Submitted to: Virology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/13/2011
Publication Date: 4/1/2011
Citation: Chen, L.M., Rivailler, P., Hossain, J.M., Carney, P., Balish, A., Perry, I., Davis, C.T., Garten, R., Shu, B., Xu, X., Klimov, A., Paulson, J.C., Cox, N.J., Swenson, S., Stevens, J., Vincent, A., Gramer, M., Donis, R.O. 2011. Receptor specificity of subtype H1 influenza A viruses isolated from swine and humans in the United States. Virology. 412(2):401-410. Interpretive Summary: One of the well-known restrictions on the ability of an avian influenza A virus to infect mammalian host species, such as human or swine, is the ability to attach to molecular structures called receptors in the host. In this study, the attachment or binding patterns to "avian-like" or "mammalian-like" receptors of the 2009 H1N1 human pandemic virus and classical swine-lineage viruses from the United States were analyzed in a laboratory assay called glycan microarrays. Classical swine influenza viruses isolated between 1945 and 2009 revealed a binding profile very similar to that of 2009 human pandemic H1N1 viruses, with a preference for mammalian-like receptors and very limited binding to'avian-like receptors. Despite considerable changes since their introduction to the swine population, the 'human-like' H1N1 viruses circulating in swine retained strong binding preference for mammalian-like receptors, with a similar pattern to their human seasonal H1N1 virus precursor. Transmission of H1N1 influenza viruses from swine to humans or from humans to swine does not appear to have generated viruses with distinct or novel receptor binding pattern specificities. Classical swine and human seasonal H1N1 influenza viruses have similar and conserved specificity for mammalian-like receptors over long time periods in the glycan microarray, suggesting that humans and swine have similar receptor binding recognition. Additional unknown factors are likely playing an important role in limiting frequent exchanges of viruses between humans and pigs.
Technical Abstract: The evolution of receptor specificity of classical swine influenza viruses leading to the 2009 H1N1 pandemic virus was analyzed in glycan microarrays. Classical influenza viruses from the alpha, beta, and gamma antigenic clusters isolated between 1945 and 2009 revealed a binding profile very similar to that of 2009 pandemic H1N1 viruses, with selectivity for alpha2-6-linked sialosides and very limited binding to alpha2-3 sialosides. Despite considerable genetic evolution, the 'human-like' H1N1 viruses circulating in swine retained strong binding preference for alpha2-6 sialylated glycans, typical of their ancestral human seasonal H1N1 viruses. Interspecies transmission of H1N1 influenza viruses from swine to humans or from humans to swine has not driven selection of viruses with distinct novel receptor binding specificities. Classical swine and human seasonal H1N1 influenza viruses have conserved specificity for similar alpha2-6-sialoside receptors during long term evolution, suggesting that humans and swine impose analogous selection pressures on the evolution of receptor binding function.