喜树碱对小鼠T淋巴细胞活化、增殖以及细胞周期的影响

目的： 研究喜树碱（CPT）对刀豆蛋白A(ConA)介导的小鼠T淋巴细胞体外活化、增殖及细胞周期的影响。方法：以ConA刺激小鼠T淋巴细胞，建立小鼠T淋巴细胞活化、增殖的模型，以不同浓度的CPT作用于该模型，流式细胞术检测T细胞早期活化标志CD69分子的表达；以活体染料羧基荧光素乙酰乙酸（CFDA-SE）染色流式细胞术分析CPT 在Con A刺激下小鼠淋巴细胞的增殖相关指数（PI）；以碘化丙啶染色流式细胞术分析细胞周期的分布情况。 结果： ConA作用6 h后流式细胞术分析显示CD69的表达率为（58.88±0.55）%，不同浓度的CPT组（10 nmol/L、20 nmol/L、50 nmol/L、100 nmol/L）CD69的表达率分别为（55.48±0.98）%、（54.67±1.05）%、（50.40±0.82）%、（42.47±1.32）%，均可明显抑制CD69的表达(P<0.01)；ConA刺激48 h后流式细胞术分析显示，不同浓度的 CPT 组（10 nmol/L、20 nmol/L、50 nmol/L、100 nmol/L）的增殖指数（PI）明显低于对照组(P<0.05)；细胞周期分析显示刺激48 h后不同浓度的CPT组（10 nmol/L、20 nmol/L、50 nmol/L、100 nmol/L）均出现明显的凋亡峰（apoptosis peak，AP），sub-G1期、G₀/G₁期细胞的比率明显高于ConA刺激组(P<0.01)。结论：CPT可明显抑制ConA刺激的T淋巴细胞的活化、增殖，同时使淋巴细胞阻滞于G₀/G₁期。

Effect of camptothecin on the activation, proliferation and cell cycle distribution of the mouse T lymphocytes in vitro

AIM: To study the effects of camptothecin (CPT) on the activation, proliferation and cell-cycle distribution of the mouse T lymphocytes stimulated by concanvalin A (ConA) in vitro. METHODS: A model of T cell activation and proliferation was established by stimulated the cells with Con A. T cells were treated with different concentrations of CPT. The expression of CD69, the early marker of CD3+ T cell activation, was measured by FACS. The proliferation index was determined by carboxyl fluorescin diacetate succinmidyl ester by flow cytometry. The cell-cycle distribution was analyzed by propidium iodide staining. RESULTS: After stimulation with Con A for 6 h, the activation rate of CD69+ T cell in Con A group was (58.88±0.55)%. The percentages of CD69 positive cells were (55.48±0.98)%, (54.67±1.05)%, (50.40±0.82)%, (42.47±1.32)%, correspond to the treatments with different concentrations of CPT (10 nmol/L, 20 nmol/L, 50 nmol/L, 100 nmol/L), respectively. After 48 h treatment with Con A, the proliferation index in different concentrations of CPT treatment (10 nmol/L, 20 nmol/L, 50 nmol/L and 100 nmol/L) exerted a definite inhibitory effect on the proliferation (P<0.01). Moreover, the cell-cycle distribution analysis showed that apoptosis peak was observed in different concentrations of CPT treatment after 48 h cultured with Con A. CONCLUSION: CPT significantly inhibits the early stages of the Con A-induced T cell activation and proliferation, and detents the T lymphocytes in G₀/G₁ phase.