RECEPTOR-LIGAND INTERACTIONS IN T-CELL DIFFERENTIATION

T 细胞分化中的受体-配体相互作用

• 批准号: 6795630
• 负责人: STANISLAV VUKMANOVIC
• 金额: $ 17.29万
• 依托单位: CHILDREN'S RESEARCH INSTITUTE
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-02-01 至 2007-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6795630
• 关键词: T cell receptor; T lymphocyte; antigen presentation; autoantigens; autoimmunity; biological signal transduction; cell differentiation; enzyme activity; gene mutation; genetically modified animals; histocompatibility antigens; laboratory mouse; mass spectrometry; mitogen activated protein kinase; molecular biology information system; organ culture; receptor binding; synthetic peptide; thymus

DESCRIPTION (provided by applicant): My long-term goal is to obtain a cellular and molecular understanding of the complex intercellular interactions that result in terminal differentiation of bone marrow-derived precursors into mature effector T cells. The focus of the present application is characterization of self ligands that induce positive selection in the thymus. The application is based on our recent discovery of a novel strategy of predicting and identifying self peptides promoting positive selection. The approach consists of generation of large databases of potential self peptides (made possible by the mouse genome project) and bioinformatics-based selection from these databases of small groups of candidate peptides. Selected peptides are tested for positive selection in fetal thymic organ cultures and MHC presentation of peptides is verified by screening self peptide pools by mass spectrometry analysis. In Specific aim 1 we will expand this strategy to identify multiple positively selecting peptides in four T cell receptor transgenic models. We will also experimentally test whether similarity of self peptides to antigen is a working principle of positive selection. The similarity scores of self-ligands identified by three independent means will be plotted against the ability to induce positive selection. A complementary approach will consist of generating synthetic peptide libraries of graded similarity to antigen. The ability of these libraries to induce positive selection will be determined. In the Specific Aim 2 we will determine if and how the duration of T cell receptor signaling affects positive and negative selection. Using a novel in vitro experimental delivery of positively selecting signals we will observe the kinetics of MAP kinase activation induced by negatively or positively selecting ligands. In a complementary approach we will assess the effects on positive versus negative selection of limiting the duration of signaling. In Specific aim 3 we will determine the structural basis for selective involvement of amino-terminal portion of peptide in positive selection. These findings should greatly contribute to our knowledge of the formation of functional TCR repertoire. This information will be valuable for vaccine development, immunomodulation therapy in organ transplantation, autoimmune diseases, lymphoproliferative diseases and cancer.

描述（由申请人提供）：我的长期目标是获得对复杂细胞间相互作用的细胞和分子理解，从而导致骨髓衍生的前体终末分化为成熟的效应T细胞。当前应用的重点是对胸腺中阳性选择的自我配体的表征。该应用是基于我们最近发现的一种新型策略，即预测和识别促进阳性选择的自我肽。该方法包括生成潜在的自肽的大数据库（由鼠标基因组项目成为可能），以及从这些小组候选肽的这些数据库中基于生物信息学的选择。测试选定的肽在胎儿胸腺器官培养物中的阳性选择，并通过质谱分析通过筛选自肽池来验证肽的MHC呈递。在特定目标1中，我们将扩展此策略，以识别四个T细胞受体转基因模型中的多个积极选择的肽。我们还将通过实验测试自肽与抗原的相似性是否是阳性选择的工作原理。通过三种独立手段确定的自我配体的相似性得分将被绘制在诱导正选择的能力上。互补方法将包括产生与抗原分级相似性的合成肽文库。这些文库诱导阳性选择的能力将得到确定。在特定目标2中，我们将确定T细胞受体信号传导的持续时间以及如何影响正选择。使用新型的体外实验递送正面选择信号，我们将观察到通过负或积极选择配体引起的MAP激酶激活的动力学。在一种互补方法中，我们将评估对限制信号持续时间的正选择和负选择的影响。在特定目标3中，我们将确定肽的氨基末端部分选择性参与阳性选择的结构基础。这些发现应极大地有助于我们对功能性TCR曲目的形成的了解。该信息对于疫苗开发，器官移植中的免疫调节疗法，自身免疫性疾病，淋巴增生性疾病和癌症将很有价值。