title: Influenza A virus neuraminidase enhances meningococcal adhesion to epithelial cells through interaction with sialic acid-containing meningococcal capsules.
abstract: The underlying mechanisms of the epidemiological association between influenza virus infections and Neisseria meningitidis invasive infections are not fully understood. Here we report that adhesion of N. meningitidis to human Hec-1-B epithelial cells is enhanced by influenza A virus (IAV) infection. A potential role of the viral neuraminidase (NA) in facilitating meningococcal adhesion to influenza virus-infected epithelial cells was examined. Expression of a recombinant IAV NA in Hec-1-B human epithelial cells increased the adhesion of strains of N. meningitidis belonging to the sialic acid-containing capsular serogroups B, C, and W135 but not to the mannosamine phosphate-containing capsular serogroup A. Adhesion enhancement was not observed with an inactive NA mutant or in the presence of an NA inhibitor (zanamivir). Furthermore, purified IAV NA was shown to cleave sialic acid-containing capsular polysaccharides of N. meningitidis. On the whole, our findings suggest that a direct interaction between the NA of IAV and the capsule of N. meningitidis enhances bacterial adhesion to cultured epithelial cells, most likely through cleavage of capsular sialic acid-containing polysaccharides. A better understanding of the association between IAV and invasive meningococcal infections should help to set up improved control strategies against these seasonal dual viral-bacterial infections.
authors.affiliation: Institut Pasteur, Unité Postulante Infections Bactériennes Invasives, 75724 Paris Cedex 15, France.
authors.forename: Marie-Anne
authors.initials: MA
authors.lastname: Rameix-Welti
authors.forename: Maria Leticia
authors.initials: ML
authors.lastname: Zarantonelli
authors.forename: Dario
authors.initials: D
authors.lastname: Giorgini
authors.forename: Corinne
authors.initials: C
authors.lastname: Ruckly
authors.forename: Monica
authors.initials: M
authors.lastname: Marasescu
authors.forename: Sylvie
authors.initials: S
authors.lastname: van der Werf
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Alonso
authors.forename: Nadia
authors.initials: N
authors.lastname: Naffakh
authors.forename: Muhamed-Kheir
authors.initials: MK
authors.lastname: Taha
mesh_terms: D001422:Bacterial Adhesion; D016667:Bacterial Capsules / Q000502:physiology*; D045744:Cell Line, Tumor; D004847:Epithelial Cells / Q000382:microbiology; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000502:physiology*; D053122:Influenza A Virus, H3N2 Subtype / Q000502:physiology*; D009345:Neisseria meningitidis / Q000502:physiology*; D009439:Neuraminidase / Q000235:genetics / Q000502:physiology*; D012794:Sialic Acids / Q000502:physiology*
chemical_list: D012794:Sialic Acids; C021319:polysialic acid; D009439:Neuraminidase