Regulation of T cell exit from non-lymphoid tissues

项目摘要 炎症部位的T细胞在免疫反应中起着关键作用。在效应器阶段 据报道，作为一种免疫反应，T细胞的存在可以限制组织炎症。相比之下，周期性T细胞存在 来自慢性炎症部位的可能会防止T细胞耗尽，并维持免疫反应。作为记忆 发展，T细胞从炎症部位退出限制了常驻记忆T细胞的形成。无论T 已经离开组织的细胞成为一种独特形式的循环记忆细胞尚不清楚。总体而言， 驻留在炎症部位的记忆T细胞的功能越来越为人所知 离开炎症部位的细胞的功能尚不清楚。 调节T细胞从炎症部位退出的一个线索是信号转导脂鞘氨醇1- 磷酸盐(S1P)。一般来说，与组织相比，淋巴中的S1P水平较高，S1P引导免疫细胞 从组织中进入淋巴管。这一范例已经很好地建立了T细胞从淋巴结外送到 传出淋巴管，一些研究表明，它支持T细胞从非淋巴组织输出到淋巴中。 然而，我们并不了解免疫反应过程中非淋巴组织中S1P梯度是如何形成的， 或者S1P如何与其他可能引导T细胞从非淋巴组织中退出的信号相互作用。 回答这些问题的一个关键障碍是我们无法用空间来操纵基因表达 专一性。因此，我们不能在炎症部位永久标记T细胞，并在记忆中跟随它们 回应。同样，我们不能干扰仅在炎症部位调控趋化信号的基因， 避免对胸腺和淋巴结内T细胞发育和分化的混杂影响。 条件性基因打靶允许操纵特定细胞类型的基因表达，在某些模型中， 诱人的举止。然而，所有的小鼠靶向方法目前仅限于改变基因表达。 整个谱系，并且不可能在 动物。为了解决这个问题，我们培育了一只表达光诱导Cre重组酶(LI-Cre)的小鼠。 Cre)，它允许我们以特定位置和特定时间的方式改变感兴趣细胞中的基因表达 使用蓝光。 在这笔赠款中，我们将利用这一新颖的鼠标模型来回答关于 炎症皮肤中T细胞分泌的调节和功能。我们将讨论S1P受体1如何与 在两个明确定义的疾病模型中，其他候选退出受体询问皮肤中S1P梯度如何变化 在疾病过程中，并跟踪T细胞在记忆阶段和 召回回复。

Project Abstract T cell exit from a site of inflammation plays key roles in the immune response. At the effector phase of an immune response, T cell exit has been reported to limit tissue inflammation. By contrast, periodic T cell exit from a site of chronic inflammation might prevent T cell exhaustion and sustain the immune response. As memory develops, T cell exit from a site of inflammation limits the formation of resident memory T cells. Whether the T cells that have exited the tissue become a unique form of circulating memory cells is unknown. Overall, while the function of resident memory T cells remaining at a site of inflammation is increasingly well understood, the function of cells that have left a site of inflammation remains unclear. One cue that regulates T cell exit from a site of inflammation is the signaling lipid sphingosine 1- phosphate (S1P). Generally, S1P levels are high in lymph compared to tissues, and S1P guides immune cells out of tissues into lymphatics. This paradigm has been well-established for T cell exit from lymph nodes into efferent lymphatics, and some studies indicate that it holds for T cell exit from non-lymphoid tissues into lymph. Yet we do not understand how S1P gradients are shaped in non-lymphoid tissues during an immune response, or how S1P might interact with other cues that might guide T cell exit from non-lymphoid tissues. A key barrier to answering these questions is our inability to manipulate gene expression with spatial specificity. Thus, we cannot permanently mark T cells at a site of inflammation and follow them through a memory response. Similarly, we cannot disrupt genes that regulate chemotactic cues only at a site of inflammation, avoiding confounding effects on T cell development and differentiation in the thymus and lymph nodes. Conditional gene targeting allows manipulation of gene expression in a cell-type specific and, in some models, inducible manner. However, all murine targeting approaches are currently limited to altering gene expression in entire lineages, and it is not possible to institute permanent changes in cells within a specific location in the animal. To address this problem, we have generated a mouse expressing a light-inducible Cre recombinase (LI- Cre), which allows us to alter gene expression in cells of interest in a location-specific and time-specific manner using blue light. In this grant, we will take advantage of this novel mouse model to answer key questions about the regulation and function of T cell exit from inflamed skin. We will address how S1P receptor 1 cooperates with other candidate exit receptors in two well-defined models of disease, ask how S1P gradients change in the skin during the course of disease, and track the fate of T cells that have exited the skin in the memory phase and in recall responses.