ANIMAL MODELS OF HYPERTHYROIDISM

 描述(申请人提供)：Graves病是一种自身免疫性疾病，由致病性甲状腺刺激性抗体(TSAb)引起，TSAb模拟TSH激活TSH受体(TSHR)。由此产生的甲亢是可以治疗的，但没有治愈的方法。研究其发病机制以及研究新疗法的一个关键障碍是格雷夫斯病只发生在人类身上。因此，自发产生致病TSHR抗体的小鼠模型的发展将是一个非常重要的进步，为Graves病的发病机制提供洞察力，并促进研究用于治愈而不是治疗这种常见人类疾病的特定免疫疗法的潜在方法。通过将在甲状腺中表达人TSHR A亚单位的转基因小鼠与另一个自发患甲状腺炎的小鼠品系杂交，我们开发了第一个自发产生致病TSAb的动物模型hTSHR/NOD-H2h4小鼠。我们的第一个目标将是优化和表征hTSHR/NOD-H_2H4小鼠模型。我们将完成与亲本品系的回交，共10代，以确保hTSHR/NOD-H2H4小鼠具有100%的NOD-H2H4背景基因。然后，我们将确定致病性TSHR抗体产生、滴度和水平维持的时间进程，以及对甲状腺功能、甲状腺组织学和甲状腺自身抗体的完整概要进行表征。我们的第二个目的是通过测量人TSHR A亚单位(和其他甲状腺抗原)在胸腺内的表达，来研究在该模型中可能影响致病性TSAb自发形成的因素，包括中枢耐受的作用。我们还将评估调节性T细胞对TSHR抗体形成的影响，确定T细胞识别的表位，以及环境因素(维生素D3和硒)对TSAb水平的影响。我们的第三个目标是遏制TSAB的发展，特别是正在进行的生产。将使用的方法是注射TSHR A亚单位蛋白，这种方法可能导致TSAb偏离良性、非致病形式。我们还将尝试通过一些方法来诱导对TSHR的耐受，包括注射用纯化的TSHR A亚单位蛋白冲击的未成熟树突状细胞，以及通过阻断T细胞和抗原提呈细胞之间的“第二信号”。

 DESCRIPTION (provided by applicant): Graves' disease is an autoimmune disorder caused by pathogenic thyroid stimulating antibodies (TSAb) that mimic TSH in activating the TSH receptor (TSHR). The resulting hyperthyroidism can be treated but there is no cure. A critical barrier to studying its pathogenesis, as well as investigation of novel therapies, is that Graves' disease only occurs in humans. Therefore, the development of a mouse model that spontaneously develops pathogenic TSHR antibodies would represent a highly significant advance, providing insight into the pathogenesis of Graves' disease and facilitating investigation of potential approaches for specific immunotherapy for cure, rather than treatment of this common human disease. By crossing transgenic mice that express the human TSHR A-subunit in the thyroid to another mouse strain that spontaneously develops thyroiditis, we have developed the first animal model, hTSHR/NOD-H2h4 mice, that spontaneously develops pathogenic TSAb. Our first aim will be to optimize and characterize the hTSHR/NOD-H2h4 mouse model. We will complete back-crossing to the parent strain for a total of 10 generations to ensure that hTSHR/NOD-H2h4 mice have 100% of NOD-H2h4 background genes. We will then determine the time course of pathogenic TSHR antibody generation, titer and maintenance of levels, as well as characterize the model for thyroid function, thyroid histology and the full compendium of thyroid autoantibodies. Our second aim is to investigate factors that may influence the spontaneous development of pathogenic TSAb in this model including the role of central tolerance by measuring intrathymic expression of the human TSHR A-subunit (and the other thyroid antigens). We will also assess the influence of regulatory T cells on TSHR Ab development, determine epitopes recognized by T-cells, as well as the influence of environmental factors (vitamin D3 and selenium) on TSAb levels. Our third aim is to suppress the development and, particularly on-going production, of TSAb. Approaches to be used will be injecting TSHR A-subunit protein, an approach that may cause deviation of TSAb to a benign, non-pathogenic form. We will also attempt to induce tolerance to the TSHR by a number of approaches, including injecting immature dendritic cells pulsed with purified TSHR A-subunit protein, as well as by blocking the "second signal" between T-cells and antigen presenting cells.