Hu Recom IL-2 (E.coli Expr.), 1000 µg

STEMCELL Technologies offers this recombinant human interleukin-2 (IL-2), a monomeric cytokine originally identified as a T cell growth factor, expressed in E. coli and supplied as a lyophilized powder formulated from a sterile-filtered aqueous solution containing 0.1% trifluoroacetic acid. The protein binds heterotrimeric receptors composed of CD25, CD122, and CD132, activating JAK3-, STAT5-, and AKT-dependent signaling pathways that drive cellular proliferation and survival. IL-2 is secreted mainly by activated CD4+ and CD8+ T cells, with smaller contributions from B cells and dendritic cells. It downregulates immune responses during thymic development to help prevent autoimmunity, influences the development of CD4+CD25+ regulatory T cells, and affects the development of follicular helper T cells, while also controlling inflammation by inhibiting Th17 differentiation. Elevated serum levels have been linked with progression of scleroderma, rheumatoid arthritis, and gastric and non-small cell lung cancer.

The product has a predicted molecular mass of 15.5 kDa and a stated purity of ≥ 97%. Activity is determined by a CTLL-2 cell proliferation assay, with an EC50 ≤ 3 ng/mL and a specific activity of approximately 1.8 x 10^4 IU/µg, calibrated against the human recombinant IL-2 WHO International Standard (NIBSC code: 86/500). Endotoxin level is measured by kinetic Limulus amebocyte lysate (LAL) analysis and is ≤ 0.1 EU/µg protein. For preparation, the vial should be centrifuged before opening and reconstituted in sterile 10 mM hydrochloric acid to at least 0.1 mg/mL without vortexing. The product should be stored at -20 to -80°C, where it remains stable for 12 months from the date of receipt, and repeated freeze-thaw cycles should be avoided. This product is for research use only and not intended for human or animal diagnostic or therapeutic uses.