New England harbor seal H3N8 influenza virus retains avian-like receptor specificity

An influenza H3N8 virus, carrying mammalian adaptation mutations, was isolated from New England harbor seals in 2011. We sought to assess the risk of its human transmissibility using two complementary approaches. First, we tested the binding of recombinant hemagglutinin (HA) proteins of seal H3N8 an...

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Bibliographic Details
Main Authors: Krammer, Florian, Estrin, Michael, Viswanathan, Karthik, Stebbins, Nathan W., Sasisekharan, Ram, Runstadler, Jonathan, Hussein, Islam, Ma, Eric Jinglong, Quinlan, Devin Scott
Other Authors: Massachusetts Institute of Technology. Department of Biological Engineering
Format: Article
Language:en_US
Published: Nature Publishing Group 2016
Online Access:http://hdl.handle.net/1721.1/101878
https://orcid.org/0000-0002-1288-9965
https://orcid.org/0000-0002-2085-7840
https://orcid.org/0000-0002-6747-7765
https://orcid.org/0000-0003-0041-5989
https://orcid.org/0000-0002-6528-0125
https://orcid.org/0000-0002-6977-7403
Description
Summary:An influenza H3N8 virus, carrying mammalian adaptation mutations, was isolated from New England harbor seals in 2011. We sought to assess the risk of its human transmissibility using two complementary approaches. First, we tested the binding of recombinant hemagglutinin (HA) proteins of seal H3N8 and human-adapted H3N2 viruses to respiratory tissues of humans and ferrets. For human tissues, we observed strong tendency of the seal H3 to bind to lung alveoli, which was in direct contrast to the human-adapted H3 that bound mainly to the trachea. This staining pattern was also consistent in ferrets, the primary animal model for human influenza pathogenesis. Second, we compared the binding of the recombinant HAs to a library of 610 glycans. In contrast to the human H3, which bound almost exclusively to α-2,6 sialylated glycans, the seal H3 bound preferentially to α-2,3 sialylated glycans. Additionally, the seal H3N8 virus replicated in human lung carcinoma cells. Our data suggest that the seal H3N8 virus has retained its avian-like receptor binding specificity, but could potentially establish infection in human lungs.