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: 8261913
• 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/8261913
• 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; public health relevance; 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（由申请人提供）：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腺 β 细胞的破坏。重要的是，早期研究表明，针对 β 细胞抗原的免疫记忆在其破坏过程中发挥着重要作用，这构成了胰岛细胞移植物长期接受的主要障碍 (1-3)。目前已达成共识，CD8 T 细胞是新发患者胰岛炎的主要 T 细胞类型 (4)。这种 CD8 T 细胞可能非常有害，因为如果足够多的 MHC I 类在其表面上调，它们已被证明很容易在体内杀死人类 β 细胞 (5)。然而，对于胰岛中存在的整体 CD8 特异性和频率以及它们进入和激活的原因知之甚少。可能的靶标是源自 β 细胞的已知自身抗原，例如胰岛素、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，这些蛋白可能会出现），但也可能出现病毒蛋白，例如肠道病毒决定簇。因此，该提案的总体目标是揭示人类胰岛中发现的 CD8 T 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，我们的目的是确认我们的初步数据，这些数据表明胰岛浸润可能会持续很长时间超出临床诊断范围，并且在这种情况下，在定量和定性方面都遵循连续的过程。后者的发现将对长期患者的实验性耐受疗法的可行性产生广泛的影响。]我们的首要目标是系统地检测人类胰岛内的自身反应性 CD8 T 细胞，并将其数量和激活状态与胰岛的局部组织病理学相关联。将使用现可通过独特的 nPOD 器官库获得的新鲜冷冻人胰腺和胰腺淋巴结的原位四聚体染色。此外，表达人源化 HLA A2 的转基因小鼠将用于绘制对新型细胞基质（自身）表位的反应图谱，然后在人体组织上进行验证。我们的第二个目标是在胰岛中寻找 [CVB] 特异性 T 细胞，并解决重要问题：病毒感染是否会使胰岛更容易接触自身反应性 T 细胞，反之亦然。为此，将与 Heikki Hyoty 和 Stephen Tracy 合作，用 [CVB 特异性] 四聚体探测糖尿病患者胰腺的人体切片，并检测病毒核酸。此外，易患糖尿病的HLA-A2人源化小鼠和荧光标记的柯萨奇B病毒株将用于解决基本的“先有鸡还是先有蛋”的问题，即病毒感染对于调节胰岛自身反应性淋巴细胞进入和破坏是否更重要，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。 公共健康相关性：我们希望系统地研究免疫细胞的特异性，这些免疫细胞会破坏从 1 型糖尿病患者身上获得的胰腺组织中产生胰岛素的 β 细胞。此外，我们将在患者和小鼠模型中评估肠道病毒在 1 型糖尿病发展中的潜在作用。这项研究将扩大我们对易感个体如何引发疾病以及如何针对这些细胞进行治疗以恢复耐受性的了解。