Insights into erythropoietin homeostasis: Identifying the autoantigen targeted in the TEMPI syndrome

深入了解促红细胞生成素稳态：识别 TEMPI 综合征中针对的自身抗原

• 批准号: 10511508
• 负责人: David B Sykes
• 金额: $ 26.29万
• 依托单位: MASSACHUSETTS GENERAL HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-07-06 至 2024-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10511508
• 关键词: Affect; Affinity; Antibodies; Antigens; Appearance; Autoantibodies; Autoantigens; Automobile Driving; Binding; Bone Marrow; Cells; Chromosome abnormality; Classification; Clone Cells; Collection; Data; Development; Diagnosis; Disease; Disease Progression; Endothelium; Enzyme-Linked Immunosorbent Assay; Erythropoietin; Face; Functional disorder; Gender; Gene Expression; Gene Mutation; Genetic Transcription; Geography; Goals; Hematopoietic Neoplasms; Homeostasis; Hypoxemia; Hypoxia Pathway; Immunohistochemistry; Immunology; In Vitro; Individual; Kidney; Label; Life; Light; Liquid substance; Lung; Lymphoid Tissue; Microscopic; Modeling; Monoclonal Antibodies; Monoclonal Gammapathies; Monoclonal gammopathy of uncertain significance; Multiple Myeloma; Mus; Mutation; Paraneoplastic Syndromes; Pathogenesis; Pathogenicity; Patients; Plasma Cell Neoplasm; Plasma Cells; Population; Production; Rare Diseases; Recombinant Antibody; Recombinants; Recurrence; Red Blood Cell Count; Regulation; Resolution; Sampling; Serum; Signal Pathway; Signal Transduction; Skin; Source; Spider Veins; Symptoms; Syndrome; Telangiectasis; Time; Western Blotting; Work; World Health Organization; angiogenesis; base; exome sequencing; experimental study; extracellular; hematopoietic tissue; in vivo; insight; mouse model; neovascularization; novel; novel strategies; targeted treatment; tool; treatment response

Project Summary The TEMPI syndrome is a rare disorder characterized by five features: (1) Telangiectasias, (2) elevated Erythropoietin and erythrocytosis, (3) Monoclonal gammopathy, (4) Perinephric fluid collections and (5) Intrapulmonary shunting. This is a syndrome that we first identified and described in 2011 and have since found 27 patients worldwide. The TEMPI syndrome is an acquired disorder that appears to be driven by the presence of an abnormal autoantibody, i.e., the monoclonal gammopathy. In patients who have required treatment, therapies that target plasma cells and eradicate the antibody have led to a complete resolution of the other features of the TEMPI syndrome, implicating the antibody as a pathogenic driver of the disease. Patients with TEMPI syndrome present with serum erythropoietin (EPO) levels that can range as high as 500x the upper limit of normal. This suggests that the pathway of hypoxia sensing, and EPO production are dramatically dysregulated. Taken together, this further implicates the abnormal autoantibody as a pathogenic driver of EPO production. In this proposal we aim to identify the antigenic target of the monoclonal gammopathy. Understanding how this antibody-antigen interaction can drive both EPO production from the kidneys and drive neovascularization within the endothelium of the skin (telangiectasias) and lungs (shunting) has the potential to identify an entirely new signaling mechanism triggered by extracellular antibody binding. We will couple multiple approaches to antigen identification with gene expression and mutational profiling of the monoclonal plasma cells. Our approach takes advantage of available patient samples that have been carefully and longitudinally banked from patients of this ultra-rare disease. Our preliminary data demonstrates that we can successfully identify and clone the heavy and light chain monoclonal antibody sequences, and this has permitted the in vitro production of recombinant antibody from one patient already. In an exciting recent experiment, we have demonstrated that this recombinant antibody is capable of driving erythrocytosis when introduced into mice, lending strong support to our hypothesis that the monoclonal gammopathy is pathogenic. In this proposal, we will build on this preliminary data, and generate recombinant monoclonal antibodies from additional patients with the TEMPI syndrome will the goal of using these antibodies as tools for antigen identification. Pilot attempts using crude patient serum as a source of antibody for antigen identification have been unsuccessful, leading us to surmise that the antibody-antigen interaction may be of low-affinity. Thus, we are proposing a multi-pronged approach using both traditional immunology approaches as well as a new approach of proximity labeling. If successful, our proposal will identify the antigenic target of the monoclonal gammopathy in patients with TEMPI syndrome and in doing so will identify a novel antibody- antigen interaction that drives EPO production and neovascularization.

项目摘要 TEMPI综合征是一种罕见的疾病，其特征在于五个特征：（1）毛细血管扩张，（2）升高 促红细胞生成素和红细胞增多症，（3）单克隆丙种球蛋白病，（4）肾周积液， (5)肺内分流。这是我们在2011年首次发现和描述的一种综合征， 在全球范围内发现了27名患者。TEMPI综合征是一种获得性疾病，似乎是由 存在异常自身抗体，即，单克隆丙种球蛋白病在需要的患者中 治疗，靶向浆细胞和根除抗体的疗法已经导致完全解决， TEMPI综合征的其他特征，暗示抗体是疾病的致病驱动因素。 TEMPI综合征患者的血清促红细胞生成素（EPO）水平可高达500倍 正常的上限。这表明缺氧感应和EPO产生的途径是 严重失调总之，这进一步暗示异常自身抗体是致病性的， 促红细胞生成素生产的驱动力。在这个建议中，我们的目标是确定单克隆抗体的抗原靶点。 丙种球蛋白了解这种抗体-抗原相互作用如何能够驱动EPO的产生， 肾脏和驱动皮肤（毛细血管扩张）和肺（分流）内皮内的新血管形成 有可能识别由细胞外抗体结合触发的全新信号传导机制。 我们将结合多种方法，抗原鉴定与基因表达和突变谱， 单克隆浆细胞我们的方法利用了可用的患者样本， 从这种罕见疾病的患者中仔细纵向收集。我们的初步数据显示 我们可以成功地鉴定和克隆重链和轻链单克隆抗体序列， 这已经允许从一个患者体外生产重组抗体。在一个令人兴奋 最近的实验，我们已经证明这种重组抗体能够驱动红细胞增多症 当被引入小鼠体内时，有力地支持了我们的假设，即单克隆丙种球蛋白病是 致病的在本提案中，我们将在此初步数据的基础上， 来自其他TEMPI综合征患者的抗体将是使用这些抗体作为工具的目标 用于抗原鉴定。使用患者粗血清作为抗原抗体来源的试验性尝试 鉴定不成功，使我们推测抗体-抗原相互作用可能是 低亲和力。因此，我们提出了一个多管齐下的方法，使用传统的免疫学方法 以及一种新的邻近标记方法。如果成功，我们的建议将确定抗原的目标， TEMPI综合征患者的单克隆丙种球蛋白病，并在此过程中鉴定出一种新的抗体- 促红细胞生成素产生和新血管形成的抗原相互作用。