Unraveling the molecular mechanisms of impaired central tolerance in COPA syndrome

揭示 COPA 综合征中枢耐受受损的分子机制

• 批准号: 10581676
• 负责人: Anthony Shum
• 金额: $ 68.74万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-03-01 至 2027-02-28
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10581676
• 关键词: Agonist; Animal Model; Animals; Antinuclear Antibodies; Autoantibodies; Autoimmune; Autoimmune Diseases; Autoimmunity; Autophagocytosis; Binding; Bone Marrow; CD4 Positive T Lymphocytes; Cell Maturation; Cell physiology; Cells; Childhood; Chimera organism; Chronic; Clinical; Data; Defect; Development; Disease; Epithelium; Exhibits; Genetic; Goals; Golgi Apparatus; Grant; Harvest; Image; Immune; Immune Complex Glomerulonephritis; Immunologic Deficiency Syndromes; Immunologics; Impairment; Infection; Inflammation; Inflammatory Arthritis; Interferon Type I; Interferons; Interstitial Lung Diseases; Joints; Kidney; Knock-in Mouse; Lung; Lung diseases; Malignant Neoplasms; Mass Spectrum Analysis; Mediating; Missense Mutation; Molecular; Mus; Online Mendelian Inheritance In Man; Organ; Patients; Peptides; Peripheral Blood Mononuclear Cell; Pharmaceutical Preparations; Phenotype; Proteins; Pulmonary Inflammation; Role; SLEB3 gene; STING agonists; Shapes; Signal Transduction; Syndrome; System; Systemic Lupus Erythematosus; Systemic infection; T cell response; T cell therapy; T-Cell Development; T-Lymphocyte; Testing; Thymic epithelial cell; Thymocyte Development; Thymocyte Selection; Thymus Gland; Work; arthropathies; autoreactive T cell; cancer therapy; central tolerance; cytokine; ds-DNA; experimental study; genetic signature; in vivo; inhibitor; insight; joint inflammation; mouse model; mutant; novel; novel therapeutics; pharmacologic; small molecule; small molecule inhibitor; systemic inflammatory response; thymocyte; thymus transplantation

PROJECT SUMMARY: Our lab discovered COPA syndrome, a monogenic autoimmune disorder that involves inflammation of the lungs, joints and kidneys. We established a mouse model of COPA syndrome by generating CopaE241K/+ knock-in mice that spontaneously developed clinical and immunologic features of patients, including interstitial lung disease (ILD) and increased levels of activated, cytokine-secreting T cells. We performed bone marrow chimera and thymic transplant experiments to reveal that expression of mutant COPA in the thymic stroma is sufficient to cause a defect in negative selection of CD4+ T cells. Our work revealed that a key step in the initiation of disease in COPA syndrome is a breakdown in central tolerance. The goal of this grant is to unravel the mechanisms by which mutant COPA causes impaired thymic tolerance. COPA syndrome presents in childhood with inflammatory arthritis of the small and large joints and lung disease that manifests as pulmonary capillaritis or ILD. Patients develop clinical features that are observed in systemic lupus erythematosus (SLE) including high-titer anti-nuclear antibodies, autoantibodies to double stranded DNA and immune complex glomerulonephritis. In addition, peripheral blood mononuclear cells from all COPA syndrome subjects exhibit a markedly elevated type I interferon stimulated gene signature, a hallmark of SLE. We recently demonstrated that activation of type I interferon (IFN) signaling in COPA syndrome is caused by constitutive activation of the innate immune adapter molecule STING, which is missorted at the Golgi by mutant COPA. Mutant COPA-mediated STING activation upregulates IFNs in immune cells of CopaE241K/+ mice, and remarkably, also within the thymic epithelium. Taken together, this suggests STING has a functional role in the thymus with the potential to alter thymocyte selection and/or development. We hypothesize mutant COPA breaks central tolerance by causing activation of STING in thymic epithelial cells (TEC). We will use our mouse model to determine how activated STING in thymic epithelial cells alters T cell maturation and selection. We will define the cellular and molecular mechanisms by which mutant COPA impairs autophagic flux and determine whether proteins missorted by mutant COPA are involved in STING-induced autophagy. Finally, we will test whether small molecule STING agonists and inhibitors can fine-tune STING signaling in the thymus to alter thymocyte development and selection. Taken together, our work provides new insight into how activated STING in the thymus shapes the T cell repertoire to cause autoimmunity and immune dysregulation. These findings have important implications for settings in which systemic inflammation causes activation of STING in the thymic stroma including cancer therapy and infections.

项目总结： 我们实验室发现了COPA综合征，这是一种单基因自身免疫性疾病，涉及 肺、关节和肾脏。我们通过产生CopaE241K/+建立了COPA综合征的小鼠模型 自发产生患者临床和免疫学特征的敲入小鼠，包括间质 肺部疾病(ILD)和激活的、分泌细胞因子的T细胞水平增加。我们做了骨髓检查 嵌合体和胸腺移植实验揭示突变的CopA在胸腺基质中的表达 足以导致CD4+T细胞阴性选择的缺陷。我们的工作揭示了启蒙过程中的关键一步 COPA综合征的主要疾病是中枢耐受性的崩溃。这笔赠款的目标是解开 突变的COPA导致胸腺耐受性受损的机制。 COPA综合征表现为儿童时期的大小关节和肺部炎性关节炎 表现为肺毛细管炎或ILD的疾病。患者出现临床特征，可观察到 系统性红斑狼疮(SLE)包括高效价抗核抗体、自身抗体双倍 DNA滞留和免疫复合体肾炎。此外，所有患者的外周血单核细胞 COPA综合征患者表现出I型干扰素刺激的基因签名显著升高，这是 SLE。我们最近证实，在COPA综合征中，I型干扰素信号的激活是导致 通过先天性免疫适配器分子刺痛的结构性激活，该分子在高尔基体上被错误地分类 变种人科帕。突变型CopA介导的刺激性上调CopaE241K/+小鼠免疫细胞中的IFN 值得注意的是，也在胸腺上皮内。综上所述，这表明斯汀在 具有改变胸腺细胞选择和/或发育的潜力的胸腺。我们假设突变的COPA 通过激活胸腺上皮细胞(TEC)中的刺激物来破坏中枢耐受。 我们将使用我们的小鼠模型来确定胸腺上皮细胞中激活的刺痛如何改变T细胞 成熟和选择。我们将定义突变的COPA损伤的细胞和分子机制 自噬通量和确定突变的CopA错误分选的蛋白质是否参与了刺痛诱导 自噬。最后，我们将测试小分子刺痛激动剂和抑制剂是否可以微调刺痛。 胸腺中的信号以改变胸腺细胞的发育和选择。综上所述，我们的工作提供了新的 深入了解胸腺中激活的刺痛如何塑造T细胞谱系以导致自身免疫和 免疫失调。这些发现对全身性炎症的环境有重要的影响 导致胸腺基质中刺痛的激活，包括癌症治疗和感染。