Extrinsic mechanisms of the apoptosis of Jurkat cells induced by mDRA-6

Objective: To investigate extrinsic mechanisms of a novel agonistic anti-human death receptor 5(DR5) monoclonal antibody(mDRA-6)inducing apoptosis human leukemia Jurkat cell.Methods: After affected by mDRA 6,the apoptotic morphology changes of Jurkat cells were observed with microscope.The apoptotic rate of mDRA-6 on Jurkat cells was detected by flow cytometry with Annexin V-FITC / PI double staining.The apoptotic signals proteins active cleavage products of Caspase 10,Caspase 9,Caspase 8,Caspase 7 and Caspase 3 were analyzed by Westernand blotting after mDRA-6 treatment.Results: Jurkat cells displayed typical apoptotic morphology after mDRA-6 treatment for 30 min,When treated with 5.0 mg/L mDRA-6,the apoptosis rates of Jurkat cells were 30.20% at 0.5 h,69.2% at 1 h,and 79.55% at 2 h.Western blotting revealed active fragments of Caspase 9,Caspase 8,Caspase 7 and Caspase 3 respectively,and the proenzyme of Caspase-10 showed no change and no cleavage products of Caspase-10 were detectable.Conclusion: Apoptotic pathway induced by mDRA 6 in Jurkat cells can be initiated extrinsic signal transduction pathway of membrane death receptor pathway,followed by recruitment Fas associated death domain protein leaded to direct activation of the Caspase cascade,which may be a useful agent in investigating anti-tumor therapy by usingTRAIL/DR5.