牙龈卟啉单胞菌诱导T淋巴细胞活化、凋亡的体外研究

T lymphocytes apoptosis induced by Porphyromonas gingivalis in vitro

目的检测牙龈卟啉单胞菌对人外周血中T淋巴细胞活化及凋亡的作用,并检测Fas/FasL在牙龈卟啉单胞菌（Porphyrom onas gingivalis,Pg）诱导的T淋巴细胞凋亡中的表达。方法选取10例全身及牙周组织健康受试者,分离外周血中T淋巴细胞,在有/无Pg情况下培养0~96 h,用荧光探针（Annexin V-FITC、PI、CD69）及特殊的单克隆抗体（Fas、FasL）进行标记,并进行流式细胞仪检测。结果 CD69＋淋巴细胞＋Pg组Annexin V＋/PI-细胞百分数在各个时间点上都明显高于T淋巴细胞＋Pg组（P〈0.01）。Fas和FasL的表达量明显上调。用抗Fas单克隆抗体阻滞Fas-FasL相互作用导致T细胞凋亡的明显减少,百分比为（20.56±2.43）%,未加抗体的为（50.41±2.68）%。但残余的细胞凋亡活动与阴性对照相比仍高。结论 Pg能够诱导人外周血中T淋巴细胞活化,并且能够通过活化促进其凋亡,Pg诱导T淋巴细胞凋亡主要通过Fas-FasL途径,并具有时间依赖性。

Objective To investigate the induction effects of Porphyromonas gingivalis（Pg） on the activation and apoptosis of human peripheral blood T lymphocytes and explore the involvement of Fas/FasL-mediated apoptotic pathway in Porphyromonas gingivalis（Pg）-induced T-cell apoptosis.Method Ten systemically and periodontally healthy subjects participated in this study.Venous blood was drawn and peripheral blood mononuclear cells（PBMC） was isolated.T lymphocytes were stimulated with Pg and the cells were labled by the special monoclonal antibodies and analyzed by flow cytometry.Result The percentages of Annexin V＋/PI-cells in the group of T lymphocytes with Pg were greater than those in the group of CD69＋T lymphocytes with Pg（P0.01）.The stimulation of T cells with Pg led to the up-regulation of Fas and FasL.The blocking of Fas-FasL interaction with anti-Fas monoclonal antibody significantly led to T-cell apoptosis to reduce to（20.56±2.43）%,and（50.41±2.68）% in the group without the antibody blocking,but the residual apoptosis activity remained higher than background.Conclusion Pg can induce the activation of T lymphocytes and promote the T lymphocytes apoptosis through activating the Fas-FasL pathway.