Visualizing regulatory T cell control of autoimmunity

调节性 T 细胞对自身免疫的控制可视化

• 批准号: 6962937
• 负责人: Qizhi Tang
• 金额: $ 22.73万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-07-01 至 2007-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6962937
• 关键词: CD28 molecule; NOD mouse; T lymphocyte; antigen presenting cell; autoimmunity; cell cell interaction; cell migration; confocal scanning microscopy; flow cytometry; helper T lymphocyte; immunocytochemistry; immunofluorescence technique; immunoregulation; inflammation; interleukin 10; intravital microscopy; leukocyte activation /transformation; leukocyte adhesion molecules; luciferin monooxygenase; lymph nodes; pancreatic islet transplantation; suppressor T lymphocyte; transforming growth factors

Accumulating evidence suggests that CD4+CD25+ regulatory T cells (Tregs) are an essential component of immune regulation, and loss of Treg functions may be one of the underlying causes of autoimmunity. However, how Tregs suppress immune responses in vivo remains unclear. This is likely due to the low frequency of Tregs and the difficulty in analyzing in vivo responses. We have recently developed a robust system to restore Tregs and control autoimmune diabetes in non-obese diabetic mice by transferring in vitro expanded islet antigen-specific Tregs purified from the BDC2.5 TCR transgenic mice. We hypothesize that Tregs both control immune homeostasis in steady state and respond to inflammatory stimuli to suppress immune responses at local tissue sites. New imaging technologies offer the most direct and unmanipulated ways to analyze in vivo cellular activities. However the field is facing the challenges of moving into clinically relevant disease models and establishing causal relationships between various imaging observations with functional outcomes. We will directly analyze both the steady-state and inflammatory responses of Tregs in vivo in our model system using novel in vivo imaging technologies. Specifically, we will use bioluminescence to monitor the lymph node homing and tissue trafficking of luciferase-tagged diabetogenic CD4 and CDS T cells in the presence and absence of co-transferred BDC Tregs. We will analyze the priming and effector function development of the diabetogenic T cells using two-photon laser scanning microscopy and determine the effect of BDC Tregs on these activities in both LN and islet tissues. We will directly visualize Treg interaction with antigen presenting cells and effector T cells in vivo with two-photon microscopy to determine the direct cellular target of the Tregs. Finally, we will examine the roles of immunosuppressive molecules IL-10, TGF- beta, and CTLA-4 using this novel technology and determine the effect of these molecules on the homing, trafficking, priming, and effector function development of the diabetogenic T cells. We will combine the imaging analysis with conventional cellular immunological approaches, multicolor immunofluorescence and immunohistochemistry techniques to pinpoint the time and location of Treg activation and function. The results of these studies will provide new insights into our understanding of autoimmune diseases by specifically studying the balance between immune regulation and auto-aggression

越来越多的证据表明，CD4+CD25+调节性T细胞（Treg）是免疫调节的重要组成部分，Treg功能的丧失可能是自身免疫的根本原因之一。 然而，Tregs如何抑制体内免疫反应仍不清楚。这可能是由于 Tregs 的出现频率较低且难以分析体内反应。我们最近开发了一个强大的系统，通过转移从 BDC2.5 TCR 转基因小鼠中纯化的体外扩增的胰岛抗原特异性 Tregs 来恢复非肥胖糖尿病小鼠的 Tregs 并控制自身免疫糖尿病。我们假设 Tregs 既能控制稳定状态下的免疫稳态，又能对炎症刺激作出反应，抑制局部组织部位的免疫反应。新的成像技术提供了最直接、最不受操作的方法来分析体内细胞活动。然而，该领域面临着进入临床相关疾病模型以及建立各种成像观察与功能结果之间因果关系的挑战。我们将使用新颖的体内成像技术直接分析模型系统中 Tregs 的稳态和炎症反应。 具体来说，我们将使用生物发光来监测在存在和不存在共转移的 BDC Tregs 的情况下荧光素酶标记的致糖尿病 CD4 和 CDS T 细胞的淋巴结归巢和组织运输。我们将使用双光子激光扫描显微镜分析致糖尿病 T 细胞的启动和效应功能发育，并确定 BDC Tregs 对 LN 和胰岛组织中这些活动的影响。我们将通过双光子显微镜直接观察体内 Treg 与抗原呈递细胞和效应 T 细胞的相互作用，以确定 Tregs 的直接细胞靶标。最后，我们将利用这项新技术研究免疫抑制分子 IL-10、TGF-β 和 CTLA-4 的作用 并确定这些分子对致糖尿病 T 细胞的归巢、运输、启动和效应功能发育的影响。我们将成像分析与传统细胞免疫学方法、多色免疫荧光和免疫组织化学技术相结合，以查明 Treg 激活和功能的时间和位置。这些研究的结果将为我们通过专门研究免疫调节与自身攻击之间的平衡来理解自身免疫性疾病提供新的见解