Differences between influenza virus receptors on target cells of duck and chicken.

H5, H7, and H9 subtype influenza viruses in land-based poultry often differ from viruses of wild aquatic birds by deletions in the stalk of the neuraminidase, by the presence of additional carbohydrates on the hemagglutinin, and by occasional changes in the receptor specificity. To test whether these differences could reflect distinctions between the virus receptors in different avian species, we compared the binding of duck, chicken and human influenza viruses to cell membranes and gangliosides from epithelial tissues of duck, chicken and African green monkey. Human viruses bound to cell membranes of monkey and chicken but not to those of duck, suggesting that chicken cells unlike duck cells contain Sia(alpha2-6)Gal-terminated receptors recognized by human viruses. 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. Our data suggest that the spectrum of sialylglycoconjugates which can serve as influenza virus receptors in chicken is more similar to the spectrum of receptors in the respiratory epithelia of monkey than to that in the epithelial tissues of duck. This notion could explain the recent emergence of avian H9N2 virus lineage with human virus-like receptor specificity and emphasizes the role of the chicken as a potential intermediate host for the transmission of viruses from aquatic birds to humans.