251
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Wang L, Pu KY, Li J, Qi X, Li H, Zhang H, Fan C, Liu B. A graphene-conjugated oligomer hybrid probe for light-up sensing of lectin and Escherichia coli. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2011; 23:4386-4391. [PMID: 21960474 DOI: 10.1002/adma.201102227] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2011] [Revised: 07/13/2011] [Indexed: 05/31/2023]
Affiliation(s)
- Lihua Wang
- Department of Chemical and Biomolecular Engineering, 4 Engineering Drive 4, National University of Singapore, Singapore
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252
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Scharenberg M, Abgottspon D, Cicek E, Jiang X, Schwardt O, Rabbani S, Ernst B. A Flow Cytometry-Based Assay for Screening FimH Antagonists. Assay Drug Dev Technol 2011; 9:455-64. [DOI: 10.1089/adt.2010.0357] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Meike Scharenberg
- Institute of Molecular Pharmacy, Pharmacenter, University of Basel, Basel, Switzerland
| | - Daniela Abgottspon
- Institute of Molecular Pharmacy, Pharmacenter, University of Basel, Basel, Switzerland
| | - Evelin Cicek
- Institute of Molecular Pharmacy, Pharmacenter, University of Basel, Basel, Switzerland
| | - Xiaohua Jiang
- Institute of Molecular Pharmacy, Pharmacenter, University of Basel, Basel, Switzerland
| | - Oliver Schwardt
- Institute of Molecular Pharmacy, Pharmacenter, University of Basel, Basel, Switzerland
| | - Said Rabbani
- Institute of Molecular Pharmacy, Pharmacenter, University of Basel, Basel, Switzerland
| | - Beat Ernst
- Institute of Molecular Pharmacy, Pharmacenter, University of Basel, Basel, Switzerland
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253
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Pieters RJ. Carbohydrate mediated bacterial adhesion. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2011; 715:227-40. [PMID: 21557067 DOI: 10.1007/978-94-007-0940-9_14] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In the process of adhesion, bacteria often carry proteins on their surface, adhesins, that bind to specific components of tissue cells or the extracellular matrix. In many cases these components are carbohydrate structures. The carbohydrate binding specificities of many bacteria have been uncovered over the years. The design and synthesis of inhibitors of bacterial adhesion has the potential to create new therapeutics for the prevention and possibly treatment of bacterial infections. Unfortunately, the carbohydrate structures often bind only weakly to the adhesion proteins, although drug design approaches can improve the situation. Furthermore, in some cases linking carbohydrates covalently together, to create so-called multivalent systems, can also significantly enhance the inhibitory potency. Besides adhesion inhibition as a potential therapeutic strategy, the adhesion proteins can also be used for detection. Novel methods to do this are being developed. These include the use of microarrays and glyconanoparticles. New developments in these areas are discussed.
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Affiliation(s)
- Roland J Pieters
- Department of Medicinal Chemistry and Chemical Biology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, The Netherlands.
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254
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Almant M, Moreau V, Kovensky J, Bouckaert J, Gouin SG. Clustering of Escherichia coli Type-1 Fimbrial Adhesins by Using Multimeric Heptyl α-D-Mannoside Probes with a Carbohydrate Core. Chemistry 2011; 17:10029-38. [DOI: 10.1002/chem.201100515] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2011] [Revised: 06/16/2011] [Indexed: 11/10/2022]
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255
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Louie MW, Liu HW, Lam MHC, Lam YW, Lo KKW. Luminescent rhenium(I) polypyridine complexes appended with an α-D-glucose moiety as novel biomolecular and cellular probes. Chemistry 2011; 17:8304-8. [PMID: 21714023 DOI: 10.1002/chem.201101399] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2011] [Indexed: 11/10/2022]
Affiliation(s)
- Man-Wai Louie
- Department of Biology and Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, P.R. China
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256
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Hartmann M, Lindhorst TK. The Bacterial Lectin FimH, a Target for Drug Discovery – Carbohydrate Inhibitors of Type 1 Fimbriae‐Mediated Bacterial Adhesion. European J Org Chem 2011. [DOI: 10.1002/ejoc.201100407] [Citation(s) in RCA: 146] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Mirja Hartmann
- Otto Diels Institute of Organic Chemistry, Christiana Albertina University of Kiel Otto‐Hahn‐Platz 3/4, 24098 Kiel, Germany, Fax: +49‐431‐880‐7410
| | - Thisbe K. Lindhorst
- Otto Diels Institute of Organic Chemistry, Christiana Albertina University of Kiel Otto‐Hahn‐Platz 3/4, 24098 Kiel, Germany, Fax: +49‐431‐880‐7410
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257
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Shelburne SA, Sahasrobhajane P, Suber B, Keith DB, Davenport MT, Horstmann N, Kumaraswami M, Olsen RJ, Brennan RG, Musser JM. Niche-specific contribution to streptococcal virulence of a MalR-regulated carbohydrate binding protein. Mol Microbiol 2011; 81:500-14. [PMID: 21645132 DOI: 10.1111/j.1365-2958.2011.07708.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Low G+C Gram-positive bacteria typically contain multiple LacI/GalR regulator family members, which often have highly similar amino-terminal DNA binding domains, suggesting significant overlap in target DNA sequences. The LacI/GalR family regulator catabolite control protein A (CcpA) is a global regulator of the Group A Streptococcus (GAS) transcriptome and contributes to GAS virulence in diverse infection sites. Herein, we studied the role of the maltose repressor (MalR), another LacI/GalR family member, in GAS global gene expression and virulence. MalR inactivation reduced GAS colonization of the mouse oropharynx but did not detrimentally affect invasive infection. The MalR transcriptome was limited to only 25 genes, and a highly conserved MalR DNA-binding sequence was identified. Variation of the MalR binding sequence significantly reduced MalR binding in vitro. In contrast, CcpA bound to the same DNA sequences as MalR but tolerated variation in the promoter sequences with minimal change in binding affinity. Inactivation of pulA, a MalR regulated gene which encodes a cell surface carbohydrate binding protein, significantly reduced GAS human epithelial cell adhesion and mouse oropharyngeal colonization but did not affect GAS invasive disease. These data delineate a molecular mechanism by which hierarchical regulation of carbon source utilization influences bacterial pathogenesis in a site-specific fashion.
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Affiliation(s)
- Samuel A Shelburne
- Department of Infectious Diseases, MD Anderson Cancer Center, Houston, TX 77030, USA.
