Relevance of Host Cell Surface Glycan Structure for Cell Specificity of Influenza A Viruses

Abstract

Influenza A viruses (IAVs) initiate infection via binding of the viral hemagglutinin (HA) to sialylated glycans on host cells. HA’s receptor specificity towards individual glycans is well studied and clearly critical for virus infection, but the contribution of the highly heterogeneous and complex glycocalyx to virus–cell adhesion remains elusive. Here, we use two complementary methods, glycan arrays and single-virus force spectroscopy (SVFS), to compare influenza virus receptor specificity with virus binding to live cells. Unexpectedly, we found that HA’s receptor binding preference does not necessarily reflect virus–cell specificity. We propose SVFS as a tool to elucidate the cell binding preference of IAVs, thereby including the complex environment of sialylated receptors within the plasma membrane of living cells.

A Complex-Type N-Glycan-Specific Lectin Isolated from Green Alga Halimeda borneensis Exhibits Potent Anti-Influenza Virus Activity

“…In this study, the anti-influenza activity of an algal lectin, HBL40, was demonstrated by an in vitro experiment using cultured human cells and the influenza virus A/H3N2/Udorn/72. On the other hand, it is important to examine the in vivo inhibitory effect of the lectin because the local organization and environment of the receptors or other cell surface molecules may alter the binding specificity of the lectin [27]. Furthermore, the infections of influenza viruses are affected by heterologous polarized cells with virus receptors in the respiratory tract, which form an apical surface facing the external environments and a basal surface attached to the basement layer [28].…”