HLA Alleles, Self-Peptides and Microbial Mimicry in SSc

SSc 中的 HLA 等位基因、自肽和微生物拟态

• 批准号: 6407027
• 负责人: J. Lee Nelson
• 金额: $ 32.19万
• 依托单位: FRED HUTCHINSON CANCER RESEARCH CENTER
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-09-30 至 2006-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6407027
• 关键词: MHC class I antigen; MHC class II antigen; T lymphocyte; alleles; antigen presenting cell; autoantigens; biomimetics; biotechnology; cell cell interaction; clinical research; enzyme linked immunosorbent assay; flow cytometry; gene expression; genetic polymorphism; genetic susceptibility; high performance liquid chromatography; human genetic material tag; human subject; hybrid antibody; immunoaffinity chromatography; immunologic substance development /preparation; monoclonal antibody; pathologic process; polymerase chain reaction; synthetic antigens; systemic scleroderma

DESCRIPTION (provided by applicant): The studies in this proposal test the hypothesis that HLA alleles, HLA self-peptides and microbial mimicry, in concert, contribute to the pathogenesis of systemic sclerosis (SSc). Observations leading to the hypothesis point to a central role for the HLA-DRP I molecule and are at least fourfold. The first is the finding that a woman's risk of SSc is significantly increased by prior birth of a child who was HLA-compatible for DRbeta1. Second, particular HLA alleles increase risk of SSc, and include an amino acid sequence of the DR11 DRbeta1 chain (aa67-71, "FLEDR") that is shared with DRbeta5. Third, human cytomegalovirus (HCMV) is known to negatively impact conditions of chimerism that arise from transplantation and spontaneously occurring microchimerism has recently been implicated in SSc, as has HCMV. Finally, HCMV has sequence identity with a conserved sequence of HLA-DRbeta1 (aa 53-57), that extends further (aa 53-58, "LGRPDE") for DRB1 alleles that encode for DR11, which is associated with SSc. The proposed experiments will provide the initial test of the concept that HLA peptides derived from DRbeta1 function in cellular communications among host cells and between host and non-host cells. The first Specific Aim will design candidate peptides that encompass the identified sequences of the DRbeta1 molecule and will test them in binding and functional T cell assays. The second and third Specific Aims will identify, enumerate and characterize peptide specific T cells using artificial antigen presenting cells (aAPC) complexed with the HLA self-peptides and peptides derived from the homologous HCMV sequence. The aAPC is a very recently developed technique that offers an advantage over tetramers in capturing low affinity interactions due to permissive movement within a liposorne membrane. The aAPC will be used in a T cell capture assay to isolate peptide specific T cells which will then be phenotypically and functionally characterized in SSc patients and in controls. Analysis will be conducted for cytokine production and differential gene expression from sorted cells of SSc patients and controls. Finally, in the fourth Specific Aim, Real-Time PCR will be used to quantitatively assess microchimerism in peripheral blood mononuclear cell subsets from the same patients and controls. The results of the proposed experiments will permit the initial test of a model of pathogenesis that incorporates a concert of contributory factors including specific HLA alleles, HLA-relationships among host and non-host cells, and microbial mimicry in disease pathogenesis. Studies are designed so as to maximize the potential to advance understanding of disease pathogenesis in a way that could potentially lead to the development of new therapeutic modalities for this difficult disease.

描述（由申请人提供）：本提案中的研究测试了 假设 HLA 等位基因、HLA 自肽和微生物拟态 协同作用，有助于系统性硬化症（SSc）的发病机制。 导致该假设的观察表明 HLA-DRP 的核心作用 I 分子 和 至少有四倍。第一个发现是，女性 先前出生的孩子患有 SSc 的风险会显着增加 DRbeta1 的 HLA 兼容。其次，特定的 HLA 等位基因会增加以下风险： SSc，并包括 DR11 DRbeta1 链的氨基酸序列（aa67-71， “FLEDR”）与 DRbeta5 共享。第三，人类巨细胞病毒（HCMV） 已知会对嵌合状态产生负面影响 移植和自发发生的微嵌合现象最近被 与 SSc 相关，HCMV 也如此。最后，HCMV 具有序列同一性 HLA-DRbeta1 的保守序列（氨基酸 53-57），进一步延伸（氨基酸 53-58， “LGRPDE”）代表编码 DR11 的 DRB1 等位基因，该等位基因与 SSc 相关。 所提出的实验将为HLA这一概念提供初步测试。 源自 DRbeta1 的肽在宿主细胞通讯中发挥作用 细胞之间以及宿主细胞和非宿主细胞之间。第一个具体目标将设计 包含已识别的 DRbeta1 序列的候选肽 分子并将在结合和功能性 T 细胞测定中对其进行测试。第二个 第三个具体目标将识别、枚举和表征肽 使用人工抗原呈递细胞 (aAPC) 复合的特定 T 细胞 具有 HLA 自身肽和源自同源 HCMV 的肽 顺序。 aAPC 是一项最近开发的技术，可提供 在捕获低亲和力相互作用方面优于四聚体，因为 脂质体膜内的允许运动。 aAPC将用于T 细胞捕获试验分离肽特异性 T 细胞，然后将其 SSc 患者和对照组的表型和功能特征。 对细胞因子产生和差异基因进行分析 SSc 患者和对照的分选细胞中的表达。最后，在 第四个具体目标，将使用实时PCR进行定量评估 外周血单个核细胞亚群中的微嵌合现象 患者和对照。所提出的实验结果将允许 发病机制模型的初步测试，其中包含一系列的 影响因素包括特定的 HLA 等位基因、HLA 之间的关系 宿主和非宿主细胞，以及疾病发病机制中的微生物拟态。研究 旨在最大限度地发挥促进理解的潜力 疾病的发病机制可能会导致疾病的发展 针对这种疑难疾病的新治疗方法。