title: Development and characterization of a novel ELISA based assay for the quantitation of sub-nanomolar levels of neoepitope exposed NITEGE-containing aggrecan fragments.
abstract: Osteoarthritis (OA) is associated with the degradation of aggrecan by aggrecanases (e.g. ADAMTS-4, ADAMTS-5) ultimately leading to the reduction of daily physical activity in aged individuals. The cleavage of aggrecan by aggrecanases generates a series of neoepitope exposed fragments (e.g. NITEGE) in both animal models and osteoarthritic patients. These aggrecan fragments can be used for identifying disease associated biomarkers for the purpose of measuring the efficacy of therapeutic agents in vivo. A monoclonal antibody, 681-3 mab was developed which recognizes the C-terminal neoepitope NITEGE following aggrecan cleavage by aggrecanases. The 681-3 mab has a K(D) of 4.03 x 10(-10) M as determined by Biacore analysis. A polyclonal antibody, NEP522 which specifically binds to intact aggrecan was also developed. These antibodies were used to develop a highly sensitive assay with lower detection limits of 125 pM which was capable of detecting NITEGE fragments in ADAMTS-4/5 digested human aggrecan and in IL-1 alpha stimulated bovine nasal cartilage disk cultures. The NITEGE 681-3/NEP522 sandwich ELISA has applications for screening compounds for aggrecanase(s) inhibitory activity, selection of appropriate OA models, the evaluation of compound efficacy in vivo, as well as the potential to stratify patients for clinical trial design.
authors.affiliation: Integrative Biology, Lilly Research Laboratories, Eli Lilly and Company, Greenfield, IN 46140, USA.
authors.forename: Quincy L
authors.initials: QL
authors.lastname: Carter
authors.forename: Joe
authors.initials: J
authors.lastname: Dotzlaf
authors.forename: Craig
authors.initials: C
authors.lastname: Swearingen
authors.forename: Isabelle
authors.initials: I
authors.lastname: Brittain
authors.forename: Mark
authors.initials: M
authors.lastname: Chambers
authors.forename: Kevin
authors.initials: K
authors.lastname: Duffin
authors.forename: Peter
authors.initials: P
authors.lastname: Mitchell
authors.forename: Kannan
authors.initials: K
authors.lastname: Thirunavukkarasu
mesh_terms: D051722:ADAM Proteins / Q000378:metabolism; D000071096:ADAMTS Proteins; D053674:Aggrecans / Q000032:analysis* / Q000276:immunology / Q000378:metabolism; D000818:Animals; D000906:Antibodies / Q000276:immunology; D000911:Antibodies, Monoclonal / Q000276:immunology; D000918:Antibody Specificity; D002358:Cartilage, Articular / Q000737:chemistry; D002417:Cattle; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D000939:Epitopes / Q000276:immunology; D006801:Humans; D051379:Mice; D010455:Peptides / Q000032:analysis* / Q000276:immunology; D011348:Procollagen N-Endopeptidase / Q000378:metabolism
chemical_list: D053674:Aggrecans; D000906:Antibodies; D000911:Antibodies, Monoclonal; D000939:Epitopes; D010455:Peptides; D051722:ADAM Proteins; D000071096:ADAMTS Proteins; C434951:ADAMTS3 protein, human; D011348:Procollagen N-Endopeptidase