This Article Full Text (PDF) Other Versions of this Article: IAI.00439-08v1 76/10/4378    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Google Scholar Articles by Farfan, M. J. Articles by Nataro, J. P. PubMed PubMed Citation Articles by Farfan, M. J. Articles by Nataro, J. P.

 Previous Article  |  Next Article 

Infect. Immun. doi:10.1128/IAI.00439-08
Copyright (c) 2008, American Society for Microbiology and/or the Listed Authors/Institutions. All Rights Reserved.

The major pilin subunit of the AAF/II fimbriae from enteroaggregative E. coli mediates binding to extracellular matrix proteins

Center for Vaccine Development, Department of Pediatrics, University of Maryland School of Medicine, Baltimore; Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore

^* To whom correspondence should be addressed. Email: jnataro{at}medicine.umaryland.edu.

	Abstract

Enteroaggregative E. coli (EAEC) adherence to human intestinal tissue is mediated by aggregative adherence fimbriae (AAF); however, the receptors involved in EAEC adherence remain uncharacterized. Adhesion to extracellular matrix proteins is commonly observed among enteric pathogens, so we addressed the hypothesis that EAEC may bind to extracellular matrix proteins commonly found in the intestine. W e found that EAEC prototype strain 042 adheres more abundantly to surfaces that were pre-coated with the extracellular matrix proteins fibronectin, laminin and type IV collagen. Differences in fibronectin binding of almost two orders of magnitude were observed between EAEC 042 and a mutant in the AAF/II major pilin gene, aafA. Purified AafA, refolded as a donor strand complementation construct, bound fibronectin in a dose-dependent manner. Addition of fibronectin to the apical surface of polarized T84 cell monolayers augmented EAEC 042 adherence, and this effect required expression of aafA. Finally, increased bacterial adherence was observed when apical secretion of fibronectin was induced by adenosine in polarized T84 cells. Binding to fibronectin may contribute to colonization of the gastrointestinal tract by EAEC.