Understanding ERAP molecular mechanism of MHC I antigen processing

了解 MHC I 抗原加工的 ERAP 分子机制

基本信息

批准号：
9383415
负责人：
MARLENE BOUVIER
金额：
$ 39.98万
依托单位：
UNIVERSITY OF ILLINOIS AT CHICAGO
依托单位国家：
美国
项目类别：
财政年份：
2017
资助国家：
美国
起止时间：
2017-07-15 至 2022-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9383415
关键词：
Address Affect Alleles Alpha Cell Aminopeptidase Ankylosing spondylitis Antigen Presentation Pathway Autoimmune Diseases Binding Biochemical Biological Cell-Free System Cells Characteristics Chronic Disease Communicable Diseases Complex Computational Technique Crystallization Cytotoxic T-Lymphocytes Data Development Disease Endoplasmic Reticulum Enzymes Event Genetic Polymorphism Goals HLA-B Antigens HLA-B27 Antigen Histocompatibility Antigens Class I Human I-antigen Immune response Immune system Immunologics Immunotherapy In Vitro Invaded Knowledge Length Light Link Major Histocompatibility Complex Mediating Medical Modeling Molecular Molecular Conformation Molecular Mechanisms of Action N-terminal Pathogenesis Peptide Transport Peptides Physiological Play Process Property Proteins Publishing Roentgen Rays Role Specificity Structure Structure-Activity Relationship System Techniques antigen processing base chronic autoimmune disease genetic linkage insight interest novel pathogen peptide I response tapasin tool

项目摘要

ABSTRACT Advances in characterization of the class I antigen presentation pathway over the last decade have taught us that antigen processing, peptide transport, peptide trimming, peptide selection, and peptide loading are critical events for the development of optimal peptide repertoires presented by major histocompatibility complex (MHC) class I molecules to cytotoxic T lymphocytes (CTLs). These events influence the tight binding of peptides needed to generate conformationally stable MHC I/peptide complexes. Evidence has been provided that changes in the overall quality of the MCH I peptide repertoire can have profound effects on CTL responses. Therefore, studies that characterize basic biological events in MHC I maturation are essential not only for advances in fundamental principles of antigen processing and presentation, but also to better comprehend how these maturation events modulates immune responses. We have studied the molecular and structural basis of mechanisms of peptide loading and selection by MHC I for more than 20 years. Recently, the endoplasmic reticulum-aminopeptidases associated with antigen processing (ERAP1, ERAP2, and ERAP1,2 heterodimer; referred to as ERAP) have emerged as key proteins for influencing formation of the MHC I peptide repertoire. To date, our understanding of how ERAP functions as a peptide editor is however obscure. Similarly, the question of how ERAP1 and ERAP2 polymorphisms play a role in chronic autoimmune diseases such as HLA-B*27-associated ankylosing spondylitis (AS), and how ERAP1 and ERAP2 interact with disease-associated MHC I molecules, still remain unclear. In this application, we will use a comprehensive approach to shed some light on the function of ERAPs and on the molecular crosstalk between ERAPs and MHC I molecules. Using a cell-free system composed of ERAPs, MHC class I molecules, and synthetic and natural N-terminally extended peptides, and in combination with biochemical, molecular, and crystallographic techniques, we will characterize the function of ERAPs towards free and MHC I-bound peptides (Aim #1); elucidate the functional links between ERAP1, HLA-B*27, and AS (Aim #2); and determine the x-ray crystal structure of an HLA-B*0801/precursor complex, with and without ERAP1 (Aim #3). Overall, our study is fundamentally significant because it will provide new knowledge to better understand how ERAPs function and influence formation of the MHC I peptide repertoire, novel insights into molecular events underlying the pathogenesis of AS, and will reveal the molecular interaction between ERAP1 and MHC I molecules. The medical relevance of our studies is immense.

抽象的过去十年中 I 类抗原呈递途径的表征进展表明我们认为抗原加工、肽转运、肽修剪、肽选择和肽装载是主要组织相容性所呈现的最佳肽库开发的关键事件复合体 (MHC) I 类分子与细胞毒性 T 淋巴细胞 (CTL) 的结合。这些事件影响紧密结合生成构象稳定的 MHC I/肽复合物所需的肽。证据已前提是 MCH I 肽库整体质量的变化会对 CTL 产生深远的影响回应。因此，表征 MHC I 成熟过程中基本生物学事件的研究并不重要。不仅是为了抗原加工和呈递基本原理的进步，也是为了更好地了解这些成熟事件如何调节免疫反应。我们通过以下方法研究了肽加载和选择机制的分子和结构基础： MHC I 已有 20 多年的历史。最近，与抗原相关的内质网氨基肽酶加工（ERAP1、ERAP2 和 ERAP1,2 异二聚体；简称 ERAP）已成为关键蛋白影响 MHC I 肽库的形成。迄今为止，我们对 ERAP 如何发挥作用的理解然而，肽编辑器却很晦涩。同样，ERAP1 和 ERAP2 多态性如何发挥作用的问题在慢性自身免疫性疾病（如 HLA-B*27 相关强直性脊柱炎 (AS)）中的作用，以及如何 ERAP1 和 ERAP2 与疾病相关 MHC I 分子的相互作用仍不清楚。在这个应用程序中，我们将使用一种综合方法来阐明 ERAP 的功能和分子生物学 ERAP 和 MHC I 分子之间的串扰。使用由 ERAP、MHC I 类组成的无细胞系统分子，以及合成和天然的 N 末端延伸肽，并与生化结合，通过分子和晶体学技术，我们将描述 ERAP 对游离和 MHC 的功能 I 结合肽（目标#1）；阐明 ERAP1、HLA-B*27 和 AS 之间的功能联系（目标 #2）；和确定 HLA-B*0801/前体复合物的 X 射线晶体结构，有或没有 ERAP1（目标 #3）。总的来说，我们的研究具有根本意义，因为它将提供新知识以更好地理解 ERAP 如何发挥作用并影响 MHC I 肽库的形成，对分子的新见解 AS 发病机制背后的事件，并将揭示 ERAP1 和 MHC 之间的分子相互作用我分子。我们的研究的医学意义是巨大的。