Structure-Function Relationships of Immunoreceptors

免疫受体的结构与功能关系

基本信息

批准号：
8017441
负责人：
Barbara A Baird
金额：
$ 38.66万
依托单位：
CORNELL UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
1981
资助国家：
美国
起止时间：
1981-08-01 至 2015-02-28
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8017441
关键词：
Actins Affect Affinity Allergic Allergic Disease Antigens B-Lymphocytes Basal Cell Binding Biochemical Biological Biological Assay Biological Models Cell Communication Cell membrane Cell physiology Cells Cellular biology Chemicals Cholesterol Clathrin Cytoskeleton Data Analyses Dimensions Disease Dynamin Electron Spin Resonance Spectroscopy Environment Eukaryotic Cell Event Family Fluorescence Fluorescence Microscopy Fluorescence Resonance Energy Transfer Goals Health IgE IgE Receptors Image Immune Immune response Individual Infection Integrins Intervention Investigation Label Length Life Lipids Malignant Neoplasms Measurable Measurement Measures Mediating Medical Membrane Membrane Lipids Membrane Microdomains Membrane Proteins Microscopy Modification Molecular Monitor Nerve Degeneration Optics Pattern Phagocytosis Phagosomes Phase Phospholipids Phosphotransferases Play Polymers Process Property Proteins Public Health Regulation Research Resolution Role Scanning Electron Microscopy Scheme Signal Transduction Spectrum Analysis Spin Labels Stimulus Structure Structure-Activity Relationship Surface T-Cell Receptor Techniques Testing Therapeutic Time Work antigen binding base cholesterol analog computerized data processing crosslink insight knock-down mast cell membrane assembly nanometer nanopattern nanoscale novel strategies particle photo switch physical property public health relevance receptor receptor-mediated signaling research study response segregation two-dimensional

项目摘要

DESCRIPTION (provided by applicant): This research is aimed at elucidating the collective molecular events of cellular signaling that are initiated by plasma membrane immunoreceptors and are highly orchestrated in space and time. Focus is primarily on the high affinity receptor for IgE, Fc5RI, on mast cells, which plays a central role in the allergic immune response and serves as a valuable model system for these studies. The goal of these studies is to understand structural interactions of proteins and lipids occurring within the plasma membrane environment that are altered by antigen crosslinking of IgE-Fc5RI and result in transmembrane triggering of the intracellular signaling cascade. The central hypothesis is that interactions between crosslinked IgE-Fc5RI, Lyn kinase, and other early signaling components are coordinated within the heterogeneous structure of the membrane including its interactions with the cytoskeleton. Proposed studies will investigate the roles of dynamic membrane structure and interactions in Fc5RI signaling, and, in particular, the participation of ordered membrane domains (commonly called "rafts"). Specific Aim 1 will continue to develop chemically modified substrates for patterning antigen on micro- and nanometer lengths scales, including use of thermosensitive polymers for rapidly triggered exposure of antigen. Spatially controlled, micron scale assemblies of co- clustered IgE-Fc5RI and cytoskeleton will be investigated as structures involved in initiation of internalization and phagocytosis. Specific Aim 2 will examine spatial regulation and dynamics of IgE-Fc5RI-mediated signaling assemblies on the nanoscale with scanning electron microscopy and super high-resolution fluorescence microscopy, and apertures for near-field optical microscopy will be nanofabricated as a novel approach for measuring motional and interactional dynamics of individual membrane components. Together with data analysis, a theoretical framework will be developed to describe how clustered receptors synchronize their activation state via the membrane. Specific Aim 3 will focus on participation of lipids in the membrane structural assemblies that spatially regulate IgE-Fc5RI mediated signaling using high resolution microscopies and electron spin resonance measurements of phase-like properties. Changes in proximity between Fc5RI and order- vs disorder- preferring lipids will be measured with fluorescence resonance energy transfer. Cholesterol distribution across the outer and inner leaflets of the plasma membrane will be assessed, and how perturbations of this distribution affect cell signaling events will be evaluated. These investigations integrate diverse physical, chemical and cell biological approaches to provide new insights into plasma membrane structure and dynamics and their roles in immunoreceptor signaling. PUBLIC HEALTH RELEVANCE: The heterogeneous plasma membrane millieu of eukaryotic cells maintains a steady state of protein and lipid interactions that support basal cell function and, while serving as a selective barrier, is poised to respond to environmental stimuli. Hijacking or disrupting these highly orchestrated membrane interactions is involved in numerous disease states, including pathogenic infection, neurodegeneration, and some cancers. In recent years the intricate participation of the plasma membrane in spatially regulating receptor-mediated signaling events has become increasingly appreciated. A prominent example is the receptor for IgE, Fc5RI, on mast cells, which plays a central role in the allergic immune response. The immediate goal of our studies is molecular level elucidation of the structural interactions occurring within dynamic plasma membrane domains that are altered by antigen crosslinking of IgE-Fc5RI and result in transmembrane triggering of the intracellular signaling cascade and immune cell responses. More generally, a detailed characterization of plasma membrane participation in cellular responses will provide new opportunities for intervention in therapeutic applications and a clearer understanding of the cell biology of health and disease.

