Receptor Specificity of Influenza A Viruses from Sea Mammals Correlates with Lung Sialyloligosaccharides in These Animals

Abstract

The distribution of specific receptors on target organs is a major factor in the host range restriction of influenza A viruses. To assess the correlation between host receptors and the receptor specificity of influenza A viruses from sea mammals, we examined the receptors for influenza A virus in seal and whale lungs. A binding assay using two sialyloligosaccharide (SAα2,3Gal and SAα2,6Gal)-specific lectins showed that SAα2,3Gal, but not SAα2,6Gal, was found in both seal and whale lungs. Correspondingly, seal and whale influenza viruses preferentially recognized SAα2,3Gal, but not SAα2,6Gal. These results indicate that sialyloligosaccharides present at the replication site of influenza A viruses correlate with the receptor recognition of the viruses isolated from sea mammals.