H7N9 Influenza Viruses Interact Preferentially With α2,3-linked Sialic Acids and Bind Weakly to α2,6-linked Sialic Acids

J Gen Virol. 2013 Nov;94(Pt 11):2417-2423. doi: 10.1099/vir.0.056184-0. Epub 2013 Aug 15.


The recent human outbreak of H7N9 avian influenza A virus has caused worldwide concerns. Receptor binding specificity is critical for viral pathogenicity, and still not thoroughly studied for this emerging virus. Here, we evaluated the receptor specificity of the haemagglutinin (HA) of two human H7N9 isolates (A/Shanghai/1/13 and A/Anhui/1/13) through a solid-phase binding assay and a flow cytometry-based assay. In addition, we compared it with those from several HAs from human and avian influenza viruses. We observed that the HAs from the novel H7 isolates strongly interacted with α2,3-linked sialic acids. Importantly, they also showed low levels of binding to α2,6-linked sialic acids, but significantly higher than other avian H7s.

Publication types

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

MeSH terms

  • Animals
  • Birds
  • China
  • Hemagglutinin Glycoproteins, Influenza Virus / metabolism*
  • Host-Pathogen Interactions*
  • Humans
  • Influenza A Virus, H7N9 Subtype / genetics
  • Influenza A Virus, H7N9 Subtype / metabolism*
  • Influenza A Virus, H7N9 Subtype / pathogenicity
  • Influenza in Birds / virology
  • Influenza, Human / virology
  • Receptors, Virus / metabolism*
  • Sialic Acids / chemistry
  • Sialic Acids / metabolism*
  • Viral Tropism*


  • Hemagglutinin Glycoproteins, Influenza Virus
  • Receptors, Virus
  • Sialic Acids