A mouse monoclonal IgE antibody anti bovine milk beta-lactoglobulin allows studies of allergy in the gastrointestinal tract.

A monoclonal IgE antibody directed against bovine milk beta-lactoglobulin (beta-LG) was produced by fusion of NSI myeloma cells with spleen cells of Balb/c mice immunized with alum-precipitated beta-LG. This antibody was found by radioimmunoassay to react with both native and aggregated beta-LG, but a positive passive cutaneous anaphylaxis reaction (PCA) was evident only with aggregated beta-LG. 1 ng of this purified antibody was capable of eliciting a PCA. The chemical and physical properties were characterized by amino acid and carbohydrate analysis and by ultracentrifugation. The epsilon-chain had an apparent molecular weight of 86,000 +/- 2,000 by polyacrylamide gel electrophoresis. An immediate hypersensitivity reaction within the gut was elicited by intravenous (i.v.) administration of the hybridoma ascitic fluid followed by feeding with aggregated beta-LG. Accumulation of liquid within the small intestine and diarrhoea were evident 30-90 min later. Intravenous injection of carbon particles revealed an increased permeability of the venulae from the submucosa and serosa. Histological examination showed oedema within the villae, without modification of the epithelium.