[Cytotoxic mechanism of anti-human death receptor 5 monoclonal antibody mDRA-6].
OBJECTIVE
To investigate the cytotoxic action and its mechanism of a novel anti-human DR5 monoclonal antibody (mAb mDRA-6).


METHODS
The cytotoxic action of mAb mDRA-6 on Jurkat cells and the effects of inhibitors of caspase 8 and caspase 9 on apoptosis of Jurkat cells induced with mAb mDRA-6 were detected by flow cytometry. The effects of mAb mDRA-6 on the morpha of Jurkat cells was observed by fluorescence microscope. The apoptosis of Jurkat cells was detected by flow cytometry with Annexin V-FITC/PI staining. The DNA fragmentation in Jurkat cells was analysed by agrose gel electrophoresis.


RESULTS
mAb mDRA-6 exerted cytotoxicity on Jurkat cells in dose-dependent and time-dependent manner. Jurkat cells treated with mDRA-6 exhibited typical apoptostic features in morphology, namely, membrane crenation, bubbling, chromatin condensation, and formation of apoptotic bodies. The flow cytometry analysis showed that phosphatidylserine (PS) was highly expressed in Jurkat cells treated with mDRA-6. Agrose gel electrophoresis indicated that DNA fragmentation occurred in Jurkat cells. Inhibitor of caspase 8 inhibited the apoptosis of Jurkat cells induced with mDRA-6 while Inhibitor of caspase 9 showed less effect.


CONCLUSIONS
mDRA-6 may exert cytotoxicity by inducing Jurkat cell apoptosis through signal transduction pathway of death receptors, which may be a useful tool in treating tumors with DR5 as target molecule and exploring the functional domain of DR5.
Liu
Guang-Chao
GC
Key Laboratory of Cellular and Molecular Immunology, Henan University, Kaifeng 475000, China. 333lgc@163.com
Ma
Yuan-Fang
YF
Zhang
Jun
J
Li
Shu-Lian
SL
Lu
Feng
F
Bai
Hui-Ling
HL
Zhao
Yue-Ping
YP
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology* / Q000633:toxicity*; D017209:Apoptosis / Q000187:drug effects; D061945:Caspase Inhibitors; D053938:DNA Fragmentation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005434:Flow Cytometry; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D019169:Jurkat Cells; D051379:Mice; D010718:Phosphatidylserines / Q000378:metabolism; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand / Q000276:immunology*
D000911:Antibodies, Monoclonal; D061945:Caspase Inhibitors; D004791:Enzyme Inhibitors; D010718:Phosphatidylserines; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand