| Abstract: | An in vitro experimental system for the induction of IgE production has been established with human peripheral blood lymphocytes (PBL). The stimulation of human PBL with PWM plus Cowan I induced IgM-, IgG-, and IgE- producing cells when assessed by reverse plaque assay. T cells, which had been isolated from patients with pulmonary tuberculosis and incubated with PPD plus IgE for 5 days, showed a suppressive effect on the polyclonal IgE response induced by PWM plus Cowan I. The direct addition of activated T cells, as well as the culture supernatant from activated T cells, abrogated the IgE response; the IgG response was not affected. The IgE-specific suppressive activity in the supernatant was specifically absorbed by an IgE column and could be eluted with acid buffer. The results demonstrated the presence of a human IgE binding factor(s), which showed its suppressive effect selectively in the IgE antibody response. |
