T Cell-Mediated Mechanisms of Autoimmunity in Murine and Human Biliary Atresia

T 细胞介导的小鼠和人类胆道闭锁自身免疫机制

• 批准号: 7322985
• 负责人: CARA LYNN MACK
• 金额: $ 28.68万
• 依托单位: UNIVERSITY OF COLORADO DENVER
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-08-15 至 2012-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7322985
• 关键词: Accounting; Adoptive Transfer; Antigens; Autoantigens; Autoimmune Diseases; Autoimmune Process; Autoimmune Responses; Autoimmunity; Base Sequence; Bile Duct Epithelium; Biliary; Biliary Atresia; Biliary cirrhosis; Biological Assay; Cells; Child; Childhood; Cholestasis; Cloning; Data; Delimmun; Development; Disease; Duct (organ) structure; Enzyme-Linked Immunosorbent Assay; Etiology; Expression Library; Extrahepatic; Extrahepatic Bile Ducts; Future; Generations; Goals; Human; Hybridomas; Immune; Immune response; Infant; Infection; Inflammation; Inflammatory; Injury; Intervention; Invaded; Investigation; Lead; Libraries; Liver; Macaca mulatta; Mediating; Medical; Modeling; Molecular; Molecular Cloning; Molecular Mimicry; Mus; Nature; Newly Diagnosed; Pathogenesis; Pathway interactions; Patients; Peptides; Perinatal Infection; Proteins; Research; Research Personnel; Role; Rotavirus; SCID Mice; Sclerosis; Specificity; Specimen; System; T-Cell Activation; T-Cell Receptor; T-Lymphocyte; Techniques; Technology; Testing; Th1 Cells; Therapeutic; Tissues; Translating; Viral; Viral Proteins; Virus; Week; Western Blotting; base; bile duct; biliary tract; cDNA Expression; design; enzyme linked immunospot assay; human tissue; immunopathology; infancy; insight; intrahepatic; liver transplantation; macrophage; novel; programs; response; theories; tool

DESCRIPTION (provided by applicant): Project Summary. Biliary atresia (BA) is a progressive, inflammatory, sclerosing extrahepatic and intrahepatic cholangiopathy which presents in infancy and leads to bile duct obstruction and biliary cirrhosis. Intrahepatic biliary inflammation and sclerosis progresses in most patients with the resulting need for liver transplantation in 80% of patients, accounting for half of all pediatric liver transplants. Current therapy for BA is inadequate because the etiology and pathogenesis of BA is not understood, however the role of perinatal infection and autoimmune-mediated bile duct injury have been proposed to be involved. The hypothesis to be tested in this proposal is that BA is a viral-induced autoimmune disease of the biliary system, in which T cell-mediated autoimmune responses target bile duct epithelia. Due to the rarity of BA and the limited accessibility to human tissue, the Rhesus rotavirus (RRV)-induced murine model of BA will be utilized in these investigations. We will examine two distinct mechanisms by which infections are known to trigger autoimmune disease: molecular mimicry and bystander activation. Preliminary data for this application demonstrate that autoreactive bile duct epithelial-specific T cells infiltrate the livers of RRV-induced BA mice, and that adoptive transfer of these T cells into naTve SCID recipients leads to bile duct targeted inflammation. Complementary studies will also be performed with human BA tissue. In human BA, the periductal inflammation is composed of Th1 cells and macrophages. We have recently determined that the T cells are oligoclonal in nature, suggesting specific antigen-driven T cell activation. Thus, the specific aims of this proposal are to investigate in detail the role of T cell-mediated autoimmune mechanisms in bile duct injury in both murine and human BA. Specific Aim I is to determine the antigen specificity of liver T cell hybridomas generated from BA mice. Hybridoma technology is a powerful tool used to study the fine specificity of antigen recognition by the T cell receptor. Specific Aim II is to identify the bile duct epithelial peptide that is the target of T cell activation by molecular cloning from a bile duct epithelial cDNA expression library. In Specific Aim III we will analyze the T cells from human BA livers and extrahepatic bile duct remnants and determine the stimulating protein (virus or bile duct epithelia) responsible for the T cell activation and proliferation. Relevance. The significance of this proposal lies in carefully defining the immunopathogenesis of BA in the murine model which will then be translated into investigations in tissues from infants with BA. Delineating the pathways of autoimmune mediated injury in the murine model of BA should stimulate development of novel medical interventions for humans aimed at suppressing the immune response and decreasing bile duct injury. The overall goal of this research program is to use these molecular and immunological insights as a basis for development of future therapeutic and preventative strategies for this important disease.

描述（由申请人提供）：项目摘要。胆道闭锁（BA）是一种进行性、炎症性、硬化性肝外和肝内胆管病，出现于婴儿期，导致胆管阻塞和胆汁性肝硬化。大多数患者肝内胆道炎症和硬化进展，导致 80% 的患者需要肝移植，占所有儿童肝移植的一半。目前对 BA 的治疗还不够充分，因为 BA 的病因和发病机制尚不清楚，但有人提出与围产期感染和自身免疫介导的胆管损伤有关。该提案要测试的假设是，BA 是一种病毒诱导的胆道系统自身免疫性疾病，其中 T 细胞介导的自身免疫反应针对胆管上皮。由于 BA 的稀有性和人体组织的可及性有限，恒河猴轮状病毒 (RRV) 诱导的 BA 小鼠模型将用于这些研究。我们将研究已知感染引发自身免疫性疾病的两种不同机制：分子拟态和旁观者激活。该应用的初步数据表明，自身反应性胆管上皮特异性 T 细胞浸润 RRV 诱导的 BA 小鼠的肝脏，并且这些 T 细胞过继转移到天然 SCID 受体中会导致胆管靶向炎症。还将利用人类 BA 组织进行补充研究。在人类 BA 中，导管周围炎症由 Th1 细胞和巨噬细胞组成。我们最近确定 T 细胞本质上是寡克隆的，这表明特异性抗原驱动的 T 细胞激活。因此，本提案的具体目的是详细研究 T 细胞介导的自身免疫机制在小鼠和人类 BA 胆管损伤中的作用。具体目标 I 是确定 BA 小鼠产生的肝 T 细胞杂交瘤的抗原特异性。杂交瘤技术是用于研究 T 细胞受体抗原识别的精细特异性的强大工具。具体目标 II 是通过从胆管上皮 cDNA 表达文库中进行分子克隆来鉴定作为 T 细胞激活靶标的胆管上皮肽。在特定目标 III 中，我们将分析来自人类 BA 肝脏和肝外胆管残余物的 T 细胞，并确定负责 T 细胞激活和增殖的刺激蛋白（病毒或胆管上皮）。关联。该提议的意义在于仔细定义小鼠模型中 BA 的免疫发病机制，然后将其转化为对 BA 婴儿组织的研究。描述 BA 小鼠模型中自身免疫介导损伤的途径应该会刺激人类新型医疗干预措施的开发，旨在抑制免疫反应和减少胆管损伤。该研究计划的总体目标是利用这些分子和免疫学见解作为开发这种重要疾病的未来治疗和预防策略的基础。