Glycopolymers as Antiadhesives of E. coli Strains Inducing Inflammatory Bowel Diseases

Abstract

n-Heptyl α-d-mannose (HM) is a nanomolar antagonist of FimH, a virulence factor of E. coli. Herein we report on the construction of multivalent HM-based glycopolymers as potent antiadhesives of type 1 piliated E. coli. We investigate glycopolymer/FimH and glycopolymer/bacteria interactions and show that HM-based glycopolymers efficiently inhibit bacterial adhesion and disrupt established cell-bacteria interactions in vitro at very low concentration (0.1 μM on a mannose unit basis). On a valency-corrected basis, HM-based glycopolymers are, respectively, 10(2) and 10(6) times more potent than HM and d-mannose for their capacity to disrupt the binding of adherent-invasive E. coli to T84 intestinal epithelial cells. Finally, we demonstrate that the antiadhesive capacities of HM-based glycopolymers are preserved ex vivo in the colonic loop of a transgenic mouse model of Crohn's disease. All together, these results underline the promising scope of HM-based macromolecular ligands for the antiadhesive treatment of E. coli induced inflammatory bowel diseases.

Glycoconjugates and Glycomimetics as Microbial Anti-Adhesives

“…against gut-colonizing AIEC), or when FimH adhesion is exploited to achieve bacterial aggregation and biofilm disruption. They vary from medium-sized scaffolds [19][20][21][22][23], to dendrimers [3,24], polymers [25] and nanoparticles [26][27][28][29]. Despite the spacing between fimbriae can vary between strains and depends on growth conditions [30], only the largest of these materials are likely to engage more than one protein at the time, because the FimH binding site can interact with only one mannose residue at the time and each of the fimbriae carries only a single copy of FimH.…”

“…In most other systems, the multivalency effects observed are not likely to depend on chelation, but rather on increased local concentration of the ligand (statistical rebinding). Affinity improvements have been measured also for materials of moderate valency (up to 12 mannose units) in inhibition experiments with isolated FimH E. coli aggregation in water solution, using large polyvmannosylated constructs is under active examination for detection and removal from polluted water [27] and as a model system for anti-infective studies in vivo [21] or ex vivo [25,29]. Glyconanodiamonds (GNDs) have been used towards this end.…”

“…Recently [25], polymers of different size and topology were synthesized by co-polymeraztion of N-(α-mannopyranosyloxy)heptyl]methacrylamide (HMM) with different monomers, to obtain a set of defined linear or star glycopolymers carrying from 31 to 269 copies of α-D-HM 2. Interaction of the polymers with FimH adhesin was studied by DLS and AFM, revealing the formation of large (1400 nm length x 210 nm diameter) cylindrical aggregates, showing the ability of each glycopolymer to accommodate multiple copies of the adhesin.…”

“…Modification of the same position by conjugation of tri-or nonavalent manno-dendrons (23 and 24 respectively, Figure 3a) bearing an azido functionality at the focal point, allowed the controlled display at a very high valency of the mannosylated dendrons. The final constructs 25 and 26 bear up to 1,620 units of mannose and were found to be active in low nM (25) or high pM (26) concentration in the Ebola model infection test.…”

Brilliant glyconanocapsules for trapping of bacteria

“…Furthermore, the multiple n-heptyl a-D-mannose motifs present at the capsule surface strongly interact with the lectin sugarbinding sites (adhesin FimH) of adhesive proteinaceous hair-like organelles (type 1 fimbrae) expressed by Escherichia coli (E. coli) to promote adhesion and infection of tissues. 8 The construction of tag-labelled nanocapsules, with bright fluorophores and/or coated magnetic nanoparticles, is exploited here to monitor aggregation kinetics between the mannosylated nano-objects and AdherentInvasive E. coli bacteria (AIEC) and promote bacterial removal. A water-soluble random copolymer of N- [7-(a-D-mannopyranosyloxy)heptyl] methacrylamide (HMM) and glycidyl methacrylate (GMA) was prepared by 4-cyano-4-(phenylcarbonothioylthio) pentanoic acid-mediated RAFT polymerization (P(HMM 206 -stat-GMA 17 ), M n NMR = 77.1 kg mol…”