Peptide Binding to Class I MHC

与 I 类 MHC 的肽结合

• 批准号: 7095910
• 负责人: EDWARD John COLLINS
• 金额: $ 31.67万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-08-01 至 2008-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7095910
• 关键词: MHC class I antigen; NOD mouse; T cell receptor; X ray crystallography; antibody specificity; antigen presenting cell; calcium flux; cell adhesion; cytokine; cytotoxic T lymphocyte; developmental immunology; immune tolerance /unresponsiveness; immunologic assay /test; insulin dependent diabetes mellitus; laboratory mouse; leukocyte activation /transformation; receptor binding; site directed mutagenesis; surface plasmon resonance; thermodynamics

DESCRIPTION (provided by applicant): Physical interactions define how a TCR recognizes an antigen, but not the mechanism. How that interaction results in specific T cell responses is unknown. The primary critical event that determines whether a cytolytic T cell (CTL) kills an antigen-presenting cell is the interaction between the T cell receptor (TCR) and the peptide/MHC complex (pMHC). We have observed that the xenoreactive pair of p1049/A2 and AHIII 12.2 TCR dock in an orthogonal rather than diagonal orientation seen in other TCK:pMHC pairs. We hypothesize that this unorthodox binding is a result of the absence of T cell selection on HLA-A2.1 by the AHIII12.2 T cell. A large panel of peptides that bind to the syngeneic MHC H-2Db and are recognized by AHIII12.2 has been examined. A second set of peptides, recognized by the P14 T cell, has also been tested. These two sets of peptides and two TCR will be used to probe the biochemical parameters that control T cell activity. There are significant disagreements as to whether affinity (KD) or microscopic rate constants (koff or kon) between pMHC and TCR are the key factors that control T cell activity. We hypothesize that the disagreements stem from the small number of observations made to date of pMHC binding constants to individual TCR. This application explores the physical interactions between pMHC and TCR using a well-defined T cell model systems and a large set of pMHC ligands. This approach is powerful because of the large sample size of pMHC to be assayed and because an interdisciplinary set of physical tools and immunological assays will be used. These tools include: protein crystallography, surface plasmon resonance (SPR) and site-directed mutagenesis. The biophysical measurements will be correlated with T cell responses such as: Ca flux, proliferation, cytokine secretion and cytolytic activity. A hypothesis for a quantitative model of T cell responses derived from the physical interactions of TCR and pMHC will be tested. In Aim 1, we ask whether non-diagonal orientations are common to T cells that have not gone through thymic selection on the restricting MHC. In aim 2, which binding properties between pMHC and TCR are found to be predictive of T cell responses is studied. In Aim 3, we extend our observations to autoimmune diabetes and determine if autoimmune dual-reactive TCR interact with pMHC in a diagonal fashion like that seen for A2 binding to AHIII12.2. These studies will prove to be useful in immunological therapy of autoimmunity, chronic viral infection, cancer and transplantation.

描述（由申请人提供）：物理相互作用定义了 TCR 如何识别抗原，但不定义机制。这种相互作用如何导致特定的 T 细胞反应尚不清楚。决定溶细胞 T 细胞 (CTL) 是否杀死抗原呈递细胞的主要关键事件是 T 细胞受体 (TCR) 与肽/MHC 复合物 (pMHC) 之间的相互作用。我们观察到 p1049/A2 和 AHIII 12.2 TCR 的异种反应对以正交方向而不是其他 TCK:pMHC 对中看到的对角线方向对接。我们假设这种非正统结合是 AHIII12.2 T 细胞对 HLA-A2.1 缺乏 T 细胞选择的结果。已经检查了一大组与同源 MHC H-2Db 结合并被 AHIII12.2 识别的肽。 P14 T 细胞识别的第二组肽也经过了测试。这两组肽和两个 TCR 将用于探测控制 T 细胞活性的生化参数。关于 pMHC 和 TCR 之间的亲和力 (KD) 或微观速率常数（koff 或 kon）是否是控制 T 细胞活性的关键因素，存在显着分歧。我们假设分歧源于迄今为止对 pMHC 与个体 TCR 结合常数的观察数量较少。该应用程序使用明确的 T 细胞模型系统和大量 pMHC 配体探索 pMHC 和 TCR 之间的物理相互作用。这种方法非常强大，因为要测定的 pMHC 样本量很大，并且将使用一套跨学科的物理工具和免疫学测定。这些工具包括：蛋白质晶体学、表面等离子共振 (SPR) 和定点诱变。生物物理测量将与 T 细胞反应相关，例如：Ca 通量、增殖、细胞因子分泌和细胞溶解活性。将测试源自 TCR 和 pMHC 物理相互作用的 T 细胞反应定量模型的假设。在目标 1 中，我们询问非对角方向对于未经过限制性 MHC 胸腺选择的 T 细胞是否常见。在目标 2 中，研究了 pMHC 和 TCR 之间的哪些结合特性可以预测 T 细胞反应。在目标 3 中，我们将观察范围扩展到自身免疫性糖尿病，并确定自身免疫性双反应性 TCR 是否以对角线方式与 pMHC 相互作用，就像 A2 与 AHIII12.2 结合所看到的那样。这些研究将被证明可用于自身免疫、慢性病毒感染、癌症和移植的免疫治疗。

项目成果

Rescue of cytotoxic function in the CD8alpha knockout mouse by removal of MHC class II.

通过去除 MHC II 类来挽救 CD8α 敲除小鼠的细胞毒功能。

• DOI: 10.1002/eji.200737710
• 发表时间: 2008
• 期刊: European journal of immunology
• 影响因子: 5.4
• 作者: Riddle,DavidS;Miller,PeterJ;Vincent,BenjaminG;Kepler,ThomasB;Maile,Rob;Frelinger,JeffreyA;Collins,EdwardJ
• 通讯作者: Collins,EdwardJ