title: Broad cross-reactive epitopes of the H5N1 influenza virus identified by murine antibodies against the A/Vietnam/1194/2004 hemagglutinin.
abstract: There is an urgent need for a rapid diagnostic system to detect the H5 subtype of the influenza A virus. We previously developed monoclonal antibodies (mAbs) against the H5 hemagglutinin (HA) for use in a rapid diagnostic kit. In this study, we determined the epitopes of the anti-H5 HA murine mAbs OM-b, AY-2C2, and YH-1A1. Binding assays of the mAbs to different strains of H5 HAs indicated that OM-b and AY-2C2 cross-reacted with HAs from clades 1, 2.1.3.2, 2.2, and 2.3.4, whereas YH-1A1 failed to bind to those of clades 2.1.3.2 and 2.3.4. HA chimeras revealed that the epitopes for each of the mAbs were in the HA1 region. Analysis of escape mutants revealed that OM-b and AY-2C2 mAbs interacted mainly with amino acid residues D43 and G46, and the YH-1A1 mAb interacted with G139 and K or R140 of H5 HA. Multiple alignments of H5 HA protein sequences showed that D43 and G46 were very conserved among H5N1 HAs, except those in clade 2.2.1 and clade 7 (88.7%). The epitope for YH-1A1 mAb was highly variable in the HAs of H5N1, although it was well conserved in those of H5N2-N9. The OM-b and AY-2C2 mAbs could bind to the HAs of clades 1.1 and 2.3.2.1 that are currently epidemic in Asia, and we conclude that these would be effective for the detection of H5N1 infections in this region.
authors.affiliation: Department of Immunology, National Institute of Infectious Diseases, Shinjuku, Tokyo, Japan.
authors.forename: Mie
authors.initials: M
authors.lastname: Kobayashi-Ishihara
authors.affiliation: Influenza Virus Research Center, National Institute of Infectious Diseases, Musashimurayama, Tokyo, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Takahashi
authors.affiliation: Department of Immunology, National Institute of Infectious Diseases, Shinjuku, Tokyo, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Ohnishi
authors.affiliation: Tsuruga Institute of Biotechnology, Toyobo, Co., Ltd., Tsuruga, Fukui, Japan.
authors.forename: Kengo
authors.initials: K
authors.lastname: Nishimura
authors.affiliation: Department of Immunology, National Institute of Infectious Diseases, Shinjuku, Tokyo, Japan.
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Terahara
authors.affiliation: Department of Immunology, National Institute of Infectious Diseases, Shinjuku, Tokyo, Japan.
authors.forename: Manabu
authors.initials: M
authors.lastname: Ato
authors.affiliation: Influenza Virus Research Center, National Institute of Infectious Diseases, Musashimurayama, Tokyo, Japan.
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Itamura
authors.affiliation: Influenza Virus Research Center, National Institute of Infectious Diseases, Musashimurayama, Tokyo, Japan.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Kageyama
authors.affiliation: Department of Immunology, National Institute of Infectious Diseases, Shinjuku, Tokyo, Japan; Department of Medical Technology, School of Human Sciences, Tokyo University of Technology, Ohta-ku, Tokyo, Japan.
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Tsunetsugu-Yokota
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D003429:Cross Reactions / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D018604:Epitope Mapping; D000939:Epitopes / Q000276:immunology; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000276:immunology / Q000302:isolation & purification*; D006801:Humans; D053124:Influenza A Virus, H5N1 Subtype / Q000276:immunology / Q000302:isolation & purification* / Q000472:pathogenicity; D007251:Influenza, Human / Q000175:diagnosis* / Q000473:pathology / Q000821:virology; D051379:Mice
chemical_list: D000911:Antibodies, Monoclonal; D000939:Epitopes; D019267:Hemagglutinin Glycoproteins, Influenza Virus; C109963:hemagglutinin, avian influenza A virus