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258
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Aprikian P, Interlandi G, Kidd BA, Le Trong I, Tchesnokova V, Yakovenko O, Whitfield MJ, Bullitt E, Stenkamp RE, Thomas WE, Sokurenko EV. The bacterial fimbrial tip acts as a mechanical force sensor. PLoS Biol 2011; 9:e1000617. [PMID: 21572990 PMCID: PMC3091844 DOI: 10.1371/journal.pbio.1000617] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2010] [Accepted: 03/30/2011] [Indexed: 02/02/2023] Open
Abstract
The subunits that constitute the bacterial adhesive complex located at the tip of the fimbria form a hook-chain that acts as a rapid force-sensitive anchor at high flow. There is increasing evidence that the catch bond mechanism, where binding becomes stronger under tensile force, is a common property among non-covalent interactions between biological molecules that are exposed to mechanical force in vivo. Here, by using the multi-protein tip complex of the mannose-binding type 1 fimbriae of Escherichia coli, we show how the entire quaternary structure of the adhesive organella is adapted to facilitate binding under mechanically dynamic conditions induced by flow. The fimbrial tip mediates shear-dependent adhesion of bacteria to uroepithelial cells and demonstrates force-enhanced interaction with mannose in single molecule force spectroscopy experiments. The mannose-binding, lectin domain of the apex-positioned adhesive protein FimH is docked to the anchoring pilin domain in a distinct hooked manner. The hooked conformation is highly stable in molecular dynamics simulations under no force conditions but permits an easy separation of the domains upon application of an external tensile force, allowing the lectin domain to switch from a low- to a high-affinity state. The conformation between the FimH pilin domain and the following FimG subunit of the tip is open and stable even when tensile force is applied, providing an extended lever arm for the hook unhinging under shear. Finally, the conformation between FimG and FimF subunits is highly flexible even in the absence of tensile force, conferring to the FimH adhesin an exploratory function and high binding rates. The fimbrial tip of type 1 Escherichia coli is optimized to have a dual functionality: flexible exploration and force sensing. Comparison to other structures suggests that this property is common in unrelated bacterial and eukaryotic adhesive complexes that must function in dynamic conditions. Noncovalent biological interactions are commonly subjected to mechanical force, particularly when they are involved in adhesion or cytoskeletal movements. While one might expect mechanical force to break these interactions, some of them form so-called catch bonds that lock on harder under force, like a nanoscale finger-trap. In this study, we show that the catch-bond forming adhesive protein FimH, which is located at the tip of E. coli fimbriae, allows bacteria to bind to urinary epithelial cells in a shear-dependent manner; that is, they bind at high but not at low flow. We show that isolated fimbrial tips, consisting of elongated protein complexes with FimH at the apex, reproduce this behavior in vitro. Our molecular dynamics simulations of the fimbrial tip structure show that FimH is shaped like a hook that is normally rigid but opens under force, causing structural changes that lead to firm anchoring of the bacteria on the surface. In contrast, the more distal adaptor proteins of the fimbrial tip create a flexible connection of FimH to the rigid fimbria, enhancing the ability of the adhesin to move into position and form bonds with mannose on the surface. We suggest that the entire tip complex forms a hook-chain, ideal for rapid and stable anchoring in flow.
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Affiliation(s)
- Pavel Aprikian
- Department of Microbiology, University of Washington, Seattle, Washington, United States of America
| | - Gianluca Interlandi
- Department of Bioengineering, University of Washington, Seattle, Washington, United States of America
| | - Brian A. Kidd
- Department of Bioengineering, University of Washington, Seattle, Washington, United States of America
| | - Isolde Le Trong
- Departments of Biological Structure and Biochemistry, University of Washington, Seattle, Washington, United States of America
| | - Veronika Tchesnokova
- Department of Microbiology, University of Washington, Seattle, Washington, United States of America
| | - Olga Yakovenko
- Department of Bioengineering, University of Washington, Seattle, Washington, United States of America
| | - Matt J. Whitfield
- Department of Bioengineering, University of Washington, Seattle, Washington, United States of America
| | - Esther Bullitt
- Department of Physiology & Biophysics, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Ronald E. Stenkamp
- Departments of Biological Structure and Biochemistry, University of Washington, Seattle, Washington, United States of America
| | - Wendy E. Thomas
- Department of Bioengineering, University of Washington, Seattle, Washington, United States of America
- * E-mail: (EVS); (WET)
| | - Evgeni V. Sokurenko
- Department of Microbiology, University of Washington, Seattle, Washington, United States of America
- * E-mail: (EVS); (WET)
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259
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Hadjifrangiskou M, Kostakioti M, Chen SL, Henderson JP, Greene SE, Hultgren SJ. A central metabolic circuit controlled by QseC in pathogenic Escherichia coli. Mol Microbiol 2011; 80:1516-29. [PMID: 21542868 DOI: 10.1111/j.1365-2958.2011.07660.x] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The QseC sensor kinase regulates virulence in multiple Gram-negative pathogens, by controlling the activity of the QseB response regulator. We have previously shown that qseC deletion interferes with dephosphorylation of QseB thus unleashing what appears to be an uncontrolled positive feedback loop stimulating increased QseB levels. Deletion of QseC downregulates virulence gene expression and attenuates enterohaemorrhagic and uropathogenic Escherichia coli (EHEC and UPEC), Salmonella typhimurium, and Francisella tularensis. Given that these pathogens employ different infection strategies and virulence factors, we used genome-wide approaches to better understand the role of the QseBC interplay in pathogenesis. We found that deletion of qseC results in misregulation of nucleotide, amino acid, and carbon metabolism. Comparable metabolic changes are seen in EHEC ΔqseC, suggesting that deletion of qseC confers similar pleiotropic effects in these two different pathogens. Disruption of representative metabolic enzymes phenocopied UPEC ΔqseC in vivo and resulted in virulence factor downregulation. We thus propose that in the absence of QseC, the constitutively active QseB leads to pleiotropic effects, impairing bacterial metabolism, and thereby attenuating virulence. These findings provide a basis for the development of antimicrobials targeting the phosphatase activity of QseC, as a means to attenuate a wide range of QseC-bearing pathogens.
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Affiliation(s)
- Maria Hadjifrangiskou
- Department of Molecular Microbiology and Microbial Pathogenesis, Washington University in Saint Louis School of Medicine, 660 S Euclid, St Louis, MO 63110-1010, USA
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260
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A glycobiology review: carbohydrates, lectins and implications in cancer therapeutics. Acta Histochem 2011; 113:236-47. [PMID: 20199800 DOI: 10.1016/j.acthis.2010.02.004] [Citation(s) in RCA: 294] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2009] [Revised: 02/14/2010] [Accepted: 02/16/2010] [Indexed: 12/18/2022]
Abstract
This review is intended for general readers who would like a basic foundation in carbohydrate structure and function, lectin biology, and the implications of glycobiology in human health and disease, particularly in cancer therapeutics. These topics are among the hundreds included in the field of glycobiology and are treated here because they form the cornerstone of glycobiology or the focus of many advances in this rapidly expanding field.