描述（由申请人提供）：这项研究旨在阐明质膜免疫受体启动的细胞信号的集体分子事件，并在时空上进行了高度精心策划。重点主要放在肥大细胞上IgE，FC5RI的高亲和力受体上，该受体在过敏反应中起着核心作用，并作为这些研究的有价值的模型系统。这些研究的目的是了解在质膜环境中发生的蛋白质和脂质的结构相互作用，这些蛋白质和脂质通过IGE-FC5RI的抗原交联改变，并导致细胞内信号级联反应的跨膜触发。中心假设是，在膜的异质结构内协调了交联的IgE-FC5RI，LYN激酶和其他早期信号成分之间的相互作用，包括其与细胞骨架的相互作用。拟议的研究将研究动态膜结构和相互作用在FC5RI信号传导中的作用，尤其是有序的膜结构域的参与（通常称为“筏”）。具体的目标1将继续开发化学修饰的底物，以在微观和纳米长度尺度上构图抗原，包括使用热敏聚合物来快速触发抗原。在空间控制的IGE-FC5RI和细胞骨架的空间控制的微米尺度组件将被研究为涉及内在化和吞噬作用的结构。具体目标2将检查纳米级上IGE-FC5RI介导的信号组件的空间调节和动力学，并使用扫描电子显微镜和超高分辨率荧光显微镜进行扫描，而近场光学显微镜的孔径将作为测量动作和相互作用的单个含膜组合的新型方法。与数据分析一起，将开发一个理论框架，以描述聚类受体如何通过膜同步其激活状态。特定的目标3将集中于脂质参与膜结构组件中，该膜结构组件使用高分辨率显微镜和电子旋转谐振测量值测量了膜状介导的信号传导。 FC5RI和秩序与疾病之间的接近度变化将通过荧光共振能量转移来测量。将评估质膜外部和内部小叶的胆固醇分布，并评估该分布的扰动如何影响细胞信号传导事件。这些研究整合了多种物理，化学和细胞生物学方法，以提供有关质膜结构和动力学及其在免疫受体信号传导中的作用的新见解。公共卫生相关性：真核细胞的异质质膜millieu保持稳定的蛋白质和脂质相互作用，这些蛋白质和脂质相互作用支持基础细胞功能，并且在作为选择性障碍的同时，仍准备对环境刺激做出反应。劫持或破坏这些高度精心策划的膜相互作用与许多疾病状态有关，包括致病性感染，神经变性和某些癌症。近年来，质膜在空间调节受体介导的信号传导事件中的复杂参与变得越来越多。一个突出的例子是肥大细胞上IgE，FC5RI的受体，它在过敏反应中起着核心作用。我们研究的直接目的是阐明在动态质膜结构域中发生的结构相互作用，这些结构通过IGE-FC5RI的抗原交联改变，并导致跨膜触发细胞内信号级联反应和免疫细胞反应。更一般而言，质膜参与细胞反应的详细表征将为干预治疗应用提供新的机会，并对健康和疾病的细胞生物学有更清晰的了解。