HLA Alleles, Self-Peptides and Microbial Mimicry in SSc

描述(由申请人提供)：本建议书中的研究测试 假设人类白细胞抗原的等位基因，即人类白细胞抗原自肽和微生物拟态，在 导致系统性硬化症(SSC)的发病机制。 导致这一假说的观察结果指出了人类白细胞抗原-DRP的核心作用 我是分子，至少是四倍。第一个是发现一个女人的 SSC的风险显著增加，因为以前出生的孩子 与DRbeta1兼容的HL。第二，特定的人类白细胞抗原等位基因会增加罹患癌症的风险 SSC，并包括DR11 DRbeta1链的氨基酸序列(aa67-71， “FLEDR”)，与DRbeta5共享。第三，人巨细胞病毒(HCMV) 已知会对嵌合体的条件产生负面影响 移植和自发发生的微嵌合体最近被 与SSC有牵连，与人巨细胞病毒有关。最后，人巨细胞病毒与一个 人类白细胞抗原-DRbeta1的保守序列(aa53-57)，进一步延伸(aa53-58， “LGRPDE”)，用于编码与SSC相关的DR11的DRB1等位基因。 拟议的实验将提供对人类白细胞抗原概念的初步测试 DRbeta1来源的多肽在宿主细胞通讯中的作用 细胞之间以及宿主细胞和非宿主细胞之间。第一个具体目标是设计 包含已识别的DRbeta1序列的候选肽 分子，并将在结合和功能T细胞分析中测试它们。第二 第三个特定目标将鉴定、列举和表征多肽 利用人工抗原提呈细胞(AAPC)复合的特异性T细胞 与人类白细胞抗原自身多肽和来源于同源人巨细胞病毒的多肽 序列。AAPC是最近开发的一种技术，它提供了一种 在捕捉低亲和力相互作用方面优于四聚体，这是由于 脂质体膜内的允许运动。AAPC将用于T 细胞捕获试验分离多肽特异性T细胞，然后 SSc患者和对照组的表型和功能特征。 将对细胞因子产生和差异基因进行分析 自发性硬化症患者和对照组分选细胞的表达。最后，在 第四个具体目标，实时荧光定量聚合酶链式反应将用于定量评估 外周血单个核细胞亚群中的微嵌合体 病人和对照组。拟议的实验结果将允许 对包含一系列致病因素的致病模型的初步测试 致病因素包括特定的人类白细胞抗原等位基因、人类白细胞抗原之间的关系 宿主细胞和非宿主细胞，以及微生物在疾病发病机制中的拟态。研究 旨在最大限度地提高对 疾病的发病机制可能会导致 治疗这一疑难疾病的新方法。

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.