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261
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Glycosylation changes as important factors for the susceptibility to urinary tract infection. Biochem Soc Trans 2011; 39:349-54. [PMID: 21265802 DOI: 10.1042/bst0390349] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
FimH is the type 1 fimbrial tip adhesin and invasin of Escherichia coli. Its ligands are the glycans on specific proteins enriched in membrane microdomains. FimH binding shows high-affinity recognition of paucimannosidic glycans, which are shortened high-mannose glycans such as oligomannose-3 and -5. FimH can recognize equally the (single) high-mannose glycan on uroplakin Ia, on the urinary defence protein uromodulin or Tamm-Horsfall glycoprotein and on the intestinal GP2 glycoprotein present in Peyer's patches. E. coli bacteria may attach to epithelial cells via hundreds of fimbriae in a multivalent fashion. This binding is considered to provoke conformational changes in the glycoprotein receptor that translate into signalling in the cytoplasm of the infected epithelial cell. Bladder cell invasion by the uropathogenic bacterium is the prelude to recurrent and persistent urinary tract infections in humans. Patients suffering from diabetes mellitus are more prone to contract urinary tract infections. In a study of women, despite longer treatments with a more potent antibiotic, these patients also have more often recurrences of urinary tract infections compared with women without diabetes. Type 1 fimbriae are the most important virulence factors used not only for adhesion of E. coli in the urinary tract, but also for the colonization by E. coli in patients with Crohn's disease or ulcerative colitis. It appears that the increased prevalence of urinary tract infections in diabetic women is not the result of a difference in the bacteria, but is due to changes in the uroepithelial cells leading to an increased adherence of E. coli expressing type 1 fimbriae. Hypothetically, these changes are in the glycosylation of the infected cells. The present article focuses on possible underlying mechanisms for glycosylation changes in the uroepithelial cell receptors for FimH. Like diabetes, bacterial adhesion induces apoptosis that may bring the endoplasmic reticulum membrane with immature mannosylated glycoproteins to the surface. Indicatively, clathrin-mediated vesicle trafficking of glucose transporters is disturbed in diabetics, which would interfere further with the biosynthesis and localization of complex N-linked glycans.
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262
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Schierholt A, Hartmann M, Lindhorst TK. Bi- and trivalent glycopeptide mannopyranosides as inhibitors of type 1 fimbriae-mediated bacterial adhesion: variation of valency, aglycon and scaffolding. Carbohydr Res 2011; 346:1519-26. [PMID: 21645881 DOI: 10.1016/j.carres.2011.04.023] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2011] [Revised: 04/12/2011] [Accepted: 04/16/2011] [Indexed: 11/27/2022]
Abstract
In order to test relevant structural parameters for effective inhibition of mannose-specific bacterial adhesion, bi- and trivalent glycopeptide α-D-mannopyranosides were synthesized that differ in their conformational properties as well as in the spatial arrangement of attached mannosyl residues. They were tested in an inhibition adhesion assay with fluorescent Escherichia coli bacteria and testing results were referenced to the inhibitory potency of methyl α-D-mannopyranoside. It was shown, that besides the nature of the mannoside aglycon moiety, scaffolding of α-D-mannopyranosides on a peptide backbone was important for the performance of the synthesized glycopeptides as inhibitors of bacterial adhesion.
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Affiliation(s)
- Alexander Schierholt
- Otto Diels Institute of Organic Chemistry, Christiana Albertina University of Kiel, Otto-Hahn-Platz 3/4, 24098 Kiel, Germany
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263
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Grabosch C, Hartmann M, Schmidt-Lassen J, Lindhorst TK. Squaric Acid Monoamide Mannosides as Ligands for the Bacterial Lectin FimH: Covalent Inhibition or Not? Chembiochem 2011; 12:1066-74. [DOI: 10.1002/cbic.201000774] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2010] [Indexed: 11/11/2022]
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264
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Korea CG, Ghigo JM, Beloin C. The sweet connection: Solving the riddle of multiple sugar-binding fimbrial adhesins in Escherichia coli. Bioessays 2011; 33:300-11. [DOI: 10.1002/bies.201000121] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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265
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Van Gerven N, Waksman G, Remaut H. Pili and flagella biology, structure, and biotechnological applications. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2011; 103:21-72. [PMID: 21999994 DOI: 10.1016/b978-0-12-415906-8.00005-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Bacteria and Archaea expose on their outer surfaces a variety of thread-like proteinaceous organelles with which they interact with their environments. These structures are repetitive assemblies of covalently or non-covalently linked protein subunits, organized into filamentous polymers known as pili ("hair"), flagella ("whips") or injectisomes ("needles"). They serve different roles in cell motility, adhesion and host invasion, protein and DNA secretion and uptake, conductance, or cellular encapsulation. Here we describe the functional, morphological and genetic diversity of these bacterial filamentous protein structures. The organized, multi-copy build-up and/or the natural function of pili and flagella have lead to their biotechnological application as display and secretion tools, as therapeutic targets or as molecular motors. We review the documented and potential technological exploitation of bacterial surface filaments in light of their structural and functional traits.
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Affiliation(s)
- Nani Van Gerven
- Structural & Molecular Microbiology, VIB/Vrije Universiteit Brussel, Brussels, Belgium
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266
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Durka M, Buffet K, Iehl J, Holler M, Nierengarten JF, Taganna J, Bouckaert J, Vincent SP. The functional valency of dodecamannosylated fullerenes with Escherichia coli FimH—towards novel bacterial antiadhesives. Chem Commun (Camb) 2011; 47:1321-3. [DOI: 10.1039/c0cc04468g] [Citation(s) in RCA: 126] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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267
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Euzen R, Reymond JL. Glycopeptide dendrimers: tuning carbohydrate–lectin interactions with amino acids. ACTA ACUST UNITED AC 2011; 7:411-21. [DOI: 10.1039/c0mb00177e] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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268
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Rabbani S, Jiang X, Schwardt O, Ernst B. Expression of the carbohydrate recognition domain of FimH and development of a competitive binding assay. Anal Biochem 2010; 407:188-95. [DOI: 10.1016/j.ab.2010.08.007] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2010] [Revised: 07/26/2010] [Accepted: 08/04/2010] [Indexed: 10/19/2022]
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269
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Klein T, Abgottspon D, Wittwer M, Rabbani S, Herold J, Jiang X, Kleeb S, Lüthi C, Scharenberg M, Bezençon J, Gubler E, Pang L, Smiesko M, Cutting B, Schwardt O, Ernst B. FimH Antagonists for the Oral Treatment of Urinary Tract Infections: From Design and Synthesis to in Vitro and in Vivo Evaluation. J Med Chem 2010; 53:8627-41. [DOI: 10.1021/jm101011y] [Citation(s) in RCA: 155] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Tobias Klein
