Discription：Interleukin-18 （IL-18） is a proinflammatory cytokine in the IL-1 family that exerts distinct immune effects depending on the local cytokine environment. IL-18 activation is induced by infection or tissue damage and contributes to disease pathology in chronic inflammation. IL-18 binds to the widely expressed IL-18 R alpha which recruits IL-18 Rβ to form the signaling receptor complex. Its bioactivity is negatively regulated by interactions with IL-18 binding proteins and virally encoded IL-18BP homologs. IL-18 also promotes myeloid dendritic cell maturation and triggers neutrophil respiratory burst. In cancer, IL-18 exhibits diverse activities including enhancing anti-tumor immunity, inhibiting or promoting angiogenesis, and promoting tumor cell metastasis. Alternative splicing in human ovarian cancer generates an isoform that is resistant to Caspase-1 activation. A cell surface form can be expressed on M-CSF induced macrophages and released in response to bacterial endotoxin. Mature human IL-18 shares approximately 63％ amino acid sequence identity with mouse and rat IL-18. Recombinant IL-18 is a single non-glycosylated polypeptide chain containing 157 amino acids
