Adaptation of novel H7N9 influenza A virus to human receptors

Sci Rep. 2013 Oct 28:3:3058. doi: 10.1038/srep03058.

Abstract

The emergence of the novel H7N9 influenza A virus (IAV) has caused global concerns about the ability of this virus to spread between humans. Analysis of the receptor-binding properties of this virus using a recombinant protein approach in combination with fetuin-binding, glycan array and human tissue-binding assays demonstrates increased binding of H7 to both α2-6 and α2-8 sialosides as well as reduced binding to α2-3-linked SIAs compared to a closely related avian H7N9 virus from 2008. These differences could be attributed to substitutions Q226L and G186V. Analysis of the enzymatic activity of the neuraminidase N9 protein indicated a reduced sialidase activity, consistent with the reduced binding of H7 to α2-3 sialosides. However, the novel H7N9 virus still preferred binding to α2-3- over α2-6-linked SIAs and was not able to efficiently bind to epithelial cells of human trachea in contrast to seasonal IAV, consistent with its limited human-to-human transmission.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Epithelial Cells / metabolism
  • Fetuins / chemistry
  • Fetuins / metabolism*
  • HEK293 Cells
  • Hemagglutinins / genetics
  • Hemagglutinins / metabolism*
  • Humans
  • Influenza A Virus, H7N9 Subtype / metabolism*
  • Lung / metabolism
  • Lung / pathology
  • Lung / virology
  • Mutation
  • Neuraminidase / genetics
  • Neuraminidase / metabolism*
  • Polysaccharides / metabolism
  • Protein Binding
  • Recombinant Proteins / biosynthesis
  • Recombinant Proteins / genetics
  • Trachea / metabolism
  • Trachea / pathology
  • Trachea / virology

Substances

  • Fetuins
  • Hemagglutinins
  • Polysaccharides
  • Recombinant Proteins
  • Neuraminidase