自身免疫性甲状腺炎大鼠CD4^＋CD25^＋调节性T细胞变化及意义

目的研究CD4^＋CD25^＋Foxp3^＋调节性T细胞在自身免疫性甲状腺炎（AITD）大鼠外周血中的比例变化，并初步探讨其在疾病进程中的意义。方法选取17例A1TD大鼠，取静脉血，应用流式细胞术及定量PCR的方法，分别在蛋白质和mRNA水平检测Foxp3^＋表达，并与甲状腺炎球蛋白抗体（TgAb），甲状腺过氧化酶抗体（TPOAb），甲状腺微粒体抗体（TmAb）和甲状腺组织活检结果作相关分析。取正常大鼠作为对照。结果AITD大鼠CD4^＋CD25^＋调节性T细胞（5．35％±1．27％）显著低于正常对照组（8．02％±2．29％，P〈0．01），AITD大鼠CD4^＋CD25^＋Foxp3^＋T细胞占CD4‘T细胞比例（3．12％±0．78％）明显低于正常对照组（6．45％±2．12％，P〈0．01），AITD大鼠Treg与TgAb、TmAb、TPOAb呈负相关（r=-0．291，-0．357，-0．389，P〈0．05，0．05，0．05），并与小鼠甲状腺组织的炎症程度呈负相关（r=-0．511，P〈0．01）；Foxp3mRNA表达水平与蛋白质表达水平变化相一致。结论AITD大鼠CD4^＋CD25^＋T细胞明显减少，这群调节性T细胞可能参与了AITD的病理进程。

The change and siynificance of CD4+CD25+Foxp3+ regulatory T cells in rats of experimental autoimmune thyroiditis

Objective To investigate the roles of CD4^＋ CD25^ ＋ regulatory T cells （Treg） in the Rats of experimental autoimmune thyroiditis（ AITD）. Methods Treg in cardiac blood from 17 Rats of experimental autoimmune thyroiditis and 17 healthy subjects were quantitatively analyzed by flow cytometry. Foxp3 and Foxp3mRNA were analyzed by intracellular cytokine straining. TgAb, TPOAb and TmAb were detected by ECLIA or RIA at same time. Thyroid biopsy was detected after experiment. Results AITD rats presented a lower fraction of circulating Treg （5.35 % ± 1.27 % ）, comparing with healthy subjects（8.02 % ± 2.29 %, P 〈 0.01 ）. Fraction of circulating CD4^＋ CD25^ ＋ Foxp^3 ＋ regulatory T cells in AITD rats （3.12% ± 0.78% % ）was lower than those in healthy subjects（6.45% ± 2.12%, P 〈 0. 01 ）. The results of real time PCR was consistent with that of flow eytometry . The first corrclation was found between Treg and TgAb, TmAb,TPOAb level（ r = -0. 291, - 0. 357, - 0. 389, P 〈 0.05,0.05,0.05 ）. The second correlation was found between Treg and infiltrated of lymphocyte （ r = - 0.511, P 〈 0. 01 ）. Conclusion Treg in the Rats of experimental autoimmune thyroiditis is inercased and the inerease is linked to TgAb,TmAb,TPOAb level and infiltrated of lymphocyte. Treg may contribute to pathological process in such disease.