- Institute of Molecular Pharmacy, Pharmacenter, University of Basel, Klingelbergstrasse 50, CH-4056 Basel, Switzerland
| | - Daniela Abgottspon
- Institute of Molecular Pharmacy, Pharmacenter, University of Basel, Klingelbergstrasse 50, CH-4056 Basel, Switzerland
| | - Matthias Wittwer
- Institute of Molecular Pharmacy, Pharmacenter, University of Basel, Klingelbergstrasse 50, CH-4056 Basel, Switzerland
| | - Said Rabbani
- Institute of Molecular Pharmacy, Pharmacenter, University of Basel, Klingelbergstrasse 50, CH-4056 Basel, Switzerland
| | - Janno Herold
- Institute of Molecular Pharmacy, Pharmacenter, University of Basel, Klingelbergstrasse 50, CH-4056 Basel, Switzerland
| | - Xiaohua Jiang
- Institute of Molecular Pharmacy, Pharmacenter, University of Basel, Klingelbergstrasse 50, CH-4056 Basel, Switzerland
| | - Simon Kleeb
- Institute of Molecular Pharmacy, Pharmacenter, University of Basel, Klingelbergstrasse 50, CH-4056 Basel, Switzerland
| | - Christine Lüthi
- Institute of Molecular Pharmacy, Pharmacenter, University of Basel, Klingelbergstrasse 50, CH-4056 Basel, Switzerland
| | - Meike Scharenberg
- Institute of Molecular Pharmacy, Pharmacenter, University of Basel, Klingelbergstrasse 50, CH-4056 Basel, Switzerland
| | - Jacqueline Bezençon
- Institute of Molecular Pharmacy, Pharmacenter, University of Basel, Klingelbergstrasse 50, CH-4056 Basel, Switzerland
| | - Erich Gubler
- Institute of Molecular Pharmacy, Pharmacenter, University of Basel, Klingelbergstrasse 50, CH-4056 Basel, Switzerland
| | - Lijuan Pang
- Institute of Molecular Pharmacy, Pharmacenter, University of Basel, Klingelbergstrasse 50, CH-4056 Basel, Switzerland
| | - Martin Smiesko
- Institute of Molecular Pharmacy, Pharmacenter, University of Basel, Klingelbergstrasse 50, CH-4056 Basel, Switzerland
| | - Brian Cutting
- Institute of Molecular Pharmacy, Pharmacenter, University of Basel, Klingelbergstrasse 50, CH-4056 Basel, Switzerland
| | - Oliver Schwardt
- Institute of Molecular Pharmacy, Pharmacenter, University of Basel, Klingelbergstrasse 50, CH-4056 Basel, Switzerland
| | - Beat Ernst
- Institute of Molecular Pharmacy, Pharmacenter, University of Basel, Klingelbergstrasse 50, CH-4056 Basel, Switzerland
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270
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Azizi A, Kumar A, Diaz-Mitoma F, Mestecky J. Enhancing oral vaccine potency by targeting intestinal M cells. PLoS Pathog 2010; 6:e1001147. [PMID: 21085599 PMCID: PMC2978714 DOI: 10.1371/journal.ppat.1001147] [Citation(s) in RCA: 125] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The immune system in the gastrointestinal tract plays a crucial role in the control of infection, as it constitutes the first line of defense against mucosal pathogens. The attractive features of oral immunization have led to the exploration of a variety of oral delivery systems. However, none of these oral delivery systems have been applied to existing commercial vaccines. To overcome this, a new generation of oral vaccine delivery systems that target antigens to gut-associated lymphoid tissue is required. One promising approach is to exploit the potential of microfold (M) cells by mimicking the entry of pathogens into these cells. Targeting specific receptors on the apical surface of M cells might enhance the entry of antigens, initiating the immune response and consequently leading to protection against mucosal pathogens. In this article, we briefly review the challenges associated with current oral vaccine delivery systems and discuss strategies that might potentially target mouse and human intestinal M cells.
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Affiliation(s)
- Ali Azizi
- Infectious Disease and Vaccine Research Center, Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada.
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271
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Klemm P, Hancock V, Schembri MA. Fimbrial adhesins from extraintestinal Escherichia coli. ENVIRONMENTAL MICROBIOLOGY REPORTS 2010; 2:628-640. [PMID: 23766248 DOI: 10.1111/j.1758-2229.2010.00166.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Extraintestinal pathogenic Escherichia coli (ExPEC) represent an important subclass of E. coli that cause a wide spectrum of diseases in human and animal hosts. Fimbriae are key virulence factors of ExPEC strains. These long surface located rod-shaped organelles mediate receptor-specific attachment to host tissue surfaces (tissue tropism). Some ExPEC fimbriae have additional functions such as the promotion of biofilm formation, cell aggregation and adherence to abiotic surfaces. Here we review the structure, function and contribution to virulence of fimbriae associated with ExPEC strains.
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Affiliation(s)
- Per Klemm
- Microbial Adhesion Group, DTU Food, Technical University of Denmark, Lyngby, Denmark. School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Qld 4072, Australia
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272
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Lindhorst TK, Märten M, Fuchs A, Knight SD. En route to photoaffinity labeling of the bacterial lectin FimH. Beilstein J Org Chem 2010; 6:810-22. [PMID: 20978617 PMCID: PMC2956469 DOI: 10.3762/bjoc.6.91] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2010] [Accepted: 07/21/2010] [Indexed: 11/23/2022] Open
Abstract
Mannose-specific adhesion of Escherichia coli bacteria to cell surfaces, the cause of various infections, is mediated by a fimbrial lectin, called FimH. X-ray studies have revealed a carbohydrate recognition domain (CRD) on FimH that can complex α-D-mannosides. However, as the precise nature of the ligand-receptor interactions in mannose-specific adhesion is not yet fully understood, it is of interest to identify carbohydrate recognition domains on the fimbrial lectin also in solution. Photoaffinity labeling serves as an appropriate methodology in this endeavour and hence biotin-labeled photoactive mannosides were designed and synthesized for photoaffinity labeling of FimH. So far, the photo-crosslinking properties of the new photoactive mannosides could be detailed with the peptide angiotensin II and labeling of FimH was shown both by MS/MS studies and by affino dot-blot analysis.
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Affiliation(s)
- Thisbe K Lindhorst
- Christiana Albertina University of Kiel, Otto Diels Institute of Organic Chemistry, Otto-Hahn-Platz 4, D-24098 Kiel, Germany.
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273
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Lindhorst TK, Bruegge K, Fuchs A, Sperling O. A bivalent glycopeptide to target two putative carbohydrate binding sites on FimH. Beilstein J Org Chem 2010; 6:801-9. [PMID: 20978621 PMCID: PMC2956480 DOI: 10.3762/bjoc.6.90] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2010] [Accepted: 07/22/2010] [Indexed: 11/25/2022] Open
Abstract
FimH is a mannose-specific bacterial lectin found on type 1 fimbriae with a monovalent carbohydrate recognition domain (CRD) that is known from X-ray studies. However, binding studies with multivalent ligands have suggested an additional carbohydrate-binding site on this protein. In order to prove this hypothesis, a bivalent glycopeptide ligand with the capacity to bridge two putative carbohydrate binding sites on FimH was designed and synthesized. Anti-adhesion assays with the new bivalent ligand and type 1-fimbriated bacteria have revealed, that verification of the number of carbohydrate binding sites on FimH with a tailor-made bivalent glycopeptide requires further investigation to be conclusive.
