Pathogenicity of modified bat influenza virus with different M genes and its reassortment potential with swine influenza A virus

J Gen Virol. 2017 Apr;98(4):577-584. doi: 10.1099/jgv.0.000715. Epub 2017 Apr 20.

Abstract

In our previous studies, the reassortant virus containing only the PR8 H1N1 matrix (M) gene in the background of the modified bat influenza Bat09 : mH1mN1 virus could be generated. However, whether M genes from other origins can be rescued in the background of the Bat09 : mH1mN1 virus and whether the resulting novel reassortant virus is virulent remain unknown. Herein, two reassortant viruses were generated in the background of the Bat09 : mH1mN1 virus containing either a North American or a Eurasian swine influenza virus M gene. These two reassortant viruses and the reassortant virus with PR8 M as well as the control Bat09 : mH1mN1 virus replicated efficiently in cultured cells, while the reassortant virus with PR8 M grew to a higher titre than the other three viruses in tested cells. Mouse studies showed that reassortant viruses with either North American or Eurasian swine influenza virus M gene did not enhance virulence, whereas the reassortant virus with PR8 M gene displayed higher pathogenicity when compared to the Bat09 : mH1mN1 virus. This is most likely due to the fact that the PR8 H1N1 virus is a mouse-adapted virus. Furthermore, reassortment potential between the Bat09 : mH1mN1 virus and an H3N2 swine influenza virus (A/swine/Texas/4199-2/1998) was investigated using co-infection of Madin-Darby canine kidney cells, but no reassortant viruses were detected. Taken together, our results indicate that the modified bat influenza virus is most likely incapable of reassortment with influenza A viruses with in vitro co-infection experiments, although reassortant viruses with different M genes can be generated by reverse genetics.

MeSH terms

  • Animals
  • Chiroptera
  • Disease Models, Animal
  • Genetic Variation*
  • Influenza A Virus, H1N1 Subtype / classification
  • Influenza A Virus, H1N1 Subtype / genetics*
  • Influenza A Virus, H1N1 Subtype / isolation & purification
  • Influenza A Virus, H1N1 Subtype / pathogenicity*
  • Mice
  • Orthomyxoviridae Infections / pathology
  • Orthomyxoviridae Infections / veterinary*
  • Orthomyxoviridae Infections / virology
  • Reassortant Viruses / genetics*
  • Reassortant Viruses / isolation & purification*
  • Swine
  • Viral Load
  • Viral Matrix Proteins / genetics*
  • Virulence
  • Virus Replication

Substances

  • M1 protein, Influenza A virus
  • Viral Matrix Proteins