ANIMAL MODELS OF HYPERTHYROIDISM

甲亢动物模型

• 批准号: 7837581
• 负责人: Sandra M McLachlan
• 金额: $ 35.85万
• 依托单位: CEDARS-SINAI MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-02-15 至 2013-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7837581
• 关键词: Address; Adenoviruses; Animal Model; Antibodies; Antigen-Presenting Cells; Antigens; Autoantibodies; Autoantigens; Autoimmune Process; Autoimmune Responses; Autoimmunity; Breeding; Cell Maturation; Cells; Chemicals; Chimeric Proteins; Complex; Constitution; Dendritic Cells; Disease; Disease model; Dose; Engineering; Etiology; Eye diseases; Gene Dosage; Genes; Goals; Gonadotropin Receptors; Graves' Disease; Human; Hyperthyroidism; Hypothyroidism; Immune; Immune Tolerance; Immune response; Immune system; Immunity; Immunization; Inflammation; Iodide Peroxidase; Knockout Mice; Lead; Link; Lymphocytic Infiltrate; MHC Class II Genes; Mediating; Messenger RNA; Molecular; Monoclonal Antibodies; Mouse Strains; Mus; Organ; Outcome Study; Pathogenesis; Peripheral; Postpartum Period; Process; Proteins; Recombinants; Regulatory T-Lymphocyte; Role; Self Tolerance; Signal Transduction; Structure; T-Lymphocyte; T-Lymphocyte Epitopes; Testing; Thymus Gland; Thyroglobulin; Thyroid Gland; Thyroid stimulating immunoglobulins; Thyroiditis; Thyrotropin Receptor; Transgenic Mice; Transgenic Organisms; disulfide bond; efficacy testing; insight; mouse model; novel; prevent; promoter; public health relevance; response; single molecule; transgene expression

DESCRIPTION (provided by applicant): Graves' disease, a common disorder, has an unusual etiology: the immune system targets one molecule, the thyrotropin receptor (TSHR), autoantibodies mediate disease, and the target organ is stimulated not destroyed. The TSHR is unusual because it undergoes intramolecular cleavage into an A-subunit linked by disulfide bonds to a transmembrane B-subunit. Shed A-subunits drive immunity leading to thyroid stimulating antibodies and hyperthyroidism. Immunization using an adenovirus (Ad) engineered to express the A-subunit is an effective approach to induce thyroid stimulating antibodies and hyperthyroidism in mice. Our goal is to use this Graves' disease model to provide insight into the following important issues: 1. Tolerance to the TSHR. We generated transgenic mice with the human TSHR A-subunit targeted to the thyroid. These mice are unresponsive, or "tolerant", to A-subunit-Ad immunization. Tolerance is a complex process that may involve the Autoimmune Regulator (Aire) protein and/or regulatory T cells (Treg). The role of Aire can be studied in Aire knockout mice; Treg can be depleted by pretreatment with specific antibodies. To investigate tolerance to the TSHR, we will cross our A-subunit transgenics to Aire deficient mice and study the outcome of A-subunit-Ad immunization in untreated or Treg depleted mice. 2. TSHR-associated thyroid inflammation: A-subunit-Ad immunization of some A-subunit transgenics depleted of Treg induces thyroid lymphocytic infiltrates, hypothyroidism and murine thyroglobulin and thyroid peroxidase antibodies. Mice without infiltrates lack these antibodies. Moreover, TSHR autoantibody and T cell epitopes are highly restricted. We will further characterize immune responses to the TSHR and other thyroid autoantigens in mice with thyroid infiltrates. These studies will provide insight into the relationship between thyroiditis, auto antibodies and TSHR T cell epitopes in mice and possibly also into the pathogenesis of human thyroid autoimmunity. 3. Induced tolerance to prevent or treat experimental Graves' disease. Dendritic cells (DC) are potent antigen-presenting cells. In the "mature" state, DC initiate immunity but immature DC induce antigen-specific tolerance. We will target the TSHR A-subunit to these cells using antibodies to a DC-specific marker (DEC205) and test the abilityof these antibody:A-subunit complexes to blunt responses to A-subunit-Ad immunization. These studies will demonstrate the feasibility of antigen-specific immune tolerance and, if successful, could be adapted for use in humans to more intractable aspects of Graves' disease, namely ophthalmopathy and dermopathy. PUBLIC HEALTH RELEVANCE: Graves' hyperthyroidism, a common disease in humans, is caused by an abnormal immune response to a "self" protein in the thyroid gland called the thyrotropin receptor. We will use a mouse model of Graves' disease to provide insight into the factors involved in the breakdown in "self tolerance" to self proteins that lead to the abnormal autoimmune response to the thyrotropin receptor. Moreover, we will test the efficacy of an approach to block autoimmune responses to the thyrotropin receptor in order to prevent or treat Graves' disease, initially in mice and ultimately in humans.

