Interleukin-1 receptor type 1 (IL-1R1) (IL-1R1)

Interleukin-1 receptor type 1 (IL-1R1) is a pivotal transmembrane protein expressed on a wide array of immune cells, including monocytes, macrophages, and T-lymphocytes, where it functions as the primary signaling receptor for the pro-inflammatory cytokines IL-1 alpha and IL-1 beta [UniProt P14778]. Upon binding its ligands, IL-1R1 recruits the IL-1 receptor accessory protein (IL-1RAP) to form a high-affinity complex that initiates intracellular signaling via the MyD88-dependent pathway, ultimately activating NF-kappa-B and mitogen-activated protein kinases (MAPKs) [PubMed: 26133395]. This signaling cascade drives the production of various inflammatory mediators, such as IL-6 and prostaglandins, which are essential for the innate immune response but can lead to tissue damage if dysregulated [StatPearls: NBK554444]. Consequently, IL-1R1 is a major therapeutic target in autoinflammatory diseases, rheumatoid arthritis, and other conditions characterized by excessive IL-1 activity [PubMed: 29147252]. Drugs like Anakinra, a recombinant IL-1 receptor antagonist, work by competitively binding to IL-1R1, thereby blocking the pro-inflammatory effects of IL-1 and providing significant clinical benefit in systemic inflammatory states [FDA: Kineret Label]. However, because IL-1 signaling is crucial for host defense, therapeutic inhibition of this receptor is associated with an increased risk of serious infections and requires careful patient monitoring [PubMed: 15546612].

Other names

CD121aIL1R1IL1RAIL-1R-alphaP80Antigen CD121aIL1RT1

Anakinra acts as a competitive antagonist by binding to the Interleukin-1 receptor type 1 (IL-1R1), thereby preventing the binding of the pro-inflammatory cytokines IL-1 alpha and IL-1 beta. This blockade inhibits the recruitment of the IL-1 receptor accessory protein (IL-1RAP) and prevents the activation of downstream signaling pathways, such as NF-kappa-B and MAPK, which are responsible for the expression of inflammatory genes [PubMed: 26133395, FDA: Kineret Label].