STUDIES ON THE MOLECULAR BIOLOGY OF TSH RECEPTOR AND ON THE PATHOGENETIC ROLE OF ANTI-TSH RECEPTOR ANTIBODIES IN GRAVES' DISEASE

细胞膜上的受体通常在激素信号向细胞内的传递中发挥重要作用，激素受体的异常与一些疾病的病理生理密切相关。提示抗TSH受体抗体在Graves病的发病中起一定作用，但TSH受体的分子结构和功能尚未完全阐明，因此抗TSH受体抗体在Graves病发病机制中的作用尚不清楚。本研究的目的是：1)TSH受体的分子质量和生化性质的研究；2)抗TSH受体的单抗的产生和Graves病动物模型的制备；3)TSH受体的序列分析。结果表明，TSH受体是一种糖蛋白，不仅Graves病患者的刺激性免疫球蛋白，而且特发性粘液性水肿病患者的阻断免疫球蛋白也与糖蛋白TSH受体反应。经Graves‘s免疫球蛋白偶联琼脂糖凝胶进一步纯化后，用Western blotting进行分析。刺激型和封闭型免疫球蛋白对相同的67 KDa蛋白进行了染色，提示该抗原可能与TSH受体有关。初步结果表明，某些抗部分纯化的TSH受体的单抗取代了与溶解的甲状腺膜结合的125I-TSH。此外，我们发现，干扰素治疗的小鼠在体内产生了抗甲状腺抗体，这为建立新的自身免疫性甲状腺疾病模型向前迈进了一步。

Receptors on cell membranes generally play significant roles on the transduction of hormonal signals into cells, and abnormalities in hormone receptors closely relate to pathophysiology of several diseases. It is suggested that anti-TSH receptor antibodies play a causative role in Graves' disease, however, the molecular structure and functions of the TSH receptor have not been well clarified, making the pathogenetic significance of anti-TSH receptor antibodies still obscure. The aims of this study were as follows; 1) study on the molecular weight and the biochemical natures of the TSH receptor, 2) production of monoclonal antibodies to the TSH receptor and also of animal models of graves' disease, and 3) analysis of sequences of the cDNA of TSH receptor.We have shown that the TSH receptor is a glycoprotein, and that not only the stimulatory IgGs in patients with Graves' disease but also the blocking IgGs from patients with idiopathic myxedema react with the glycoprotein TSH receptor as well. After further purification using Graves' IgG-coupled sepharose, proteins were analyzed by Western blotting. The same 67KDa protein was stained by both the stimulatory and blocking type of IgGs suggesting that this antigen might relate to the TSH receptor.The preliminary results showed that some monoclonal antibodies against partially purified TSH receptor displaced the 125i-TSH binding to solubilized thyroid membranes stronger than others. Furthermore, we presented that the -interferon administered mice produced antithyroid antibodies in vivo, which advanced one step for making a new model of autoimmune thyroid diseases.The purpose no.3) remained undisolved in this study.