雷公藤内酯醇诱导人淋巴细胞凋亡的作用与细胞周期的关系

目的：通过观察雷公藤仙酯醇诱导淋巴细胞发生凋亡与细胞周期的关系。探讨该化合物导致细胞凋亡作用的机制。方法；以人外周血Ｔ细胞为研究对象，选择流式细胞分析术，ＤＮＡ凝胶电泳及ＤＮＡ片段测定等作为检测细胞凋亡的方法。结果；雷公藤内酯醇只能造成活化的Ｔ细胞发生细胞凋亡，且与雷公藤内酯醇的浓度正相关；雷公藤内酯醇诱导活化Ｔ细胞发生细胞凋亡的作用与细胞活化的程度密切相关；

Relationship between cell cycle and apoptosis of activated T lymphocyctes induced by triptolide

Objective:In order to explored the mechanisms of triptolide induced apoptosis,the relationship between cell cycle and apoptosis of activated T cell induced were studied.Methods:Human peripheral T cells were stimulated with mitogen.To test the susceptibility to cell death by triptolide whether resulted from the process of coninuous cell cycling or ,alternatively,from the entry into a vulnerable stage of the cell cycle,T cell were cultured with agent that the cell at different stages.For the cell cycle analysis,cells were collected and stained with propidium iodide,then analyzed with a flow cytometer(EPICS XL,Coulter).In addition,apoptosis was confirmed with DNA fragmentation and membrane damage.Results:The degree of susceptibility to apoptosis correlated with the level of cell cycling as measured by thymidine incorporation during S phase;and DNA fragmentation associated with entry into S phase.The number of cells in S phase was proporational to amount of apoptotic cell induced by triptolide.Prevention of cell death correlated with delayed entry into S phase from G1 following triptolide added.Treatment of activative T cell with dBcAMP or forskolin,which block primary activated T cells in G1 phase ,also inhibited triptolide induced cell death.In contrast,the DNA synthesis inhibitor aphidicolin arrested activated T cell cycle pregression in S phase and failed to prevent the apoptotic cell death.Conclusion:Triptolide induced apoptosis of activated T cells is cell cycle dependent,and this may be one of the mechanisms of triptolide for the immune system.