Hu Recom IL-2 (CHO Expr.), 1000 µg

A recombinant human cytokine from STEMCELL Technologies, Interleukin-2 (IL-2) is produced by expression in CHO cells and is supplied as a lyophilized powder prepared by dialysis against phosphate-buffered saline. The product is designated for laboratory research use only and is not intended for human or animal diagnostic or therapeutic applications.

IL-2 is a monomeric cytokine originally characterized as a T cell growth factor. It binds heterotrimeric receptors composed of CD25, CD122, and CD132 and triggers JAK3-, STAT5-, and AKT-dependent signalling that supports cellular proliferation and survival. The majority of IL-2 is secreted by activated CD4+ and CD8+ T cells, although B cells and dendritic cells can produce it in small amounts. The cytokine downregulates immune responses during thymic development, influences the development of CD4+CD25+ regulatory T cells, affects follicular helper T cell development, and limits inflammation by inhibiting Th17 differentiation.

The protein has a predicted molecular mass of 15.3 kDa. Biological activity is determined in a CTLL-2 cell proliferation assay with an EC50 of ≤ 2 ng/mL (1.2 ng/mL in the example provided). Specific activity is approximately 4.1 x 10^4 IU/µg as calibrated against the human recombinant IL-2 WHO International Standard (NIBSC code: 86/500). Purity is ≥ 95% and endotoxin level is ≤ 0.2 EU/µg protein by kinetic LAL analysis. The product is reconstituted in sterile water to at least 0.1 mg/mL by pipetting down the sides of the vial (do not vortex), stored at ≤ -80 °C, and is stable as supplied for 12 months from the date of receipt. As a general guide, do not store at 2–8 °C for more than 1 week or at -20 °C to -80 °C for more than 2 months, and avoid repeated freeze-thaw cycles.