David Deniaud, Medy C. Nongbe, Ludovic Landemarre, Benoît Roubinet, Madeleine Cauwel, Sébastien G. Gouin, Julie Bouckaert, Adeline Sivignon, François-Xavier Felpin, Nicolas Barnich, Clarisse Bridot, Chimie Et Interdisciplinarité : Synthèse, Analyse, Modélisation (CEISAM), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Microbes, Intestin, Inflammation et Susceptibilité de l'Hôte (M2iSH), Institut National de la Recherche Agronomique (INRA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre de Recherche en Nutrition Humaine d'Auvergne (CRNH d'Auvergne), Unité de Glycobiologie Structurale et Fonctionnelle UMR 8576 (UGSF), Université de Lille-Centre National de la Recherche Scientifique (CNRS), GLYcoDiag, Institut des Sciences Moléculaires (ISM), Université Montesquieu - Bordeaux 4-Université Sciences et Technologies - Bordeaux 1 (UB)-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Adaptations Métaboliques à l'Exercice en Conditions Physiologiques et Pathologiques (AME2P), Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-UFR Sciences et Techniques des Activités Physiques et Sportives - Clermont-Auvergne (UFR STAPS - UCA), Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Université Clermont Auvergne [2017-2020] (UCA [2017-2020]), Laboratoire de Synthèse Organique (Hétérochimie organique, organoéléments et matériaux) (LSOHOOM), Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS), Université de Lille, CNRS, Unité de Glycobiologie Structurale et Fonctionnelle - UMR 8576 [UGSF], Unité de Glycobiologie Structurale et Fonctionnelle UMR 8576 [UGSF], Bouckaert, Julie, Université de Nantes - Faculté des Sciences et des Techniques, Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS), Microbes, Intestin, Inflammation et Susceptibilité de l'Hôte - Clermont Auvergne (M2iSH), Institut National de la Recherche Agronomique (INRA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Clermont Auvergne (UCA)-Centre de Recherche en Nutrition Humaine d'Auvergne (CRNH d'Auvergne), Unité de Glycobiologie Structurale et Fonctionnelle (UGSF), CNRS, UMR 8576, GLYcoDIAG, Université d'Orléans (UO), Université Montesquieu - Bordeaux 4-Université Sciences et Technologies - Bordeaux 1-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Centre National de la Recherche Scientifique (CNRS), Unité de Glycobiologie Structurale et Fonctionnelle - UMR 8576 (UGSF), Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA), Laboratoire des Adaptations Métaboliques à l’Exercice en conditions Physiologiques et Pathologiques (AME2P), Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre de Recherche en Nutrition Humaine d'Auvergne (CRNH d'Auvergne)-Institut National de la Recherche Agronomique (INRA), Institut National de la Recherche Agronomique (INRA)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), and Université Montesquieu - Bordeaux 4-Université Sciences et Technologies - Bordeaux 1-École Nationale Supérieure de Chimie et de Physique de Bordeaux (ENSCPB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
International audience; We developed a chemical method to covalently functionalize cellulose nanofibers and cellulose paper with mannoside ligands displaying a strong affinity for the FimH adhesin from pathogenic E. coli strains. Mannose-grafted cellulose proved efficient to selectively bind FimH lectin and discriminate pathogenic E. coli strains from non-pathogenic ones. These modified papers are valuable tools for diagnosing infections promoted by E.coli, such as cystitis or inflammatory bowel diseases, and the concept may be applicable to other life-threatening pathogens. The worldwide spread of antibiotic resistances raises serious health problems, and has driven the identification of new virulence factors and development of alternative antibacterial therapeutics. Mannose-binding FimH adhesin, expressed by Escherichia coli strains has been extensively studied as a target for disrupting bacterial attachment to the host cells. 1 Impressive results were obtained in the context of urinary tract infections (UTI), a prevalent infection type generally mediated by the attachment of uropathogenic E. coli strains (UPEC) to the highly mannosylated uroplakin transmembrane protein of urothelial lining cells. FimH antagonists orally administered to in vivo UTI mouse models, were shown to decrease the E.coli load in the bladder by several orders of magnitude, 2-4 making them competitive with conventional antibiotic treatment. 5,6 This concept was more recently extended to Crohn's disease (CD), an inflammatory disorder of the intestine where an altered gut microbiota, particularly the presence of adherent-invasive E. coli strains (AIEC), is suspected to play a key role in the pathogenesis. 7 Synthetic derivatives of heptylmannoside (HMan), a nanomolar FimH antagonist, 8 were shown to lower the AIEC bacterial level, signs of colitis and gut inflammation when administered per os (10 mg/kg) in CD mouse models. 9,10 Sensitive and rapid diagnostic systems are essential to evaluate the presence of E. coli expressing FimH adhesin in gut microenvironments in order to properly stratify patients before treatment. While the high prevalence of UPEC in the normally sterile urinary tract environment facilitates diagnosis, the AIEC niche is more complex, located at the ileal mucosa in 21 to 63% of CD patients, 11,12 within an ecological community of hundreds of symbiotic microorganisms. Furthermore, no specific biomarkers are currently effective at distinguishing AIEC from other commensal E. coli of the gut microbiota. Previously, it has been shown that AIEC pathobiont possesses specific allelic variants in the fimH gene, conferring them a high ability to adhere in vitro and to colonize the gut of CEABAC10 mice. 13 Establishing an approach to discriminate the strong mannose-binders from other bacteria would therefore be of tremendous importance for efficient diagnosis. In this work, we developed a heterogeneous support to specifically trap and accumulate pathogenic E.coli from biological fluids. Heptyl-α-D-mannoside (HMan) was grafted by click chemistry techniques onto cellulose nanofibers (CN) and cellulose paper (CP). HMan was previously identified as a potent binder of the isolated FimH lectin domain. 8 It should be noted that the lectin domain represents the high-affinity state of FimH under mechanical force and that full-length FimH display a lower affinity for mannosides. 14,15 Covalently functionalized CN or CP were characterized by Fourier transform spectroscopy (FTIR), elemental analysis, X-ray photo-electron spectrometry (XPS), and scanning electron microscopy (SEM). HMan-CN was first compared in vitro against CN grafted with lower FimH affinity ligands i.e. Man-CN lacking the hydrophobic heptyl chain, and HGlc-CN an analog with a glucose sugar that is not recognized by FimH lectin (Scheme 1). In addition, we switched the anomeric oxygen atom to a sulfur and synthesized HSMan-CN to prevent potential sugar hydrolysis from the surface by mannosidases. The modified CN were first assessed for their faculty to bind FimH and to prevent AIEC adhesion to intestinal cells. HMan-CN was then orally administered to the CEABAC10 mouse model of CD to assess its capacity to decrease AIEC in the feces of AIEC-infected mice and to act as a potential CD therapeutic. HM was next coated on CP and the capacity of the HMan-CP to selectively catch AIEC in solution was analyzed. Scheme 1. Chemical synthesis of the sugar-coated cellulose fibers.