The main goal of this competing renewal proposal is to study how shear force that is created by the fluid flow affects the uropathogenicity-relevant functional properties of the Escherichia coli fimbriae, withprimary focus on the mannose-sensitive, type 1fimbrial adhesin, FimH. Analysis of naturalvariants of FlmH protein has been the focus of our current grant that led us to the finding that strength of the FimH-mediated mannose- binding is dramatically enhanced by the presence of shear stress. We demonstrated that tensile mechanical force is likely to induce specific conformational changes in the FimH protein that are associated with the shear-dependent binding phenotype. In this renewal proposal we intend to use different shear-associated variants of FimH to understand possible roles of the shear-enhanced mode of the FimH-mediated adhesion that is relevantto colonization of the urinarytract by E, coli. We will perform functional analysis of various naturally-occurring FimH variants and determine binding shear-spectrum of wild-typeE. coli strains and FimH-functionalized beads. To characterize physiological significanceof the FimH shear-associated phenotypes we also will determine FimH-mediated binding to natural-likereceptors and variable shear conditions; adhesion and invasion of uroepithelial cells, and colonization in animal model of urinary tract infection. In addition, we will characterize inhibitorsof the FimH-mediated bindingunder different shear. Studies proposed here will serve as model ones to provide a spectrum of novel information regarding shear effects on bacterial adhesion, particularlyin connection to the bacterial pathogenesis.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI045820-08
Application #
7367140
Study Section
Bacterial Pathogenesis Study Section (BACP)
Program Officer
Korpela, Jukka K
Project Start
2000-05-01
Project End
2011-02-28
Budget Start
2008-03-01
Budget End
2009-02-28
Support Year
8
Fiscal Year
2008
Total Cost
$297,196
Indirect Cost
Name
University of Washington
Department
Microbiology/Immun/Virology
Type
Schools of Medicine
DUNS #
605799469
City
Seattle
State
WA
Country
United States
Zip Code
98195
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Le Trong, Isolde; Aprikian, Pavel; Kidd, Brian A et al. (2010) Structural basis for mechanical force regulation of the adhesin FimH via finger trap-like beta sheet twisting. Cell 141:645-55
Sokurenko, Evgeni V; Vogel, Viola; Thomas, Wendy E (2008) Catch-bond mechanism of force-enhanced adhesion: counterintuitive, elusive, but ... widespread? Cell Host Microbe 4:314-23
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Nilsson, Lina M; Thomas, Wendy E; Trintchina, Elena et al. (2006) Catch bond-mediated adhesion without a shear threshold: trimannose versus monomannose interactions with the FimH adhesin of Escherichia coli. J Biol Chem 281:16656-63
Nair, Bindu M; Joachimiak, Lukasz A; Chattopadhyay, Sujay et al. (2005) Conservation of a novel protein associated with an antibiotic efflux operon in Burkholderia cenocepacia. FEMS Microbiol Lett 245:337-44
Thomas, Wendy E; Nilsson, Lina M; Forero, Manu et al. (2004) Shear-dependent 'stick-and-roll' adhesion of type 1 fimbriated Escherichia coli. Mol Microbiol 53:1545-57
Thomas, Wendy E; Trintchina, Elena; Forero, Manu et al. (2002) Bacterial adhesion to target cells enhanced by shear force. Cell 109:913-23
Van Loy, Cristina P; Sokurenko, Evgeni V; Moseley, Steve L (2002) The major structural subunits of Dr and F1845 fimbriae are adhesins. Infect Immun 70:1694-702

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