Influenza binds phosphorylated glycans from human lung

Area of Science:

• Virology
• Glycobiology
• Respiratory Medicine

Background:

• Influenza A virus species specificity is linked to binding sialic acid linkages (avian: α2,3; mammalian: α2,6).
• Previous studies relied on hemagglutination assays or synthetic analogs, not natural human lung receptors.

Purpose of the Study:

• To identify natural N-glycan receptors for avian and mammalian influenza A viruses in the human lung.
• To investigate the complete glycan-binding profile of influenza viruses in the human respiratory tract.

Main Methods:

• N-glycome analysis of the human lung.
• Binding assays using various avian and mammalian influenza A virus strains.
• Characterization of glycan determinants recognized by influenza viruses.

Main Results:

• The human lung N-glycome contains both α2,3- and α2,6-linked sialylated glycans, consistent with known binding preferences.
• All tested influenza A viruses, regardless of origin (avian or mammalian), demonstrated binding to phosphorylated, nonsialylated glycans.
• This indicates additional, previously unrecognized binding sites for influenza viruses in the human lung.

Conclusions:

• The human lung presents a complex array of glycan receptors for influenza A viruses.
• Phosphorylated, nonsialylated glycans represent a novel class of receptors for influenza A viruses in the human respiratory system.
• Understanding these interactions is crucial for developing broad-spectrum antiviral strategies.