Specificity of CD8 cells in islets from type 1 diabetes patients

1 型糖尿病患者胰岛中 CD8 细胞的特异性

• 批准号: 8195256
• 负责人: Matthias G. Von Herrath
• 金额: $ 40.14万
• 依托单位: LA JOLLA INSTITUTE FOR IMMUNOLOGY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-05-02 至 2016-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8195256
• 关键词: Abbreviations; Accounting; Address; Antibodies; Antigens; Apoptosis; Autoantigens; Autoimmune Process; Autoimmunity; Benchmarking; Beta Cell; Blood; CD4 Positive T Lymphocytes; CD8-Positive T-Lymphocytes; CD8B1 gene; CXCL10 gene; Cell Fraction; Cell physiology; Cells; Characteristics; Chickens; Chronic; Clonality; Collaborations; Consensus; Coxsackie B Viruses; Cytoskeleton; Data; Detection; Development; Diabetes Mellitus; Diagnosis; Disease; Drug or chemical Tissue Distribution; Enterovirus; Epitopes; Event; Finland; Freezing; Frequencies; Goals; HLA-A2 Antigen; Histopathology; Human; Immune; In Situ; Inbred NOD Mice; Individual; Infection; Infiltration; Inflammation; Inflammatory; Insulin; Insulin-Dependent Diabetes Mellitus; Interferons; Islet Cell; Islets of Langerhans; Knowledge; Label; Libraries; Lymphocyte; MHC Class I Genes; Maps; Mediating; Memory; Methods; Molecular; Mus; Nature; Nebraska; Netherlands; Nucleic Acids; Organ; Pancreas; Patients; Peptides; Peripheral; Phenotype; Play; Proteins; Research; Role; Sampling; Specificity; Spleen; Staining method; Stains; Structure of beta Cell of islet; Surface; T cell response; T-Cell Immunologic Specificity; T-Lymphocyte; Time; Tissues; Transgenic Mice; Translating; Universities; Up-Regulation; Viral; Viral Antigens; Viral Proteins; Virus; Virus Diseases; autoreactive T cell; base; cell type; clinical Diagnosis; diabetic; diabetic patient; egg; human tissue; in vivo; islet; killings; lymph nodes; mouse model; novel; repository; response; viral detection

DESCRIPTION (provided by applicant): Human type 1 diabetes (T1D) is characterized by the specific immune-mediated destruction of insulin- producing pancreatic beta cells. Importantly, earlier studies demonstrated that immune memory to beta cell antigens plays a significant role in their destruction, which constitutes a major obstacle for long-term acceptance of islet cell grafts (1-3). There is now consensus that CD8 T cells constitute the principal T cell type in insulitis in recent-onset patients (4). Such CD8 T cells are potentially very harmful, since they have been shown to readily kill human beta cells in vivo, if enough MHC class I is upregulated on their surface (5). However, not much is known about the overall CD8 specificities and frequencies present in islets and the cause for their entry and activation. Possible targets are known autoantigens derived from beta cells such as insulin, IGRP, IA-2 and GAD (see Table 1 for abbreviations) and cellular matrix proteins, which could become presented when beta cells are destroyed but also viral proteins for example enteroviral determinants. The overall objective of this proposal is therefore to reveal the specificity of CD8 T lymphocytes that are found in human islets and address whether viral infections may play a role in this scenario. [In parallel studies, we aim to confirm our preliminary data showing that islet infiltration may persist long beyond clinical diagnosis and in such cases follows a continuous course both quantitatively and qualitatively. The latter finding would have broad implications on the feasibility of experimental tolerization therapies in longstanding patients.] Our first goal is to systematically detect autoreactive CD8 T cells within human islets and correlate their numbers and activation status with the local histopathology of the islet. In situ tetramer staining of freshly frozen human pancreata and pancreatic lymph nodes now available through the unique nPOD organ repository will be used. In addition, humanized HLA A2 expressing transgenic mice will be utilized to map responses to novel cellular matrix (self) epitopes which will then be validated on human tissues. Our second goal is to search for [CVB]-specific T cells within islets and address the important question, whether viral infection makes islets more accessible for autoreactive T cell or vice versa. To this purpose human sections from pancreata of diabetic patients will be probed with [CVB-specific] tetramers and viral nucleic acids will be detected in collaboration with Heikki Hyoty and Stephen Tracy. In addition, diabetes- prone HLA-A2 humanized mice and fluorescently labeled Coxsackie B virus strains will be used to address the fundamental 'chicken-egg' question, whether viral infections are more important to condition islets for autoreactive lymphocyte entry and destruction, or, conversely, whether autoreactive attacks make islets more accessible for enteroviral infections. PUBLIC HEALTH RELEVANCE: We wish to systematically investigate the specificity of the immune cells that destroy insulin-producing beta cells in pancreas tissue obtained from patients with type 1 diabetes. Additionally, we will evaluate the potential role of enteroviruses in type 1 diabetes development in both patients and mouse models. This research will expand our knowledge on how the disease is triggered in susceptible individuals and on how we may therapeutically target these cells in order to restore tolerance.