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Affiliation(s)
- Thisbe K Lindhorst
- Christiana Albertina University of Kiel, Otto Diels Institute of Organic Chemistry, Otto-Hahn-Platz 4, D-24098 Kiel, Germany.
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274
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Klemm P, Vejborg RM, Hancock V. Prevention of bacterial adhesion. Appl Microbiol Biotechnol 2010; 88:451-9. [PMID: 20694794 DOI: 10.1007/s00253-010-2805-y] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2010] [Revised: 07/26/2010] [Accepted: 07/27/2010] [Indexed: 11/25/2022]
Abstract
Management of bacterial infections is becoming increasingly difficult due to the emergence and increasing prevalence of bacterial pathogens that are resistant to available antibiotics. Conventional antibiotics generally kill bacteria by interfering with vital cellular functions, an approach that imposes selection pressure for resistant bacteria. New approaches are urgently needed. Targeting bacterial virulence functions directly is an attractive alternative. An obvious target is bacterial adhesion. Bacterial adhesion to surfaces is the first step in colonization, invasion, and biofilm formation. As such, adhesion represents the Achilles heel of crucial pathogenic functions. It follows that interference with adhesion can reduce bacterial virulence. Here, we illustrate this important topic with examples of techniques being developed that can inhibit bacterial adhesion. Some of these will become valuable weapons for preventing pathogen contamination and fighting infectious diseases in the future.
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Affiliation(s)
- Per Klemm
- Technical University of Denmark, Lyngby, Denmark.
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275
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Abstract
The urinary tract is a common site of bacterial infections; nearly half of all women experience at least one urinary tract infection (UTI) during their lifetime. These infections are classified based on the condition of the host. Uncomplicated infections affect otherwise healthy individuals and are most commonly caused by uropathogenic Escherichia coli, whereas complicated infections affect patients with underlying difficulties, such as a urinary tract abnormality or catheterization, and are commonly caused by species such as Proteus mirabilis. Virulence and fitness factors produced by both pathogens include fimbriae, toxins, flagella, iron acquisition systems, and proteins that function in immune evasion. Additional factors that contribute to infection include the formation of intracellular bacterial communities by E. coli and the production of urease by P. mirabilis, which can result in urinary stone formation. Innate immune responses are induced or mediated by pattern recognition receptors, antimicrobial peptides, and neutrophils. The adaptive immune response to UTI is less well understood. Host factors TLR4 and CXCR1 are implicated in disease outcome and susceptibility, respectively. Low levels of TLR4 are associated with asymptomatic bacteriuria while low levels of CXCR1 are associated with increased incidence of acute pyelonephritis. Current research is focused on the identification of additional virulence factors and therapeutic or prophylactic targets that might be used in the generation of vaccines against both uropathogens.
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276
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Han Z, Pinkner JS, Ford B, Obermann R, Nolan W, Wildman SA, Hobbs D, Ellenberger T, Cusumano CK, Hultgren SJ, Janetka JW. Structure-based drug design and optimization of mannoside bacterial FimH antagonists. J Med Chem 2010; 53:4779-92. [PMID: 20507142 DOI: 10.1021/jm100438s] [Citation(s) in RCA: 180] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
FimH-mediated cellular adhesion to mannosylated proteins is critical in the ability of uropathogenic E. coli (UPEC) to colonize and invade the bladder epithelium during urinary tract infection. We describe the discovery and optimization of potent small-molecule FimH bacterial adhesion antagonists based on alpha-d-mannose 1-position anomeric glycosides using X-ray structure-guided drug design. Optimized biarylmannosides display low nanomolar binding affinity for FimH in a fluorescence polarization assay and submicromolar cellular activity in a hemagglutination (HA) functional cell assay of bacterial adhesion. X-ray crystallography demonstrates that the biphenyl moiety makes several key interactions with the outer surface of FimH including pi-pi interactions with Tyr-48 and an H-bonding electrostatic interaction with the Arg-98/Glu-50 salt bridge. Dimeric analogues linked through the biaryl ring show an impressive 8-fold increase in potency relative to monomeric matched pairs and represent the most potent FimH antagonists identified to date. The FimH antagonists described herein hold great potential for development as novel therapeutics for the effective treatment of urinary tract infections.
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Affiliation(s)
- Zhenfu Han
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, 660 S. Euclid Avenue, St. Louis, Missouri 63110, USA
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277
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Abgottspon D, Rölli G, Hosch L, Steinhuber A, Jiang X, Schwardt O, Cutting B, Smiesko M, Jenal U, Ernst B, Trampuz A. Development of an aggregation assay to screen FimH antagonists. J Microbiol Methods 2010; 82:249-55. [PMID: 20620174 DOI: 10.1016/j.mimet.2010.06.015] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2010] [Revised: 06/19/2010] [Accepted: 06/29/2010] [Indexed: 11/16/2022]
Abstract
Alpha-D-mannopyranosides are potent FimH antagonists, which inhibit the adhesion of Escherichia coli to highly mannosylated uroplakin Ia on the urothelium and therefore offer an efficient therapeutic opportunity for the treatment and prevention of urinary tract infection. For the evaluation of the therapeutic potential of FimH antagonists, their effect on the disaggregation of E. coli from Candida albicans and guinea pig erythrocytes (GPE) was studied. The mannose-specific binding of E. coli to yeast cells and erythrocytes is mediated by type 1 pili and can be monitored by aggregometry. Maximal aggregation of C. albicans or GPE to E. coli is reached after 600 s. Then the FimH antagonist was added and disaggregation determined by light transmission over a period of 1400 s. A FimH-deleted mutant of E. coli, which does not induce any aggregation, was used in a control experiment. The activities of FimH antagonists are expressed as IC(50)s, the half maximal inhibitory concentration of the disaggregation potential. n-Heptyl alpha-D-mannopyranoside (1) was used as a reference compound and exhibits an IC(50) of 77.14 microM , whereas methyl alpha-D-mannopyranoside (2) does not lead to any disaggregation at concentrations up to 800 microM. o-Chloro-p-[N-(2-ethoxy-3,4-dioxocyclobut-1-enyl)amino]phenyl alpha-D-mannopyranoside (3) shows a 90-fold and 2-chloro-4-nitrophenyl alpha-D-mannopyranoside (4) a 6-fold increased affinity compared to 1. Finally, 4-nitrophenyl alpha-D-mannopyranoside (5) exhibits an activity similar to 1. As negative control, D-galactose (6) was used. The standardized aggregation assay generates concentration-dependent, reproducible data allowing the evaluation of FimH antagonists according to their potency to inhibit E. coli adherence and can therefore be employed to select candidates for experimental and clinical studies for treatment and prevention of urinary tract infections.
