Differences between influenza virus receptors on target cells of duck and chicken and receptor specificity of the 1997 H5N1 chicken and human influenza viruses from Hong Kong.

To study whether influenza virus receptors in chickens differ from those in other species, we compared the binding of lectins and influenza viruses with known receptor specificity to cell membranes and gangliosides from epithelial tissues of ducks, chickens, and African green monkeys. We found that chicken cells contained Neu5Ac alpha(2-6)Gal-terminated receptors recognized by Sambucus nigra lectin and by human viruses. This finding explains how some recent H9N2 viruses replicate in chickens despite their human virus-like receptor specificity. Duck virus bound to gangliosides with short sugar chains that were abundant in duck intestine. Human and chicken viruses did not bind to these gangliosides and bound more strongly than duck virus to gangliosides with long sugar chains that were found in chicken intestinal and monkey lung tissues. Chicken and duck viruses also differed by their ability to recognize the structure of the third sugar moiety in Sia2-3Gal-terminated receptors. Chicken viruses preferentially bound to Neu5Ac alpha(2-3)Gal beta(1-4)GlcNAc-containing synthetic sialylglycopolymer, whereas duck viruses displayed a higher affinity for Neu5Ac alpha(2-3)Gal beta(1-3)GalNAc-containing polymer. Our data indicate that sialyloligosaccharide receptors in different avian species are not identical and provide a potential explanation for the differences between the hemagglutinin and neuraminidase proteins of duck and chicken viruses.