title: Identification of human S100A9 as a novel target for treatment of autoimmune disease via binding to quinoline-3-carboxamides.
abstract: Despite more than 25 years of research, the molecular targets of quinoline-3-carboxamides have been elusive although these compounds are currently in Phase II and III development for treatment of autoimmune/inflammatory diseases in humans. Using photoaffinity cross-linking of a radioactively labelled quinoline-3-carboxamide compound, we could determine a direct association between human S100A9 and quinoline-3-carboxamides. This interaction was strictly dependent on both Zn++ and Ca++. We also show that S100A9 in the presence of Zn++ and Ca++ is an efficient ligand of receptor for advanced glycation end products (RAGE) and also an endogenous Toll ligand in that it shows a highly specific interaction with TLR4/MD2. Both these interactions are inhibited by quinoline-3-carboxamides. A clear structure-activity relationship (SAR) emerged with regard to the binding of quinoline-3-carboxamides to S100A9, as well as these compounds potency to inhibit interactions with RAGE or TLR4/MD2. The same SAR was observed when the compound's ability to inhibit acute experimental autoimmune encephalomyelitis in mice in vivo was analysed. Quinoline-3-carboxamides would also inhibit TNFalpha release in a S100A9-dependent model in vivo, as would antibodies raised against the quinoline-3-carboxamide-binding domain of S100A9. Thus, S100A9 appears to be a focal molecule in the control of autoimmune disease via its interactions with proinflammatory mediators. The specific binding of quinoline-3-carboxamides to S100A9 explains the immunomodulatory activity of this class of compounds and defines S100A9 as a novel target for treatment of human autoimmune diseases.
authors.affiliation: Active Biotech AB, Lund, Sweden.
authors.forename: Per
authors.initials: P
authors.lastname: Björk
authors.forename: Anders
authors.initials: A
authors.lastname: Björk
authors.forename: Thomas
authors.initials: T
authors.lastname: Vogl
authors.forename: Martin
authors.initials: M
authors.lastname: Stenström
authors.forename: David
authors.initials: D
authors.lastname: Liberg
authors.forename: Anders
authors.initials: A
authors.lastname: Olsson
authors.forename: Johannes
authors.initials: J
authors.lastname: Roth
authors.forename: Fredrik
authors.initials: F
authors.lastname: Ivars
authors.forename: Tomas
authors.initials: T
authors.lastname: Leanderson
mesh_terms: D000818:Animals; D001327:Autoimmune Diseases / Q000188:drug therapy* / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D040502:Calgranulin B / Q000378:metabolism*; D004681:Encephalomyelitis, Autoimmune, Experimental / Q000188:drug therapy / Q000378:metabolism; D006801:Humans; D007155:Immunologic Factors / Q000494:pharmacology*; D007249:Inflammation / Q000378:metabolism*; D007963:Leukocytes, Mononuclear / Q000378:metabolism; D008070:Lipopolysaccharides / Q000009:adverse effects; D051218:Lymphocyte Antigen 96 / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D009000:Monocytes / Q000378:metabolism; D011804:Quinolines / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology / Q000627:therapeutic use; D000067759:Receptor for Advanced Glycation End Products; D011971:Receptors, Immunologic / Q000378:metabolism*; D013329:Structure-Activity Relationship; D051197:Toll-Like Receptor 4 / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors; D015032:Zinc / Q000378:metabolism
chemical_list: D040502:Calgranulin B; D007155:Immunologic Factors; C495377:LY96 protein, human; D008070:Lipopolysaccharides; C411728:Ly96 protein, mouse; D051218:Lymphocyte Antigen 96; D011804:Quinolines; D000067759:Receptor for Advanced Glycation End Products; D011971:Receptors, Immunologic; C495345:TLR4 protein, human; D051197:Toll-Like Receptor 4; D014409:Tumor Necrosis Factor-alpha; C541322:quinoline-3-carboxamide; D015032:Zinc; D002118:Calcium