IL-1R

Interleukin-1 Receptor (IL-1R) is a cytokine receptor that binds to interleukin 1 (IL-1α or IL-1β) and exists as two forms: the type I receptor IL-1R1 and the type II receptor IL-1R2. IL-1R1 is the predominant form found on T cells and fibroblasts, whereas IL-1R2 is the predominant form found on B cells, monocytes, neutrophils, and bone marrow cells[1]. IL-1R1 is the main receptor through which IL-1 exerts its effects and has the ability to bind to either form of IL-1, while IL-1R2 is an inactive IL-1 receptor that inhibits the effects of IL-1. In order to be active, the IL-1R1/IL-1 extracellular complex needs to bind to an additional co-receptor, IL-1 receptor paraprotein (IL-1RAcP) or IL-1R3, to form a trimer complex. IL-1RAcP is essential for signal transduction[2].