调节性T细胞在原发性干燥综合征中的异常表达

Abnormal expression of T regulatory cells in primary Sjoegren＇s syndrome

目的观察调节性T细胞在原发性干燥综合征（pSS）患者外周血和唇腺中的表达。方法选取23例pSS患者和15名健康对照组，通过流式细胞术检测2组之间外周血调节性T细胞的表达情况，采用免疫磁珠分选外周血CD4＋T细胞，提取叉头样转录因子（Foxp3）的mRNA，进行实时荧光定量的聚合酶链反应（PCR）检测。选取23例pSS患者和5例除外pSS的原发性胆汁性肝硬化（PBC）患者，通过免疫组织化学方法分析2组之间唇腺组织中CD4^＋和Foxp3^＋T细胞的表达差异。采用t检验进行统计学处理。结果pSS组[（5±6）％]外周血Foxp3^＋T细胞的表达比健康对照组[（10±5）％]明显降低（χ^2=2．190；P=-0．036）；Foxp3-mRNA的含量pSS组（0．08±0．05）与健康对照组（0．09±0．03）之间差异无统计学意义（χ^2=0．695；P〉0．05）；与PBC对照组唇腺中CD4^＋T细胞[（11±6）％]和Foxp3^＋T细胞[（3．2±1．1）％]比较，pSS患者唇腺中CD4^＋T细胞[（30±10）％]和Foxp3^＋T细胞[（10．7±5．8）％]表达增加（t=4．072，2．840；P均〈0．05）。结论调节性T细胞在pSS外周血表达降低，而在唇腺中的表达并未减少，二者之间表达不一致，Foxp3参与TpSS的发病。

Objective This study was designed to investigate the expression of T regulatory cells （Treg） in the peripheral blood and sahvary gland of patients with primary Sjoegren＇ s syndrome （pSS）. Methods The expression of Treg was measured by flow-cytometry analysis in 23 pSS patients and 15 healthy controls. CD4 positive cells were sorted by immunomagnetic beads, Forkhead box protein P3 （Foxp3） mRNA was extracted, real time polymerase chain reaction （RT-PCR） was used to measure Foxp3 mRNA. For the study of salivary gland, five primary billary cirrhosis （PBC） patients without pSS were selected as the control group, the expression of CD4^＋T cells and Foxp3^＋T ceils in salivary gland was examined by immunohistochemistry. The result was analyzed by t test. Results The expression of Treg in the peripheral blood of pSS patients [（5±6）% ] was lower than healthy controls [（10±5）% ] （t=2.190, P=0.036）. There was no significant difference in Foxp3-mRNA expression between pSS patients （0.08±0.05 ） and controls （0.09±0.03） （t =0.695, P〉0.05）. The expression of CD4^＋T cells [（30±10）%] and Foxp3^＋T cells [（10.7±5.8）%] in the salivary gland of pSS patients increased significantly when compared with PBC control group [ CD4^＋T （11±6）% and Foxp3^＋ T （3.2±1.1）% ] （t=4.072, 2.840; P〈0.05）. Conclusion For pSS patients, the expression of Treg decreases in the peripheral blood, but Treg increases in the salivary gland. The results of this study suggest that Foxp3 plays an important role in the pathogenesis of pSS.