Description
The IL-18R complex is composed of two known chains, IL-18 receptor α chain (IL-18Rα) and IL-18Rβ. IL-18Rα (IL-1R5) was originally described as IL-1 receptor-related protein (IL-1Rrp) because of its homology with the IL-1/Toll receptor family and is the extracellular binding domain of the IL-18R complex. IL- 18Rβ (also known as IL- 18RAcPL or IL-1R7) is the signal transducing chain of the IL-18R complex and is also a member of the IL-1R family. It has been widely believed that the IL-18Rα is not expressed on naive T cells, but is induced during differentiation of Th1, but not Th2, cells