HLA Alleles, Self-Peptides and Microbial Mimicry in SSc

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自身肽和微生物拟态， 协同作用，有助于系统性硬化症（SSc）的发病机制。 导致这一假设的观察结果指出HLA-DRP的核心作用 我分子和至少是四倍。第一个发现是， SSc的风险显着增加了以前出生的孩子谁是 DR β 1的HLA相容性。第二，特定的HLA等位基因增加了 SSc的氨基酸序列，并且包括DR 11 DR β 1链的氨基酸序列（aa 67 -71， “FLEDR”），与DRbeta 5共享。第三，人巨细胞病毒（HCMV）是 已知对嵌合状态产生负面影响， 移植和自发发生的微嵌合体最近被 与SSc有关，HCMV也是如此。最后，HCMV与一种具有序列同一性的病毒具有序列同一性。 HLA-DR β 1的保守序列（aa 53-57），进一步延伸（aa 53-58， “LGRPDE”），其用于编码与SSc相关的DR 11的DRB 1等位基因。 拟议的实验将提供初步测试的概念，HLA 来源于DR β 1的肽在宿主间的细胞通讯中起作用 细胞之间以及宿主和非宿主细胞之间。第一个具体目标将设计 包含DR β 1的鉴定序列的候选肽 分子，并将在结合和功能性T细胞测定中测试它们。第二 和第三个特定目标将识别，计数和表征肽 使用人工抗原呈递细胞（aAPC）复合的特异性T细胞 用HLA自身肽和来自同源HCMV的肽 顺序aAPC是一种最近开发的技术， 在捕获低亲和力相互作用方面优于四聚体， 允许在脂质体膜内移动。aAPC将用于T 细胞捕获测定以分离肽特异性T细胞，然后将其 在SSc患者和对照中的表型和功能特征。 将对细胞因子产生和差异基因进行分析 来自SSc患者和对照的分选细胞的表达。最后在 第四个特异性目的，实时PCR将用于定量评估 外周血单个核细胞亚群中的微嵌合体 患者和对照组。拟议实验的结果将允许 初步测试的发病机制模型，包括音乐会， 贡献因素包括特定的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 旨在最大限度地提高对 疾病的发病机制，在某种程度上，可能会导致发展 新的治疗方法来治疗这一疑难病症。

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.