Lymphocyte subpopulations in man: B-cell stimulation induced by pokeweed mitogen and irradiated T cells.

The enhanced stimulation of human B lymphocytes by pokeweed mitogen in the presence of irradiated T helper lymphocytes has been studied, revealing that the proliferative responses measured by incorporation of thymidine in cultures of B lymphocytes and irradiated T lymphocytes in a 1:2 or 1:4 ratio is mostly a function of the B cells. Only a minimal number, if any, of the T cells contaminating the B cell suspensions is stimulated to proliferation. This is in contrast to stimulation of the B-cell suspensions without addition of irradiated T cells, where both B cells and T cells proliferate. The irradiated T helper cells have no FcR for antigen-bound IgG, and as well allogeneic as autologous T cells exhibit helper capacity of equal strength. The test system described makes it possible selectively to test one B-cell function and the corresponding T helper capacity.