中文摘要：

目的 探讨γ-干扰素（interferon-γ,IFN-γ）对甲状腺细胞内吲哚胺2,3-双加氧酶（IDO）和色氨酰-tRNA合成酶（TTS）表达的影响及其在Graves病中的免疫病理意义.方法 采用实时荧光定量PCR技术,检测经IFN-γ刺激后甲状腺细胞系Nthy-ori3-1和人甲状腺原代细胞内IDO和TTS mRNA表达情况,及甲状腺组织内IDO和TTS mRNA表达.结果 人甲状腺细胞系Nthy-ori3-1和人甲状腺原代细胞均可低表达IDO和TTS,经IFN-γ刺激后IDO和TTS mRNA量显著增加（P＜0.01）;Graves病患者甲状腺组织高表达TTS,较对照组有统计学差异（P=0.018 2）,IDO mRNA水平与对照组相比无明显统计学差异,但与IFN-y mRNA水平呈显著相关性（R2=0.716,P=0.002）.结论 Graves病发病早期,甲状腺细胞可能通过IFN-y上调IDO,TTS的表达,降解局部色氨酸,抑制自身反应性淋巴细胞功能,平衡过度的自身免疫反应.

英文摘要：

Objective To investigate the effect of interferon-γ（IFN-γ） on the expression of indoleamine 2,3-dioxygenase（IDO）,and tryptophanyl-tRNA-synthetase （TTS） in thyrocytes; and to study the relevant immunopathological significance in Graves＇ disease.Methods The expressions of IDO and TTS genes in IFN-γ stimulated Nthy-ori3-1 cell line and human thyrocytes,as well as in human thyroid tissues were determined by realtime quantitative PCR.Results IDO and TTS genes were expressed slightly in both Nthy-ori3-1 cell line and human thyrocytes,and were significantly up-regulated after IFN-γ stimulation（P＜0.01）.Compared to healthy controls,TTS mRNA level was higher in thyroid tissues of patients with Graves＇ disease （P =0.018 2）,while IDO mRNA level showed no difference,but was notably correlated with IFN-γ mRNA level （R2 =0.716,P =0.002）.Conclusion In the early stage of Graves＇ disease,thyrocytes may decompose local tryptophan by enhancing the expression of IDO and TTS under IFN-γstimulation,thus inhibit auto-reactive function of lymphocytes and balance excessive autoimmune reaction.