title: Characterization of the sialic acid binding activity of influenza A viruses using soluble variants of the H7 and H9 hemagglutinins.
abstract: Binding of influenza viruses to target cells is mediated by the viral surface protein hemagglutinin. To determine the presence of binding sites for influenza A viruses on cells and tissues, soluble hemagglutinins of the H7 and H9 subtype were generated by connecting the hemagglutinin ectodomain to the Fc portion of human immunoglobulin G (H7Fc and H9Fc). Both chimeric proteins bound to different cells and tissues in a sialic acid-dependent manner. Pronounced differences were observed between H7Fc and H9Fc, in the binding both to different mammalian and avian cultured cells and to cryosections of the respiratory epithelium of different virus host species (turkey, chicken and pig). Binding of the soluble hemagglutinins was similar to the binding of virus particles, but showed differences in the binding pattern when compared to two sialic acid-specific plant lectins. These findings were substantiated by a comparative glycan array analysis revealing a very narrow recognition of sialoglycoconjugates by the plant lectins that does not reflect the glycan structures preferentially recognized by H7Fc and H9Fc. Thus, soluble hemagglutinins may serve as sialic acid-specific lectins and are a more reliable indicator of the presence of binding sites for influenza virus HA than the commonly used plant lectins.
authors.affiliation: Institute of Virology, University of Veterinary Medicine, Hannover, Germany.
authors.forename: Anne-Kathrin
authors.initials: AK
authors.lastname: Sauer
authors.affiliation: Genomics Research Center, Academia Sinica, Taipei, Taiwan.
authors.forename: Chi-Hui
authors.initials: CH
authors.lastname: Liang
authors.affiliation: Friedrich-Loeffler-Institut, Institute of Molecular Biology, Greifswald Insel Riems, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Stech
authors.affiliation: Central Veterinary Institute, Lelystad, Netherlands.
authors.forename: Ben
authors.initials: B
authors.lastname: Peeters
authors.affiliation: Institut National de la Recherche Agronomique Centre Val de Loire, Unité mixte de recherche 1282, Infectiologie et Santé Publique, Nouzilly, France.
authors.forename: Pascale
authors.initials: P
authors.lastname: Quéré
authors.affiliation: Institute of Virology, University of Veterinary Medicine, Hannover, Germany.
authors.forename: Christel
authors.initials: C
authors.lastname: Schwegmann-Wessels
authors.affiliation: Genomics Research Center, Academia Sinica, Taipei, Taiwan.
authors.forename: Chung-Yi
authors.initials: CY
authors.lastname: Wu
authors.affiliation: Genomics Research Center, Academia Sinica, Taipei, Taiwan.
authors.forename: Chi-Huey
authors.initials: CH
authors.lastname: Wong
authors.affiliation: Institute of Virology, University of Veterinary Medicine, Hannover, Germany.
authors.forename: Georg
authors.initials: G
authors.lastname: Herrler
mesh_terms: D000818:Animals; D001665:Binding Sites; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D045744:Cell Line, Tumor; D002645:Chickens; D004848:Epithelium / Q000821:virology; D006017:Glycolipids / Q000378:metabolism; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D009980:Influenza A virus / Q000502:physiology*; D008562:Membrane Glycoproteins / Q000378:metabolism; D008969:Molecular Sequence Data; D019158:N-Acetylneuraminic Acid / Q000737:chemistry / Q000378:metabolism*; D009439:Neuraminidase / Q000737:chemistry; D011485:Protein Binding; D020545:Respiratory Mucosa / Q000821:virology; D034421:Sus scrofa; D014422:Turkeys; D053585:Virus Attachment
chemical_list: D006017:Glycolipids; D019267:Hemagglutinin Glycoproteins, Influenza Virus; D008562:Membrane Glycoproteins; C109963:hemagglutinin, avian influenza A virus; D009439:Neuraminidase; D019158:N-Acetylneuraminic Acid