title: The new temperature-sensitive mutation PA-F35S for developing recombinant avian live attenuated H5N1 influenza vaccine.
abstract: BACKGROUND
  H5N1 highly pathogenic avian influenza virus (HPAIV) is continuously circulating in many Asian countries and threatening poultry industry and human population. Vaccination is the best strategy to control H5N1 HPAIV infection in poultry and transmission to human population. The aim of this study is to identify new temperature-sensitive (ts) mutations for developing recombinant avian live attenuated H5N1 influenza vaccine.
  
  
  RESULTS
  A "6 + 2" recombinant virus C4/W1 that contained NA gene and modified HA gene from virus A/chicken/Hubei/327/2004 (H5N1) (C4), and six internal genes from virus A/duck/Hubei/W1/2004 (H9N2) (W1) was generated using reverse genetics and subsequently passaged in chicken eggs at progressively lower temperatures (32°C, 28°C and 25°C). The resulting virus acquired ts phenotype and one of its amino acid mutations, PA (F35S), was identified as ts mutation. Furthermore, when used as live attenuated vaccine, the recombinant virus with this ts mutation PA (F35S) provided efficient protection for chickens against H5N1 HPAIV infection.
  
  
  CONCLUSIONS
  These findings highlight the potential of the new ts mutation PA (F35S) in developing recombinant avian live attenuated H5N1 influenza vaccine.
authors.affiliation: Unit of Animal Infectious Diseases, National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, P. R. China.
authors.forename: Wenting
authors.initials: W
authors.lastname: Zhang
authors.forename: Jiagang
authors.initials: J
authors.lastname: Tu
authors.forename: Zongzheng
authors.initials: Z
authors.lastname: Zhao
authors.forename: Huanchun
authors.initials: H
authors.lastname: Chen
authors.forename: Meilin
authors.initials: M
authors.lastname: Jin
mesh_terms: D000818:Animals; D002645:Chickens; D053124:Influenza A Virus, H5N1 Subtype / Q000235:genetics* / Q000276:immunology / Q000502:physiology*; D053127:Influenza A Virus, H9N2 Subtype / Q000235:genetics / Q000276:immunology / Q000502:physiology; D007252:Influenza Vaccines / Q000235:genetics* / Q000276:immunology; D005585:Influenza in Birds / Q000517:prevention & control; D020125:Mutation, Missense; D012324:RNA-Dependent RNA Polymerase / Q000235:genetics*; D013696:Temperature; D014613:Vaccines, Attenuated / Q000235:genetics / Q000276:immunology; D014614:Vaccines, Synthetic / Q000235:genetics / Q000276:immunology; D014764:Viral Proteins / Q000235:genetics*; D014779:Virus Replication
chemical_list: D007252:Influenza Vaccines; C061290:PA protein, influenza viruses; D014613:Vaccines, Attenuated; D014614:Vaccines, Synthetic; D014764:Viral Proteins; D012324:RNA-Dependent RNA Polymerase