STUCTURE-FUNCTION RELATIONSHIPS OF IMMUNORECEPTORS

免疫受体的结构与功能关系

• 批准号: 6362277
• 负责人: Barbara A Baird
• 金额: $ 27.18万
• 依托单位: CORNELL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1981
• 资助国家: 美国
• 起止时间: 1981-08-01 至 2005-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6362277
• 关键词: actins; antibody receptor; antireceptor antibody; biological signal transduction; electron spin resonance spectroscopy; fluorescence microscopy; immunoglobulin E; mass spectrometry; membrane activity; protein structure function; protein tyrosine kinase; site directed mutagenesis; tissue /cell culture

The multi-chain immune recognition receptors (MIRR) which mediate cell activation in the immune response include T cell receptors for antigen, B cell receptors, and Fc receptors. The structural basis for MIRR function at the plasma membrane will be investigated, using as a paradigm the high affinity Fc receptor (FcepsilonRI) for immunoglobulin E (IgE) which plays a central role in the allergic immune response. Proposed studies will focus on plasma membrane heterogeneity, dynamics and structure as these are involved in IgE-FcepsilonRI signaling, and in particular on the role liquid-ordered, detergent-resistant regions play in the initial coupling between FcepsilonRI and Lyn tyrosine kinase. Specific aim 1 will examine features of FcepsilonRI structure that are critical for its interaction with detergent resistant membranes, using several different chimeric receptors, together with site-specific mutagenesis and cholesterol photoaffinity labeling studies. Specific aim 2 will apply advanced biophysical methods including quantitative fluorescence microscopy, electron spin resonance and mass spectrometry to characterize these cholesterol-dependent, detergent-resistant regions in plasma membranes of whole cells and sub-cellular preparations; structural changes that occur as a result of cell activation will be investigated. For example, real time interactions between Lyn anchored to the inner leaflet of the plasma membrane and antigen-aggregated FcepsilonRI will be monitored on intact cells using green fluorescent protein-conjugated analogues to detect proximity changes with fluorescence resonance energy transfer and mobility changes with fluorescence correlation spectroscopy and imaging. The structural basis for the interaction of F- actin with the plasma membrane and its regulation of FcepsilonRI signaling will also be investigated. These studies will test te general hypothesis that structural organization at the plasma membrane is important for receptor-mediated signaling in the immune response.

介导免疫反应中细胞活化的多链免疫识别受体（MIRR）包括抗原，B细胞受体和FC受体的T细胞受体。将研究质膜上MIRR功能的结构基础，以作为免疫球蛋白E（IgE）的高亲和力FC受体（FCEPSILONRI）的范式，该范例在过敏免疫反应中起着核心作用。拟议的研究将重点关注质膜异质性，动力学和结构，因为它们与Ige-Fcepsilonri信号传导有关，尤其是在Fcepsilonri和Lyn酪氨酸酪氨酸激酶之间的初始耦合中，尤其是液体订购的，耐药的区域的作用。具体的目标1将检查Fcepsilonri结构的特征，这些特征对于使用几种不同的嵌合受体以及位点特异性诱变和胆固醇光相关标记研究至关重要。特定的目标2将采用先进的生物物理方法，包括定量荧光显微镜，电子自旋共振和质谱法来表征这些胆固醇依赖性的，耐洗涤剂的区域在整个细胞和亚细胞制剂的质膜中。细胞激活导致的结构变化将被研究。例如，将使用绿色荧光蛋白偶联的类似物在完整的细胞上监测固定在质膜内部传单与抗原聚集的Fcepsilonri之间的LYN之间的实时相互作用，以检测与荧光共振能量转移和移动性随荧光相关型光谱型和成像的变化的接近变化。还将研究F-肌动蛋白与质膜相互作用的结构基础及其调节Fcepsilonri信号传导。这些研究将测试一般假设，即质膜上的结构组织对于免疫反应中受体介导的信号传导很重要。