Xue Chen, Lan-Lan Wang, Bei Cai, Jie Chen, Wei-Hua Feng
Division of clinical immunological laboratory, Department of Laboratory Medicine, West China Hospital, Sichuan University, Chengdu 610041, China [corrected]
Cell Immunol. 2006 Feb;239(2):121-8. doi: 10.1016/j.cellimm.2006.05.003. Epub 2006 Jun 30.
To explore the relationships between Fas-FasL-mediated signaling pathway and apoptosis disturbance of T lymphocyte subset in patients with SLE.
Flow cytometry was used to determine the percentage of apoptotic lymphocytes and necrotic lymphocytes by AnnexinV-FITC/PI double staining. Cell surface expression rates of Fas, FasL, and intracellular expression rates of activated caspase-3 were evaluated by two-color flow cytometry analysis in peripheral T lymphocyte subsets of SLE patients with inactive disease (n=22) and with active disease (n=17). The serum concentration of anti-nucleosome antibodies in SLE patients were assayed by ELISA immunoassay methods. Health volunteers (n=13) served as controls.
The percentage of early apoptotic cells was enhanced in patients with active disease (P=0.001, vs. control) and in patients with inactive disease (P=0.004, vs. control). Compared with health control, the percentage of necrotic cells was significant higher in patients with active disease (P=0.001). The percentages of CD4(+)T cells expressing Fas (P=0.023, vs. control) and FasL (P=0.001, vs. control) were increased in patients with active disease. But there were no obvious differences of expression rates of Fas and FasL on T cell subset between two disease groups (P>0.05). In patients with active disease the percentage of CD4(+)T cells or CD8(+)T cells expressing intracellular activated caspase-3 significantly increased compared to inactive disease patients (P=0.018, P=0.027, respectively) and health controls (P=0.001, P=0.001, respectively). The serum concentration of anti-nucleosome antibodies was strikingly higher in patients with active disease (P=0.002, vs. patients with inactive disease; P=0.001, vs. control, respectively), however, the serum concentration of anti-nucleosome antibodies was not obviously different between patients with inactive disease and health control group (P=0.473). The percentage of apoptotic cells correlated with the serum concentration of anti-nucleosome antibodies in SLE patients (r(s)=0.350, P=0.031).
Apoptosis of T lymphocyte subset in SLE patients increases. CD4(+)T cells are a state of active apoptosis. Fas/FasL-mediated apoptotic pathways are especially important for CD4(+)T cells undergoing apoptosis in SLE patients with active disease. Increased Fas expression results in a higher susceptibility to Fas-mediated apoptosis, which contributes to the increased levels of intracellular activated caspase-3 and accelerates apoptosis of T lymphocytes. The degree of lymphocytic apoptosis disturbance correlates with the level of anti-nucleosome antibodies in the circulation. Acceleration of lymphocytic apoptosis plays important roles in immune pathologic injury and immune regulation dysfunction.
探讨Fas - FasL介导的信号通路与系统性红斑狼疮（SLE）患者T淋巴细胞亚群凋亡紊乱之间的关系。
采用流式细胞术通过AnnexinV - FITC/PI双染法检测凋亡淋巴细胞和坏死淋巴细胞的百分比。采用双色流式细胞术分析评估病情稳定的SLE患者（n = 22）和病情活动的SLE患者（n = 17）外周血T淋巴细胞亚群中Fas、FasL的细胞表面表达率以及活化的半胱天冬酶 - 3的细胞内表达率。采用ELISA免疫分析方法检测SLE患者血清抗核小体抗体浓度。健康志愿者（n = 13）作为对照。
病情活动患者（P = 0.001，与对照组相比）和病情稳定患者（P = 0.004，与对照组相比）早期凋亡细胞百分比均升高。与健康对照相比，病情活动患者坏死细胞百分比显著更高（P = 0.001）。病情活动患者中表达Fas（P = 0.023，与对照组相比）和FasL（P = 0.001，与对照组相比）的CD4(+)T细胞百分比增加。但两组疾病患者T细胞亚群上Fas和FasL的表达率无明显差异（P>0.05）。与病情稳定患者相比，病情活动患者中表达细胞内活化半胱天冬酶 - 3的CD4(+)T细胞或CD8(+)T细胞百分比显著增加（分别为P = 0.018，P = 0.027），与健康对照相比也显著增加（分别为P = 0.001，P = 0.001）。病情活动患者血清抗核小体抗体浓度显著高于病情稳定患者（P = 0.002，与病情稳定患者相比；P = 0.001，与对照组相比），然而，病情稳定患者与健康对照组之间血清抗核小体抗体浓度无明显差异（P = 0.473）。SLE患者中凋亡细胞百分比与血清抗核小体抗体浓度相关（r(s)=0.350，P = 0.031）。
SLE患者T淋巴细胞亚群凋亡增加。CD4(+)T细胞处于活跃凋亡状态。Fas/FasL介导的凋亡途径对于病情活动的SLE患者中发生凋亡的CD4(+)T细胞尤为重要。Fas表达增加导致对Fas介导的凋亡更敏感，这导致细胞内活化半胱天冬酶 - 3水平升高并加速T淋巴细胞凋亡。淋巴细胞凋亡紊乱程度与循环中抗核小体抗体水平相关。淋巴细胞凋亡加速在免疫病理损伤和免疫调节功能障碍中起重要作用。
