title: Characterization of monoclonal antibodies to heat-labile enterotoxin encoded by a plasmid from a clinical isolate of Escherichia coli.
abstract: Eight selected hybridoma cell lines that produced monoclonal antibodies against heat-labile enterotoxin from an Escherichia coli strain of human origin (LTh) were characterized. Antibodies produced by these cell lines were tested for binding specificity in a series of solid-phase radioimmunoassays and Western blots by using as test antigens LTh, the A, A1, A2, and B polypeptides of LTh, the heat-labile enterotoxin from an E. coli strain of porcine origin, and cholera toxin. The monoclonal antibodies were also tested for isotype and ability to neutralize LTh. Two of the anti-LTh monoclonal antibodies cross-reacted with cholera toxin, and six were specific for determinants of LTh that were not present on cholera toxin. One was specific for a unique epitope of LTh that was not shared by the heat-labile enterotoxin from an E. coli strain of porcine origin or cholera toxin. Four antibodies specific for epitopes on the B subunit of LTh (LTh-B) reacted with pentameric LTh-B but did not react in Western blots with monomeric LTh-B. The remaining four antibodies were specific for epitopes on LTh-A; two of these antibodies bound to A1, one reacted with A2, and one recognized only intact LTh-A. Only one monoclonal antibody had detectable neutralizing activity, and it was specific for LTh-A.
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000032:analysis / Q000096:biosynthesis / Q000276:immunology*; D000911:Antibodies, Monoclonal / Q000032:analysis / Q000096:biosynthesis / Q000276:immunology*; D001427:Bacterial Toxins / Q000276:immunology* / Q000378:metabolism; D001666:Binding Sites, Antibody; D003429:Cross Reactions; D004768:Enterotoxins / Q000276:immunology* / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000276:immunology*; D004927:Escherichia coli Infections / Q000276:immunology / Q000382:microbiology; D029968:Escherichia coli Proteins; D006801:Humans; D006825:Hybridomas / Q000276:immunology; D007074:Immunoglobulin G / Q000096:biosynthesis / Q000378:metabolism; D007075:Immunoglobulin M / Q000096:biosynthesis / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D009500:Neutralization Tests; D010957:Plasmids
chemical_list: D000907:Antibodies, Bacterial; D000911:Antibodies, Monoclonal; D001427:Bacterial Toxins; D004768:Enterotoxins; D029968:Escherichia coli Proteins; D007074:Immunoglobulin G; D007075:Immunoglobulin M; C027538:heat-labile enterotoxin, E coli