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Comparative analysis of EspF from enteropathogenic and enterohemorrhagic Escherichia coli in alteration of epithelial barrier function.
- Source :
-
Infection and immunity [Infect Immun] 2004 Jun; Vol. 72 (6), pp. 3218-27. - Publication Year :
- 2004
-
Abstract
- Enteropathogenic Escherichia coli (EPEC) and enterohemorrhagic E. coli (EHEC) are related intestinal pathogens that harbor highly similar pathogenicity islands known as the locus of enterocyte effacement (LEE). Despite their genetic similarity, these two pathogens disrupt epithelial tight junction barrier function with distinct kinetics. EHEC-induced reduction in transepithelial electrical resistance (TER), a measure of barrier function disruption, is significantly slower and more modest in comparison to that induced by EPEC. The variation in bacterial adherence only partially accounted for these differences. The LEE-encoded effector protein EspF has been shown to be critical for EPEC-induced alterations in TER. EspF from both EPEC and EHEC is expressed and secreted upon growth in tissue culture medium. The mutation of EHEC cesF suggested that the optimal expression and secretion of EHEC EspF required its chaperone CesF, as has been shown for EPEC. In contrast to EPEC espF and cesF, mutation of the corresponding EHEC homologs did not dramatically alter the decrease in TER. These differences could possibly be explained by the presence of additional espF-like sequences (designated U- and M-espF, where the letter designations refer to the specific cryptic prophage sequences on the EHEC chromosome closest to the respective genes) in EHEC. Reverse transcription-PCR analyses revealed coordinate regulation of EHEC U-espF and the LEE-encoded espF, with enhanced expression in bacteria grown in Dulbecco-Vogt modified Eagle's medium compared to bacteria grown in Luria broth. Both EHEC espF and U-espF complemented an EPEC espF deletion strain for barrier function alteration. The overexpression of U-espF, but not espF, in wild-type EHEC potentiated the TER response. These studies reveal further similarities and differences in the pathogenesis of EPEC and EHEC.
- Subjects :
- Bacterial Adhesion
Caco-2 Cells
Cell Line, Tumor
Epithelial Cells cytology
Escherichia coli classification
Escherichia coli genetics
Escherichia coli Proteins genetics
Gene Expression Regulation, Bacterial
Humans
Intestines cytology
Intestines microbiology
Microscopy, Fluorescence
Molecular Chaperones metabolism
Tight Junctions physiology
Virulence
Epithelial Cells pathology
Escherichia coli pathogenicity
Escherichia coli Proteins metabolism
Intestines pathology
Tight Junctions pathology
Subjects
Details
- Language :
- English
- ISSN :
- 0019-9567
- Volume :
- 72
- Issue :
- 6
- Database :
- MEDLINE
- Journal :
- Infection and immunity
- Publication Type :
- Academic Journal
- Accession number :
- 15155623
- Full Text :
- https://doi.org/10.1128/IAI.72.6.3218-3227.2004