描述（申请人提供）：Graves病是一种常见疾病，其病因不寻常：免疫系统靶向一种分子，促甲状腺素受体（TSHR），自身抗体介导疾病，刺激而非破坏靶器官。TSHR是不寻常的，因为它经历了分子内裂解成a亚基，通过二硫键连接到跨膜b亚基。脱落的a亚基驱动免疫，导致甲状腺刺激抗体和甲状腺功能亢进。表达a亚基的腺病毒（Ad）免疫是诱导小鼠甲状腺刺激抗体和甲亢的有效方法。我们的目标是利用格雷夫斯疾病模型来深入了解以下重要问题：对TSHR的耐受性。我们产生了具有针对甲状腺的人TSHR a亚基的转基因小鼠。这些小鼠对a -亚单位- ad免疫没有反应或“耐受”。耐受性是一个复杂的过程，可能涉及自身免疫调节蛋白（Aire）和/或调节性T细胞（Treg）。可以在Aire基因敲除小鼠中研究Aire的作用；Treg可以通过特异性抗体预处理来清除。为了研究对TSHR的耐受性，我们将把我们的a亚基转基因应用于Aire缺陷小鼠，并研究在未治疗或Treg缺失小鼠中a亚基ad免疫的结果。2. tshr相关的甲状腺炎症：a亚单位- ad免疫一些缺乏Treg的a亚单位转基因诱导甲状腺淋巴细胞浸润、甲状腺功能减退和小鼠甲状腺球蛋白和甲状腺过氧化物酶抗体。没有浸润的小鼠缺乏这些抗体。此外，TSHR自身抗体和T细胞表位受到高度限制。我们将进一步描述甲状腺浸润小鼠对TSHR和其他甲状腺自身抗原的免疫反应。这些研究将有助于了解小鼠甲状腺炎、自身抗体和TSHR T细胞表位之间的关系，也可能有助于了解人甲状腺自身免疫的发病机制。3. 诱导耐受性预防或治疗实验性格雷夫斯病。树突状细胞（DC）是一种有效的抗原呈递细胞。在“成熟”状态下，DC启动免疫，而未成熟DC诱导抗原特异性耐受。我们将使用针对dc特异性标记物（DEC205）的抗体将TSHR a亚基靶向这些细胞，并测试这些抗体：a亚基复合物对a亚基ad免疫反应的钝化能力。这些研究将证明抗原特异性免疫耐受的可行性，如果成功，可以适用于人类治疗更棘手的格雷夫斯病，即眼病和皮肤病。公共卫生相关性：格雷夫斯甲亢是人类的一种常见疾病，是由对甲状腺中称为促甲状腺素受体的“自我”蛋白的异常免疫反应引起的。我们将使用格雷夫斯病的小鼠模型来深入了解导致对自身蛋白的“自我耐受性”崩溃的因素，从而导致对促甲状腺素受体的异常自身免疫反应。此外，我们将测试阻断对促甲状腺素受体的自身免疫反应的方法的有效性，以预防或治疗格雷夫斯病，最初在小鼠身上，最终在人类身上。