally identified as a T cell growth factor, IL-2 is supplied by STEMCELL Technologies as a human recombinant protein expressed in CHO cells. The lyophilized product is formulated after dialysis against phosphate-buffered saline. IL-2 binds heterotrimeric receptors composed of CD25, CD122, and CD132, activating JAK3-, STAT5-, and AKT-dependent signaling pathways that result in cellular proliferation and survival. The majority of IL-2 is secreted by activated CD4+ and CD8+ T cells, with smaller contributions from B cells and dendritic cells.

IL-2 downregulates immune responses to prevent autoimmunity during thymic development, influences the development of CD4+CD25+ regulatory T cells, affects the development of follicular helper T cells, and controls inflammation by inhibiting Th17 differentiation. Elevated serum IL-2 levels have been associated with progression of scleroderma, rheumatoid arthritis, and gastric and non-small cell lung cancer. Alternative names include Aldesleukin and T cell growth factor (TCGF), with UniProt accession number P60568.

The predicted molecular mass is 15.3 kDa, with purity ≥ 95% and endotoxin ≤ 0.2 EU/μg protein as measured by kinetic Limulus amebocyte lysate (LAL) analysis. Biological activity is determined by a cell proliferation assay using CTLL-2 cells, with an EC50 ≤ 2 ng/mL and a specific activity of approximately 4.1 × 10⁴ IU/µg calibrated against the human recombinant IL-2 WHO International Standard (NIBSC code: 86/500). The product should be stored at ≤ -80°C and is stable as supplied for 12 months from date of receipt. Centrifuge the vial before opening and reconstitute in sterile water to at least 0.1 mg/mL without vortexing.