Changes in the Length of the Neuraminidase Stalk Region Impact H7N9 Virulence in Mice

J Virol. 2015 Dec 9;90(4):2142-9. doi: 10.1128/JVI.02553-15. Print 2016 Feb 15.

Abstract

The neuraminidase stalk of the newly emerged H7N9 influenza virus possesses a 5-amino-acid deletion. This study focuses on characterizing the biological functions of H7N9 with varied neuraminidase stalk lengths. Results indicate that the 5-amino-acid deletion had no impact on virus infectivity or replication in vitro or in vivo compared to that of a virus with a full-length stalk, but enhanced virulence in mice was observed for H7N9 encoding a 19- to 20-amino-acid deletion, suggesting that N9 stalk length impacts virulence in mammals, as N1 stalk length does.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Body Weight
  • Cytokines / analysis
  • Histocytochemistry
  • Influenza A Virus, H7N9 Subtype / genetics*
  • Influenza A Virus, H7N9 Subtype / pathogenicity*
  • Lung / pathology
  • Lung / virology
  • Mice, Inbred BALB C
  • Neuraminidase / genetics*
  • Orthomyxoviridae Infections / pathology
  • Orthomyxoviridae Infections / virology*
  • Sequence Deletion
  • Viral Load
  • Viral Proteins / genetics*
  • Virulence
  • Virulence Factors / genetics*

Substances

  • Cytokines
  • Viral Proteins
  • Virulence Factors
  • NA protein, influenza A virus
  • Neuraminidase