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High avidity chimeric monoclonal antibodies against the extracellular domains of human aquaporin‐4 competing with the neuromyelitis optica autoantibody, NMO‐IgG
Author(s) -
MiyazakiKomine Kaori,
Takai Yoshiki,
Huang Ping,
KusanoArai Osamu,
Iwanari Hiroko,
Misu Tatsuro,
Koda Katsushi,
Mitomo Katsuyuki,
Sakihama Toshiko,
Toyama Yoshiaki,
Fujihara Kazuo,
Hamakubo Takao,
Yasui Masato,
Abe Yoichiro
Publication year - 2016
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/bph.13340
Subject(s) - neuromyelitis optica , monoclonal antibody , avidity , antibody , autoantibody , aquaporin 4 , water channel , microbiology and biotechnology , aquaporin 1 , extracellular , biology , chemistry , immunology , biochemistry , mechanical engineering , engineering , inlet
Background and Purpose 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. Experimental Approach 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. Key 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 and Implications 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.