【摘要】 目的研究重症肌无力(MG)患者循环T细胞受体(TCR)β链基因亚家族的优先表达,以及β链3号互补决定区(CDR3)基因片断的长度谱型特征,以探讨MG患者体内是否存在病理性T细胞的单克隆或寡克隆增殖。方法收集64例初诊MG患者和16名健康献血者外周静脉血,通过反转录多聚酶链反应(RT PCR)扩增样本中不同亚家族含CDR3的大片段,分析TCRVβ6、8、12、15亚家族的表达,用长度谱型技术研究CDR3谱型特征。结果64例MG患者中, 41例优先表达TCRVβ6、8、12、15中1~2种亚家族,且部分为单克隆或寡克隆性T细胞增殖,另一部分为多克隆增殖;而16名健康对照外周血表达TCRVβ6、8、12、15中3 ~4种亚家族,且全部为多克隆分布。结论TCRVβ6、8、12、15亚家族在MG患者中呈优势表达、优先表达或倾斜性分布,并出现T细胞的克隆性扩增(单克隆或寡克隆),提示这些亚家族参与MG的致病。更多还原

【Abstract】 Objective To investigate the preferential usage of T cell receptor (TCR) Vβ subfamilies on circulating T cells in patients with myasthenia gravis (MG), and characteristics of the third complementarity-determining region (CDR3) size spectratypes of TCR Vβ gene,as to exploring whether autoreactive T cells are monoclonally or oligoclonally expanded. Methods Peripheral venous blood samples of 64 MG patients and 16 healthy controls were collected. The levels of TCR Vβ6、8、12、15 gene subfamily expression were analyzed by RT-PCR. CDR3 was amplified by semi-nest PCR with a fluorescence marker,and analyzed by CDR3 size spectratyping.Results 1-2 TCR Vβ subfamilies were preferentially expressed in 41 of the 64 MG patients, and the partial of them displayed monoclonal or oligoclonal expansion of T cells, and the others were suggestive of polyclonal expansion. In contrast, 3-4 TCR Vβ subfamilies are equally expressed in the peripheral blood of 16 healthy controls,and the expressed TCR Vβ were polyclonal.Conclusions Some TCR Vβ subfamilies, for example TCR Vβ6、8、12、15, are selectively expressed in patients with MG, so there exists preferential usage of TCR Vβ subfamilies. Our data showed that the abnormally monoclonal or oligoclonal expansion of T cells had been demonstrated among TCR Vβ6、8、12、15 by determining the CDR3 size spectratypes, suggesting that in some cases the clonally proliferated T cells should be involved in MG pathogenesis.更多还原