抗人DR5功能性单克隆抗体诱导Jurkat细胞凋亡的线粒体途径的分子机制

目的:探讨抗人死亡受体5(DR5)功能性单克隆抗体(mDRA-6)对Jurkat细胞诱导凋亡的线粒体途径的分子机制。方法:MTT法检测单克隆抗体(mDRA-6)对Jurkat细胞生长抑制作用的剂量-效果及时间-效果关系;JC-1单染流式细胞术定量分析技术对凋亡的Jurkat细胞线粒体膜电位的变化进行分析;免疫印迹技术检测凋亡细胞的Caspase-8、3、9及Bid、Bax、Bcl-2、Cytoc等凋亡相关蛋白的表达情况。结果:mDRA-6对Jurkat细胞抑制具有明显剂量-效果和时间-效果关系;流式细胞仪检测显示,2.0μg/ml浓度的mDRA-6作用15、30、60和120分钟时,Jurkat细胞线粒体膜电位改变率分别为20.14%、19.34%、21.11%、30.90%,呈逐渐增高趋势。免疫印迹技术检测显示,mDRA-6作用后,Jurkat细胞Caspase-8、9及Bid、Bax、Bcl-2、Cytoc等表达活性增加,并且Cytoc在线粒体内为递减而在胞浆呈递增的表达现象。结论:mDRA-6通过激活外源性膜受体,继而启动细胞线粒体途径导致Jurkat细胞凋亡。本研究为mDRA-6对白血病治疗奠定实验基础。

The mitochondrial-dependent molecular mechanisms for inducing apoptosis in Jurkat cells by a novel agonistic anti-human DR5 monoclonal antibody

Objective:To investigate mitochondrial-dependent molecular mechanisms of a novel agonistic anti-human death receptor 5 (DR5) monoclonal antibody(mDRA-6) inducing apoptosis in Jurkat cell.Methods:The dose-dependent and time-dependent cell growth suppression of mDRA-6 in Jurkat cells was determined by MTT assay.The measurement of the mitochondrial transmembrane potential(ΔΨm) of Jurkat cells was detected by flow cytometry with JC-1 single staining.Caspase-8,9 as well as Bid,Bax,Bcl-2 and Cyto c of apoptotic Jurkat cells were analyzed by Western blot after mDRA-6 treatment.Results:The mDRA-6 induced cell growth suppression and cytotoxicity in dose-dependent manner and time-dependent manner.After mDRA-6 treatment at 2.0 μg/ml for15 min,30 min,60 min and 120 min,the change in ΔΨm were 20.14 %,19.34 %,21.11% and 30.90% respectively by JC-1 single staining.Western blot revealed that the level of active fragments of Caspase-8,9 and Bid,Bax,Bcl-2 and Cyto c respectively,and the amount of Cyto c was increased in cytosol concomitant with the related attenuation of Cyto c in mitochondria.Conclusion: Apoptotic pathway of Jurkat cells induced by mDRA-6 is initiated upon DR5 ligatian to mDRA-6 and exogenic Caspase-dependent cell apoptotic cascades is activated,and endogenic mitochondrial-dependent cell apoptosis pathway is activated.mDRA-6 may be a useful agent in investigating human leukemia therapy by using TRAIL/DR5.