Treg Migration and Function During Autoimmunity within Peripheral Tissue

周围组织内自身免疫过程中 Treg 的迁移和功能

• 批准号: 9322541
• 负责人: John E Harris
• 金额: $ 36.85万
• 依托单位: UNIV OF MASSACHUSETTS MED SCH WORCESTER
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-15 至 2020-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9322541
• 关键词: Address; Affect; Antigens; Apoptosis; Area; Autoimmune Diseases; Autoimmune Process; Autoimmunity; CXC chemokine receptor 3; CXCL10 gene; CXCR3 gene; Cell Communication; Cell physiology; Confocal Microscopy; Crohn' s disease; Dendritic Cells; Disease; Epidermis; Eragrostis; Event; Flow Cytometry; Goals; Human; Immunophenotyping; In Situ; In Vitro; Inflammation; Inflammatory Bowel Diseases; Insulin-Dependent Diabetes Mellitus; Langerhans cell; Learning; Lymphoid; MHC Interaction; Mediating; Modeling; Multiple Sclerosis; Mus; Organ; Organ Model; Pathway interactions; Patients; Pattern; Peripheral; Phenotype; Play; Recruitment Activity; Regulatory T-Lymphocyte; Role; Sampling; Severities; Signal Transduction; Skin; T-Cell Receptor; T-Lymphocyte; Testing; Thyroid Diseases; Tissues; Ulcerative Colitis; Vitiligo; Work; biobank; chemokine; disorder control; human tissue; in vivo Model; killings; migration; mouse model; public health relevance; response; skin disorder; skin lesion; treatment strategy

 DESCRIPTION (provided by applicant): T regulatory cells (Tregs) play a critical role in controlling organ-specific autoimmune diseases, including type 1 diabetes, multiple sclerosis, and vitiligo. Most studies that address Treg function are performed in vitro or in secondary lymphoid organs (SLOs), and little is known about how Tregs function within peripheral tissues. Tregs must first identify the correct tissue, find the focus of inflammation, and then co-localize with effector T cells (Teffs), yet how this is done efficiently in peripheral tissues is unknown. Te central hypothesis in this proposal is that Tregs require chemokine signals and tissue-specific dendritic cell interactions to find and regulate Teffs within peripheral tissues. These mechanisms cannot be appropriately studied outside of peripheral tissues, and therefore require an in vivo model of organ-specific autoimmunity to define them. We created a mouse model of the autoimmune skin disease vitiligo, in which CXCL10 is required to direct Teff migration into skin and epidermis to drive disease. We have extensively developed this model using genetically modified mice, skin flow cytometry, and confocal microscopy, correlating our observations to human tissues in order to better understand T cell function during autoimmunity. To test our hypothesis, we will perform functional studies in our mouse model of vitiligo and correlate these findings to an existing biobank of human vitiligo skin samples. We found that Tregs suppress vitiligo and localize to CXCL10 in our mouse model. We hypothesize that Tregs are recruited by CXCL10 to co-localize with Teffs and suppress their function. We will test this in Aim 1, where we will determine whether Tregs migrate with Teffs, if they require the CXCL10 receptor CXCR3, and whether human Treg localization in the skin predicts vitiligo severity. We found that Langerhans cells (LHCs) are major producers of CXCL10 in the skin during vitiligo, are required for epidermal Treg accumulation, and for control of disease. We hypothesize that Tregs and Teffs require tethering to LHCs through TCR-MHC interactions and CXCL10 to promote their co-localization. We will test this in Aim 2, where we will determine whether Teff/Treg interactions with LHCs is antigen-specific, whether CXCL10 stabilizes their interaction, and how frequently Teff-Treg-LHC interactions occur in human vitiligo skin. In the absence of Tregs or LHCs, Teffs accumulate in large numbers in the skin during vitiligo, independent of proliferation. We hypothesize that Tregs directly promote Teff egress from the skin. We will test this in Aim 3, where we will define the phenotype of Teffs after suppression by Tregs, determine whether Tregs promote Teff egress from the skin, and correlate the immunophenotype of regulated Teffs in mouse and human vitiligo. Vitiligo serves as an ideal model to investigate fundamental mechanisms by which Tregs suppress Teffs within peripheral tissues during autoimmunity. This work has the potential to define pathways that can be targeted as a new treatment strategy for multiple organ-specific autoimmune diseases.

 描述（由申请人提供）：调节性T细胞（T细胞）在控制器官特异性自身免疫性疾病（包括1型糖尿病、多发性硬化和白癜风）中起关键作用。大多数针对Treg功能的研究都是在体外或次级淋巴器官（SLO）中进行的，对Treg在外周组织中的功能知之甚少。T细胞必须首先识别正确的组织，找到炎症的焦点，然后与效应T细胞（Teffs）共定位，但如何在外周组织中有效地完成这一点尚不清楚。该建议的核心假设是Teffs需要趋化因子信号和组织特异性树突状细胞相互作用来发现和调节外周组织中的Teffs。这些机制不能在外周组织外进行适当的研究，因此需要器官特异性自身免疫的体内模型来定义它们。我们建立了自身免疫性皮肤病白癜风的小鼠模型，其中需要CXCL 10来指导Teff迁移到皮肤和表皮中以驱动疾病。我们已经使用转基因小鼠，皮肤流式细胞术和共聚焦显微镜广泛开发了这种模型，将我们的观察结果与人体组织相关联，以便更好地了解自身免疫过程中的T细胞功能。为了验证我们的假设，我们将在我们的白癜风小鼠模型中进行功能研究，并将这些发现与现有的人类白癜风皮肤样本生物库相关联。我们发现，在我们的小鼠模型中，TIPs抑制白癜风并定位于CXCL 10。我们假设Teffs被CXCL 10招募与Teffs共定位并抑制其功能。我们将在Aim 1中对此进行测试，其中我们将确定TcR是否与Teff一起迁移，如果它们需要CXCL 10受体CXCR 3，以及皮肤中的人类Treg定位是否预测白癜风的严重程度。我们发现朗格汉斯细胞（LHC）是白癜风皮肤中CXCL 10的主要生产者，是表皮Treg积累和疾病控制所必需的。我们假设TCRs和Teffs需要通过TCR-MHC相互作用和CXCL 10与LHC拴系以促进其共定位。我们将在目标2中对此进行测试，其中我们将确定Teff/Treg相互作用是否 与LHC的相互作用是否是抗原特异性的，CXCL 10是否稳定它们的相互作用，以及在人类白癜风皮肤中发生Teff-Treg-LHC相互作用的频率。在没有Teffs或LHC的情况下，Teffs在白癜风期间在皮肤中大量积累，独立于增殖。我们假设Teff直接促进Teff从皮肤排出。我们将在目标3中对此进行测试，其中我们将定义Teff抑制后的Teff表型，确定Teff是否促进Teff从皮肤排出，并将小鼠和人类白癜风中调节的Teff的免疫表型相关联。白癜风作为一个理想的模型，以研究的基本机制，Teffs抑制外周组织中的自身免疫过程中。这项工作有可能定义可以作为多器官特异性自身免疫性疾病的新治疗策略的途径。