Anti-human DR5 monoclonal antibody induced apoptosis in Jurkat/U937 cell by mitochondrial signal pathway

Objective:To explore the mitochondrial pathway in the apoptosis of Jurkat and U937 cells induced by anti-human DR5 monoclonal antibody-mDRA-6.Methods:The inhibition and apoptosis of Jurkat and U937 cells after treating with mDRA-6 or/and caspases inhibitors were analyzed using MTT and FITC Annexin V/PI staining.The DNA ladder of Jurkat and U937 cells treated with mDRA-6(10 mg/L) for 6 h was analyzed by 1% agrose gel electrophoresis.The expression of bax,bcl-2,bcl-xl,Cyt c,caspase-9,caspase-3 of Jurkat and U937 cells after treating with mDRA-6 were detected by Western blot,respectively.Results:The proliferation of Jurkat and U937 cell after treating with mDRA-6 was inhibited in dose-dependent and time-dependent manner;DNA fragmentation detection indicated Jurkat and U937 cell apoptosis induced by mDRA-6.When the cells were treated with mDRA-6,analysis by immunoblotting indicated that bax and Cyt c was increased,while bcl-2 and bcl-xl was decreased in time dependent manner,caspases-9 and caspases-3 were activated in Jurkat and U937 cells.Jurkat and U937 cells were incubated with the inhibitors of caspase-9 for one hour,respectively,and then the cells were treated with mDRA-6,Jurkat and U937 cells inhibition induced by mDRA-6 were reduced by 24.36%(t=5.44,P﹤0.01) and 20.82%(t=4.29,P﹤0.01),Jurkat and U937 cells apoptosis induced by mDRA-6 were reduced by 32.89% and 23.97%,respectively.Conclusion:Anti-human DR5 monoclonal antibody-mDRA-6 induce the apoptosis of Jurkat and U937 cells through involves mitochondrial signal pathway.