title: A seven-segmented influenza A virus expressing the influenza C virus glycoprotein HEF.
abstract: Influenza viruses are classified into three types: A, B, and C. The genomes of A- and B-type influenza viruses consist of eight RNA segments, whereas influenza C viruses only have seven RNAs. Both A and B influenza viruses contain two major surface glycoproteins: the hemagglutinin (HA) and the neuraminidase (NA). Influenza C viruses have only one major surface glycoprotein, HEF (hemagglutinin-esterase fusion). By using reverse genetics, we generated two seven-segmented chimeric influenza viruses. Each possesses six RNA segments from influenza virus A/Puerto Rico/8/34 (PB2, PB1, PA, NP, M, and NS); the seventh RNA segment encodes either the influenza virus C/Johannesburg/1/66 HEF full-length protein or a chimeric protein HEF-Ecto, which consists of the HEF ectodomain and the HA transmembrane and cytoplasmic regions. To facilitate packaging of the heterologous segment, both the HEF and HEF-Ecto coding regions are flanked by HA packaging sequences. When introduced as an eighth segment with the NA packaging sequences, both viruses are able to stably express a green fluorescent protein (GFP) gene, indicating a potential use for these viruses as vaccine vectors to carry foreign antigens. Finally, we show that incorporation of a GFP RNA segment enhances the growth of seven-segmented viruses, indicating that efficient influenza A viral RNA packaging requires the presence of eight RNA segments. These results support a selective mechanism of viral RNA recruitment to the budding site.
authors.affiliation: Department of Microbiology, Mount Sinai School of Medicine, Box 1124, One Gustave L. Levy Place, New York, NY 10029, USA.
authors.forename: Qinshan
authors.initials: Q
authors.lastname: Gao
authors.forename: Edward W A
authors.initials: EW
authors.lastname: Brydon
authors.forename: Peter
authors.initials: P
authors.lastname: Palese
mesh_terms: D015153:Blotting, Western; D002460:Cell Line; D004591:Electrophoresis, Polyacrylamide Gel; D005818:Genetic Engineering / Q000379:methods; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006389:Hemagglutinins, Viral / Q000235:genetics* / Q000378:metabolism*; D006801:Humans; D009980:Influenza A virus / Q000235:genetics* / Q000378:metabolism; D010957:Plasmids / Q000235:genetics; D011994:Recombinant Proteins / Q000235:genetics* / Q000378:metabolism; D014760:Viral Fusion Proteins / Q000235:genetics* / Q000378:metabolism*
chemical_list: D006389:Hemagglutinins, Viral; D011994:Recombinant Proteins; D014760:Viral Fusion Proteins; C060814:hemagglutinin esterase; D049452:Green Fluorescent Proteins