Mouse IL-6 Bioactivity

IL-6 acts as both a pro-inflammatory and anti-inflammatory cytokine. It is secreted by T cells and macrophages to stimulate immune response to trauma, especially burns or other tissue damage leading to inflammation. IL-6 is also produced from muscle, and is elevated in response to muscle contraction. It is significantly elevated with exercise and precedes the appearance of other cytokines in the circulation. Osteoblasts secrete IL-6 to stimulate osteoclast formation. Smooth muscle cells also produce IL-6 as a pro-inflammatory cytokine. The role of IL-6 as an anti-inflammatory cytokine is mediated through its inhibitory effects on TNF-alpha and IL-1 and activation of IL-1ra and IL-10.

Kingfisher Biotech’s Mouse IL-6 (cat # RP0380M) activity was accessed and shown to be active and comparable with other commercially available Mouse IL-6 protein. This work was done by an independent lab with expertise in bioassays. Both samples of Mouse IL-6 were reconstituted with 0.1% BSA in PBS prior to assay. Kingfisher Biotech’s Mouse IL-6 protein concentration was determined by BCA. Protein determination of the competitor’s protein is unknown. Kingfisher Biotech’s mouse IL-6 was expressed in yeast so it is naturally endotoxin-free and post-translationally modified. Mouse IL-6 purchased from Competitor A was produced in E. coli.

Method

The biological activity of Kingfisher Biotech Recombinant Mouse IL-6 was verified by proliferation of 7TD1 cells, a mouse IL-6-dependant B-cell hybridoma cell line. Briefly, 7TD1 cells were incubated with various concentrations of recombinant Mouse IL-6 protein in a dose dependent manner in complete medium containing 10% calf serum and Gentamicin for 64 hours at 37°C, 5% CO2 in a 96-well tissue culture plate. Cell proliferation was measured utilizing Promega Substrate Cell Titer 96 Aqueous One Solution Reagent and measuring the optical density of the final solution at 490 nm. The ED50 of Kingfisher Biotech Recombinant Mouse IL-6 protein was determined to be 0.006-0.009 ng/ml.