Visualizing Endogenous CD8 T Cell Migration to Infection

描述（由申请人提供）：该申请为Leo Lefrancois博士实验室的Damon Runyon博士后Kamal M. Khanna博士提出了职业发展计划。这一建议集中在了解内源性CD8 T细胞感染后介导迁移和运输模式的机制。在三个具体目标中，目标1将在指导阶段完整地完成。此外，一些支持目标2和3的初步实验也将在K99阶段进行，但是目标2和3将在合同的独立阶段大部分完成。项目总结：虽然以前的研究已经检查了脾淋巴结构，但驱动原发性和继发性CD8 T细胞对感染反应的解剖事件尚未明确描述。我们的工作已经开始有条不紊地检查大面积脾组织，而不干扰器官内细胞室的个体结构和定位，为免疫反应的分析增加了一个新的维度。这种类型的成像分析使我们能够获得有关抗菌内源性CD8 T细胞群的运动、位置和保留的相关和重要的生理数据。我们的数据揭示了局部细胞迁移的逐步进展，导致CD8 T细胞扩增，离开脾脏，并在离散的脾室中定位产生记忆性CD8 T细胞。成像显示先前未被发现的子代CD8 T细胞与大量携带抗原的树突状细胞的二次相遇。记忆性CD8 T细胞不经历二次激活事件和大簇形成，而是在再激活后通过桥接通道迅速从B细胞滤泡转移到红髓。因此，这些研究为确定控制驱动反应的每个解剖阶段的过程的因素奠定了基础。因此，本建议的总体目标是确定这些因素，并试图确定它们在控制原发性和继发性免疫反应的解剖结构中所起的作用。在此过程中，我们希望阐明在淋巴和非淋巴组织感染和回忆反应期间指导T细胞复杂运动的潜在机制。拟议的研究将帮助我们了解有效的免疫反应是如何在体内发生的，这些信息将为改进疫苗设计提供线索。

DESCRIPTION (provided by applicant): The application proposes a career development plan for Dr. Kamal M. Khanna, a Damon Runyon post-doctoral Fellow in the laboratory of Dr. Leo Lefrancois. This proposal is centered upon understanding the mechanisms that mediate the migration and trafficking patterns of endogenous CD8 T cells after infection. Of the three specific aims, aim 1 will be completed in its entirety during the mentored phase. In addition, some preliminary experiments supporting aim 2 and 3 will also be conducted during the K99 phase, however both aim 2 and 3 will be largely completed during the independent phase of the award. Project summary: Although previous studies have examined splenic lymphoid architecture, the anatomical events driving primary and secondary CD8 T cell responses to infection have not been clearly delineated. Our work has begun to methodically examine large areas of splenic tissue without disturbing the individual structures and localization of cellular compartments within the organ, adding a new dimension to the analysis of immune responses. This type of imaging analysis allowed us to derive relevant and significant physiologic data concerning the movements, location and retention of an antibacterial endogenous CD8 T cell population. Our data reveal a step-wise progression of local cellular migration leading to CD8 T cell expansion, exit from the spleen and localization of resulting memory CD8 T cells in discrete splenic compartments. Imaging revealed previously unappreciated secondary encounters of daughter CD8 T cells with antigen-bearing dendritic cells in large clusters. Memory CD8 T cells did not undergo secondary activation events and large cluster formation but upon reactivation rapidly moved from the B cell follicles to the red pulp via bridging channels. Thus, these studies have set the stage for identification of the factors that control the processes driving each anatomical phase of the response. Therefore the overall goal of this proposal is to identify these factors and attempt to determine the roles they play in controlling the anatomy of a primary and secondary immune response. In doing so, we hope to explicate the underlying mechanisms that guide the complex movement of T cells during infection and recall responses in lymphoid and non-lymphoid tissues. The proposed studies will help us understand how a productive immune response takes place in vivo, and this information will provide clues to improving vaccine design. RELEVANCE: Discovering the mechanisms that mediate the local and systemic migration of endogenous T cells after infection will help us understand how a productive immune response takes place in vivo, and this information will provide clues to improving vaccine design.