title: T-lymphocyte dependency of B-lymphocyte blastogenic response to phytomitogens.
abstract: Human peripheral blood T and B lymphocytes were separated by a method based on the stable rosette formation of T lymphocytes with neuraminidase-treated sheep erythrocytes, followed by centrifugation over a Ficoll-Hypaque gradient. Monocytes were isolated from the T-depleted B lymphocyte preparation by allowing the monocytes to ingest iron particles and by subsequent centrifugation over a Ficoll-Hypaque gradient. The T lymphocytes responded extremely well to PHA and very well to PWM, while the B lymphocytes were unresponsive to either PHA or PWM. However, when the B lymphocytes were cultured together with irradiated autologous or allogeneic T lymphocytes (1:1, 1:2 or 1:4 ratio), both PHA and PWM became mitogenic to B lymphocytes. Irradiated T lymphocytes alone did not respond to either PHA or PWM, indicating that the 3H-thymidine incorporation seen in the mixed-cell culture was due to the activation of unirradiated B lymphocytes. The B lymphocytes failed to respond to these phytomitogens in the presence of lower concentrations of irradiated T lymphocytes. The monocytes were found to be incapable of helping the B lymphocytes to respond to PHA or PWM.
mesh_terms: D001402:B-Lymphocytes / Q000276:immunology*; D006801:Humans; D037102:Lectins / Q000494:pharmacology*; D008213:Lymphocyte Activation; D009000:Monocytes / Q000276:immunology / Q000528:radiation effects; D010835:Phytohemagglutinins / Q000494:pharmacology; D011043:Pokeweed Mitogens / Q000494:pharmacology; D013601:T-Lymphocytes / Q000276:immunology* / Q000528:radiation effects
chemical_list: D037102:Lectins; D010835:Phytohemagglutinins; D011043:Pokeweed Mitogens