IFN-γ对甲状腺细胞内TTS及IDO表达的影响及其在Graves病中的免疫病理意义

Study on the influence of IFN- γon the expression of TTS and IDO in thyroid cells and its immunopathological significance in Graves' disease

目的探讨γ-干扰素(IFN-γ)对甲状腺细胞色氨酰(TTS)及2,3-双氧加酶(IDO)表达水平的影响及其在Graves病中作用机制。方法通过培养分离正常甲状腺组织细胞及Graves病患者甲状腺组织细胞,采用IFN-γ诱导培养获得人甲状腺原代细胞及甲状腺细胞系Nthyori3-1,采用实时PCR测定不同时间梯度及不同浓度梯度中TTS、IDO表达。结果与正常甲状腺组相比,Graves组患者TTS及IDO表达水平显著升高(P<0.05)。TTS及IDO表达强度与IFN-γmRNA水平呈正相关(P<0.05)。人TTS及IDO在甲状腺原代细胞及甲状腺细胞系Nthyori3-1中均呈低表达,经IFN-γ诱导培养后甲状腺细胞内TTS及IDO表达水平显著升高(P<0.05)。结论 Graves早期病变中甲状腺细胞可通过上调IFN-γ水平而上调TTS及IDO表达,起到抑制自身淋巴免疫功能从而平衡过度自身免疫反应的作用。

Objective To explore the influence of γ- interferon（ IFN- γ） on the expression levels of tryptophyl（ TTS） and 2,3- bis- O- enzyme（ IDO） in thyroid cells and their impact on pathogenesis of Graves＇ disease. Methods Normal thyroid tissue cells and thyroid tissue cells of patients with Graves＇ disease were isolated by using IFN- γ induced primary cultured human thyroid cells of thyroid cell line Nthyori3- 1,and the determination of expression levels of TTS and IDO was carried out by using real- time PCR assay with different time gradient and different concentration gradient. Results In comparison with normal thyroid tissue,expression levels of TTS and IDO were significantly elevated in patients with Graves＇ disease（ P〈0. 05）. The intensity of expression levels of TTS and IDO and level of IFN- γ mRNA were positively correlated（ P〈0. 05）. Human TTS and IDO showed low expression in primary thyroid cells and thyroid cell line Nthyori3- 1,and the expression of TTS and IDO in IFN- γ- induced cultured thyroid cells was significantly increased（ P〈0. 05）. Conclusion The thyroid cells in early lesions of patients with Graves＇ disease can up- regulate the expression levels of TTS and IDO through up- regulating IFN- γ level,and restrain autoimmune lymphatic function to balance the hyperactive autoimmune reaction.