title: Mucosal IgM Antibody with d-Mannose Affinity in FuguTakifugu rubripesIs Utilized by a Monogenean ParasiteHeterobothrium okamotoifor Host Recognition.
abstract: How parasites recognize their definitive hosts is a mystery; however, parasitism is reportedly initiated by recognition of certain molecules on host surfaces. Fish ectoparasites make initial contact with their hosts at body surfaces, such as skin and gills, which are covered with mucosa that are similar to those of mammalian guts. Fish are among the most primitive vertebrates with immune systems that are equivalent to those in mammals, and they produce and secrete IgM into mucus. In this study, we showed that the monogenean parasiteHeterobothrium okamotoiutilizes IgM to recognize its host, fuguTakifugu rubripesOncomiracidia are infective larvae ofH. okamotoithat shed their cilia and metamorphose into juveniles when exposed to purified d-mannose-binding fractions from fugu mucus. Using liquid chromatography-tandem mass spectrometry analysis, proteins contained in the fraction were identified as d-mannose-specific IgM with two d-mannose-binding lectins. However, although deciliation was significantly induced by IgM and was inhibited by d-mannose or a specific Ab against fugu IgM, other lectins had no effect, and IgM without d-mannose affinity induced deciliation to a limited degree. Subsequent immunofluorescent staining experiments showed that fugu d-mannose-specific IgM binds ciliated epidermal cells of oncomiracidium. These observations suggest that deciliation is triggered by binding of fugu IgM to cell surface Ags via Ag binding sites. Moreover, concentrations of d-mannose-binding IgM in gill mucus were sufficient to induce deciliation in vitro, indicating thatH. okamotoiparasites initially use host Abs to colonize host gills.
authors.affiliation: School of Marine Biosciences, Kitasato University, Kanagawa 252-0373, Japan.
authors.forename: Kento
authors.initials: K
authors.lastname: Igarashi
authors.affiliation: Fisheries Laboratory, The University of Tokyo, Shizuoka 431-0214, Japan; and.
authors.forename: Ryohei
authors.initials: R
authors.lastname: Matsunaga
authors.affiliation: Faculty of Marine Bioscience, Fukui Prefectural University, Fukui 917-0003, Japan.
authors.forename: Sachi
authors.initials: S
authors.lastname: Hirakawa
authors.affiliation: Fisheries Laboratory, The University of Tokyo, Shizuoka 431-0214, Japan; and.
authors.forename: Sho
authors.initials: S
authors.lastname: Hosoya
authors.affiliation: Faculty of Marine Bioscience, Fukui Prefectural University, Fukui 917-0003, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Suetake
authors.affiliation: Fisheries Laboratory, The University of Tokyo, Shizuoka 431-0214, Japan; and.
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Kikuchi
authors.affiliation: Fisheries Laboratory, The University of Tokyo, Shizuoka 431-0214, Japan; and.
authors.forename: Yuzuru
authors.initials: Y
authors.lastname: Suzuki
authors.affiliation: School of Marine Biosciences, Kitasato University, Kanagawa 252-0373, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Nakamura
authors.affiliation: Faculty of Marine Bioscience, Fukui Prefectural University, Fukui 917-0003, Japan.
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Miyadai
authors.affiliation: Fisheries Laboratory, The University of Tokyo, Shizuoka 431-0214, Japan; and atasumi@mail.ecc.u-tokyo.ac.jp tsutsui@kitasato-u.ac.jp.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tasumi
authors.affiliation: School of Marine Biosciences, Kitasato University, Kanagawa 252-0373, Japan; atasumi@mail.ecc.u-tokyo.ac.jp tsutsui@kitasato-u.ac.jp.
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Tsutsui
mesh_terms: D000818:Animals; D000915:Antibody Affinity; D001666:Binding Sites, Antibody; D002853:Chromatography, Liquid; D002923:Cilia / Q000502:physiology; D005880:Gills / Q000469:parasitology; D018928:Immunity, Mucosal; D007075:Immunoglobulin M / Q000276:immunology* / Q000378:metabolism; D007814:Larva / Q000276:immunology / Q000502:physiology; D008358:Mannose / Q000276:immunology / Q000378:metabolism*; D009092:Mucous Membrane / Q000276:immunology* / Q000469:parasitology; D023741:Takifugu / Q000276:immunology* / Q000469:parasitology*; D053719:Tandem Mass Spectrometry; D014200:Trematoda / Q000502:physiology*
chemical_list: D007075:Immunoglobulin M; D008358:Mannose