紫杉醇对小鼠T细胞的影响

Observations on the effects of Paclitaxel on T lymphocytes

为研究抗癌药紫杉醇(PTX)对T细胞行为的影响及其分子机制,利用流式细胞术分析多克隆刺激剂ConA刺激下T细胞行为:羧基荧光素乙酰乙酸琥珀酰亚胺酯(CFSE)标记技术分析T细胞增殖相关指数;碘化丙锭染色分析细胞周期分布;AnnexinV-PI染色检测T细胞凋亡;荧光标记的单克隆抗体染色检测T细胞活化表达CD25的百分率。结果显示.PTX对ConA刺激下小鼠T细胞增殖具有明显的抑制作用,且呈剂量依赖性。该浓度范围PTX阻滞T细胞于G2/M期,诱导凋亡及抑制CD25表达。25nmol/L的PTX与10nmol/L的环孢素A(CsA)具有明显的协同抑制效应。以上结果表明PTX可明显抑制多克隆刺激剂ConA诱导的T细胞体外增殖,是G2/M期阻滞、凋亡诱导和CD25表达抑制等多种机制共同作用的结果。

To investigate the effects of a anti-neoplastic drug Paclitaxel (PTX) on T lymphocytes in order to explore its anti-neoplastic and immuno-suppressive mechanisms, the behaviors of the T lymphocytes stimulated by con-canavalin A (ConA) were evaluated with flow cytometry, and the related indices of T cell proliferation were determined by carboxyi fluorescin diacetate succinmidyl ester (CFSE) labeling technique. The distribution of the cell cycles was analyzed with propidium iodide (PI) staining, and the double staining with Annexin V-PI was used to detect cell apoptosis. The percentage of the expression level of CD25 by activated T cells was evaluated by fluorescent-conjugated monoclonal antibody labeling technique. It was found that PTX could show a definite inhibitory effect on the proliferation of the ConA stimulated T lymphocytes in a dose-dependent manner. Moreover, PTX could also block the progression of cell cycle in G2/M phase, induce the development of cell apoptosis and down-regulate the expression level of CD25. In combination of 25 nmol/L of PTX with 10 nmol/L of cyclosporine A (CsA), a definite synergistic effect could be found. These results indicate that PTX shows a definite inhibitory effect on the proliferation of the ConA stimulated T lymphocytes and this effect might be caused by multiple mechanisms, such as arrest at G2/M stage of cell cycles, induction of cell apoptosis and the down-regulated expression of CD25 molecule.