IL18

IL18, or interleukin 18, is a cytokine encoded by the IL18 gene in the human body and is a member of the IL-1 family.IL18 is expressed in a variety of cell types, including T cells, NK cells, and dendritic cells. Its mechanism of action involves binding to the IL18 receptor, which consists of an α-chain and a β-chain, where the α-chain is responsible for ligand binding and the β-chain mediates signaling.IL18 activates downstream signaling pathways through binding to its receptor, such as through the JAK/STAT pathway, which in turn affects cell proliferation, differentiation, and effector functions.

The biological significance of IL18 is mainly reflected in its role as an immunomodulatory factor involved in inflammation and immune response process. It induces T cells to produce interferon-γ (IFN-γ), promotes the activation of NK cells and other immune cells, as well as stimulates the production of cytokines such as tumor necrosis factor-α (TNF-α), IL-1β, etc. IL18 plays an important role in promoting the Th1-type immune response and is closely related to the development of a variety of inflammatory diseases, tumors, and autoimmune diseases. For example, IL18 expression levels are elevated in certain autoimmune diseases and may serve as a marker of disease activity. In addition, the maturation process of IL18 involves a non-classical inflammatory vesicle pathway, in which activation of caspase-4/5 cleaves the precursor IL18, releasing its mature form for biological function.