描述(申请人提供)：人类1型糖尿病(T1D)的特征是特异性免疫介导的产生胰岛素的胰岛β细胞的破坏。重要的是，早期的研究表明，对β细胞抗原的免疫记忆在它们的破坏中起着重要作用，这构成了胰岛细胞移植长期接受的主要障碍(1-3)。目前已达成共识，认为CD8T细胞是新近发病的患者中的主要T细胞类型。这种CD8T细胞可能非常有害，因为已经证明，如果它们的表面上调了足够多的MHC I类分子，它们很容易在体内杀死人类β细胞(5)。然而，对于胰岛中存在的CD8的整体特异性和频率以及它们进入和激活的原因还知之甚少。可能的目标是来自β细胞的已知自身抗原，如胰岛素、IGRP、IA-2和GAD(缩写见表1)和细胞基质蛋白，当β细胞被破坏时可能出现这些蛋白，但也包括病毒蛋白，例如肠道病毒决定簇。因此，这项建议的总体目标是揭示在人类胰岛中发现的CD8T淋巴细胞的特异性，并解决病毒感染是否可能在这种情况下发挥作用。[在平行研究中，我们的目标是证实我们的初步数据，即胰岛浸润可能会持续很长时间，超过临床诊断，在这种情况下，无论是定量还是定性，都遵循一个连续的过程。后者的发现将对长期患者进行实验性耐受治疗的可行性产生广泛的影响。]我们的第一个目标是系统地检测人类胰岛中的自身反应性CD8 T细胞，并将它们的数量和激活状态与胰岛的局部组织病理学联系起来。对新鲜冷冻的人胰腺和胰腺淋巴结进行原位四聚体染色，现在可以通过独特的nPOD器官储存库获得。此外，人源化的表达HLAA2的转基因小鼠将被用来映射对新的细胞基质(SELF)表位的反应，然后在人类组织上进行验证。我们的第二个目标是在胰岛中寻找[CVB]特异性T细胞，并解决一个重要的问题，即病毒感染是否使胰岛更容易被自身反应性T细胞访问，反之亦然。为此，将使用[CVB特异性]四聚体探测糖尿病患者胰腺的人体切片，并将与Heikki Hyoty和Stephen Tracy合作检测病毒核酸。此外，易患糖尿病的人类白细胞抗原A2人源化小鼠和荧光标记的柯萨奇B病毒株将被用于解决基本的“鸡-蛋”问题，即病毒感染是否对胰岛的自身反应性淋巴细胞进入和破坏更重要，或者相反，自身反应性攻击是否使胰岛更容易受到肠道病毒感染。 公共卫生相关性：我们希望系统地研究破坏1型糖尿病患者胰腺组织中产生胰岛素的β细胞的免疫细胞的特异性。此外，我们将在患者和小鼠模型中评估肠道病毒在1型糖尿病发生中的潜在作用。这项研究将扩大我们的知识，了解这种疾病是如何在易感个体中触发的，以及我们如何通过治疗性地针对这些细胞来恢复耐受性。