Receptor specificity, host range, and pathogenicity of influenza viruses

摘要

This short review outlines current knowledge on variation of receptor specificity of avian influenza viruses and discusses data on receptor specificity and cell tropism of the novel swine-origin pandemic virus (HINlpdm) and its mutants associated with severe and fatal cases of infection.Receptor specificity of influenza viruses in different birds The cell-surface receptors of influenza viruses are sialic acid-containing glycoproteins and glycolipids (for review, see refs.). Influenza viruses discriminate between 3-linked and 6-linked sialic acid (Sia) sequences (Neu5Acalpha2-3Gal and Neu5Acalpha2-6Gal), and the preference for one or another sequence correlates with its abundance at the site of virus replication in a given host species. Human and swine viruses preferentially bind to 6-linked Sia, whereas viruses from other natural hosts typically bind to 3-linked Sia. Among laboratory hosts, mice and monkeys mainly express 3-linked sequences, whereas ferrets mainly express 6-linked ones.