中文摘要：

目的银杏内酯B（GB）是已知的天然而强效的血小板激活因子（PAF）受体（PAFR）拮抗剂,本文研究GB对小鼠T淋巴细胞活化、增殖及凋亡3大体外行为的影响,初步探讨其潜在的免疫调节作用与机制,从而为临床应用提供可靠的实验依据。方法分离小鼠淋巴细胞,培养前以不同浓度的GB预孵;以刀豆蛋白A（Con A）诱导细胞的活化与增殖,以荧光抗体双色标记（anti-CD3 mAb-PE/anti-CD69 mAb-FITC、anti-CD3 mAb-PE/anti-CD25 mAb-FITC）结合流式细胞术分别检测T淋巴细胞早、中期活化标志--表面抗原CD69与CD25的表达,以活体荧光染料CFDA-SE标记结合流式细胞术检测细胞增殖并用MTT法佐证;以地塞米松（Dex）诱导细胞的凋亡,以荧光染料双色标记[DiOC6（3）/PI]结合流式细胞术区别凋亡、死亡与活细胞群。结果 Con A刺激后6 h和24 h,T细胞早期活化标志CD69和中期活化标志CD25分别大量表达,Con A刺激后48 h活化的T细胞增殖至第4代,而经终浓度为5、10、20μmol/L GB在Con A刺激前对细胞进行4 h预孵处理可以显著下调T细胞表面抗原CD69、CD25的表达并能有效抑制细胞增殖。Dex诱导后12 h细胞凋亡和死亡群显著增大,而经同样的GB预孵处理可以在一定程度上抑制细胞的凋亡进程,对细胞凋亡显示出一定的保护作用。结论 GB能有效抑制小鼠T淋巴细胞的活化与增殖,并且对细胞凋亡起到一定的保护作用,凭借GB对T细胞此3大行为出色的调节作用,理应将其作为天然的免疫抑制剂候选者进行更深入的研究。

英文摘要：

To explore the potential immunomodulatory effects and related mechanisms of ginkgolide B（GB）,a known potent antagonist of platelet-activating factor receptor,we investigated the behaviors of T lymphocytes,including activation,proliferation and apoptosis.T lymphocytes were prepared from murine lymph nodes,and then treated with different concentrations of GB before cultivation.Activation and proliferation of T cells were induced by polyclonal activator concanavalin（Con A）.Fluorescence conjugated monoclonal antibodies and flow cytometry were used to detect the expression of CD3/CD69 and CD3/CD25;CFDA-SE labeling and flow cytometry were used to trace the proliferation of T lymphocytes and an MTT assay was taken to re-prove.Apoptosis of T cells were induced by dexamethasone（Dex）,while [DiOC6（3）/PI] staining and flow cytometry were used to distinguish apoptotic,dead and living cell populations.In a dose-dependent manner,GB（5,10,and 20 μmol/L） significantly suppressed the expression of CD69 at 6th h and CD25 at 24th h,as well as inhibited cell proliferation at 48th h after Con A stimulation.To some extent,GB also exhibited protective effect on T lymphocytes from Dex-induced apoptosis.According to these interesting effects of GB on T lymphocytes behaving and functioning,it’s quite reasonable to do further studies of GB as a nature occurring immunomodulator candidate.