Characterize the Landscape and Origin of Hybrid Peptides in Beta Cells

描述 Beta 细胞中混合肽的景观和起源

基本信息

批准号：
10438838
负责人：
THOMAS DELONG
金额：
$ 46.65万
依托单位：
UNIVERSITY OF COLORADO DENVER
依托单位国家：
美国
项目类别：
财政年份：
2018
资助国家：
美国
起止时间：
2018-09-25 至 2023-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10438838
关键词：
Address Algorithms Amino Acid Sequence Animal Model Antigens Autoimmune Diseases Automobile Driving Beta Cell Biochemical Bioinformatics CD4 Positive T Lymphocytes Cell Extracts Cells Chemicals Clone Cells Custom Cytoplasmic Granules Data Data Set Databases Development Diabetes Mellitus Disease Environment Epitopes Family Genome Grant Human Hybrids Immune Targeting Immune system Immunologics Inbred NOD Mice Insulin Insulin-Dependent Diabetes Mellitus Ions Islets of Langerhans Knowledge Ligands Mass Spectrum Analysis Mediating Metals Methods Modification Mus Onset of illness Organ Donor Organism Peptide Fragments Peptide Sequence Determination Peptides Play Post-Translational Protein Processing Protein Family Protein Fragment Proteins Proteome Proteomics Reaction Reagent Research Design Residual state Role Scoring Method Secretory Vesicles Structure of beta Cell of islet T-Lymphocyte T-Lymphocyte Epitopes Technology Testing Tissues Virus autoreactive T cell bioinformatics tool cell type covalent bond crosslink human tissue insulin dependent diabetes mellitus onset insulinoma islet novel pathogen prevent protein aminoacid sequence success synthetic peptide tool type I diabetic

项目摘要

In type 1 diabetes autoreactive T cells mediate the destruction of insulin producing beta cells. A key question in the study of this disease is why T cells, which are there to protect us from pathogens such as viruses, turn against the body’s own cells. Protein modifications that form within cells provide a plausible explanation for this misguided attack as the composition of proteins is altered, making them appear foreign to the immune system. Using mass spectrometric analyses on beta cell extracts, we recently identified a new family of protein modifications that forms in beta cells and is targeted by disease driving T cells in a major animal model of type 1 diabetes. Furthermore, we demonstrated that autoreactive T cells, that were isolated from the residual islets of type 1 diabetic organ donors, also target proteins carrying this type of modification. The modification is a result of insulin fragments that are cross-linked to other protein fragments, leading to the formation of hybrid peptides. At the junction those peptides contain new amino acid sequences that are not encoded by the organism’s genome. These non-germline encoded sequences deliver plausible targets for autoreactive T cells that mediate the destruction of beta cells. Here we will (1) search for hybrid peptides in human beta cells by mass spectrometry, (2) study the mechanism that leads to the formation of hybrid peptides, and (3) devise new bioinformatics tools that will allow us to confidently and rapidly identify hybrid peptides in beta cells by searching mass spectrometric datasets. Identification of hybrid peptides in human tissue will provide us with valuable tools to devise new strategies to predict, prevent or reverse type 1 diabetes. Understanding the mechanism that leads to the formation of hybrid peptides will allow us to test strategies which prevent the formation of those peptides, rendering beta cells invisible to disease driving T cells. Bioinformatics tools will allow us to characterize the vast number of potential hybrid peptides that may form in beta cells as well as additional cells types that are targeted in other autoimmune diseases. In summary, success in any of the aims of this grant will provide us with valuable tools and reagents to study type 1 diabetes in unprecedented detail.

在 1 型糖尿病中，自身反应性 T 细胞介导对产生胰岛素的 β 细胞的破坏，这种疾病研究的一个关键问题是，为什么保护我们免受病毒等病原体侵害的 T 细胞会对抗人体自身的细胞蛋白质。细胞内形成的修饰为这种误导性攻击提供了合理的解释，因为蛋白质的组成发生了改变，使它们对免疫系统显得陌生。通过对β细胞提取物进行质谱分析，我们最近发现了一种新的蛋白质修饰家族。在β细胞中并且是此外，我们还证明，从 1 型糖尿病器官捐献者的残余胰岛中分离出来的自身反应性 T 细胞也靶向携带这种修饰的蛋白质。是胰岛素片段与其他蛋白质片段交联的结果，导致在连接处形成杂合肽，这些肽包含不由生物体基因组编码的新氨基酸序列。序列为介导β细胞破坏的自身反应性T细胞提供合理的靶标，在这里我们将（1）通过质谱法寻找人类β细胞中的混合肽，（2）研究导致混合肽形成的机制，以及(3) 设计新的生物信息学工具，使我们能够通过搜索质谱数据集自信而快速地识别β细胞中的混合肽。人体组织中混合肽的识别将为我们提供有价值的工具。设计新的策略来预测、预防或逆转 1 型糖尿病，了解导致混合肽形成的机制将使我们能够测试阻止这些肽形成的策略，从而使疾病驱动的 T 细胞看不见。将使我们能够表征β细胞中可能形成的大量潜在杂合肽以及针对其他自身免疫性疾病的其他细胞类型。总之，这项资助的任何目标的成功都将为我们提供有价值的工具。和以前所未有的细节研究 1 型糖尿病的试剂。