Hu Recom IL-2 (CHO Expr.), 50 µg

STEMCELL Technologies supplies a recombinant human Interleukin-2 (IL-2) expressed in CHO cells. Also referred to as Aldesleukin, T cell growth factor, and TCGF (UniProt accession P60568), IL-2 is a monomeric cytokine originally identified as a T cell growth factor. It binds heterotrimeric receptors composed of CD25, CD122, and CD132, activating JAK3-, STAT5-, and AKT-dependent signalling pathways that drive cellular proliferation and survival. Most IL-2 is secreted by activated CD4+ and CD8+ T cells, while B cells and dendritic cells produce smaller amounts. The cytokine downregulates immune responses to prevent autoimmunity during thymic development, shapes the development of CD4+CD25+ regulatory T cells and follicular helper T cells, and limits 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, although no known disease has been directly attributed to IL-2 deficiency or excess.

The lyophilized product, formulated after dialysis against phosphate-buffered saline, has a predicted molecular mass of 15.3 kDa. Purity is ≥ 95%, and the endotoxin level is ≤ 0.2 EU/μg protein as measured by kinetic Limulus amebocyte lysate (LAL) analysis. Biological activity was determined by a cell proliferation assay using CTLL-2 cells, with an EC50 of ≤ 2 ng/mL; a representative experiment yielded 1.2 ng/mL. The specific activity is approximately 4.1 x 10^4 IU/µg, calibrated against the human recombinant IL-2 WHO International Standard (NIBSC code: 86/500).

Store at ≤ -80°C; the vial is stable as supplied for 12 months from the date of receipt. Centrifuge the vial before opening. Reconstitute in sterile water to at least 0.1 mg/mL by pipetting the solution down the sides of the vial without vortexing. For research use only.