SPECIFICITY AND DEGENERACY OF AUTOREACTIVE T CELL RECEPT

自身反应性 T 细胞受体的特异性和简并性

• 批准号: 6394217
• 负责人: Kai W Wucherpfennig
• 金额: $ 31.11万
• 依托单位: DANA-FARBER CANCER INST
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-07-01 至 2003-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6394217
• 关键词: Baculoviridae; MHC class II antigen; T cell receptor; X ray crystallography; autoimmune disorder; cell mediated cytotoxicity; cellular immunity; clone cells; cross immunity; crystallization; cytotoxic T lymphocyte; disease /disorder etiology; immunoaffinity chromatography; immunologic memory; immunoregulation; leukocyte activation disorder; major histocompatibility complex; multiple sclerosis; myelin basic proteins; peptide library; protein binding; protein sequence; protein structure function; surface plasmon resonance

This project focuses on the recognition of HLA-DR2/peptide complexes by myelin basic protein (MBP) specific T cell receptors (TCRs) that have been isolated from multiple sclerosis (MS) patients. It was previously thought that TCRs are highly specific for particular foreign or self-peptides. However, a number of studies performed over the past several years have demonstrated that there is a substantial degree of degeneracy in TCR recognition of MHC/peptide complexes. Microbial peptides can activate autoreactive T cell clones, despite having relatively little sequence homology with the self-peptide. The structural and functional basis of degenerate peptide recognition by TCRs will be examined in the proposed experiments. Combinatorial peptide libraries will be used to examine the sequence diversity of peptides that activate autoreactive T cell clones specific for myelin basic protein (Aim 1). MBP specific TCRs will be expressed as soluble proteins in the Baculovirus system and the binding affinity of these TCRs for different HLA-DR2/peptide complexes will be examined (Aim 2). A soluble MBP specific TCR will be co-crystallized with the HLA-DR2/MBP peptide complex and a crossreactive HLA-DR2/peptide complex. The structures of these TCR/HLA-DR2/peptide complexes will be determined by X-ray crystallography (Aim 3). Analysis of the structural requirements for peptide binding and TCR recognition may have important implications for understanding the pathogenesis of MS and for designing peptide-based therapies.

该项目的重点是髓磷脂碱性蛋白（MBP）特异性T细胞受体（TCR）对HLA-DR2/肽复合物的识别，这些蛋白（MBP）已从多发性硬化症患者（MS）患者中分离出来。 以前认为TCR对特定的外肽或自肽高度具体。 然而，在过去几年中进行的许多研究表明，TCR识别MHC/肽复合物具有很大程度的退化。 尽管与自肽的序列同源性相对较小，但微生物肽可以激活自动反应性T细胞克隆。 在拟议的实验中，将检查TCR退化肽识别的结构和功能基础。组合肽库将用于检查激活对髓磷脂碱性蛋白特异性自动反应性T细胞克隆的肽的序列多样性（AIM 1）。 MBP特异性TCR将以杆状病毒系统中的可溶性蛋白表示表示，这些TCR对不同HLA-DR2/肽复合物的结合亲和力将被检查（AIM 2）。 可溶性MBP特异性TCR将与HLA-DR2/MBP肽复合物和交叉反应性HLA-DR2/肽复合物共结晶。 这些TCR/HLA-DR2/肽配合物的结构将由X射线晶体学确定（AIM 3）。 分析肽结合和TCR识别的结构要求可能对理解MS的发病机理和设计基于肽的疗法具有重要意义。