Structure-Function Relationships of Immunoreceptors

免疫受体的结构与功能关系

• 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
• 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

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）：本研究旨在阐明细胞信号传导的集体分子事件，这些事件由质膜免疫受体启动，并在空间和时间上高度协调。主要关注肥大细胞上IgE的高亲和力受体Fc 5 RI，其在过敏性免疫应答中起核心作用，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质膜环境中发生的蛋白质和脂质的结构相互作用，这些相互作用通过IgE-Fc 5 RI的抗原交联而改变，并导致细胞内信号级联的跨膜触发。中心假设是交联的IgE-Fc 5 RI、林恩激酶和其他早期信号组分之间的相互作用在膜的异质结构内协调，包括其与细胞骨架的相互作用。拟议的研究将调查动态膜结构和相互作用在Fc 5 RI信号转导中的作用，特别是有序膜结构域（通常称为“筏”）的参与。具体目标1将继续开发化学改性基质，用于在微米和纳米长度尺度上对抗原进行图案化，包括使用热敏聚合物快速触发抗原暴露。共簇IgE-Fc 5 RI和细胞骨架的空间控制的微米级组装体将作为参与内化和吞噬作用起始的结构进行研究。具体目标2将检查空间调节和动态的IgE-Fc 5 RI介导的信号组件在纳米尺度上与扫描电子显微镜和超高分辨率荧光显微镜，和孔径近场光学显微镜将nanofabricated作为一种新的方法来测量运动和interactiondynamics的个别膜组件。与数据分析一起，将开发一个理论框架来描述集群受体如何通过膜同步其激活状态。具体目标3将侧重于脂质在膜结构组件中的参与，这些组件使用高分辨率显微镜和电子自旋共振测量类相位特性在空间上调节IgE-Fc 5 RI介导的信号传导。将用荧光共振能量转移测量Fc 5 RI和有序与无序偏好脂质之间的接近度的变化。将评估跨质膜外叶和内叶的胆固醇分布，并将评价该分布的扰动如何影响细胞信号传导事件。这些研究整合了不同的物理，化学和细胞生物学方法，为质膜结构和动力学及其在免疫受体信号传导中的作用提供了新的见解。 公共卫生关系：真核细胞的异质质膜微区维持蛋白质和脂质相互作用的稳定状态，支持基础细胞功能，同时作为选择性屏障，准备对环境刺激作出反应。劫持或破坏这些高度协调的膜相互作用涉及许多疾病状态，包括病原性感染，神经变性和一些癌症。近年来，质膜在空间调节受体介导的信号转导事件中的复杂参与越来越受到重视。一个突出的例子是肥大细胞上的IgE受体Fc 5 RI，它在过敏性免疫反应中发挥着核心作用。我们研究的直接目标是分子水平阐明动态质膜结构域内发生的结构相互作用，这些结构相互作用通过IgE-Fc 5 RI的抗原交联而改变，并导致细胞内信号级联和免疫细胞应答的跨膜触发。更一般地说，质膜参与细胞反应的详细表征将为治疗应用中的干预提供新的机会，并更清楚地了解健康和疾病的细胞生物学。