Interaction of a 60-kilodalton D-mannose-containing salivary glycoprotein with type 1 fimbriae of Escherichia coli

J P Babu, S N Abraham, M K Dabbous, E H Beachey
1986 Infection and Immunity  
A 60-kilodalton glycoprotein previously isolated and purified from human saliva (J. P. Babu, E. H. Beachey, D. L. Hasty, and W. A. Simpson, Infect. Immun. 51:405-413, 1986) was found to interact with type 1 fimbriae and prevent adhesion of type 1 fimbriated Escherichia coli to animal cells in a D-mannose-sensitive manner. Purified salivary glycoprotein agglutinated type 1 fimbriated E. coli and, at subagglutinating concentrations, blocked the ability of type 1 fimbriated E. coli to attach to
more » ... oli to attach to human buccal epithelial cells or agglutinate guinea pig erythrocytes. Both interactions were inhibited by a-methyl-D-mannoside but not by a-methyl-D-glucoside. Complexing of the glycoprotein to type 1 fimbriae was demonstrated by molecular sieve chromatography and modified Western blots. When mixed with type 1 fimbriae, the radiolabeled salivary glycoprotein coeluted with type 1 fimbriae from a column of Sepharose 4B. When blotted from a sodium dodecyl sulfate gel to nitrocellulose sheets, the glycoprotein interacted directly with type 1 fimbriae applied to the blots. Both of the latter interactions also were blocked by a-methyl-D-mannoside but not by ot-methyl-D-glucoside. Chemical modification of the glycoprotein with sodium metaperiodate abolished its ability to interact with isolated type 1 fimbriae or type 1 fimbriated E. coli. These results suggest that the carbohydrate moiety of the 60-kilodalton glycoprotein serves as a receptor for type 1 fimbriae in the oral cavity, and we postulate that the interaction may cause agglutination and early removal of E. coli, thereby preventing colonization by these organisms of oropharyngeal mucosae and dental tissues. followed by a boost of 200 ,ug of fimbriae 2 weeks later in 104 on May 9, 2020 by guest Downloaded from
doi:10.1128/iai.54.1.104-108.1986 fatcat:q4f3bvnqebhkfmutkjwsiepvsm