IL-37 (human) (monomeric):Fc-KIH (human) (rec.)

IL-37 (IL-1F7, IL-1H4) is an IL-1 family member that is expressed only in certain types of human organs and cells such as heart, thymus, testis, kidney, mononuclear cells (PBMCs) and dendritic cells. IL-37 is a soluble and secreted cytokine of 218 residues that shares the beta-trefoil fold common to IL-1 family cytokines. But IL-37 is an atypical member of the IL-1 family of cytokines as it functions to inhibit many of the major pathways of innate and adaptive immunity and inflammation. It binds to the interleukin-18 receptor (IL-18R) and its co-receptor SIGIRR. IL-37 is secreted as a full-length and as a processed form starting from amino acid Val46 and assembles into an activity-limiting dimer with a dimerization constant in the nanomolar range. IL-37 mutations that lock the cytokine into its monomeric conformation (e.g. Y85A and D73K) are more active at blocking inflammation than wild-type dimer-forming IL-37 in a broad range of in vitro and in vivo activity assays. IL-37 also inhibited Lipopolysaccharide (LPS)-induced immunological reaction and LPS-induced osteoclast formation and bone resorption. IL-37 (human) (monomeric):Fc-KIH (human) (rec.) (Prod. No. AG-40B-0221) is a new recombinant monomeric IL-37 produced in mammalian cells that has enhanced stability and activity compared to the classical human recombinant IL-37 produced in bacteria. This monomeric IL-37 protein is produced by using two different vectors, one encoding for the IL-37 (monomeric):Fc Knobs sequence (synthesizing a protein of 50kDa) and one encoding for the Fc Holes sequence (synthesizing a protein of 28kDa). Both vectors transfected into HEK293 cells produce both Fc molecules (Knobs-into-Holes technology, J.B. Ridgway, et al., Protein Eng. 9, 617 (1996)) required for dimerization and for secretion of the final protein IL-37 (human) (monomeric):Fc-KIH (human) (rec.).