title: Inhibition of interleukin 1 (IL-1) binding and bioactivity in vitro and modulation of acute inflammation in vivo by IL-1 receptor antagonist and anti-IL-1 receptor monoclonal antibody.
abstract: Recombinant human interleukin 1 receptor antagonist (IL-1ra) and 35F5, a neutralizing monoclonal antibody (mAb) to the type I mouse IL-1 receptor, were examined for their ability to bind to IL-1 receptors (IL-1Rs) on various types of mouse cells and to block immune and inflammatory responses to IL-1 in vitro and in mice. IL-1ra competed for binding of 125I-IL-1 alpha to type I IL-1R present on EL-4 thymoma cells, 3T3 fibroblasts, hepatocytes, and Chinese hamster ovary cells expressing recombinant mouse type I IL-1R. The IC50 values for IL-1ra binding (ranging from 2 to 4 ng/ml) were similar to those of IL-1 alpha. In contrast, IL-1ra bound with very low affinity (IC50 values ranging from 10 to 200 micrograms/ml) to cells expressing type II IL-1R, i.e., 70Z/3 pre-B cell line and polymorphonuclear leukocytes (PMN) derived from bone marrow and acute inflammatory exudates. The mAb 35F5 bound specifically to type I IL-1R; no inhibition of 125I-IL-1 alpha binding to cells having type II IL-1R was observed with very high concentrations of antibody. While neither IL-1ra nor 35F5 had intrinsic activity in bioassays using T helper D10.G4.1 cells and mouse thymocytes, both agents blocked the ability of IL-1 to stimulate proliferation of these cells. The effects of IL-1ra and 35F5 on acute inflammatory responses in mice were also evaluated. IL-1ra and 35F5 blocked the local accumulation of PMN after intraperitoneal injection of rIL-1 alpha. The response to IL-1 was inhibited when IL-1ra or 35F5 was administered simultaneously with or before administration of IL-1. IL-1ra and 35F5 also blocked PMN accumulation after intraperitoneal injection of lipopolysaccharide or proteose peptone, suggesting IL-1 is important in mediating responses to these agents. In addition, IL-1ra and 35F5 significantly blocked the ability of IL-1 to stimulate egress of PMN from bone marrow, to induce a transient neutrophilia, and to elevate serum levels of hepatic acute phase proteins, IL-6, and corticosterone. Thus, IL-1ra and 35F5 competitively inhibit the binding of IL-1 to the IL-1R on certain cell types. These two IL-1 receptor antagonists act to inhibit biological responses induced by IL-1 and other inflammatory agents.
authors.affiliation: Department of Immunopharmacology, Roche Research Center, Hoffmann-LaRoche Inc, Nutley, New Jersey 07110.
authors.forename: K W
authors.initials: KW
authors.lastname: McIntyre
authors.forename: G J
authors.initials: GJ
authors.lastname: Stepan
authors.forename: K D
authors.initials: KD
authors.lastname: Kolinsky
authors.forename: W R
authors.initials: WR
authors.lastname: Benjamin
authors.forename: J M
authors.initials: JM
authors.lastname: Plocinski
authors.forename: K L
authors.initials: KL
authors.lastname: Kaffka
authors.forename: C A
authors.initials: CA
authors.lastname: Campen
authors.forename: R A
authors.initials: RA
authors.lastname: Chizzonite
authors.forename: P L
authors.initials: PL
authors.lastname: Kilian
mesh_terms: D000210:Acute-Phase Reaction; D000818:Animals; D000911:Antibodies, Monoclonal; D001667:Binding, Competitive; D001854:Bone Marrow Cells; D002364:Caseins / Q000494:pharmacology; D003345:Corticosterone / Q000097:blood; D007111:Immunity, Cellular; D007249:Inflammation / Q000503:physiopathology*; D053590:Interleukin 1 Receptor Antagonist Protein; D007375:Interleukin-1 / Q000037:antagonists & inhibitors*; D015850:Interleukin-6 / Q000096:biosynthesis; D008070:Lipopolysaccharides / Q000494:pharmacology; D051379:Mice; D008815:Mice, Inbred Strains; D009504:Neutrophils / Q000502:physiology; D010446:Peptide Fragments / Q000494:pharmacology; D011506:Proteins / Q000494:pharmacology*; D011971:Receptors, Immunologic / Q000037:antagonists & inhibitors* / Q000145:classification / Q000276:immunology; D017472:Receptors, Interleukin-1; D012795:Sialoglycoproteins; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D002364:Caseins; C507763:IL1RN protein, human; C507764:Il1rn protein, mouse; D053590:Interleukin 1 Receptor Antagonist Protein; D007375:Interleukin-1; D015850:Interleukin-6; D008070:Lipopolysaccharides; D010446:Peptide Fragments; D011506:Proteins; D011971:Receptors, Immunologic; D017472:Receptors, Interleukin-1; D012795:Sialoglycoproteins; C018135:proteose-peptone; D003345:Corticosterone