N. Cruz et al., ROLE OF MUCIN, MANNOSE, AND BETA-1 INTEGRIN RECEPTORS IN ESCHERICHIA-COLI TRANSLOCATION ACROSS CACO-2 CELL MONOLAYERS, Shock, 2(2), 1994, pp. 121-126
Our previous work suggests that Caco-2 cells play an active role in ba
cterial translocation (BT). Since bacterial enterocyte interactions ma
y be receptor-mediated, the current study was performed to investigate
the role of beta 1 integrin and mannose receptors as well as the gene
ral protective effect of the mucous layer in this process. Caco-2 cell
s grown to confluence on semipermeable membranes contained in the uppe
r compartment of a two compartment system were utilized. BT was assess
ed by quantitating the number of Escherichia coli crossing the monolay
ers after challenge with 10(8) E. ColiC25. Pretreatment of the Caco-2
cells with the beta 1 integrin receptor competitive inhibitors fibrone
ctin or RGD did not inhibit BT; while pretreatment of Caco-2 cells wit
h the LFA-1 (lectin) receptor competitive inhibitor mannose (12 mg/ml)
or purified mucin (8 mg/ml) decreased BT compared to control membrane
s (p < .001). Transepithelial resistance was similar among all the gro
ups indicating maintenence 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.