Analyzing genetic and environmental molecular mechanisms causing autoimmune thyroid diseases

分析导致自身免疫性甲状腺疾病的遗传和环境分子机制

• 批准号: 10517531
• 负责人: MIHAELA STEFAN-LIFSHITZ
• 金额: $ 42万
• 依托单位: ALBERT EINSTEIN COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-01 至 2025-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10517531
• 关键词: Adenovirus Vector; Alprostadil; Apoptosis; Autoantigens; Autoimmune Diseases; Autoimmune Process; Autoimmunity; Autophagocytosis; Binding; Biological Assay; Biotin; Cathepsin L; Cell Line; Cells; Co-Immunoprecipitations; Complementary DNA; Complex; Development; Disease; Electron Microscopy; Environmental Risk Factor; Genes; Genetic; Goals; Graves' Disease; Hashimoto Disease; Hormones; Human; Immune; Immune checkpoint inhibitor; Immunization; Inflammation; Interferon alpha; Interferons; Label; Lead; Ligation; Maps; Mass Spectrum Analysis; Mediating; Mediator of activation protein; Modeling; Molecular; Molecular Analysis; Mus; Mutate; Mutation; Pathway interactions; Patients; Peptides; Peripheral Blood Mononuclear Cell; Pharmaceutical Preparations; Phenotype; Post-Translational Protein Processing; Process; Proteins; Role; Signal Transduction; Stress; Susceptibility Gene; T-Lymphocyte; T-Lymphocyte Epitopes; Techniques; Testing; Thyroglobulin; Thyroid Gland; Thyroiditis; Time; Toxic effect; Translating; Up-Regulation; Variant; Viral; Virus Diseases; anti-PD-L1; autoimmune thyroid disease; base; cytokine; design; endoplasmic reticulum stress; experience; genetic analysis; immunogenic; immunogenicity; in vivo; mouse model; multidisciplinary; mutant; new therapeutic target; novel; novel therapeutics; overexpression; prevent; programmed cell death ligand 1; programmed cell death protein 1; protective effect; response

The autoimmune thyroid diseases (AITD), Graves’ disease (GD) and Hashimoto’s thyroiditis (HT), are the most common autoimmune diseases. Because their mechanisms are not fully understood, AITD are treated symptomatically (hormone replacement in HT or hormone suppression in GD) and as a result, patients are often difficult to manage. Therefore, new therapies are needed that target the autoimmune mechanisms causing AITD. AITD are complex diseases caused by interactions between susceptibility genes and environmental triggers. We and others have mapped & confirmed several AITD genes, including thyroglobulin (Tg). We have also shown that interferon alpha (IFNα), produced during viral infections, is the key cytokine triggering AITD. The current proposal aims to dissect the genetic and environmental mechanisms causing AITD in order to target them with novel therapies. Our focus is on genetic mechanisms predisposing to AITD (Aim 1), environmental triggers of AITD (Aim 2), and medication triggers of AITD (Aim 3). In Aim 1 we will test the hypothesis that missense SNPs in Tg that are associated with AITD predispose to AITD by increasing Tg misfolding and enhancing its degradation into immunogenic peptides. We will use a novel muse model of AITD developed by us, in which autoimmune thyroiditis is induced by immunization with human Tg cDNA in a non-replicating Adenovirus vector. This model enables us to test the effects of different Tg SNPs shown to be susceptible or protective for AITD, and to assess in vivo mechanisms by which these Tg variants trigger AITD. In Aim 2 we will test the hypothesis that IFNα triggers AITD by engaging the autophagic degradation of Tg into immunogenic peptides. We will use cell lines and a mouse model with thyroid over-expression of IFNα to define the autophagy-lysosomal pathways of Tg degradation; we will also test the immunogenicity of the generated Tg peptides in mouse models and PBMC’s from AITD patients. This aim will define a new unifying mechanism for triggering autoimmunity by IFNα-mediated autoantigen degradation. In Aim 3 we will test the hypothesis that Programmed death-ligand 1 (PD-L1) expressed on thyrocytes has intrinsic activity protecting them from intracellular stress during inflammation, and that Immune Checkpoint Inhibitors (ICI’s) trigger thyroiditis by blocking these intrinsic protective effects of PD-L1. We will use a new mouse model of ICI-thyroiditis we developed to dissect the mechanisms by which PD-L1 blockade triggers thyroiditis in vivo. This aim will define the mechanisms of ICI-induced thyroiditis as well as the role of thyroidal PD-L1 in AITD. Collectively, the studies in this proposal will help advance our long-term goal, to design targeted mechanism-based therapies for autoimmune thyroid diseases.

自身免疫性甲状腺疾病（AITD），即Graves病（GD）和桥本甲状腺炎（HT），是最常见的自身免疫性疾病。由于其机制尚不完全清楚，AITD的治疗方法是药物治疗（HT中的激素替代或GD中的激素抑制），因此，患者通常难以管理。因此，需要靶向导致AITD的自身免疫机制的新疗法。AITD是由易感基因和环境触发因素之间的相互作用引起的复杂疾病。我们和其他人已经绘制并确认了几个AITD基因，包括甲状腺球蛋白（Tg）。我们还发现，在病毒感染期间产生的干扰素α（IFNα）是触发AITD的关键细胞因子。目前的提案旨在剖析导致AITD的遗传和环境机制，以便用新的疗法靶向它们。我们的重点是诱发AITD的遗传机制（目标1），AITD的环境触发因素（目标2）和AITD的药物触发因素（目标3）。在目的1中，我们将检验以下假设：与AITD相关的Tg中的错义SNP通过增加Tg错误折叠并增强其降解成免疫原性肽而易患AITD。我们将使用我们开发的一种新的AITD缪斯模型，其中通过在非复制型腺病毒载体中用人Tg cDNA免疫诱导自身免疫性甲状腺炎。该模型使我们能够测试显示对AITD易感或保护的不同Tg SNP的作用，并评估这些Tg变体触发AITD的体内机制。在目的2中，我们将检验IFNα通过将Tg自噬降解为免疫原性肽而触发AITD的假设。我们将使用细胞系和甲状腺过度表达IFNα的小鼠模型来定义Tg降解的自噬-溶酶体途径;我们还将在小鼠模型和AITD患者PBMC中测试生成的Tg肽的免疫原性。这一目标将确定一个新的统一的机制，触发自身免疫的干扰素α介导的自身抗原降解。在目标3中，我们将检验以下假设：甲状腺细胞上表达的程序性死亡配体1（PD-L1）具有内在活性，可在炎症期间保护它们免受细胞内应激，免疫检查点抑制剂（ICI）通过阻断PD-L1的这些内在保护作用而引发甲状腺炎。我们将使用我们开发的ICI-甲状腺炎的新小鼠模型来剖析PD-L1阻断在体内触发甲状腺炎的机制。这一目标将确定ICI诱导的甲状腺炎的机制以及甲状腺PD-L1在AITD中的作用。总的来说，本提案中的研究将有助于推进我们的长期目标，即设计针对自身免疫性甲状腺疾病的靶向机制治疗。