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Affiliation(s)
- Daniela Abgottspon
- Institute of Molecular Pharmacy, Pharmacenter, University of Basel, Switzerland
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278
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Structural basis for mechanical force regulation of the adhesin FimH via finger trap-like beta sheet twisting. Cell 2010; 141:645-55. [PMID: 20478255 DOI: 10.1016/j.cell.2010.03.038] [Citation(s) in RCA: 201] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2009] [Revised: 12/24/2009] [Accepted: 03/03/2010] [Indexed: 12/28/2022]
Abstract
The Escherichia coli fimbrial adhesive protein, FimH, mediates shear-dependent binding to mannosylated surfaces via force-enhanced allosteric catch bonds, but the underlying structural mechanism was previously unknown. Here we present the crystal structure of FimH incorporated into the multiprotein fimbrial tip, where the anchoring (pilin) domain of FimH interacts with the mannose-binding (lectin) domain and causes a twist in the beta sandwich fold of the latter. This loosens the mannose-binding pocket on the opposite end of the lectin domain, resulting in an inactive low-affinity state of the adhesin. The autoinhibition effect of the pilin domain is removed by application of tensile force across the bond, which separates the domains and causes the lectin domain to untwist and clamp tightly around the ligand like a finger-trap toy. Thus, beta sandwich domains, which are common in multidomain proteins exposed to tensile force in vivo, can undergo drastic allosteric changes and be subjected to mechanical regulation.
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279
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Ting SRS, Min EH, Zetterlund PB, Stenzel MH. Controlled/Living ab Initio Emulsion Polymerization via a Glucose RAFTstab: Degradable Cross-Linked Glyco-Particles for Concanavalin A/FimH Conjugations to Cluster E. coli Bacteria. Macromolecules 2010. [DOI: 10.1021/ma1004937] [Citation(s) in RCA: 127] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- S. R. Simon Ting
- Centre for Advanced Macromolecular Design, School of Chemical Engineering, University of New South Wales (UNSW), Sydney NSW 2052, Australia
| | - Eun Hee Min
- Centre for Advanced Macromolecular Design, School of Chemical Engineering, University of New South Wales (UNSW), Sydney NSW 2052, Australia
| | - Per B. Zetterlund
- Centre for Advanced Macromolecular Design, School of Chemical Engineering, University of New South Wales (UNSW), Sydney NSW 2052, Australia
| | - Martina H. Stenzel
- Centre for Advanced Macromolecular Design, School of Chemical Engineering, University of New South Wales (UNSW), Sydney NSW 2052, Australia
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280
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Schierholt A, Hartmann M, Schwekendiek K, Lindhorst TK. Cysteine-Based Mannoside Glycoclusters: Synthetic Routes and Antiadhesive Properties. European J Org Chem 2010. [DOI: 10.1002/ejoc.201000185] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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281
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Sivick KE, Mobley HLT. Waging war against uropathogenic Escherichia coli: winning back the urinary tract. Infect Immun 2010; 78:568-85. [PMID: 19917708 PMCID: PMC2812207 DOI: 10.1128/iai.01000-09] [Citation(s) in RCA: 157] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Urinary tract infection (UTI) caused by uropathogenic Escherichia coli (UPEC) is a substantial economic and societal burden-a formidable public health issue. Symptomatic UTI causes significant discomfort in infected patients, results in lost productivity, predisposes individuals to more serious infections, and usually necessitates antibiotic therapy. There is no licensed vaccine available for prevention of UTI in humans in the United States, likely due to the challenge of targeting a relatively heterogeneous group of pathogenic strains in a unique physiological niche. Despite significant advances in the understanding of UPEC biology, mechanistic details regarding the host response to UTI and full comprehension of genetic loci that influence susceptibility require additional work. Currently, there is an appreciation for the role of classic innate immune responses-from pattern receptor recognition to recruitment of phagocytic cells-that occur during UPEC-mediated UTI. There is, however, a clear disconnect regarding how factors involved in the innate immune response to UPEC stimulate acquired immunity that facilitates enhanced clearance upon reinfection. Unraveling the molecular details of this process is vital in the development of a successful vaccine for prevention of human UTI. Here, we survey the current understanding of host responses to UPEC-mediated UTI with an eye on molecular and cellular factors whose activity may be harnessed by a vaccine that stimulates lasting and sterilizing immunity.
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Affiliation(s)
- Kelsey E. Sivick
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan 48109
| | - Harry L. T. Mobley
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan 48109
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282
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Abstract
From the authors' opinion, this chapter constitutes a modest extension of the seminal and inspiring contribution of Stowell and Lee on neoglycoconjugates published in this series [C. P. Stowell and Y. C. Lee, Adv. Carbohydr. Chem. Biochem., 37 (1980) 225-281]. The outstanding progresses achieved since then in the field of the "glycoside cluster effect" has witnessed considerable creativity in the design and synthetic strategies toward a vast array of novel carbohydrate structures and reflects the dynamic activity in the field even since the recent chapter by the Nicotra group in this series [F. Nicotra, L. Cipolla, F. Peri, B. La Ferla, and C. Radaelli, Adv. Carbohydr. Chem. Biochem., 61 (2007) 353-398]. Beyond the more classical neoglycoproteins and glycopolymers (not covered in this work) a wide range of unprecedented and often artistically beautiful multivalent and monodisperse nanostructures, termed glycodendrimers for the first time in 1993, has been created. This chapter briefly surveys the concept of multivalency involved in carbohydrate-protein interactions. The topic is also discussed in regard to recent steps undertaken in glycobiology toward identification of lead candidates using microarrays and modern analytical tools. A systematic description of glycocluster and glycodendrimer synthesis follows, starting from the simplest architectures and ending in the most complex ones. Presentation of multivalent glycostructures of intermediate size and comprising, calix[n]arene, porphyrin, cyclodextrin, peptide, and carbohydrate scaffolds, has also been intercalated to better appreciate the growing synthetic complexity involved. A subsection describing novel all-carbon-based glycoconjugates such as fullerenes and carbon nanotubes is inserted, followed by a promising strategy involving dendrons self-assembling around metal chelates. The chapter then ends with those glycodendrimers that have been prepared using commercially available dendrimers possessing varied functionalities, or systematically synthesized using either divergent or convergent strategies.
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283
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Ting SRS, Chen G, Stenzel MH. Synthesis of glycopolymers and their multivalent recognitions with lectins. Polym Chem 2010. [DOI: 10.1039/c0py00141d] [Citation(s) in RCA: 321] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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284
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Zav'yalov V, Zavialov A, Zav'yalova G, Korpela T. Adhesive organelles of Gram-negative pathogens assembled with the classical chaperone/usher machinery: structure and function from a clinical standpoint. FEMS Microbiol Rev 2009; 34:317-78. [PMID: 20070375 DOI: 10.1111/j.1574-6976.2009.00201.x] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
This review summarizes current knowledge on the structure, function, assembly and biomedical applications of the superfamily of adhesive fimbrial organelles exposed on the surface of Gram-negative pathogens with the classical chaperone/usher machinery. High-resolution three-dimensional (3D) structure studies of the minifibers assembling with the FGL (having a long F1-G1 loop) and FGS (having a short F1-G1 loop) chaperones show that they exploit the same principle of donor-strand complementation for polymerization of subunits. The 3D structure of adhesive subunits bound to host-cell receptors and the final architecture of adhesive fimbrial organelles reveal two functional families of the organelles, respectively, possessing polyadhesive and monoadhesive binding. The FGL and FGS chaperone-assembled polyadhesins are encoded exclusively by the gene clusters of the γ3- and κ-monophyletic groups, respectively, while gene clusters belonging to the γ1-, γ2-, γ4-, and π-fimbrial clades exclusively encode FGS chaperone-assembled monoadhesins. Novel approaches are suggested for a rational design of antimicrobials inhibiting the organelle assembly or inhibiting their binding to host-cell receptors. Vaccines are currently under development based on the recombinant subunits of adhesins.
