Suppression of pokeweed mitogen-induced differentiation of human B cells by in vitro levamisole-treated T lymphocytes.

The generation of immunoglobulin-producing cells from human peripheral blood lymphocytes in pokeweed mitogen-simulated cultures was significantly suppressed by levamisole. Greatest suppression was observed when cells were incubated with levamisole at a concentration of 10(-6) M for 20 min or more prior to culture. Such suppression occurred when untreated as well as levamisole-treated B cells were co-cultured only with levamisole-treated T cells. Adding of levamisole-treated T cells to a combination of untreated autologous B and T cells resulted in the suppression of B cell differentiation. The results suggest that levamisole treatment of lymphocytes exerts suppression on pokeweed mitogen-induced B cell differentiation through its effect on T cell regulatory properties.