IL-27 (human): Fc (human) (rec.)

Unfortunately, most cytokines have short circulating half-lives. With the creation of a group of new immunoglobulin- based cytokine fusion proteins, in which a cytokine sequence had been genetically fused to the hinge, CH2 and CH3 regions of an immunoglobulin, these cytokine fusion proteins possess both the biological functions of the cytokine moiety and the prolonged circulating half-life determined by the Fc domain. Interleukin-27 (IL-27) is a heterodimeric group 2 receptor ligand molecule that belongs to the IL-6/IL-12 family of long type I cytokines. It is composed of EBI3 (EBV-induced gene 3), a 34 kDa glycoprotein that is related to the p40 subunit of IL-12 and IL-23, and p28, the cloned 28 kDa glycoprotein that is related to the p35 chain of IL-12. IL-27 is expressed by monocytes, endothelial cells and dendritic cells. IL-27 binds to and signals through a heterodimeric receptor complex composed of WSX1 (TCCR) and gp130. Evidence suggests IL-27 interacts only with WSX-1. IL-27 has both anti- and proinflammatory properties. As an antiinflammatory, IL-27 seems to induce a general negative feedback program that limits T and NK-T cell activity. At the onset of infection, IL-27 induces an IL-12 receptor on naïe CD4 T cells, making them susceptible to subsequent IL-12 activity (and possible Th1 development). Notably, IL-12 family cytokines are both induced and inhibited by bacterial products. Microbes promote IL-27 secretion through TLR4, and also block IL-27 production via C5a induction.