[Source: PLoS ONE, full page: (LINK). Abstract, edited.]

Open Access / Peer-Reviewed / Research Article

Characterization of the Sialic Acid Binding Activity of Influenza A Viruses Using Soluble Variants of the H7 and H9 Hemagglutinins

Anne-Kathrin Sauer, Chi-Hui Liang, J?rgen Stech, Ben Peeters, Pascale Qu?r?, Christel Schwegmann-Wessels, Chung-Yi Wu, Chi-Huey Wong, Georg Herrler

Published: February 21, 2014 / DOI: 10.1371/journal.pone.0089529


Binding of influenza viruses to target cells is mediated by the viral surface protein hemagglutinin. To determine the presence of binding sites for influenza A viruses on cells and tissues, soluble hemagglutinins of the H7 and H9 subtype were generated by connecting the hemagglutinin ectodomain to the Fc portion of human immunoglobulin G (H7Fc and H9Fc). Both chimeric proteins bound to different cells and tissues in a sialic acid-dependent manner. Pronounced differences were observed between H7Fc and H9Fc, in the binding both to different mammalian and avian cultured cells and to cryosections of the respiratory epithelium of different virus host species (turkey, chicken and pig). Binding of the soluble hemagglutinins was similar to the binding of virus particles, but showed differences in the binding pattern when compared to two sialic acid-specific plant lectins. These findings were substantiated by a comparative glycan array analysis revealing a very narrow recognition of sialoglycoconjugates by the plant lectins that does not reflect the glycan structures preferentially recognized by H7Fc and H9Fc. Thus, soluble hemagglutinins may serve as sialic acid-specific lectins and are a more reliable indicator of the presence of binding sites for influenza virus HA than the commonly used plant lectins.

Citation: Sauer A-K, Liang C-H, Stech J, Peeters B, Qu?r? P, et al. (2014) Characterization of the Sialic Acid Binding Activity of Influenza A Viruses Using Soluble Variants of the H7 and H9 Hemagglutinins. PLoS ONE 9(2): e89529. doi:10.1371/journal.pone.0089529

Editor: Volker Thiel, Kantonal Hospital St. Gallen, Switzerland

Received: November 25, 2013; Accepted: January 22, 2014; Published: February 21, 2014

Copyright: ? 2014 Sauer et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Funding: This work was supported by a fund to G.H. and C.S.-W. from the German FluResearchNet, a nationwide research network on zoonotic influenza sponsored by the Ministry of Education and Research. Further financial support to G.H. was provided by DFG (SFB587, TPA1, and SFB621, TPB7). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Competing interests: The authors have declared that no competing interests exist.