槲皮素对小鼠T细胞体外活化的抑制作用

The inhibitory effect of quercetin on in vitro activation of T lymphocytes

目的 :通过分析槲皮素对淋巴细胞早期活化标记物CD6 9表达的影响 ,探讨其对T淋巴细胞体外活化抑制作用的机制。方法 :分离小鼠淋巴结细胞 ,加入多克隆刺激剂及槲皮素共同培养 ,分别于 2、6、2 4h收获细胞 ,进行双色免疫荧光标记 ,以流式细胞仪对T细胞的CD6 9分子表达情况进行分析并计算抑制率。结果 :槲皮素 (终浓度 10 μmol/L)对未受刺激的T细胞CD6 9表达百分率无明显影响 ,而经佛波醇酯 (PDB)及刀豆蛋白A(ConA)活化同时加入槲皮素的T细胞CD6 9表达百分率在 2h、6h及 2 4h均显著下降 (P <0 .0 1)。槲皮素对PDB的抑制率随作用时间延长而明显下降 ,对ConA的抑制率平缓而持久。结论 :槲皮素对PDB、ConA活化的T淋巴细胞均显示明显的抑制效应 ,表明该药可能作用于T细胞活化信号传递通路蛋白激酶Cθ或其下游部位 ,并且 ,这种抑制效应表现出一定的可逆性。

AIM: To investigate the inhibitory effect of quercetin on in vitro activation of T lymphocytes by polyclonal activators with CD69 expression as an activation marker. METHODS: After being separated from lymphoid nodes of a C57BL/6 mouse, the lymphocytes were exposed to polyclonal activators (PDB or Con A) with or without quercetin. Then they were harvested at 2 h, 6 h and 24 h, respectively. The expressional rates of CD69 on T lymphocytes were assessed by two-color immunofluorescent staining and flow cytometry, and the inhibitory rates of quercetin at different time points were estimated. RESULTS: Quercetin had no effect on the expressional rate of CD69 on T lymphocytes under resting states. After the stimulation with PDB or Con A, the expressional rates of CD69 on T lymphocytes in the present of quercetin (10 μmol/L) showed significant decrease compared with those of control groups at different time points (P<0.01). The inhibitory rate of quercetin on CD69 expression stimulated by PDB dropped sharply from 2 h to 24 h, whereas the inhibitory rate of quercetin on Con A action were relatively stable. CONCLUSION: Quercetin has inhibitory effects on the activation of T lymphocytes by Con A or PDB, suggesting that the action site of quercetin may be on PKCθ or its downstream. Furthermore,these inhibitory effect seems to be reversible.