Cloning, Expression And Function Of Human Interleukin 22

Interleukin-22 (IL-22) is a cytokine derived from actived T lymphocytes and belongs to the IL-10 family of cytokines. IL-22 exerts its functions by binding to a receptor complex composed of 2 chains: IL-22R 1 and IL-10R2. Both chains are necessary to assemble the functional receptor complex able to induce signaling after binding IL-22. However, none of them are capable of transducing IL-22-signaling alone. IL-22 also has been shown to activate multiple signaling pathways, including the Janus kinase-signal transducer, activator of transcription factor (STAT) and mitogen-activated protein kinase pathways in hepatic cells. It has been shown that IL-22 up-regulates the expression of acute-phase proteins in liver and of pancreatitis-associated proteins in pancreatic acinar cells, suggesting that IL-22 plays a role in inflammatory responses. IL-22 activates STAT transcription factors in neuronal cells, kidney mesangial cells, hepatocytes, melanoma and instestinal epithelial cells .IL-22 modestly inhibited production of IL-4 from Th2 cell in combination with concanavalin A. The ability of IL-22 to suppress IL-4 production might have a therapeutic potential, particularly in the treament of asthma. Recent study suggests that the T cell-derived cytokine IL-22 is a survival factor for hepatocytes; this means that T cell activation may also prevent and repair liver injury by releasing hepatoprotective cytokine IL-22.A cDNA fragment encoding mature hIL-22 was amplified by RT-PCR from mRNA extracted from anti-CD3 and ConA activated peripheral blood white cells. The gene was sequenced and consistent with that reported. A DNA fragment that encodes the IL-22 was introduced into the expression vector pBV220 and pET17b.