Alpha-2,6-linked sialic acid-containing glycan receptor (alpha2,6-SA receptor)

Host sialic acid-containing glycan receptors are terminal carbohydrate structures on glycoproteins and glycolipids that serve as the primary attachment point for the influenza A virus (Varki, 2008, Nature). The hemagglutinin (HA) protein of human-adapted H1N1 influenza specifically recognizes and binds to sialic acids linked to galactose via an alpha-2,6-glycosidic bond (alpha2,6-SA), which are predominantly expressed in the human upper respiratory tract (Shinya et al., 2006, Nature; Tumpey et al., 2007, Science). This binding event triggers receptor-mediated endocytosis, allowing the virus to enter the host cell and initiate its replication cycle. Because these glycans are essential for the initiation of infection, they are significant targets for antiviral strategies. Therapeutic approaches include the use of DAS181 (Fludase), a recombinant sialidase that enzymatically removes these receptors from the respiratory epithelium to block viral attachment (Triana-Baltzer et al., 2009, Antiviral Research). Additionally, small molecules like Umifenovir target the viral HA protein to prevent its interaction with these host receptors, while neuraminidase inhibitors like Oseltamivir prevent the virus from detaching from these receptors during the budding phase.

Other names

Sialic acid receptorNeu5Ac receptorInfluenza A virus receptorAlpha-2,6-sialylglycanHost glycan receptorN-acetylneuraminic acid receptor

Enzymatic cleavage of terminal sialic acid residues from host cell surface glycans or competitive inhibition of viral hemagglutinin binding to the receptor.