Purified anti-human IL-18

IL-18, initially described as IFN-g inducing factor (IGIF), is a pro-inflammatory cytokine. It is an 18-kD cytokine which identified as a costimulatory factor for production of interferon-gamma (IFN-gamma) in response to toxic shock and shares functional similarities with IL-12. IL-18 is synthesized as a precursor 24-kD molecule without a signal peptide and must be cleaved to produce an active molecule. IL-1 converting enzyme (ICE, Caspase-1) cleaves pro-IL-18 at aspartic acid in the P1 position, producing the mature, bioactive peptide that is readily released from the cells. It is reported that IL-18 is produced from Kupffer cells, activated macrophages, keratinocytes, intestinal epithelial cells, osteoblasts, adrenal cortex cells and murine diencephalon. The cytokine IL-18 possesses pleiotropic biological properties such as activation of NF-kb, Fas ligand expression, induction of both CC and CXC chemokines, enhancement of the production of IFN-g and GM-CSF, and induction of CD4+ cytolytic T cell response. Its role in neurodegeneartion disease has also been reported.