Visualizing regulatory T cell control of autoimmunity

越来越多的证据表明，CD 4 + CD 25+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，TdR如何抑制体内免疫应答仍不清楚。这可能是由于TdR的频率较低以及难以分析体内反应。我们最近开发了一个强大的系统，以恢复TCR 4和控制自身免疫性糖尿病在非肥胖糖尿病小鼠通过转移在体外扩增胰岛抗原特异性TCR 4纯化从BDC2.5 TCR转基因小鼠。我们假设THBE既控制稳定状态下的免疫稳态，又对炎症刺激作出反应，以抑制局部组织部位的免疫反应。新的成像技术为分析体内细胞活动提供了最直接和最不受操纵的方法。然而，该领域正面临着进入临床相关疾病模型和建立各种成像观察与功能结果之间的因果关系的挑战。我们将使用新型体内成像技术直接分析TclO在我们的模型系统中的稳态和炎症反应。 具体而言，我们将使用生物发光来监测在存在和不存在共转移的BDC T淋巴细胞的情况下，经组氨酸酶标记的致糖尿病性CD 4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的发展，并确定BDC TdR对LN和胰岛组织中这些活动的影响。我们将用双光子显微镜直接观察Treg与抗原呈递细胞和效应T细胞的体内相互作用，以确定Treg的直接细胞靶点。最后，我们将研究免疫抑制分子IL-10，TGF-β和CTLA-4使用这种新技术的作用 并确定这些分子对致糖尿病T细胞归巢、运输、引发和效应子功能发育的影响。我们将联合收割机与传统的细胞免疫学方法，免疫荧光和免疫组织化学技术相结合，以确定Treg激活和功能的时间和位置。这些研究的结果将通过专门研究免疫调节和自身攻击之间的平衡，为我们理解自身免疫性疾病提供新的见解

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