Molecular Principles of TCR Recognition and Activation by peptide-MHC

肽-MHC识别和激活TCR的分子原理

• 批准号: 7321647
• 负责人: Kenan Christopher GARCIA
• 金额: $ 27.65万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-12-15 至 2010-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7321647
• 关键词: Affinity; Allogenic; Architecture; Award; Binding; CD3 Antigens; Cell surface; Cells; Chemicals; Class; Code; Complex; Crystallization; Crystallography; Detergents; Docking; Electron Microscopy; Engineering; Epitopes; Foundations; Haplotypes; Helix (Snails); Image; Immunoglobulin Variable Region; Insecta; Length; Ligands; Maps; Membrane; Methods; Micelles; Molecular; NMR Spectroscopy; Peptide Library; Peptide Phage Display Library; Peptide/MHC Complex; Peptides; Play; Pliability; Population; Receptor-CD3 Complex, Antigen, T-Cell; Recombinants; Research Personnel; Resolution; Role; Series; Signal Transduction; Solutions; Structure; Surface; T-Lymphocyte; TCR Activation; Techniques; Variant; base; cross reactivity; ear helix; programs; reconstitution; structural biology

Structural biology has elucidated several general principles for how the ap TCR interacts with peptide- MHC ligands, but several fundamental questions, pertaining to both the recognition and activation of the TCR, remain unanswered. First, we do not yet understand the structural basis of TCR bias for MHC. Is there a recognition code underlying the loosely convergent TCR/pMHC diagonal docking orientations, or "footprints" so far seen in the different complexes ? A recent TCR/pMHC complex structure we determined suggests there may be limited sets of docking motifs that could be elucidated through structural studies of a series of related complexes. These docking topologies are likely the result of a complex interplay between junctionally-encoded TCR CDR3 interactions with peptide, and the germline- encoded Variable region interactions with the MHC helices. Therefore, we are engineering molecules for structural studies that will isolate the contributions of each of these components. Second, what is the scope of TCR cross-reactivity, and to what extent does TCR CDR conformational flexibility play a role in expanding the T cell repertoire ? Our previous studies suggest that T cell recognition is not broadly promiscuous, and yet there is a prevailing notion that CDR3 induced fit is a mechanism to expand the repertoire of pMHC recognized by the TCR. In order to better understand the role of conformational dynamics in TCR/pMHC interactions, we are determining TCR and pMHC structures, and solution interactions, using Nuclear Magnetic Resonance spectroscopy (NMR). Finally, we currently do not know how TCR and CDS interact in the TCR-CD3 complex. How is recognition of pMHC by the TCR structurally communicated to the associated CD3 subunits for subsequent signaling ? We propose to reconstitute and purify a recombinant form of a full-length, membrane-bound TCR-CD3 complex for biophysical imaging studies. In summary, during the previous term of this award we developed robust methods for expression of TCR, and peptide-MHC that now enable us to carry out a multi-disciplinary analysis of a focused set of TCR/pMHC interactions using x-ray crystallography, NMR, peptide libraries, phage display, and electron microscopy (EM).

结构生物学已经阐明了ap TCR如何与肽相互作用的几个一般原则， MHC配体，但几个基本问题，有关的识别和激活的MHC配体， 战术指挥中心，无人应答。首先，我们还不了解TCR偏向MHC的结构基础。是 在TCR/pMHC对角对接的基础上， 方向，或“足迹”，迄今为止看到的不同的复杂？一种新的TCR/pMHC复合物 我们确定的结构表明，可能有有限的对接基序集，可以阐明 通过对一系列相关配合物的结构研究。这些对接拓扑结构可能是 接头编码的TCR CDR 3与肽的相互作用之间的复杂相互作用，以及种系- 编码的可变区与MHC螺旋的相互作用。因此，我们正在设计分子， 结构研究，将分离出这些组成部分的贡献。第二，范围是什么 TCR交叉反应性，以及TCR CDR构象灵活性在多大程度上发挥作用， 扩展T细胞库我们以前的研究表明，T细胞识别并不广泛， 然而，普遍的观点是，CDR 3诱导的适应是一种扩大免疫应答的机制。 由TCR识别的pMHC库。为了更好地理解构象的作用， 在TCR/pMHC相互作用的动力学中，我们正在确定TCR和pMHC的结构， 相互作用，使用核磁共振光谱（NMR）。最后，我们目前还不知道 TCR和CDS如何在TCR-CD 3复合物中相互作用。TCR如何识别pMHC 在结构上与相关的CD 3亚基进行沟通，以进行后续的信号传导？我们建议 重组并纯化重组形式的全长膜结合TCR-CD 3复合物， 生物物理成像研究。总之，在本奖项的上一个任期内，我们开发了强大的 表达TCR和肽-MHC的方法，现在使我们能够进行多学科的研究， 使用X射线晶体学、NMR、肽文库， 噬菌体展示和电子显微镜（EM）。