title: IL-1 receptor 2 (IL-1R2) and its role in immune regulation.
abstract: The cytokine IL-1 is critical to the pathogenesis of a variety of human conditions and diseases. Unlike most other cytokines, IL-1 is counterbalanced by two endogenous inhibitors. The functional significance of IL-1 receptor antagonist (IL-1RA) is well documented due to the clinical utilization of the recombinant human IL-1RA analog, anakinra. In contrast, much less is known about the type 2 IL-1 receptor (IL-1R2), which acts as a decoy receptor for IL-1. While IL-1R2 is structurally similar to the type 1 IL-1 receptor (IL-1R1) responsible for IL-1 signal transduction, its truncated cytoplasmic domain and lack of Toll-IL-1 receptor (TIR) region renders IL-1R2 incapable of transmembrane signaling. IL-1R2 competes with IL-1R1 for ligands and for the IL-1R1 co-receptor, IL-1 receptor accessory protein (IL-1RAP). Additionally, IL-1R2 exists in both a membrane bound and soluble form (sIL-1R2) that has biological properties similar to both a decoy receptor and a binding protein. Thus far, IL-1R2 has been implicated in arthritis, endometriosis, organ transplantation, sepsis/sickness behavior, diabetes, atherosclerosis, autoimmune inner ear disease (AIED), Alzheimer's disease and ulcerative colitis. In this review, we will detail the functional properties of IL-1R2 and examine its role in human disease.
authors.affiliation: Division of Nutritional Sciences, University of Illinois, Urbana, IL 61801, USA.
authors.forename: Vanessa A
authors.initials: VA
authors.lastname: Peters
authors.forename: Jennifer J
authors.initials: JJ
authors.lastname: Joesting
authors.forename: Gregory G
authors.initials: GG
authors.lastname: Freund
mesh_terms: D000818:Animals; D001327:Autoimmune Diseases / Q000276:immunology; D006801:Humans; D007107:Immune System / Q000502:physiology*; D007249:Inflammation / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D016377:Organ Transplantation; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D053574:Receptors, Interleukin-1 Type II / Q000235:genetics / Q000502:physiology*
chemical_list: D012333:RNA, Messenger; D053574:Receptors, Interleukin-1 Type II