Binding of Influenza Viruses to Glycans

Abstract

All viruses require host cells in viral replication and have specificities of host (cell) ranges. Glycans on the cellular surface are highly diverse and species specific. Viral host specificities are often dependent on glycans expressed on the surface membranes of host cells. A representative life cycle of viral replication consists of receptor binding, entry, uncoating of viral capsid, synthesis of viral components (genomes and proteins), glycosylation of viral proteins, intracellular traffic of viral components, packaging of viral particles, and budding and release of progeny viruses on the cellular surface. In fact, since various viruses utilize specific glycans on the surface membranes of host cells as specific receptors, many researchers have studied virus binding of glycans to investigate the role of glycan as a viral receptor. Influenza viruses strongly bind to sialic acids existing at the terminal position of glycans and then initiate cell entry. Influenza viruses also have enzymes that destroy sialic acids, facilitating the release of progeny viruses from the surface membranes of infected cells and preventing self-aggregation of progeny viruses through glycans on the viral surface glycoproteins. This report presents a review in terms of viral receptors about glycans recognized by influenza viruses.