Structural and functional lesions in brush border of human polarized intestinal Caco-2/TC7 cells infected by members of the Afa/Dr diffusely adhering family of Escherichia coli.
Diffusely adhering Escherichia coli (DAEC) strains expressing F1845 fimbrial adhesin or Dr hemagglutinin belonging to the Afa/Dr family of adhesins infect cultured polarized human intestinal cells through recognition of the brush border-associated decay-accelerating factor (DAF; CD55) as a receptor. The wild-type Afa/Dr DAEC strain C1845 has been shown to induce brush border lesions by an adhesin-dependent mechanism triggering apical F-actin rearrangements. In the present study, we undertook to further characterize cell injuries following the interaction of wild-type Afa/Dr DAEC strains C1845 and IH11128 expressing fimbrial F1845 adhesin and Dr hemagglutinin, respectively, with polarized, fully differentiated Caco-2/TC7 cells. In both cases, bacterium-cell interaction was followed by rearrangement of the major brush border-associated cytoskeletal proteins F-actin, villin, and fimbrin, proteins which play a pivotal role in brush border assembly. In contrast, distribution of G-actin, actin-depolymerizing factor, and tubulin was not modified. Using draE mutants, we found that a mutant in which cysteine replaces aspartic acid at position 54 conserved binding capacity but failed to induce F-actin disassembly. Accompanying the cytoskeleton injuries, we found that the distribution of brush border-associated functional proteins sucrase-isomaltase (SI), dipeptidylpeptidase IV (DPPIV), glucose transporter SGLT1, and fructose transporter GLUT5 was dramatically altered. In parallel, SI and DPPIV enzyme activity decreased.
Peiffer
I
I
Institut National de la Santé et de la Recherche Médicale (INSERM), Unité 510, Faculté de Pharmacie Paris XI, F-92296 Châtenay-Malabry, France.
Guignot
J
J
Barbat
A
A
Carnoy
C
C
Moseley
S L
SL
Nowicki
B J
BJ
Servin
A L
AL
Bernet-Camard
M F
MF
D000199:Actins / Q000378:metabolism; D018830:Adhesins, Escherichia coli / Q000235:genetics / Q000378:metabolism*; D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000378:metabolism; D018938:Caco-2 Cells; D002118:Calcium / Q000378:metabolism; D016764:Cell Polarity; D003598:Cytoskeletal Proteins / Q000378:metabolism; D004926:Escherichia coli / Q000378:metabolism / Q000472:pathogenicity*; D006801:Humans; D007413:Intestinal Mucosa / Q000378:metabolism / Q000382:microbiology* / Q000648:ultrastructure; D008854:Microscopy, Electron; D008871:Microvilli / Q000378:metabolism / Q000382:microbiology / Q000648:ultrastructure*; D017354:Point Mutation; D014774:Virulence
D000199:Actins; D018830:Adhesins, Escherichia coli; D001426:Bacterial Proteins; D003598:Cytoskeletal Proteins; D002118:Calcium