Receptor specificity of influenza viruses from birds and mammals: new data on involvement of the inner fragments of the carbohydrate chain

Abstract

We studied receptor-binding properties of influenza virus isolates from birds and mammals using polymeric conjugates of sialooligosaccharides terminated with common Neu5Ac alpha2-3Gal beta fragment but differing by the structure of the inner part of carbohydrate chain. Viruses isolated from distinct avian species differed by their recognition of the inner part of oligosaccharide receptor. Duck viruses displayed high affinity for receptors having beta1-3 rather than beta1-4 linkage between Neu5Ac alpha2-3Gal-disaccharide and penultimate N-acetylhexosamine residue. Fucose and sulfate substituents at this residue had negative and low effect, respectively, on saccharide binding to duck viruses. By contrast, gull viruses preferentially bound to receptors bearing fucose at N-acetylglucosamine residue, whereas chicken and mammalian viruses demonstrated increased affinity for oligosaccharides that harbored sulfo group at position 6 of (beta1-4)-linked GlcNAc. These data suggest that although all avian influenza viruses preferentially bind to Neu5Ac alpha2-3Gal-terminated receptors, the fine receptor specificity of the viruses varies depending on the avian species. Further studies are required to determine whether observed host-dependent differences in the receptor specificity of avian viruses can affect their ability to infect humans.

Alterations in Receptor Binding Properties of Recent Human Influenza H3N2 Viruses Are Associated with Reduced Natural Killer Cell Lysis of Infected Cells

“…Both chemical and enzymatic methods were employed to produce biotin-labeled glycoconjugates containing defined saccharides, namely, SA-␣-2,3-lactose (3ЈSL-PAA) and SA-␣-2,6-Nacetyl lactosamine (6ЈSLN-PAA), representative of the avian (3ЈSL) and human (6ЈSLN) virus receptors, respectively. We chose to use 6ЈSLN to probe for binding to human receptors because the significance of the asialo components of the carbohydrate chain has been recognized (12,22), and a structural study identified the conformation of 6ЈSLN rather than 6ЈSL as a more likely representative of the influenza virus receptor (9). The binding affinity of all influenza viruses for the receptor analogs (3ЈSL-PAA and 6ЈSLN-PAA) was determined in a solid-phase binding assay based on previously described methods (6,19,22).…”

Only Two Residues Are Responsible for the Dramatic Difference in Receptor Binding between Swine and New Pandemic H1 Hemagglutinin

“…Although mutations in the IAV polymerase can enable such transmissions (15,16), efficient spread in the human population is very likely to also involve adaptive mutations in HA. These may involve changes in the binding preference of HA, from ␣2-3-to ␣2-6-sialyl glycans, as well as, for swine viruses already having an ␣2-6 preference, more subtle changes affecting the avidity and/or specificity with which the diverse spectrum of different ␣2-6-linked SIA receptors are recognized (17,18).…”

Receptor-Binding Profiles of H7 Subtype Influenza Viruses in Different Host Species

“…Duck influenza viruses of various HA subtypes (H1 to H5, H9 to H11) preferentially bound to receptors with type 1 and type 3 oligosaccharide sequences, i.e., having the ␤1-3 linkage between the terminal Neu5Ac␣2-3Gal moiety and the penultimate sugar residue such as Neu5Ac␣2-3Gal␤1-3GlcNAc (SLe c ) and Neu5Ac␣2-3Gal␤1-3GalNAc␣ (STF). Sulfation at the 6-OH group of the subterminal GlcNAc had little effect on binding of duck influenza viruses, whereas fucosylation of this residue reduced the binding significantly (15,17,20,21). In contrast to duck influenza viruses, the H4, H6, H13, and H14 subtype viruses isolated from gulls showed high-avidity binding to fucosylated sialyloligosaccharides Neu5Ac␣2-3Gal␤1-4(Fuc␣1-3)GlcNAc (SLe x ) and Neu5Ac␣2-3Gal␤1-3(Fuc␣1-4)GlcNAc (SLe a ) (17,67).…”