title: Glucose up-regulates expression of the differentiation-associated brush border binding site for enterotoxigenic Escherichia coli colonization factor antigen I in cultured human enterocyte-like cells.
abstract: The association of enterotoxigenic Escherichia coli expressing colonization factor antigen I (CFA/I) with the cultured human colon adenocarcinoma cell, a model of the mature enterocyte of the small intestine, is dependent on the binding of CFA/I to a brush border-associated component. Binding of the purified radiolabeled [125I]CFA/I- and 14C-labeled CFA/I-positive bacteria could be displaced by an increasing concentration of unlabeled CFA/I. Moreover, we showed that expression of the specific CFA/I binding developed as a function of cell differentiation in Caco-2 cells, whereas expression of the nonspecific binding did not. Expression of the brush border differentiation-associated component acting as a binding site for CFA/I was up-regulated by glucose. Indeed, the enterocyte-like HT-29 glc- cell subpopulation not expressing the CFA/I binding site when cultured in dialyzed serum and hexose-free medium regained the ability to bind CFA/I when the cells were returned to culture medium containing glucose. Furthermore, expression of the brush border-associated CFA/I binding site in the enterocyte-like Caco-2 cells was repressed when the cells were cultured in hexose-free conditions.
authors.affiliation: CJF 94.07 INSERM, UFR de Pharmacie Paris XI, Châtenay-Malabry, France.
authors.forename: M F
authors.initials: MF
authors.lastname: Bernet-Camard
authors.forename: F
authors.initials: F
authors.lastname: Duigou
authors.forename: S
authors.initials: S
authors.lastname: Kernéis
authors.forename: M H
authors.initials: MH
authors.lastname: Coconnier
authors.forename: A L
authors.initials: AL
authors.lastname: Servin
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D001665:Binding Sites; D004926:Escherichia coli / Q000378:metabolism; D036781:Fimbriae Proteins; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D007421:Intestine, Small / Q000378:metabolism / Q000382:microbiology*; D008871:Microvilli / Q000378:metabolism*; D014407:Tumor Cells, Cultured; D015854:Up-Regulation
chemical_list: D001426:Bacterial Proteins; C022924:colonization factor antigens; D036781:Fimbriae Proteins; D005947:Glucose