Analysis of Influenza Virus Receptor Specificity Using Glycan-Functionalized Gold Nanoparticles

Abstract

Recent cases of human infection with avian influenza H5N1 and H7N9 viruses underscore an urgent need for techniques that can rapidly assess their potential threat to the humans. Determination of the receptor-binding property of influenza virus is crucial to direct viral control and prevention measures. Current methods to perform this analysis are dependent on immunoanalytical strategies that use unstable biological components and complex procedures. We have developed a facile colorimetric assay to determine the interaction of the viral hemagglutinin (HA) protein with host glycan receptors using glycan-functionalized gold nanoparticles (gGNPs). This method is based on the color and absorbance changes of gold probes when the solution is simply mixed with HAs or intact viruses. The resulting sensitivity and selectivity has enabled HA/virus binding to various glycan structures to be differentiated visually and rapidly. Using this system, we have screened, in parallel, the receptor specificity of eight representative human and avian viral HAs and three whole viruses including an emerging H7N9 strain. Our results reveal the detailed receptor-binding profiles of H7N9 virus and its HA and show that they effectively bind to human-type receptors. This gGNP-based assay represents a strategy that would be helpful for developing simple and sensitive systems to probe glycan-mediated biological processes.

Recent advances in employing molecular modelling to determine the specificity of glycan-binding proteins

“…Identifying the glycan receptors preferred by a given GBP is an area of intense study [2–6], with applications ranging from biomass polysaccharide recognition [7–9], through fundamental biology [4,5,10,11] and medicine [3,5,12–15]. The introduction of glycan array screening has caused a paradigm shift in GBP specificity determination.…”

Dual-linker gold nanoparticles as adjuvanting carriers for multivalent display of recombinant influenza hemagglutinin trimers and flagellin improve the immunological responses in vivo and in vitro

“…It is known that HA in influenza virions function as ligands to bind to sialic acid-containing receptors on host respiratory endothelium cell surfaces to initiate a cell infection. 41,42 These results suggest that nanoparticles or antigen-onlycoated nanoparticles may induce an indirect sensing by DCs which provokes their maturation and the subsequent immune response.…”

Glyco-gold nanoparticles: synthesis and applications

“…Based on the LSPR phenomenon, the controlled aggregation and de-assembling of AuNPs is reflected in a detectable variation of the colloidal solution color. Therefore, several biosensors for the detection of proteins [42], lectin [25,27,43], cancer biomarkers [28] and viruses [44–45] were developed. Photoluminescence properties of ultrasmall gold nanoclusters and nanodots have been exploited to detect Escherichia coli (a bacteria containing mannose-binding receptors) [46] and thyroglobulin in serum [47] and to study the internalization pathway in dendritic cells, employing confocal laser microscopy (CLSM) and flow cytometry [48].…”

“…Viral hemagglutinin (HA) protein, in fact, can bind selectively sialic acid residues, but the human influenza virus recognizes the sialic acid α(2,6)galactose sequence while the avian virus recognizes sialic acid α(2,3)galactose chains [85]. GAuNPs functionalized with the exact sequence have been able to selectively recognize the influenza virus strain by means of a simple colorimetric assay, observing the hemagglutinin-induced aggregation of AuNPs [44–45]. Moreover, to improve the sialic residue display on metal surfaces, Russel and co-workers [45] employed trivalent α-thio-linked sialic residues as ligands of AuNPs, confirming the improving ability in binding selectively the human influenza strain.…”