title: High avidity chimeric monoclonal antibodies against the extracellular domains of human aquaporin-4 competing with the neuromyelitis optica autoantibody, NMO-IgG.
abstract: OBJECTIVE
  Most of the cases of neuromyelitis optica (NMO) are characterized by the presence of an autoantibody, NMO-IgG, which recognizes the extracellular domains of the water channel, aquaporin-4. Binding of NMO-IgG to aquaporin-4 expressed in end-feet of astrocytes leads to complement-dependent disruption of astrocytes followed by demyelination. One therapeutic option for NMO is to prevent the binding of NMO-IgG to aquaporin-4, using high-avidity, non-pathogenic-chimeric, monoclonal antibodies to this water channel. We describe here the development of such antibodies.
  
  
  METHODS
  cDNAs encoding variable regions of heavy and light chains of monoclonal antibodies against the extracellular domains of human aquaporin-4 were cloned from hybridoma total RNA and fused to those encoding constant regions of human IgG1 and Igκ respectively. Then mammalian expression vectors were constructed to establish stable cell lines secreting mature chimeric antibodies.
  
  
  RESULTS
  Original monoclonal antibodies showed high avidity binding to human aquaporin-4, as determined by ELISA. Live imaging using Alexa-Fluor-555-labelled antibodies revealed that the antibody D15107 more rapidly bound to cells expressing human aquaporin-4 than others and strongly enhanced endocytosis of this water channel, while D12092 also bound rapidly to human aquaporin-4 but enhanced endocytosis to a lesser degree. Chimeric D15107 prevented complement-dependent cytotoxicity induced by NMO-IgG from patient sera in vitro.
  
  
  CONCLUSIONS
  We have established non-pathogenic, high-avidity, chimeric antibodies against the extracellular domains of human aquaporin-4, which provide a novel therapeutic option for preventing the progress and recurrence of NMO/NMO spectrum disorders.
authors.affiliation: Department of Pharmacology, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan.|Department of Orthopaedic Surgery, School of Medicine, Keio University, Tokyo, Japan.
authors.forename: Kaori
authors.initials: K
authors.lastname: Miyazaki-Komine
authors.affiliation: Department of Neurology, Tohoku University School of Medicine, 1-1 Seiryomachi, Aoba-ku, Sendai, 980-8574, Japan.
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Takai
authors.affiliation: Department of Pharmacology, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan.
authors.forename: Ping
authors.initials: P
authors.lastname: Huang
authors.affiliation: Quantitative Biology and Medicine, Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8904, Japan.|Institute of Immunology Co., Ltd., 1-1-10 Koraku, Bunkyo-ku, Tokyo, 112-0004, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Kusano-Arai
authors.affiliation: Quantitative Biology and Medicine, Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8904, Japan.
authors.forename: Hiroko
authors.initials: H
authors.lastname: Iwanari
authors.affiliation: Department of Multiple Sclerosis Therapeutics, Tohoku University Graduate School of Medicine, 1-1 Seiryomachi, Aoba-ku, Sendai, 980-8574, Japan.
authors.forename: Tatsuro
authors.initials: T
authors.lastname: Misu
authors.affiliation: Research and Development Division, Perseus Proteomics Inc., 4-7-6 Komaba, Meguro-ku, Tokyo, 153-0041, Japan.
authors.forename: Katsushi
authors.initials: K
authors.lastname: Koda
authors.affiliation: Research and Development Division, Perseus Proteomics Inc., 4-7-6 Komaba, Meguro-ku, Tokyo, 153-0041, Japan.
authors.forename: Katsuyuki
authors.initials: K
authors.lastname: Mitomo
authors.affiliation: Quantitative Biology and Medicine, Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8904, Japan.
authors.forename: Toshiko
authors.initials: T
authors.lastname: Sakihama
authors.affiliation: Department of Orthopaedic Surgery, School of Medicine, Keio University, Tokyo, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Toyama
authors.affiliation: Department of Multiple Sclerosis Therapeutics, Tohoku University Graduate School of Medicine, 1-1 Seiryomachi, Aoba-ku, Sendai, 980-8574, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Fujihara
authors.affiliation: Quantitative Biology and Medicine, Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8904, Japan.
authors.forename: Takao
authors.initials: T
authors.lastname: Hamakubo
authors.affiliation: Department of Pharmacology, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan.|Keio Advanced Research Center for Water Biology and Medicine, Keio University, Tokyo, Japan.
authors.forename: Masato
authors.initials: M
authors.lastname: Yasui
authors.affiliation: Department of Pharmacology, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan.|Keio Advanced Research Center for Water Biology and Medicine, Keio University, Tokyo, Japan.
authors.forename: Yoichiro
authors.initials: Y
authors.lastname: Abe
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000915:Antibody Affinity; D051401:Aquaporin 4 / Q000737:chemistry* / Q000276:immunology*; D001253:Astrocytes / Q000276:immunology; D001323:Autoantibodies / Q000276:immunology*; D016466:CHO Cells; D002460:Cell Line; D006224:Cricetinae; D003412:Cricetulus; D004705:Endocytosis / Q000276:immunology; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology; D009471:Neuromyelitis Optica / Q000276:immunology*; D011485:Protein Binding; D017434:Protein Structure, Tertiary
chemical_list: D000911:Antibodies, Monoclonal; D051401:Aquaporin 4; D001323:Autoantibodies; D007074:Immunoglobulin G