Role of focal CXCL10 in shaping Th1 micro-positioning and function in inflamed skin

项目总结/摘要 感染组织内的炎症信号对于正确的效应细胞定位和功能是必要的。空间 淋巴结（LN）内T细胞的区室化最近已显示促进T细胞增殖。 分化具体地，LN内的Th1细胞分化显示依赖于CXCL 10（配体 对于CXCR3，在Th1细胞上高度表达），因为它作为淋巴结内定位的指导线索， T细胞引发期间的T细胞：树突状细胞相互作用。然而，决定效应T细胞空间分布的局部线索， 一旦T细胞离开LN并进入感染的组织部位，其位置和功能尚不清楚。 使用CXCL10（REX3）和活体多光子显微镜的报告小鼠，我们可以，第一次， 原位确定炎症部位CXCL 10表达细胞的分布。我们发现了一个惊人的 CXCL10生产者的密集簇与Th1细胞的积累之间的相关性。此外，Th1 细胞在密集的CXCL10-簇内减速。我们假设，空间限制的表达， CXCL10对于Th1细胞在发炎/感染环境中的适当定位和功能至关重要。 在许多慢性感染中，由于病原体诱导的宿主修饰，保护性免疫受到限制 微观环境。事实上，T细胞已经被证明对大型利什曼原虫密集区域的访问有限 （L. major）和弓形虫感染的组织中的细胞。我们的研究小组先前表明，L. major 可以主动下调感染的巨噬细胞中的CXCL 10，巨噬细胞是真皮中主要的感染细胞。我们 假设通过限制CXCL10在感染细胞中的表达，硕大乳杆菌干扰了正确的定位 和有效清除病原体所需的Th1细胞的功能。 总体目标是确定影响Th1定位和/或功能的基本机制， 在发炎的环境中富含CXCL10的微观解剖区域，并确定CXCL10的作用 Th1细胞定位和清除病原体的能力。 目标1.确定CXCL10在炎症组织内塑造T细胞运动性和功能中的作用 目标2.增强CXCL10的可用性是否会影响T细胞定位并提高对L. major的免疫力？ 了解Th1在感染组织中的定位、运动和功能的基本线索， 对于开发适当增强对疫苗的适应性免疫应答的佐剂至关重要 抗原，并开发优化慢性炎症反应的治疗方法。

PROJECT SUMMARY/ABSTRACT Inflammatory cues within infected tissues are necessary for proper effector cell location and function. Spatial compartmentalization of T cells within lymph nodes (LNs) has recently been shown to promote T cell differentiation. Specifically, Th1 cell differentiation within LNs was shown to be dependent on CXCL10 (ligand for CXCR3, highly expressed on Th1 cells), as it served as a guiding cue for intra-nodal positioning and facilitated T cell:dendritic cell interactions during T cell priming. However, local cues that dictate effector T cell spatial location and function once T cells leave the LN and enter the tissue site of infection, are poorly understood. Using a reporter mouse for CXCL10 (REX3) and intra-vital multiphoton microscopy, we could, for the first time, determine the distribution of CXCL10 expressing cells at the site of inflammation in situ. We found a striking correlation between dense clusters of CXCL10 producers and the accumulation of Th1 cells. In addition, Th1 cells decelerated within the dense CXCL10-clusters. We hypothesize that the spatially restricted expression of CXCL10 is critical for the proper localization and function of Th1 cells within the inflamed/infected milieu. In many chronic infections, protective immunity is limited due to pathogen-induced modifications to the host micro-environment. Indeed, T cells have been shown to have limited access to dense areas of Leishmania major (L.major) and Toxoplasma Gondii infected cells in infected tissues. Our group previously showed that L.major can actively down regulate CXCL10 in infected macrophages, the predominant infected cell in the dermis. We hypothesize that by limiting CXCL10 expression in infected cells, L.major interferes with the proper localization and function of Th1 cells that are required for efficient pathogen clearance. The overall goal is to define basic mechanisms that influence Th1 positioning and/or function within specific micro-anatomical regions rich in CXCL10 in the inflamed milieu, and to determine the effect of CXCL10 availability on the ability of Th1 cells to locate and clear a pathogen. Aim 1. Determine the role of CXCL10 in shaping T cell motility and function within the inflamed tissue Aim 2. Can enhancing CXCL10 availability impact T cell positioning and boost immunity against L.major? Understanding the fundamental cues for Th1 localization, motility and function within infected tissues may be critical for the development of adjuvants that suitably enhance the adaptive immune response to vaccine antigens and to develop therapeutic approaches that optimize responses to chronic inflammation.