A gel-capture assay for characterizing the sialyl-glycan selectivity of influenza viruses

Tony Velkov, Philip Thompson, Ossama El-Kabbani, F Lindh, John Stambas, Steve Rockman

Research output: Contribution to journalArticleResearchpeer-review

3 Citations (Scopus)

Abstract

Sialic acids (SA) usually linked to galactose (Gal) in an alpha 2,6- or alpha 2,3-configuration arc considered the main cell receptors for influenza viruses, in particular for their hemagglutinins (HA). The typing of influenza virus HA receptor selectivity is relevant for understanding the transmissibility of avian and swine viruses to the human population. In this study we developed a simple and inexpensive gel-capture assay (GCA) of the influenza virus HA receptor-binding selectivity. Its principle is the binding of soluble influenza virus to pentasaccharide analogs, representatives of receptors of human and avian influenza viruses, immobilized on a gel resin. The human and avian analogs consisted of a sialyllactose-N-tetraose c (LSTc) [Neu5Ac(alpha 2,6)Gal(beta 1-3) GlcNAc((beta 1-3)Gal(beta 1-4)Glc] and a sialyllactose-N-tetraose a (LSTa) [Neu5Ac(alpha 2,3)Gal(beta 1-3)GlcNAc(beta 1-3) Gal(beta 1-4)Glc], respectively. Following equilibration, the unbound virus is washed away and the bound one is assayed via HA by densitometry as a function of the analog concentration. Using GCA, the receptor selectivity of three influenza viruses of different HA subtype was investigated. The results showed that the egg-adapted A/California/07/2009 (H1N1) virus exhibited an avian alpha 2,3-linked LSTa selectivity, however, it retained the ability to bind to the alpha 2,6-linked LSTc human receptor analog. Influenza B virus B/Florida/4/2006 showed alpha 2,6-linked LSTc selectivity and a poor alpha 2,3-linked LSTa avidity. The H3N2 virus A/Wisconsin/15/2009 displayed almost comparable avidity for both receptor analogs with a marginally greater alpha 2,3-linked LSTa avidity. The described assay protocol provides a simple and rapid method for the characterization of influenza virus HA receptor binding selectivity.
Original languageEnglish
Pages (from-to)131 - 137
Number of pages7
JournalActa Virologica
Volume55
Issue number2
DOIs
Publication statusPublished - 2011

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