Abstract |
The Dr family of Escherichia coli adhesins are virulence factors associated with diarrhea and urinary tract infections. Dr fimbriae are comprised of two subunits. DraE/AfaE represents the major structural, antigenic, and adhesive subunit, which recognizes decay-accelerating factor (DAF) and carcinoembryonic antigen (CEA)-related cell adhesion molecules (CEACAMs) CEA, CEACAM1, CEACAM3, and CEACAM6 as binding receptors. The DraD/AfaD subunit caps fimbriae and has been implicated in the entry of Dr-fimbriated E. coli into host cells. In this study, we demonstrate that DAF or CEACAM receptors independently promote DraE-mediated internalization of E. coli by CHO cell transfectants expressing these receptors. We also found that DraE-positive recombinant bacteria adhere to and are internalized by primary human bladder epithelial cells which express DAF and CEACAMs. DraE-mediated bacterial internalization by bladder cells was inhibited by agents which disrupt lipid rafts, microtubules, and phosphatidylinositol 3-kinase (PI3K) activity. Immunofluorescence confocal microscopic examination of epithelial cells detected considerable recruitment of caveolin, beta(1) integrin, phosphorylated ezrin, phosphorylated PI3K, and tubulin, but not F-actin, by cell-associated bacteria. Finally, we demonstrate that the DraD subunit, previously implicated as an "invasin," is not required for beta(1) integrin recruitment or bacterial internalization.
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Authors | Natalia Korotkova, Yuliya Yarova-Yarovaya, Veronika Tchesnokova, Nina Yazvenko, Mike A Carl, Ann E Stapleton, Steve L Moseley |
Journal | Infection and immunity
(Infect Immun)
Vol. 76
Issue 9
Pg. 3869-80
(Sep 2008)
ISSN: 1098-5522 [Electronic] United States |
PMID | 18559426
(Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
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Chemical References |
- Adhesins, Bacterial
- CD55 Antigens
- Cell Adhesion Molecules
- DraD invasin, E coli
- DraE protein, E coli
- Escherichia coli Proteins
- Fimbriae Proteins
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Topics |
- Adhesins, Bacterial
(physiology)
- Animals
- Bacterial Adhesion
- CD55 Antigens
(metabolism)
- CHO Cells
- Caco-2 Cells
- Cell Adhesion Molecules
(metabolism)
- Cricetinae
- Cricetulus
- Epithelial Cells
(microbiology)
- Escherichia coli
(physiology)
- Escherichia coli Proteins
(physiology)
- Fimbriae Proteins
(physiology)
- Humans
- Protein Binding
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