Analysis of Influenza Virus Hemagglutinin Receptor Binding Mutants with Limited Receptor Recognition Properties and Conditional Replication Characteristics

• Type of Material: Article
• Authors: Konrad C. Bradley, Emory University; Summer E Galloway, Emory University; Yi Lasanajak, Emory University; Xuezheng Song, Emory University; Jamie Heimburg-Molinaro, Emory University; Hai Yu, University of California, Davis; Xi Chen, University of California, Davis; Ganesh R Talekar, Emory University; David Smith, Emory University; David Steinhauer, Emory University; Richard Cummings, Emory University
• Language: English
• Date: 2011-12
• Publisher: American Society for Microbiology
• Publication Version: Final Published Version
• Copyright Statement: © 2011, American Society for Microbiology. All Rights Reserved.
• Final Published Version (URL): http://dx.doi.org/10.1128/JVI.05570-11
• Title of Journal or Parent Work: Journal of Virology
• Volume: 85
• Issue: 23
• Start Page: 12387
• End Page: 12398
• Grant/Funding Information: Support for our work has been provided by NIH/NIAID contract HHSN266200700006C and by EUREKA funding (GM85448) to D. F. Smith. We also acknowledge the Consortium for Functional Glycomics, which is funded by NIGMS (GM62116), for support of the glycan array analysis and NIGMS (GMO7636O to X.C.) for synthesis of glycans used for the sialyl derivative array.
• Research Categories: Biology, Microbiology; Chemistry, Biochemistry; Health Sciences, Immunology

Abstract

To examine the range of selective processes that potentially operate when poorly binding influenza viruses adapt to replicate more efficiently in alternative environments, we passaged a virus containing an attenuating mutation in the hemagglutinin (HA) receptor binding site in mice and characterized the resulting mutants with respect to the structural locations of mutations selected, the replication phenotypes of the viruses, and their binding properties on glycan microarrays. The initial attenuated virus had a tyrosine-to-phenylalanine mutation at HA1 position 98 (Y98F), located in the receptor binding pocket, but viruses that were selected contained second-site pseudoreversion mutations in various structural locations that revealed a range of molecular mechanisms for modulating receptor binding that go beyond the scope that is generally mapped using receptor specificity mutants. A comparison of virus titers in the mouse respiratory tract versus MDCK cells in culture showed that the mutants displayed distinctive replication properties depending on the system, but all were less attenuated in mice than the Y98F virus. An analysis of receptor binding properties confirmed that the initial Y98F virus bound poorly to several different species of erythrocytes, while all mutants reacquired various degrees of hemagglutination activity. Interestingly, both the Y98F virus and pseudoreversion mutants were shown to bind very inefficiently to standard glycan microarrays containing an abundance of binding substrates for most influenza viruses that have been characterized to date, provided by the Consortium for Functional Glycomics. The viruses were also examined on a recently developed microarray containing glycans terminating in sialic acid derivatives, and limited binding to a potentially interesting subset of glycans was revealed. The results are discussed with respect to mechanisms for HA-mediated receptor binding, as well as regarding the species of molecules that may act as receptors for influenza virus on host cell surfaces.