系统性硬化症患者外周血中Th17细胞、CD4+CD25+Treg细胞及B细胞的研究

【作者】 姜楠；

【导师】 曾小峰；

【作者基本信息】 北京协和医学院 ， 临床医学， 2009， 博士

【摘要】 背景系统性硬化症(systemic sclerosis, SSc)是一种病因不明的慢性自身免疫性疾病,以进行性的皮肤和内脏纤维化、微血管系统改变和多种细胞、体液免疫异常为特征,最终导致组织和器官的萎缩,预后不良。T细胞和B细胞在SSc的发病中起着重要的作用,T细胞通过分泌细胞因子及与成纤维细胞直接接触促进炎症反应和纤维化发生,B细胞主要通过产生各种自身抗体介导病变发生。辅助T细胞17(T-helper17,Th17)和CD4+CD25+调节性T细胞(regulatory T cell, Treg)是两种特殊的T淋巴细胞,分别对炎症反应起正向和负向调控作用；CD27、CD38分子分别主要表达在记忆B细胞、浆细胞的表面；CD268分子是B细胞激活因子(B cell activating factor, BAFF)的主要受体。近年来,Th17、CD4+CD25+Treg、CD27、CD38、CD268在自身免疫性疾病中的作用是人们研究的热点,而它们与SSc的相关报道则不多。欧洲抗风湿病联盟硬皮病试验研究组(EULAR Scleroderma Trial and Research group, EUSTAR)是全球性的硬皮病研究组织,北京协和医院是其成员之一。本实验将选取EUSTAR项目入组患者作为研究对象。目的测定系统性硬化症病人外周血单个核细胞(peripheral blood mononuclear cells, PBMC)中Th17细胞、CD4+CD25+Treg细胞及表达CD27、CD38、CD268分子的B细胞所占比例,并分析其与病人临床数据的相关性。方法采用流式细胞仪对系统性硬化症患者及健康人PBMC中的Th17细胞(CD4+IL-17+)、Treg细胞(CD4+CD25+Foxp3+)、CD27+、CD38+、CD268+B细胞进行计数。比较患者与健康人结果的差异,并分析患者中细胞计数与患者临床数据的相关性。结果1.系统性硬化症患者外周血中Th17细胞比例较正常人显著升高,其升高程度与患者病程呈正相关；2.系统性硬化症患者外周血中CD4+CD25+Treg细胞比例较正常人显著升高；3.系统性硬化症患者外周血中B细胞比例较正常人显著降低,其降低程度与抗U1RNP抗体阳性率呈负相关；4.系统性硬化症患者外周血中CD268+B细胞比例较正常人无明显差别；5.系统性硬化症患者外周血中CD38+B细胞比例较正常人无明显差别。结论系统性硬化症中存在着明显的T细胞和B细胞异常：1.外周血Th17细胞增生,分泌IL-17,参与炎症和纤维化病变；2.外周血CD4+CD25+Treg细胞增生,参与纤维化的过程；3.外周血中幼稚B细胞增生,记忆B细胞减少；4. BAFF—BAFF-R系统的激活并不依赖于BAFF-R阳性B细胞数量的扩增。更多还原

【Abstract】 BackgroundSystemic sclerosis (SSc) is a chronic autoimmune disease of unknown origin. It is characterized by progressive fibrosis of the skin and visceral organs, microvascular alterations and a variety of cellular or humoral immune abnormalities. These changes finally lead to atrophy of the tissues and the organs, so SSc has a poor prognosis. T cells and B cells play important roles in the pathogenesis of this disease. T cells promote inflammations and fibrosis by secreting the cytokines or contact with the fibroblasts. B cells generate a series of autoantibodies to induce the alterations. T-helper17(Th17) cells and CD4+CD25+regulatory T cells (Treg) are two kinds of special T lymphocytes. They respectively enhance and control inflammatory responses. CD27molecules and CD38molecules were respectively expressed on the surface of memory B cells and plasma cells. CD268molecules are the dominant receptors of B cell activating factor (BAFF). The effects of Th17, Treg, CD27, CD38and CD268in autoimmune diseases are becoming the foci of the researchers. But there are few reports in SSc. EULAR Scleroderma Trial and Research group (EUSTAR) is a global research organization on scleroderma. Peking Union Medical College Hospital is one of its members. In our study, objects are chosen from EUSTAR patients.ObjectiveTo measure the ratios of Th17, CD4+CD25+Treg cells and cells expressing CD27, CD38or CD268molecules in the peripheral blood mononuclear cells (PBMC) of the SSc patients. To analyze the relativities of the cell ratios and the clinical data of the patients.MethodsTh17cells (CD4+IL-17+), Treg cells (CD4+CD25+Foxp3+), CD27+, CD38+or CD268+B cells in the PBMC of SSc patients and healthy controls were counted by flow cytometry. The different results of the patients and the healthy controls and the relativities of the cell counts and the clinical data in the patients were analyzed.Results1. The ratio of Th17cells in SSc patients is significantly higher than the ratio in healthy controls. The level of Th17cells correlates with the duration of the disease.2. The ratio of CD4+CD25+Treg cells in SSc patients is significantly higher than the ratio in healthy controls.3. The ratio of CD27+B cells in SSc patients is significantly lower than the ratio in healthy controls. The level of CD27+B cells negatively correlates with the anti-U1RNP antibody.4. The ratio of BAFF-R+cells in SSc patients did not show significant difference with the ratio in healthy controls.5. The ratio of CD38+cells in SSc patients did not show significant difference with the ratio in healthy controls.ConclusionsThere are remarkable T cell and B cell abnormalities in systemic sclerosis.1. Proliferation of Th17cells in the periphery:Th17cells participate in inflammatory and fibrotic processes by secreting IL-172. Proliferation of CD4+CD25+Treg cells in the periphery:Treg cells participate in fibrotic process3. Proliferation of naive B cells; Reduction of memory B cells4. Activation of BAFF--BAFF-R system does not rely on the proliferation of BAFF-R positive B cells.更多还原