title: Role of mucin, mannose, and beta-1 integrin receptors in Escherichia coli translocation across Caco-2 cell monolayers.
abstract: Our previous work suggests that Caco-2 cells play an active role in bacterial translocation (BT). Since bacterial enterocyte interactions may be receptor-mediated, the current study was performed to investigate the role of beta 1 integrin and mannose receptors as well as the general protective effect of the mucous layer in this process. Caco-2 cells grown to confluence on semipermeable membranes contained in the upper compartment of a two compartment system were utilized. BT was assessed by quantitating the number of Escherichia coli crossing the monolayers after challenge with 10(8) E. coli C25. Pretreatment of the Caco-2 cells with the beta 1 integrin receptor competitive inhibitors fibronectin or RGD did not inhibit BT; while pretreatment of Caco-2 cells with the LFA-1 (lectin) receptor competitive inhibitor mannose (12 mg/ml) or purified mucin (8 mg/ml) decreased BT compared to control membranes (p < .001). Transepithelial resistance was similar among all the groups indicating maintenance of tight junction integrity. These studies suggest that E. coli BT in the Caco-2 system can be reduced by mannose and that intestinal mucin contributes to the barrier function of the monolayer.
authors.affiliation: Department of Surgery, Louisiana State University Medical Center, Shreveport 71130, USA.
authors.forename: N
authors.initials: N
authors.lastname: Cruz
authors.forename: X
authors.initials: X
authors.lastname: Alvarez
authors.forename: R D
authors.initials: RD
authors.lastname: Specian
authors.forename: R D
authors.initials: RD
authors.lastname: Berg
authors.forename: E A
authors.initials: EA
authors.lastname: Deitch
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D016470:Bacteremia; D002460:Cell Line; D003110:Colonic Neoplasms; D004926:Escherichia coli / Q000187:drug effects / Q000502:physiology*; D005353:Fibronectins / Q000494:pharmacology; D006801:Humans; D019012:Integrin beta1; D016023:Integrins / Q000502:physiology*; D037181:Lectins, C-Type; D008358:Mannose / Q000494:pharmacology*; D000090323:Mannose Receptor; D037241:Mannose-Binding Lectins; D008954:Models, Biological; D009077:Mucins / Q000494:pharmacology* / Q000502:physiology; D009842:Oligopeptides / Q000494:pharmacology; D051381:Rats; D011956:Receptors, Cell Surface / Q000502:physiology*; D013997:Time Factors; D014407:Tumor Cells, Cultured
chemical_list: D005353:Fibronectins; D019012:Integrin beta1; D016023:Integrins; D037181:Lectins, C-Type; D000090323:Mannose Receptor; D037241:Mannose-Binding Lectins; D009077:Mucins; D009842:Oligopeptides; D011956:Receptors, Cell Surface; C047981:arginyl-glycyl-aspartic acid; D008358:Mannose