Alpha-2,6-linked sialic acid (N-acetylneuraminic acid) (Neu5Ac)

Human cell-surface sialic acid residues, specifically N-acetylneuraminic acid (Neu5Ac) with an alpha-2,6-linkage to galactose, serve as the primary attachment receptors for human influenza viruses. The viral surface glycoprotein hemagglutinin (HA) contains a specialized receptor-binding site (RBS) that recognizes these specific glycan structures on the host's respiratory epithelium to initiate viral attachment and subsequent endocytosis (Source: Nature, 2002). The prevalence and distribution of these alpha-2,6-linked residues in the human upper respiratory tract are critical determinants of the tissue tropism and efficient human-to-human transmission of seasonal influenza strains (Source: Science, 2006). Therapeutic strategies targeting these residues include the use of sialidases, such as the drug DAS181 (Fludase), which enzymatically remove the terminal sialic acids to prevent viral docking and infection (Source: Journal of Infectious Diseases, 2010). Beyond their role in viral pathogenesis, sialic acids are essential for various physiological processes, including the regulation of the immune system through interactions with Siglec receptors and the maintenance of the mucosal barrier (Source: Nature Reviews Immunology, 2014).

Other names

Sialic acidN-acetylneuraminic acidNeu5AcInfluenza receptorAlpha-2,6-Neu5AcHost cell sialic acid residues

Enzymatic removal of terminal sialic acid residues from the host cell surface to prevent viral hemagglutinin binding and entry.