Spatial coordination of CD28 and TCR signaling

描述（由申请人提供）：T细胞共刺激在协调适应性免疫系统的长期和短期反应中起着至关重要的作用。这一过程的一个新观点是，免疫突触内共刺激信号复合物的空间组织对随后的细胞激活有重要影响。为了直接测试这一概念，我们引入了一个基于平面底物的系统，该系统将多个配体呈现给T细胞TCR、CD28和LFA-1受体，从而指导这种人工免疫突触模型的组织。有了这个平台，我们之前证明了CD4+ T细胞对这些信号组织的微观变化很敏感，通过分泌IL-2来测量，小鼠和人类细胞对这些模式表现出非常不同的反应。该研究旨在利用该平台确定协调TCR和CD28信号的特定分子过程，特别是关于这些复合物的空间组织如何影响这种串扰。我们还介绍了使用多组分支持的脂质双分子层系统来探索这些界面的纳米级组织。我们特别关注PKC8和Lck作为这些通路交界处的两个公认分子，并试图定义细胞内这些蛋白质的生物物理行为如何影响整体网络功能。我们使用小鼠和人类细胞模型作为整体反应的两个极端例子，以努力确定这些分子的分布、流动性和定向运动如何响应TCR和CD28信号的不同组织，影响传统的细胞信号传导概念，如磷酸化。这些研究的成功完成将直接为PKC8和Lck如何协调T细胞共刺激提供新的见解。我们介绍的方法是广泛适用的，并将直接影响广泛的细胞系统信号的研究。

DESCRIPTION (provided by applicant): T cell costimulation plays a vital role in coordinating both long- and short-term responsiveness of the adaptive immune system. An emerging picture of this process is that the spatial organization of costimulatory signaling complexes within the immune synapse has a major influence on subsequent cell activation. To directly test this concept, we introduced a system based on a planar substrate that presents multiple ligands to the T cell TCR, CD28, and LFA-1 receptors, thereby directing the organization of this artificial model of the immune synapse. With this platform we previously demonstrated that CD4+ T cells are sensitive to microscale changes in the organization of these signals, as measured by secretion of IL-2, and that mouse and human cells exhibit very different responses to these patterns. The proposed study seeks to use this platform to identify specific molecular processes that coordinate TCR and CD28 signaling, particularly with regards to how the spatial organization of these complexes influences this crosstalk. We also introduce the use of multicomponent supported lipid bilayer systems to explore the nanoscale organization of these interfaces. We focus specifically on PKC8 and Lck as two recognized molecules at the junction of these pathways, and seek to define how the biophysical behaviors of these proteins within the cell influence overall network function. We use the mouse and human cell models as two extreme examples of the overall response, in an effort to identify how the distribution, mobility, and directed motion of these molecules, in response to different organizations of TCR and CD28 signaling, influence traditional cell signaling concepts, such as phosphorylation. Successful completion of these studies will directly provide new insight into how PKC8 and Lck coordinate T cell costimulation. The methods we introduce are widely applicable, and will directly impact the study of signaling in a wide range of cellular systems. PUBLIC HEALTH RELEVANCE: T cell costimulation is a central process of the adaptive immune system coordinating both long- and short- term responsiveness, and understanding of the underlying processes has wide impact in the design of immune-based therapies. This project applies microscale surface engineering approaches to improve understanding of the interaction between signaling pathways associated with T cell costimulation, developing the foundation for models that take into account the spatial organization of cell-cell interfaces. These studies provide new tools dissecting such pathways, and may lead to improved system for directing the activation of T cells for therapeutic applications.