title: Generation of Anti-Murine ADAMTS13 Antibodies and Their Application in a Mouse Model for Acquired Thrombotic Thrombocytopenic Purpura.
abstract: Thrombotic thrombocytopenic purpura (TTP) is a life-threatening thrombotic microangiopathy linked to a deficiency in the metalloprotease ADAMTS13. In the current study, a novel mouse model for acquired TTP was generated to facilitate development and validation of new therapies for this disease. Therefore, a large panel (n = 19) of novel anti-mouse ADAMTS13 (mADAMTS13) monoclonal antibodies (mAbs) of mouse origin was generated. Inhibitory anti-mADAMTS13 mAbs were identified using the FRETS-VWF73 assay. Four mAbs strongly inhibited mADAMTS13 activity in vitro (∼68-90% inhibition). Injecting a combination of 2 inhibitory mAbs (13B4 and 14H7, 1.25 mg/kg each) in Adamts13+/+ mice resulted in full inhibition of plasma ADAMTS13 activity (96 ± 4% inhibition, day 1 post injection), leading to the appearance of ultra-large von Willebrand factor (UL-VWF) multimers. Interestingly, the inhibitory anti-mADAMTS13 mAbs 13B4 and 14H7 were ideally suited to induce long-term ADAMTS13 deficiency in Adamts13+/+ mice. A single bolus injection resulted in full ex vivo inhibition for more than 7 days. As expected, the mice with the acquired ADAMTS13 deficiency did not spontaneously develop TTP, despite the accumulation of UL-VWF multimers. In line with the Adamts13-/- mice, TTP-like symptoms could only be induced when an additional trigger (rVWF) was administered. On the other hand, the availability of our panel of anti-mADAMTS13 mAbs allowed us to further develop a sensitive ELISA to detect ADAMTS13 in mouse plasma. In conclusion, a novel acquired TTP mouse model was generated through the development of inhibitory anti-mADAMTS13 mAbs. Consequently, this model provides new opportunities for the development and validation of novel treatments for patients with TTP. In addition, these newly developed inhibitory anti-mADAMTS13 mAbs are of great value to specifically study the role of ADAMTS13 in mouse models of thrombo-inflammatory disease.
authors.affiliation: Laboratory for Thrombosis Research, IRF Life Sciences, KU Leuven Campus Kulak Kortrijk, Kortrijk, Belgium.
authors.forename: Louis
authors.initials: L
authors.lastname: Deforche
authors.affiliation: Laboratory for Thrombosis Research, IRF Life Sciences, KU Leuven Campus Kulak Kortrijk, Kortrijk, Belgium.
authors.forename: Claudia
authors.initials: C
authors.lastname: Tersteeg
authors.affiliation: Laboratory for Thrombosis Research, IRF Life Sciences, KU Leuven Campus Kulak Kortrijk, Kortrijk, Belgium.
authors.forename: Elien
authors.initials: E
authors.lastname: Roose
authors.affiliation: Laboratory for Thrombosis Research, IRF Life Sciences, KU Leuven Campus Kulak Kortrijk, Kortrijk, Belgium.
authors.forename: Aline
authors.initials: A
authors.lastname: Vandenbulcke
authors.affiliation: Laboratory for Thrombosis Research, IRF Life Sciences, KU Leuven Campus Kulak Kortrijk, Kortrijk, Belgium.
authors.forename: Nele
authors.initials: N
authors.lastname: Vandeputte
authors.affiliation: Laboratory for Thrombosis Research, IRF Life Sciences, KU Leuven Campus Kulak Kortrijk, Kortrijk, Belgium.
authors.forename: Inge
authors.initials: I
authors.lastname: Pareyn
authors.affiliation: Laboratory for Thrombosis Research, IRF Life Sciences, KU Leuven Campus Kulak Kortrijk, Kortrijk, Belgium.
authors.forename: Elien
authors.initials: E
authors.lastname: De Cock
authors.affiliation: Baxalta Innovations GmbH, Vienna, Austria.
authors.forename: Hanspeter
authors.initials: H
authors.lastname: Rottensteiner
authors.affiliation: Laboratory for Thrombosis Research, IRF Life Sciences, KU Leuven Campus Kulak Kortrijk, Kortrijk, Belgium.
authors.forename: Hans
authors.initials: H
authors.lastname: Deckmyn
authors.affiliation: Laboratory for Thrombosis Research, IRF Life Sciences, KU Leuven Campus Kulak Kortrijk, Kortrijk, Belgium.
authors.forename: Simon F
authors.initials: SF
authors.lastname: De Meyer
authors.affiliation: Laboratory for Thrombosis Research, IRF Life Sciences, KU Leuven Campus Kulak Kortrijk, Kortrijk, Belgium.
authors.forename: Karen
authors.initials: K
authors.lastname: Vanhoorelbeke
mesh_terms: D000071120:ADAMTS13 Protein / Q000097:blood / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D000818:Animals; D000911:Antibodies, Monoclonal / Q000235:genetics / Q000276:immunology / Q000378:metabolism / Q000627:therapeutic use*; D000937:Antigen-Antibody Reactions; D004195:Disease Models, Animal; D004797:Enzyme-Linked Immunosorbent Assay; D018604:Epitope Mapping; D005260:Female; D006801:Humans; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D010976:Platelet Count; D055503:Protein Multimerization; D011697:Purpura, Thrombotic Thrombocytopenic / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000276:immunology / Q000302:isolation & purification / Q000627:therapeutic use; D015203:Reproducibility of Results; D014841:von Willebrand Factor / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D000911:Antibodies, Monoclonal; D011994:Recombinant Proteins; D014841:von Willebrand Factor; D000071120:ADAMTS13 Protein