Bcl-2 family proteins regulate T lymphocyte apoptosis mediated by CD3ε and 5-FU

Objective:To investigate the regulation of Bcl 2 family on T lymphocyte apoptosis mediated by CD3e and/or 5 FU (5 fluorouracil) and to provide a novel insight of the apoptosis signaling pathway and the implication for the clinic therapy of T lymphocyte leukemia.Methods:JK,TJK and T3JK cells stimulated with anti CD8 mAb (200 μg/ml) cross link and/or 5 FU (2 5 μg/ml) for 34 h.MTS assay was used to detect cell viability.Bcl 2 and Bid activation and expression were detcted by Western blot.Bcl 2 expression plasmid was stably transfected into TJK cells by electroporation method (250 μF,300 Volts).Results:Bid was activated in the TJK apoptosis induced by CD3e specific monoclonal antibody or 5 FU.The apoptosis rate and Bid activation increased remarkably in the TJK cells cotreated with the CD3e specific monoclonal antibody and 5 FU.Bcl 2 overexpression in the TJK cells decreased the sensitivity to 5 FU and maintained cell cycle.Conclusion:Bid plays an important role in the regulation of T lymphocyte apoptosis and is localized at the cross point of the two signaling pathway mediated by CD3e and 5 FU,respectively. [