Proliferation kinetics of human B- and T-lymphocytes

Human peripheral blood B- and T-lymphocytes, highly purified by immunological methods, were supplemented with gamma-irradiated unseparated autologous mononuclear cells to restore helper functions and stimulated with pokeweed mitogen and phytohaemagglutinin, respectively. Proliferation kinetics of the cell populations were investigated using 5-bromodeoxyuridine (BrdU) labelling of the cell cultures and chromosome preparation at different times after stimulation. The percentages of metaphase cells having replicated for one, two or three generations in the presence of BrdU were determined following sister chromatid differential staining. In all donors, the changes in these percentages were faster in B- than in T-lymphocytes, indicating a longer cell cycle time in the latter population.