Cellular and Genetic Analysis of Lymphocyte Egress

描述（由申请人提供）：T和B细胞从淋巴器官的输出是免疫监视和效应细胞功能所必需的。过去25年的研究工作为细胞如何从血液进入组织提供了详细的细胞和分子图谱。相比之下，关于细胞如何离开组织并返回循环的定义却很少。免疫抑制分子FTY720通过抑制淋巴器官的分泌而起作用，这一发现揭示了淋巴细胞分泌和淋巴细胞再循环的临床重要性。过去五年的研究已经确定了S1P受体-1 （S1P1）在淋巴器官淋巴细胞输出中的关键作用。S1P1也被发现是一个出口调控的控制点。淋巴细胞激活标记CD69作为S1P1和淋巴细胞输出的负调节因子。然而，淋巴细胞S1P1促进细胞输出的机制以及CD69介导的S1P1调控模式尚不清楚。本提案将通过三个具体目标来解决淋巴细胞出口的细胞和分子要求以及与出口调节相关的机制。第一个目标将结合细胞和多光子成像方法来表征淋巴细胞从淋巴结出口的s1p1依赖步骤。目的2将侧重于确定CD69介导的抑制S1P1功能和淋巴细胞分泌的机制。最后Aim将使用遗传方法来识别淋巴细胞出口所需的额外分子。这一目标将建立在与澳大利亚Christopher Goodnow的合作基础上，以识别和表征表现出淋巴细胞运输改变的突变小鼠系。作为这项工作的一部分，我们将精细绘制和表征导致白内障盐野鼠（CTS）胸腺出口缺陷的位点。通过这些研究获得的信息应该为免疫调节分子的开发指明新的靶点。

DESCRIPTION (provided by applicant): T and B cell egress from lymphoid organs is necessary for immune surveillance and effector cell function. Work over the last 25 years has provided a detailed cellular and molecular picture for how cells enter tissues from the blood. By contrast, very little has been defined about how cells exit tissues and return to circulation. The clinical importance of lymphocyte egress and lymphocyte recirculation has been revealed by the finding that the immunosuppressive molecule, FTY720, acts by inhibiting egress from lymphoid organs. Work over the last five years has established a critical role for S1P receptor-1 (S1P1) in lymphocyte egress from lymphoid organs. S1P1 has also been found to be a control point for egress regulation. The lymphocyte activation marker, CD69, acts as a negative regulator of S1P1 and lymphocyte egress. However, the mechanism by which lymphocyte S1P1 promotes egress, and the mode of CD69 mediated regulation of S1P1 remain undefined. This proposal will address the cellular and molecular requirements for lymphocyte egress and mechanisms associated with egress regulation through three specific aims. The first Aim will use a combination of cellular and multiphoton imaging approaches to characterize the S1P1-dependent step in lymphocyte egress from lymph nodes. Aim 2 will focus on determining the mechanism of CD69 mediated inhibition of S1P1 function and lymphocyte egress. The final Aim will use genetic approaches to identify additional molecules required for lymphocyte egress. This aim will build upon a collaboration with Christopher Goodnow in Australia to identify and characterize mutant mouse lines that exhibit alterations in lymphocyte trafficking. As part of this effort we will fine map and characterize the locus responsible for the thymic egress defect in Cataract Shionogi (CTS) mice. The information obtained through these studies should point to new targets for the development of immunomodulatory molecules.