Epitope specificity of a monoclonal antibody generated against the dissociated CFA/I fimbriae of enterotoxigenic Escherichia coli.
A monoclonal antibody (MAb 84) raised against the dissociated CFA/I fimbriae of enterotoxigenic Escherichia coli was characterized with regard to antigen binding and epitope specificity. Enzyme-linked immunosorbent assay (ELISA) showed that MAb 84 had higher affinity to CFA/I subunits than to intact CFA/I fimbriae and recognized a Salmonella flagellin carrying an insert corresponding to amino acids 32 to 45 of the CFA/I subunit. Fine epitope mapping based on the Pepscan technique showed that the peptide 39TFESY43, derived from the sequence of the mature CFA/I subunit, was specifically recognized by MAb 84. The 39TFESY43 sequence is probably not accessible on the surface of the native CFA/I fimbriae since MAb 84 did not bind to intact fimbriae as evaluated in inhibition ELISA tests. Moreover, MAb 84 did not agglutinate fimbriated ETEC cells nor inhibit CFA/I-mediated hemagglutination or the adhesion to Caco-2 cells.
de Luna
M G
MG
Disciplina de Microbiologia e Imunologia, Faculdade de Ciências Médicas, Universidade do Estado do Rio de Janeiro, RJ, Brazil. luna@uerj.br
Rudin
A
A
Vinhas
S A
SA
de Almeida
D F
DF
de Souza Ferreira
L C
LC
D000818:Animals; D000911:Antibodies, Monoclonal / Q000096:biosynthesis / Q000276:immunology*; D001422:Bacterial Adhesion / Q000276:immunology; D001425:Bacterial Outer Membrane Proteins / Q000276:immunology; D001426:Bacterial Proteins / Q000276:immunology*; D018938:Caco-2 Cells / Q000276:immunology; D003001:Cloning, Molecular; D018604:Epitope Mapping; D000939:Epitopes / Q000276:immunology*; D004926:Escherichia coli / Q000276:immunology*; D036781:Fimbriae Proteins; D010861:Fimbriae, Bacterial / Q000276:immunology*; D006385:Hemagglutination Inhibition Tests; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C
D000911:Antibodies, Monoclonal; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D000939:Epitopes; C022924:colonization factor antigens; D036781:Fimbriae Proteins