Functional roles of lipid domains in B cell signaling

项目摘要 B细胞感知并操纵许多细胞表面受体的横向组织，以促进 它们在免疫系统中的功能作用。作为信号起始的物理模式的受体聚集是 普遍存在于B细胞中，但感知和控制群集的相应一般机制 细胞内成分是未知的。簇集介导的B细胞信号转导机制的研究进展 事件是必不可少的，因为它们在免疫功能中起着重要作用，缺陷导致疾病， 癌症和免疫缺陷，以及广泛使用的免疫药物利用这些机制。目标 这项工作的重点是开发一个框架，描述受体组织如何与受体功能联系在一起， 与有序膜结构域分隔的B细胞表面受体类别。工作假设是 有序结构域的稳定性为不同B的启动和调节提供了一个基本的范例 细胞信号反应。这项研究是由B细胞受体（BCR）的预测模型指导的 信号开发在以前的资金周期和实验测试预测这个模型扩展 beyond超越BCR signaling信号alone单独.在广泛的初步数据的指导下，将追求三个具体目标： 建立通过聚集B细胞表面蛋白激活的信号传导的通用机制，2）调节B 通过支架元件的光遗传学控制的细胞膜组织和信号传导，以及3）鉴定 膜结构域在BCR信号传导中促进免疫调节作用。第一个目标是建立一个将军 一种传感机制，描述了通过超过15种不同B细胞表面蛋白的聚集而引发的信号 在文献中报道的有序域分区。第二个目标将定义脚手架如何 元件模板功能膜组织跨越质膜小叶和贡献 这种效应与配体非依赖性信号传导有关。第三个目标是识别和隔离类似阶段的角色。 膜结构域在下游细胞决策中起作用，通过调节由膜结构域引发的信号， BCR。所有目标都使用定量超分辨率荧光定位显微镜技术， 检测化学固定和活细胞中微妙结构域介导的相互作用的灵敏度。拟议的工作是 创新，因为它应用了膜组织的预测模型，并利用了 超分辨率成像、生物传感器技术和光遗传学。一个广泛适用的机械模型， B细胞信号转导将推动基础B细胞生物学的未来发展，阐明其潜在的机制， 目前广泛使用的几种B细胞靶向药物的疗效，为免疫性 疾病

PROJECT SUMMARY B cells sense and manipulate the lateral organization of numerous cell surface receptors in order to facilitate their functional roles within the immune system. Receptor clustering as a physical mode of signal initiation is ubiquitous in B cells, yet the corresponding general mechanisms by which clustering is sensed and controlled by intracellular components are unknown. A mechanistic understanding of clustering-mediated B cell signaling events is essential because they play important roles in immune function, defects lead to diseases such as cancer and immunodeficiency, and widely used immunotherapeutic drugs exploit these mechanisms. The goal of this work is to develop a framework that describes how receptor organization is tied to receptor functions for the class of B cell surface receptors that partition with ordered membrane domains. The working hypothesis is that ordered domain stabilization provides a fundamental paradigm for the initiation and regulation of diverse B cell signaling responses. The proposed research is guided by a predictive model of B cell receptor (BCR) signaling developed in the previous funding cycle and experimentally tests predictions of this model extended beyond BCR signaling alone. Guided by extensive preliminary data, three specific aims will be pursued: 1) Establish a generalized mechanism of signaling activated by clustering B cell surface proteins, 2) Modulate B cell membrane organization and signaling through optogenetic control of scaffolding elements, and 3) Identify immunomodulatory roles facilitated by membrane domains in BCR signaling. The first aim will establish a general sensing mechanism that describes signals initiated via clustering of more than 15 distinct B cell surface proteins that are reported in the literature to partition with ordered domains. The second aim will define how scaffolding elements template functional membrane organization that spans plasma membrane leaflets and the contribution of this effect to ligand-independent signaling. The third aim will identify and isolate the roles that phase-like membrane domains play in downstream cellular decision-making by modulating signals initiated through the BCR. All aims use quantitative super-resolution fluorescence localization microscopy techniques with the sensitivity to detect subtle domain-mediated interactions in chemically fixed and live cells. The proposed work is innovative because it applies predictive models of membrane organization and exploits recent advances in super-resolution imaging, biosensor technology, and optogenetics. A broadly applicable mechanistic model for B cell signaling will drive future advances in basic B cell biology, elucidate the mechanisms underlying the efficacy of several widely used B cell-targeted drugs, and provide new approaches for the treatment of immune diseases.