title: Co-operation between T and B lymphocytes from human tonsils in the response to mitogens and antigens.
abstract: Purified B lymphocytes obtained from human tonsil cell populations by removing E rosette-forming cells by density sedimentation did not proliferate at three days in response to PHA and Con A, but showed a significant 3H-labelled thymidine incorporation when the PHA response was assessed at day 6 of culture. The 6th-day responses, which was completely abolished by the reduction of T-cell contamination to less than 0-1% by re-rosetting and a second separation, was due in part to a direct activation by PHA of contaminating T cells and in part to a T cell-mediated B-cell response. When purified B cells were stimulated for 3 days by PHA in the presence of an equal number of autologous or homologous mitomycin-treated T lymphocytes a highly significant uptake of 3H-labelled thymidine was demonstrated. The majority of blast cells obtained at day 4 in  these cultures were unable to form E rosettes and showed surface immunoglobulin by immunofluorescence stain. This response was markedly decreased by previous treatment of B cells with mitomycin C and it was abolished when B cells were killed by heating at 56degrees C for 1 hr. Purified B lymphocytes from human tonsils did not respond in vitro when cultured for 6 days in the presence of soluble antigens (PPD and  Candida). However, a highly significant response to the same antigens could be demonstrated when B cells were cultured in the presence of autologous mitomycin-treated T cells. These models of T-B co-operation could provide an interesting tool for studying the differentiation and antibody production in vitro of human B lymphocytes.
mesh_terms: D000942:Antigens, Bacterial; D001402:B-Lymphocytes / Q000276:immunology*; D002469:Cell Separation; D006358:Hot Temperature; D006801:Humans; D008213:Lymphocyte Activation; D008934:Mitogens / Q000494:pharmacology; D008937:Mitomycins / Q000494:pharmacology; D014066:Palatine Tonsil / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000942:Antigens, Bacterial; D008934:Mitogens; D008937:Mitomycins