Target cell membrane sialic acid modulates both binding and fusion activity of influenza virus

Maria C. Pedroso de Lima, João Ramalho-Santos, Diana Flasher, Vladimir A. Slepushkin, Shlomo Nir, Nejat Düzguneş*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

38 Scopus citations

Abstract

Influenza virus binds to cell surface sialic acid receptors, and following endocytosis fuses with the endosome membrane at low pH. Whether sialic acid plays a role in the virus-cell membrane fusion step is not known. We investigated the effect of the removal of cell membrane sialic acid on the fusion activity of influenza virus (A/PR/8/34 strain) toward human T lymphocytic leukemia (CEM) cells at low pH. Fusion was monitored by fluorescence dequenching of octadecylrhodamine incorporated in the virus membrane. Removal of sialic acid by neuraminidase resulted in a drastic reduction in both viral binding and fusion. The association of the virus with neuraminidase-treated cells was enhanced at pH 5, compared to that at neutral pH, probably due to the unfolding of the hemagglutinin and the resulting increase in viral surface hydrophobicity, but the fusion capacity of the virus was reduced significantly. The results were analysed with a mass-action kinetic model which could explain and predict the kinetics of fusion. Our results indicate that binding of influenza virus to sialic acid residues on the cell surface leads to rapid and extensive fusion and partially inhibits the low pH-induced viral inactivation.

Original languageEnglish
Pages (from-to)323-330
Number of pages8
JournalBiochimica et Biophysica Acta - Biomembranes
Volume1236
Issue number2
DOIs
StatePublished - 14 Jun 1995

Keywords

  • CEM cell
  • Fluorescence
  • Influenza virus
  • Membrane binding
  • Membrane fusion
  • Neuraminidase
  • Sialic acid

Fingerprint

Dive into the research topics of 'Target cell membrane sialic acid modulates both binding and fusion activity of influenza virus'. Together they form a unique fingerprint.

Cite this