title: Single PA mutation as a high yield determinant of avian influenza vaccines.
abstract: Human infection with an avian influenza virus persists. To prepare for a potential outbreak of avian influenza, we constructed a candidate vaccine virus (CVV) containing hemagglutinin (HA) and neuraminidase (NA) genes of a H5N1 virus and evaluated its antigenic stability after serial passaging in embryonated chicken eggs. The passaged CVV harbored the four amino acid mutations (R136K in PB2; E31K in PA; A172T in HA; and R80Q in M2) without changing its antigenicity, compared with the parental CVV. Notably, the passaged CVV exhibited much greater replication property both in eggs and in Madin-Darby canine kidney and Vero cells. Of the four mutations, the PA E31K showed the greatest effect on the replication property of reverse genetically-rescued viruses. In a further luciferase reporter, mini-replicon assay, the PA mutation appeared to affect the replication property by increasing viral polymerase activity. When applied to different avian influenza CVVs (H7N9 and H9N2 subtypes), the PA E31K mutation resulted in the increases of viral replication in the Vero cell again. Taken all together, our results suggest the PA E31K mutation as a single, substantial growth determinant of avian influenza CVVs and for the establishment of a high-yield avian influenza vaccine backbone.
authors.affiliation: Department of Microbiology, the Institute for Viral Diseases, College of Medicine, Korea University, Seoul 02841, Republic of Korea.
authors.forename: Ilseob
authors.initials: I
authors.lastname: Lee
authors.affiliation: Department of Microbiology, the Institute for Viral Diseases, College of Medicine, Korea University, Seoul 02841, Republic of Korea.
authors.forename: Jin
authors.initials: J
authors.lastname: Il Kim
authors.affiliation: Department of Microbiology, the Institute for Viral Diseases, College of Medicine, Korea University, Seoul 02841, Republic of Korea.
authors.forename: Sehee
authors.initials: S
authors.lastname: Park
authors.affiliation: Department of Microbiology, the Institute for Viral Diseases, College of Medicine, Korea University, Seoul 02841, Republic of Korea.
authors.forename: Joon-Yong
authors.initials: JY
authors.lastname: Bae
authors.affiliation: Department of Microbiology, the Institute for Viral Diseases, College of Medicine, Korea University, Seoul 02841, Republic of Korea.
authors.forename: Kirim
authors.initials: K
authors.lastname: Yoo
authors.affiliation: Department of Microbiology, the Institute for Viral Diseases, College of Medicine, Korea University, Seoul 02841, Republic of Korea.
authors.forename: Soo-Hyeon
authors.initials: SH
authors.lastname: Yun
authors.affiliation: Division of Influenza Virus, Center for Infectious Diseases, National Institute of Health, Korea Centers for Disease Control and Prevention, Osong 28159, Republic of Korea.
authors.forename: Joo-Yeon
authors.initials: JY
authors.lastname: Lee
authors.affiliation: Division of Influenza Virus, Center for Infectious Diseases, National Institute of Health, Korea Centers for Disease Control and Prevention, Osong 28159, Republic of Korea.
authors.forename: Kisoon
authors.initials: K
authors.lastname: Kim
authors.affiliation: Division of AIDS, Center for Infectious Diseases, National Institute of Health, Korea Centers for Disease Control and Prevention, Osong 28159, Republic of Korea.
authors.forename: Chun
authors.initials: C
authors.lastname: Kang
authors.affiliation: Department of Microbiology, the Institute for Viral Diseases, College of Medicine, Korea University, Seoul 02841, Republic of Korea.
authors.forename: Man-Seong
authors.initials: MS
authors.lastname: Park
mesh_terms: D019943:Amino Acid Substitution; D000818:Animals; D002642:Chick Embryo; D002522:Chlorocebus aethiops; D004789:Enzyme Activation; D005260:Female; D005818:Genetic Engineering; D005822:Genetic Vectors / Q000235:genetics; D053124:Influenza A Virus, H5N1 Subtype / Q000235:genetics / Q000276:immunology; D009980:Influenza A virus / Q000235:genetics* / Q000276:immunology*; D007252:Influenza Vaccines / Q000235:genetics* / Q000276:immunology*; D051379:Mice; D008958:Models, Molecular; D009154:Mutation; D011487:Protein Conformation; D012324:RNA-Dependent RNA Polymerase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D013329:Structure-Activity Relationship; D014616:Vaccinia virus / Q000235:genetics; D014709:Vero Cells; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D014779:Virus Replication
chemical_list: D007252:Influenza Vaccines; C061290:PA protein, influenza viruses; D014764:Viral Proteins; D012324:RNA-Dependent RNA Polymerase