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285
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Waksman G, Hultgren SJ. Structural biology of the chaperone-usher pathway of pilus biogenesis. Nat Rev Microbiol 2009; 7:765-74. [PMID: 19820722 DOI: 10.1038/nrmicro2220] [Citation(s) in RCA: 229] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The chaperone-usher (CU) pathway of pilus biogenesis is the most widespread of the five pathways that assemble adhesive pili at the surface of Gram-negative bacteria. Recent progress in the study of the structural biology of the CU pathway has unravelled the molecular basis of chaperone function and elucidated the mechanisms of fibre assembly at the outer membrane, leading to a comprehensive description of each step in the biogenesis pathway. Other studies have provided the molecular basis of host recognition by CU pili. The knowledge that has been gathered about both the assembly of and host recognition by CU pili has been harnessed to design promising antibiotic compounds.
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Affiliation(s)
- Gabriel Waksman
- Institute of Structural and Molecular Biology, University College London and Birkbeck College, Malet Street, London, UK.
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286
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Abstract
The urinary tract is among the most common sites of bacterial infection, and Escherichia coli is by far the most common species infecting this site. Individuals at high risk for symptomatic urinary tract infection (UTI) include neonates, preschool girls, sexually active women, and elderly women and men. E. coli that cause the majority of UTIs are thought to represent only a subset of the strains that colonize the colon. E. coli strains that cause UTIs are termed uropathogenic E. coli (UPEC). In general, UPEC strains differ from commensal E. coli strains in that the former possess extragenetic material, often on pathogenicity-associated islands (PAIs), which code for gene products that may contribute to bacterial pathogenesis. Some of these genes allow UPEC to express determinants that are proposed to play roles in disease. These factors include hemolysins, secreted proteins, specific lipopolysaccharide and capsule types, iron acquisition systems, and fimbrial adhesions. The current dogma of bacterial pathogenesis identifies adherence, colonization, avoidance of host defenses, and damage to host tissues as events vital for achieving bacterial virulence. These considerations, along with analysis of the E. coli CFT073, UTI89, and 536 genomes and efforts to identify novel virulence genes should advance the field significantly and allow for the development of a comprehensive model of pathogenesis for uropathogenic E. coli.Further study of the adaptive immune response to UTI will be especially critical to refine our understanding and treatment of recurrent infections and to develop vaccines.
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287
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Abstract
Carbohydrates are the most abundant natural products. Besides their role in metabolism and as structural building blocks, they are fundamental constituents of every cell surface, where they are involved in vital cellular recognition processes. Carbohydrates are a relatively untapped source of new drugs and therefore offer exciting new therapeutic opportunities. Advances in the functional understanding of carbohydrate-protein interactions have enabled the development of a new class of small-molecule drugs, known as glycomimetics. These compounds mimic the bioactive function of carbohydrates and address the drawbacks of carbohydrate leads, namely their low activity and insufficient drug-like properties. Here, we examine examples of approved carbohydrate-derived drugs, discuss the potential of carbohydrate-binding proteins as new drug targets (focusing on the lectin families) and consider ways to overcome the challenges of developing this unique class of novel therapeutics.
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Affiliation(s)
- Beat Ernst
- Institute of Molecular Pharmacy, University of Basel, Klingelbergstrasse 50, Basel, Switzerland.
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288
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Pettigrew DM, Roversi P, Davies SG, Russell AJ, Lea SM. A structural study of the interaction between the Dr haemagglutinin DraE and derivatives of chloramphenicol. ACTA CRYSTALLOGRAPHICA. SECTION D, BIOLOGICAL CRYSTALLOGRAPHY 2009; 65:513-22. [PMID: 19465765 PMCID: PMC2685729 DOI: 10.1107/s0907444909005113] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/12/2008] [Accepted: 02/12/2009] [Indexed: 12/02/2022]
Abstract
Dr adhesins are expressed on the surface of uropathogenic and diffusely adherent strains of Escherichia coli. The major adhesin subunit (DraE/AfaE) of these organelles mediates attachment of the bacterium to the surface of the host cell and possibly intracellular invasion through its recognition of the complement regulator decay-accelerating factor (DAF) and/or members of the carcinoembryonic antigen (CEA) family. The adhesin subunit of the Dr haemagglutinin, a Dr-family member, additionally binds type IV collagen and is inhibited in all its receptor interactions by the antibiotic chloramphenicol (CLM). In this study, previous structural work is built upon by reporting the X-ray structures of DraE bound to two chloramphenicol derivatives: chloramphenicol succinate (CLS) and bromamphenicol (BRM). The CLS structure demonstrates that acylation of the 3-hydroxyl group of CLM with succinyl does not significantly perturb the mode of binding, while the BRM structure implies that the binding pocket is able to accommodate bulkier substituents on the N-acyl group. It is concluded that modifications of the 3-hydroxyl group would generate a potent Dr haemagglutinin inhibitor that would not cause the toxic side effects that are associated with the normal bacteriostatic activity of CLM.
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Affiliation(s)
- David M. Pettigrew
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, England
| | - Pietro Roversi
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, England
| | - Stephen G. Davies
- Department of Chemistry, Chemistry Research Laboratory, 12 Mansfield Road, Oxford OX1 3TA, England
| | - Angela J. Russell
- Department of Chemistry, Chemistry Research Laboratory, 12 Mansfield Road, Oxford OX1 3TA, England
| | - Susan M. Lea
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, England
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289
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Gouin SG, Wellens A, Bouckaert J, Kovensky J. Synthetic Multimeric Heptyl Mannosides as Potent Antiadhesives of UropathogenicEscherichia coli. ChemMedChem 2009; 4:749-55. [PMID: 19343765 DOI: 10.1002/cmdc.200900034] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Sébastien G Gouin
- Department of Chemistry, Laboratoire des Glucides UMR CNRS 6219, Institut de Chimie de Picardie, Université de Picardie Jules Verne, 33 Rue Saint Leu, 80039 Amiens Cedex, France.
