Virus-like glycodendrinanoparticles displaying quasi-equivalent nested polyvalency upon glycoprotein platforms potently block viral infection

Abstract

Ligand polyvalency is a powerful modulator of protein–receptor interactions. Host–pathogen infection interactions are often mediated by glycan ligand–protein interactions, yet its interrogation with very high copy number ligands has been limited to heterogenous systems. Here we report that through the use of nested layers of multivalency we are able to assemble the most highly valent glycodendrimeric constructs yet seen (bearing up to 1,620 glycans). These constructs are pure and well-defined single entities that at diameters of up to 32 nm are capable of mimicking pathogens both in size and in their highly glycosylated surfaces. Through this mimicry these glyco-dendri-protein-nano-particles are capable of blocking (at picomolar concentrations) a model of the infection of T-lymphocytes and human dendritic cells by Ebola virus. The high associated polyvalency effects (β>106, β/N ~102–103) displayed on an unprecedented surface area by precise clusters suggest a general strategy for modulation of such interactions.

Synthesis of giant globular multivalent glycofullerenes as potent inhibitors in a model of Ebola virus infection

“…28,29 The composition of compounds 17b and 17c has also been ascertained by their respective XPS analyses which showed the presence of the expected elements, according to their relative abundance (see Supplementary Figure 4 Previous inhibition studies using the same infection model and fullerenes displaying up to 36 mannoses show relative inhibitor potency (RIP) values at least two orders of magnitude smaller. 19 Moreover, huge virus-like particles (VLP) with a radius of 16 nm and up to 1640 mannoses 33 were 18 fold less potent than compound 17c described in this work (see Supplementary Table 2). These results have confirmed the efficiency of these systems to interact with DC-SIGN and to compete with Ebola virus glycoprotein-pseudotyped particles during their entry into target cells.…”

“…After 8 hours of incubation at 37º C with 5% CO2, medium on transfection plates was changed to 10 ml DMEM and once again one day after transfection to 7 ml DMEM. Transfection supernatants were harvested after 48 h, centrifuged at 1200 rpm for 10 minutes at RT to remove cell debris, and stored frozen at -80° C. 33,36 …”

Selective chemical protein modification

“…This has led to a wide range of CuAAC reagents now being commercially available for bioconjugation. Indeed, the CuAAC can be performed site-selectively with complete conversion 34 and has been used in many significant applications, such as the generation of PEGylated proteins 87 , the generation of dual PTM glycoprotein mimics due to its orthogonality to existing cysteine chemistry 34,35 , cellular proteomic analysis (BONCAT) 80 , a quantitative method for primary cell proteomics (QuaNCAT) 88 , and the construction of highly-valent protein nanoparticles 89 . Despite this compatibility, the perceived toxicity of copper has led to the exploration of alternative cycloaddition-type reactions.…”

Glycoconjugates and Glycomimetics as Microbial Anti-Adhesives

“…The dendrimer was also found to inhibit the interaction between DC-SIGN and gp120 immobilized on an SPR sensor with an IC 50 in the micromolar range (IC 50 50 µM) [57]. To the same end, also water-soluble manno-fullerenes [58], and virus-like manno-dendronanoparticles capable of mimicking pathogens both in size and in their highly glycosylated surfaces [59], were explored (Figure 3a). The latter were built using as platform Qβ, a recombinant capsid protein derived from the bacteriophage Qβ that spontaneously self-assemble to give icosahedral virus-like particles of 25 nm ca.…”