Low responsiveness of lymphocytes from normal individuals against the stimulation with pokeweed mitogen.

The responsiveness of peripheral blood lymphocytes stimulated with pokeweed mitogen (PWM) and purified protein derivative of tuberculin (PPD) as B cell activator was studied in adult healthy subjects by immunoglobulin synthesis system in culture. We have shown that lymphocytes from some healthy subjects have low responsiveness in the polyclonal antibodies secretion following PWM stimulation but not PPD stimulation by Protein A-reverse hemolytic assay. In this system, when irradiated T cells (CD4+) as helper T cell were added to B cells from autologous or allogeneic subjects, helper T cell function of immunoglobulin synthesis on the low response groups to PWM significantly decreased. Whereas normal responses to PPD stimulation were observed in the presence of helper T cells (CD4+). The low responsiveness of lymphocytes stimulated with PWM but not PPD may be related to reduced functions of helper T cell populations. Thus the healthy subjects were classified into high, normal and low response groups with PWM on the basis of antibody production.