Suppressor T cells activated by lymphoblastoid cell lines inhibit pokeweed mitogen-lnduced immunoglobulin synthesis

EBV-transformed B-cell lines of normal or malignant origin suppressed pokeweed mitogen-induced immunoglobulin synthesis of normal B cells, measured by the protein A plaque assay method. Autologous and allogeneic LCL were equally effective. Allogeneic irradiated B cells were ineffective or slightly enhancing. EBV-negative hematopoietic cell lines derived from myeloid leukemia (K562 and HL-60) were ineffective or slightly enhancing. The suppressive effect of the Burkitt lymphoma line Raji was partly due to released soluble suppressor factors, but to a larger extent to the generation of radiosensitive suppressor T cells in the responder population. Autologous and allogeneic LCL were equally effective in generating suppressor T cells. It is postulated that the suppressor circuit reflects the existence of regulatory mechanisms that govern the proliferation of B lymphocytes.