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290
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Abstract
Lectins, a class of sugar-binding and cell-agglutinating proteins, are ubiquitous in Nature, being found in all kinds of organisms, from viruses to humans. This review describes how plant lectins were developed as widely used reagents for the study of glycoconjugates in solution and on cells, and for cell characterization and separation. A summary is then given of the discoveries that demonstrated the role of lectins as cell recognition molecules of micro-organisms and of animal cells. The specialized functions of these lectins are discussed, as well as the potential medical applications of the knowledge gained. The review ends with speculations about future developments in lectin research and applications.
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291
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Knight SD, Bouckaert J. Structure, Function, and Assembly of Type 1 Fimbriae. GLYCOSCIENCE AND MICROBIAL ADHESION 2009; 288:67-107. [DOI: 10.1007/128_2008_13] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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292
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Pieters RJ. Maximising multivalency effects in protein–carbohydrate interactions. Org Biomol Chem 2009; 7:2013-25. [DOI: 10.1039/b901828j] [Citation(s) in RCA: 288] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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293
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Catch-bond mechanism of force-enhanced adhesion: counterintuitive, elusive, but ... widespread? Cell Host Microbe 2008; 4:314-23. [PMID: 18854236 DOI: 10.1016/j.chom.2008.09.005] [Citation(s) in RCA: 141] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2008] [Revised: 08/19/2008] [Accepted: 09/15/2008] [Indexed: 12/25/2022]
Abstract
Catch bonds are bonds between a ligand and its receptor that are enhanced by mechanical force pulling the ligand-receptor complex apart. To date, catch-bond formation has been documented for the most common Escherichia coli adhesin, FimH, and for P-/L-selectins, universally expressed by leukocytes, platelets, and blood vessel walls. One compelling explanation for catch bonds is that force-induced structural alterations in the receptor protein are allosterically linked to a high-affinity conformation of its ligand-binding pocket. Catch-bond properties are likely to be widespread among adhesive proteins, thus calling for a detailed understanding of their underlying mechanisms and physiological significance.
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294
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Hatch DM, Weiss AA, Kale RR, Iyer SS. Biotinylated Bi- and Tetra-antennary Glycoconjugates forEscherichia coliDetection. Chembiochem 2008; 9:2433-42. [DOI: 10.1002/cbic.200800188] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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295
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Targeting virulence traits: potential strategies to combat extraintestinal pathogenic E. coli infections. Curr Opin Microbiol 2008; 11:409-13. [DOI: 10.1016/j.mib.2008.09.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2008] [Accepted: 09/02/2008] [Indexed: 01/22/2023]
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296
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Nilsson LM, Thomas WE, Sokurenko EV, Vogel V. Beyond induced-fit receptor-ligand interactions: structural changes that can significantly extend bond lifetimes. Structure 2008; 16:1047-58. [PMID: 18611378 DOI: 10.1016/j.str.2008.03.012] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2007] [Revised: 03/20/2008] [Accepted: 03/22/2008] [Indexed: 01/15/2023]
Abstract
While the lifetime of conventional receptor-ligand interactions is shortened by tensile mechanical force, some recently discovered interactions, termed catch bonds, can be strengthened by force. Motivated by the search for the underpinning structural mechanisms, we here explore the structural dynamics of the binding site of the bacterial adhesive protein FimH by molecular dynamics and steered molecular dynamics. While the crystal structure of only one FimH conformation has been reported so far, we describe two distinctively different conformations of the mannose-bound FimH binding site. Force-induced dissociation was slowed when the mannose ring rotated such that additional force-bearing hydrogen bonds formed with the base of the FimH binding pocket. The lifetime of the complex was further enhanced significantly by rigidifying this base. We finally show how even sub-angstrom spatial alterations of the hydrogen bonding pattern within the base can lead to significantly decreased bond lifetimes.
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Affiliation(s)
- Lina M Nilsson
- Department of Materials, ETH Zürich, Wolfgang-Pauli-Strasse 10, HCI F443, CH-8093 Zürich, Switzerland
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297
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Imberty A, Chabre Y, Roy R. Glycomimetics and Glycodendrimers as High Affinity Microbial Anti-adhesins. Chemistry 2008; 14:7490-9. [DOI: 10.1002/chem.200800700] [Citation(s) in RCA: 220] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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298
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Munera D, Palomino C, Fernández LÁ. Specific residues in the N-terminal domain of FimH stimulate type 1 fimbriae assembly inEscherichia colifollowing the initial binding of the adhesin to FimD usher. Mol Microbiol 2008; 69:911-25. [DOI: 10.1111/j.1365-2958.2008.06325.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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299
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Chabre YM, Contino-Pépin C, Placide V, Shiao TC, Roy R. Expeditive Synthesis of Glycodendrimer Scaffolds Based on Versatile TRIS and Mannoside Derivatives. J Org Chem 2008; 73:5602-5. [DOI: 10.1021/jo8008935] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Yoann M. Chabre
- Department of Chemistry, Université du Québec à Montréal, P.O. Box 8888, Succ. Centre-Ville Montréal, Québec, Canada H3C 3P8
| | - Christiane Contino-Pépin
- Department of Chemistry, Université du Québec à Montréal, P.O. Box 8888, Succ. Centre-Ville Montréal, Québec, Canada H3C 3P8
| | - Virginie Placide
- Department of Chemistry, Université du Québec à Montréal, P.O. Box 8888, Succ. Centre-Ville Montréal, Québec, Canada H3C 3P8
| | - Tze Chieh Shiao
- Department of Chemistry, Université du Québec à Montréal, P.O. Box 8888, Succ. Centre-Ville Montréal, Québec, Canada H3C 3P8
| | - René Roy
- Department of Chemistry, Université du Québec à Montréal, P.O. Box 8888, Succ. Centre-Ville Montréal, Québec, Canada H3C 3P8
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300
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Van Gerven N, De Greve H, Hernalsteens JP. Inactivated Salmonella expressing the receptor-binding domain of bacterial adhesins elicit antibodies inhibiting hemagglutination. Vet Microbiol 2008; 131:369-75. [PMID: 18502056 DOI: 10.1016/j.vetmic.2008.04.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2007] [Revised: 03/25/2008] [Accepted: 04/10/2008] [Indexed: 11/28/2022]
Abstract
We examined the potential of inactivated Salmonella strains to induce protective antibodies against two adhesins of pathogenic Escherichia coli. The receptor-binding domains of the F17a-G adhesin of F17a fimbriae and of the FimH adhesin of type 1 fimbriae were fused to the translocator domain of the autotransporter AIDA-I. An IgG response against F17a-G or FimH was induced after immunization of mice with acetone-inactivated Salmonella displaying the corresponding fimbrial receptor-binding domain. These sera inhibit in vitro agglutination of erythrocytes by E. coli carrying these fimbriae. Our results demonstrate that induced and subsequently acetone-inactivated Salmonella are useful delivery vehicles for the stimulation of an IgG antibody response against heterologous antigens.
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Affiliation(s)
- Nani Van Gerven
- Onderzoeksgroep Genetische Virologie, Vrije Universiteit Brussel, B-1050 Brussels, Belgium.
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