title: Inhibition of IgE production in B hybridomas by IgE class-specific suppressor factor from T hybridomas.
abstract: The function of IgE class-specific suppressor factor (IgE-TsF) from T hybridomas was studied by employing IgE-producing B hybridomas. IgE-TsF was obtained from IgE class-specific T hybridomas, which had been established by the fusion of a phosphorylcholine-conjugated Mycobacterium-primed T cell population with the T lymphoma cell line BW5147. The absorption experiments showed that IgE-TsF from T hybridomas was composed of the binding site(s) for IgE and I region gene products as observed in conventional IgE-TsF. Incubation of IgE-producing B hybridomas with IgE-TsF for 1 hr at 37 degrees C resulted in the reduction of the number of IgE-secreting cells when assessed by a reverse plaque assay. The proportions of surface IgE-positive cells were concomitantly reduced. After 24 hr incubation with IgE-TsF, the number of cytoplasmic IgE-positive cells was reduced, showing that IgE synthesis was inhibited by IgE-TsF. Antigen-specific TsF from phosphorylcholine-specific T hybridomas did not show any inhibitory effect, and IgE-TsF did not block the antibody production of IgM-producing B hybridomas. Precapping of IgE receptors by anti-epsilon antibody or the simultaneous addition of soluble IgE with IgE-TsF abrogated the suppressive function, suggesting that IgE-TsF acted directly on B epsilon cells through binding with IgE receptors.
mesh_terms: D000818:Animals; D000921:Antibody-Producing Cells / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D006825:Hybridomas / Q000276:immunology; D007073:Immunoglobulin E / Q000096:biosynthesis* / Q000494:pharmacology*; D008222:Lymphokines / Q000494:pharmacology*; D051379:Mice; D008807:Mice, Inbred BALB C; D017455:Receptors, IgE; D011971:Receptors, Immunologic; D013491:Suppressor Factors, Immunologic; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: C037161:IGE class-specific suppressor factor; D008222:Lymphokines; D017455:Receptors, IgE; D011971:Receptors, Immunologic; D013491:Suppressor Factors, Immunologic; D007073:Immunoglobulin E