title: Stimulation of phagocytosis of influenza virus-infected cells through surface desialylation of macrophages by viral neuraminidase.
abstract: Cells infected with influenza A virus undergo apoptosis and become susceptible to phosphatidylserine-mediated phagocytosis by macrophages. This study was undertaken to elucidate the mechanism underlying our previous finding that the activity of viral neuraminidase (NA) is required for efficient phagocytosis. Treatment of macrophages, not influenza virus-infected cells, with Arthrobacter ureafaciens NA or virus-infected cells expressing viral NA augmented the level of phagocytosis of virus-infected cells but not of latex beads or cells undergoing Fas-induced apoptosis. Oligosaccharides, including sialyllactose, bound to influenza virus-infected cells and inhibited phagocytosis by macrophages. These results indicate that surface desialylation of macrophages by influenza virus NA modulates the mode of association between macrophages and target virus-infected cells and stimulates phosphatidylserine-mediated phagocytosis.
authors.affiliation: Graduate School of Medical Science, Kanazawa University, Ishikawa, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Watanabe
authors.forename: Akiko
authors.initials: A
authors.lastname: Shiratsuchi
authors.forename: Kazufumi
authors.initials: K
authors.lastname: Shimizu
authors.forename: Takenori
authors.initials: T
authors.lastname: Takizawa
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Nakanishi
mesh_terms: D000818:Animals; D017209:Apoptosis; D001173:Arthrobacter / Q000201:enzymology; D006367:HeLa Cells / Q000821:virology; D006801:Humans; D009980:Influenza A virus / Q000201:enzymology* / Q000235:genetics / Q000276:immunology; D008262:Macrophage Activation / Q000276:immunology*; D017737:Macrophages, Peritoneal / Q000276:immunology / Q000378:metabolism* / Q000821:virology; D051379:Mice; D009154:Mutation; D009439:Neuraminidase / Q000235:genetics / Q000378:metabolism*; D009844:Oligosaccharides / Q000494:pharmacology; D010587:Phagocytosis / Q000187:drug effects / Q000276:immunology*; D010718:Phosphatidylserines
chemical_list: D009844:Oligosaccharides; D010718:Phosphatidylserines; D009439:Neuraminidase