查看文章

The initial stages of an influenzaA virus infection are mediated by the binding of the viral hemagglutinin (HA) to sialylated glycan receptors on host epithelial cells.[1] The specificity of the HA is believed to be a key determinant of viral host range.[2] While all 16 influenza HA subtypes are found in avian viruses, only three are found in viruses adapted to humans (H1, H2, and H3), each resulting in a major pandemic. HAs from avian and human viruses are characterized by their preference for α2-3 and α2-6-linked sialic acids, respectively. Studies now suggest that other elements of sialoglycan sequence are also important factors of HA specificity that contribute to the species barrier.[3] Recently, human and swine respiratory epithelial cells were shown to express sialylated N-linked glycans with extended poly-N-acetyllactosamine (poly-LacNAc) chains.[4] Poly-LacNAc chains are Galβ1-4GlcNAcβ1-3 tandem repeats …