Binding of fibronectin to human buccal epithelial cells inhibits the binding of type 1 fimbriated Escherichia coli.

The interaction of purified human plasma fibronectin (FN) with human buccal epithelial cells was studied. Maximal binding of FN occurred at pH 5. The majority of the binding was specific and reversible. The binding of FN to buccal cells was saturable, reaching a maximum when 10(5) buccal cells were incubated with approximately 200 micrograms of radiolabeled protein per ml. The adherence of a type 1 fimbriated strain of Escherichia coli to buccal epithelial cells was inhibited by the addition of FN in a dose-related manner. Our results indicate that exogenous FN can bind to human buccal epithelial cells and block the attachment of a type 1 fimbriated strain of E. coli.