Interleukin‑1 receptor (IL-1R)

The Interleukin‑1 receptor (IL-1R) refers primarily to two structurally related transmembrane proteins, the type I (IL-1RI) and type II (IL-1RII) receptors, that bind cytokines IL-1α and IL-1β, key mediators of inflammation and immune responses. IL-1RI is the main signaling receptor, containing three extracellular immunoglobulin (Ig)-like domains and an intracellular Toll/IL-1 receptor (TIR) domain essential for signaling. Ligand binding by IL-1RI leads to recruitment of adaptor proteins and activation of pro-inflammatory signaling cascades such as NF-κB and MAPK pathways. IL-1RII acts mainly as a decoy receptor, sequestering IL-1 and inhibiting its activity. Both receptors play a crucial role in the body's defense against pathogens, but their overactivation is implicated in various inflammatory and autoimmune diseases as well as cancer and other pathologies. Therapeutic antagonists targeting IL-1R or its ligands are used to treat inflammatory diseases including rheumatoid arthritis and cryopyrin-associated periodic syndromes.

Other names

IL-1 receptorIL-1RInterleukin-1 receptor type I (IL-1RI)Interleukin-1 receptor type II (IL-1RII)IL1R1IL1R2

Competitive antagonism (e.g., anakinra blocks IL-1 binding to the receptor); Inhibition of cytokine signaling; Neutralization of IL-1β (e.g., canakinumab is a monoclonal antibody against IL-1β preventing its interaction with IL-1R)