Giuseppe
Emeritus
[Source: PLoS ONE, full page: (LINK). Abstract, edited.]
Research Article
Structural and Antigenic Variation among Diverse Clade 2 H5N1 Viruses
David A. Shore, Hua Yang, Amanda L. Balish, Samuel S. Shepard, Paul J. Carney, Jessie C. Chang, Charles T. Davis, Ruben O. Donis, Julie M. Villanueva, Alexander I. Klimov, James Stevens
Abstract
Antigenic variation among circulating H5N1 highly pathogenic avian influenza A viruses mandates the continuous production of strain-specific pre-pandemic vaccine candidates and represents a significant challenge for pandemic preparedness. Here we assessed the structural, antigenic and receptor-binding properties of three H5N1 HPAI virus hemagglutinins, which were recently selected by the WHO as vaccine candidates [A/Egypt/N03072/2010 (Egypt10, clade 2.2.1), A/Hubei/1/2010 (Hubei10, clade 2.3.2.1) and A/Anhui/1/2005 (Anhui05, clade 2.3.4)]. These analyses revealed that antigenic diversity among these three isolates was restricted to changes in the size and charge of amino acid side chains at a handful of positions, spatially equivalent to the antigenic sites identified in H1 subtype viruses circulating among humans. All three of the H5N1 viruses analyzed in this study were responsible for fatal human infections, with the most recently-isolated strains, Hubei10 and Egypt10, containing multiple residues in the receptor-binding site of the HA, which were suspected to enhance mammalian transmission. However, glycan-binding analyses demonstrated a lack of binding to human α2-6-linked sialic acid receptor analogs for all three HAs, reinforcing the notion that receptor-binding specificity contributes only partially to transmissibility and pathogenesis of HPAI viruses and suggesting that changes in host specificity must be interpreted in the context of the host and environmental factors, as well as the virus as a whole. Together, our data reveal structural linkages with phylogenetic and antigenic analyses of recently emerged H5N1 virus clades and should assist in interpreting the significance of future changes in antigenic and receptor-binding properties.
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Citation: Shore DA, Yang H, Balish AL, Shepard SS, Carney PJ, et al. (2013) Structural and Antigenic Variation among Diverse Clade 2 H5N1 Viruses. PLoS ONE 8(9): e75209. doi:10.1371/journal.pone.0075209
Editor: Zhiping Ye, Center for Biologics Evaluation and Research, United States of America
Received: May 16, 2013; Accepted: August 10, 2013; Published: September 27, 2013
This is an open-access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.
Funding: This work was funded by the Centers for Disease Control and Prevention. This research was supported in part by an appointment to the Research Participation Program at the Centers for Disease Control and Prevention administered by the Oak Ridge Institute for Science and Education through an interagency agreement between the U.S. Department of Energy and CDC. Use of the Advanced Photon Source at Argonne National Laboratory was supported by the U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. Glycan microarrays were produced under contract for the Centers for Disease Control by the Consortium for Functional Glycomics (CFG) funded by National Institute of General Medical Sciences Grant GM62116. 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.
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Research Article
Structural and Antigenic Variation among Diverse Clade 2 H5N1 Viruses
David A. Shore, Hua Yang, Amanda L. Balish, Samuel S. Shepard, Paul J. Carney, Jessie C. Chang, Charles T. Davis, Ruben O. Donis, Julie M. Villanueva, Alexander I. Klimov, James Stevens
Abstract
Antigenic variation among circulating H5N1 highly pathogenic avian influenza A viruses mandates the continuous production of strain-specific pre-pandemic vaccine candidates and represents a significant challenge for pandemic preparedness. Here we assessed the structural, antigenic and receptor-binding properties of three H5N1 HPAI virus hemagglutinins, which were recently selected by the WHO as vaccine candidates [A/Egypt/N03072/2010 (Egypt10, clade 2.2.1), A/Hubei/1/2010 (Hubei10, clade 2.3.2.1) and A/Anhui/1/2005 (Anhui05, clade 2.3.4)]. These analyses revealed that antigenic diversity among these three isolates was restricted to changes in the size and charge of amino acid side chains at a handful of positions, spatially equivalent to the antigenic sites identified in H1 subtype viruses circulating among humans. All three of the H5N1 viruses analyzed in this study were responsible for fatal human infections, with the most recently-isolated strains, Hubei10 and Egypt10, containing multiple residues in the receptor-binding site of the HA, which were suspected to enhance mammalian transmission. However, glycan-binding analyses demonstrated a lack of binding to human α2-6-linked sialic acid receptor analogs for all three HAs, reinforcing the notion that receptor-binding specificity contributes only partially to transmissibility and pathogenesis of HPAI viruses and suggesting that changes in host specificity must be interpreted in the context of the host and environmental factors, as well as the virus as a whole. Together, our data reveal structural linkages with phylogenetic and antigenic analyses of recently emerged H5N1 virus clades and should assist in interpreting the significance of future changes in antigenic and receptor-binding properties.
____
Citation: Shore DA, Yang H, Balish AL, Shepard SS, Carney PJ, et al. (2013) Structural and Antigenic Variation among Diverse Clade 2 H5N1 Viruses. PLoS ONE 8(9): e75209. doi:10.1371/journal.pone.0075209
Editor: Zhiping Ye, Center for Biologics Evaluation and Research, United States of America
Received: May 16, 2013; Accepted: August 10, 2013; Published: September 27, 2013
This is an open-access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.
Funding: This work was funded by the Centers for Disease Control and Prevention. This research was supported in part by an appointment to the Research Participation Program at the Centers for Disease Control and Prevention administered by the Oak Ridge Institute for Science and Education through an interagency agreement between the U.S. Department of Energy and CDC. Use of the Advanced Photon Source at Argonne National Laboratory was supported by the U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. Glycan microarrays were produced under contract for the Centers for Disease Control by the Consortium for Functional Glycomics (CFG) funded by National Institute of General Medical Sciences Grant GM62116. 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.
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