重症肌无力胸腺瘤天然调节T细胞及其影响因素

Natural T regulatory cells and its influencing factors in thymomas complicated with myasthenia gravis

目的研究伴重症肌无力(MG)胸腺瘤患者胸腺瘤中天然调节性T细胞(nTreg)的变化及其影响因素。方法采用免疫组化方法检测不同病理类型胸腺瘤中nTreg细胞的数量,通过实时定量反转录PCR检测不同病理类型胸腺瘤中FoxP3 mRNA及胸腺间质淋巴细胞生成素(thymic stromal lymphopoietin,TSLP)mRNA水平,并分析二者之间的关系。结果伴MG胸腺瘤中FoxP3+Treg细胞数量较正常胸腺组织减少,差异有统计学意义(P<0.01);伴MG胸腺瘤FoxP3 mRNA、TSLP mRNA转录水平较正常胸腺组织明显降低,差异有统计学意义(P<0.01);在各胸腺瘤亚型中,B1型FoxP3+Treg细胞数量,FoxP3 mRNA、TSLP mRNA转录水平最高;FoxP3 mRNA、TSLP mRNA水平呈显著正相关。结论伴MG胸腺瘤中nTreg减少,与胸腺瘤中TSLP转录水平下降有关,可能导致免疫调节功能紊乱,从而引起MG发病。

Objective To investigate the regulatory T cells （Treg） and its influencing factors in the thymomas complicated with myasthenia gravis （MG）.Methods The numbers of FoxP3＋ Treg cells were detected by immunohistochemical analysis,and the transcriptional levels of FoxP3 mRNA and thymic stromal lymphopoietin （TSLP） mRNA were quantitatively analyzed by real-time reverse transcription polymerase chain reaction （real-time RT-PCR）.Results CD4＋FoxP3＋ nTreg ceils in thymomas were significantly decreased compared with normal thymus （P ＜ 0.01） and the standard values of FoxP3 mRNA and TSLP mRNA were significantly decreased in thymomas （P ＜ 0.01）.Among the types of thymomas,the numbers of FoxP3＋ Treg cells,standard values of FoxP3 mRNA and TSLP mRNA were higher in B1 organoid thymomas than other types of thymomas.There was a strong positive correlation between the FoxP3 mRNA transcriptional levels and the TSLP mRNA transcriptional levels.Conclusion These results suggest that there is decreased number of CD4＋FoxP3＋ Treg cells in thymomas in patients with MG and the decreased transcriptional levels of FoxP3 may be regulated by the decreased transcription of TSLP.The decrease of CD4＋FoxP3＋ Treg cells may interfere with the immune tolerance of patients with thymomas.