IL-18

Interleukin-18 (IL-18) is a potent proinflammatory cytokine that induces interferon-γ (IFN-γ) production from T helper type 1 (Th1) cells and natural killer (NK) cells, particularly in the presence of IL-12. IL-18 also participates in the developmental regulation of Th1 cells and mediates Fas-mediated cytotoxicity. Suppression of IL-18 activity is being investigated for the treatment of chronic inflammatory diseases such as Crohn's disease and rheumatoid arthritis. IL-18 exerts its biological functions by inducing heterodimerization of the two subunits of its receptor, IL-18Rα and IL-18Rβ. These subunits share structural homology with members of the IL-1 receptor superfamily.