Monoclonal dinitrophenyl-specific murine IgE antibody: preparation, isolation, and characterization.

Abstract

Abstract A murine hybridoma secreting monoclonal IgE antibodies of anti-2,4-dinitrophenyl (DNP) specificity was generated by fusion of SP2/0 tumor cells and spleen cells from DNP-Ascaris-hyperimmunized mice. Hybridomas secreting anti-DNP antibodies of other heavy chain classes, i.e., μ, γ1 and γ2b, were also obtained from the same fusion experiment. Large quantities of IgE antibodies were obtained from ascites of mice in which the IgE-secreting hybridoma was propagated in vivo. The IgE antibodies were isolated by precipitation with ammonium sulfate followed by afinity chromatography on DNP-bovine serum albumin (BSA)-Sepharose-4B and further purified by ion-exchange chromatography on DEAE-cellulose and gel filtration on Sephadex G-200. The isolated IgE has an approximate m.w. of 184,000, a total carbohydrate content of 13.3%, and its amino acid composition has been determined. The antibody has an association constant with DNP-lysine of 1.4 × 108 M-1 at 25°C and 7.1 × 107 M-1 at 37°C. Rabbit and goat antibodies against the hybridoma IgE were prepared and the antisera were made specific for IgE by adsorption on normal mouse serum protein-Sepharose-4B. Solid phase radioimmunoassays for measuring murine antigen-specific and total IgE were developed and were shown to have high specificity and sensitivity. Finally, the isolated hybridoma IgE can mediate antigen (DNP-BSA)-induced release of mediator (serotonin) from rat basophilic leukemia cells.