The contribution of GPCRs to thymocyte medullary entry and central tolerance

GPCR 对胸腺细胞髓质进入和中枢耐受的贡献

基本信息

批准号：
8629092
负责人：
Lauren Ilyse Richie EHRLICH
金额：
$ 37.32万
依托单位：
UNIVERSITY OF TEXAS AT AUSTIN
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-03-15 至 2019-02-28
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8629092
关键词：
Affect Affinity Antigen Receptors Antigens Apoptosis Atypical lymphocyte Autoantigens Autoimmune Diseases Autoimmune Process Autoimmunity Automobile Driving CD8B1 gene Candidate Disease Gene Cells Defect Dendritic Cells Disease Ensure Epithelial Cells Etiology Expression Library Flow Cytometry G Protein-Coupled Receptor Signaling G-Protein-Coupled Receptors Gene Rearrangement Genes Genetic Genetic Recombination Goals Human Image Immune response Individual Knockout Mice Left Life Location Maintenance Major Histocompatibility Complex Microscopy Modeling Molecular Molecular Profiling Mouse Strains Mus Nature Open Reading Frames Organ Patients Peripheral Process Production Proteins Role Self Tolerance Slice Stromal Cells Syndrome T-Cell Antigen Receptor Specificity T-Cell Development T-Cell Receptor T-Lymphocyte Testing Thymic epithelial cell Thymus Gland Transgenic Organisms base cell motility central tolerance combinatorial defined contribution gain of function migration mouse model novel novel therapeutics pathogen prevent public health relevance receptor thymocyte two-photon

项目摘要

DESCRIPTION (provided by applicant): In this project we propose to determine the role of candidate G protein-coupled receptors (GPCRs) in enforcing deletion of developing auto-reactive T cells in the thymus. In order for T cells to recognize and respond to the wide array of pathogens encountered throughout life, each cell expresses a unique antigen receptor, the T cell receptor (TCR), that is capable of recognizing and responding to individual pathogens. These vastly diverse receptors are generated by random and imprecise rearrangements of gene segments encoding the TCR. Unfortunately, this random recombination process also yields autoreactive TCRs that could induce autoimmune diseases. To prevent overt autoimmunity, developing T cells are educated in the thymus through interactions with thymic stromal cells: thymocytes expressing overtly autoreactive TCRs are induced to undergo apoptosis. This process of thymic self-tolerance induction is referred to as central tolerance. Central tolerance i imposed largely within the interior, medullary region of the thymus, where thymocytes encounter a wide array of self-antigens expressed on stromal cells, namely dendritic cells and/or medullary thymic epithelial cells. It is critical that developing thymocytes enter the medulla and interact with stromal cells therein to eliminate autoreactive cells. From studies of Autoimmune Polyglandular Syndrome-I patients along with mouse models of this disorder, we know that if central tolerance induction in the medulla is impaired, multi-organ autoimmunity ensues. Based on our previous studies, GPCR signaling is required for thymocyte medullary entry. In this proposal, the role of candidate GPCRs in promoting medullary entry and self-tolerance will be evaluated. Using 2-photon microscopy, live thymocytes deficient for candidate GPCRs will be imaged to determine whether their ability to enter the medulla or to interact with medullary stromal cells is impaired. In a complementary set of traditional immunological approaches, murine models deficient for candidate GPCRs will be tested for overt autoimmunity, as well as for an inability to induce central tolerance to model medullary self- antigens. Finally, unbiased gain-of-function screens will identify additional molecular candidates that promote thymocyte medullary entry and self-tolerance. These studies will illuminate molecular mechanisms that promote thymocyte migration into the medulla and interactions with medullary stromal cells to promote central tolerance, thus broadening our understanding of the etiology of autoimmune diseases.

描述（由申请人提供）：在此项目中，我们建议确定候选G蛋白偶联受体（GPCR）在实施胸腺中产生自身反应性T细胞的缺失中的作用。为了使T细胞能够识别并应对一生中遇到的各种病原体，每个细胞表达一个独特的抗原受体T细胞受体（TCR），该受体能够识别和应对单个病原体。这些大量的受体是由编码TCR的基因段的随机和不精确的重排产生的。不幸的是，这种随机重组过程还产生了自身反应性TCR，可能诱发自身免疫性疾病。为了防止明显的自身免疫性，通过与胸腺基质细胞的相互作用在胸腺中教育发育中的T细胞：表达公开自身反应性TCR的胸腺细胞被诱导出现凋亡。胸腺自我耐受诱导的这一过程称为中心耐受性。中央耐受性I主要在胸腺内部的髓质区域内施加，胸腺细胞遇到在基质细胞上表达的广泛的自我抗原，即树突状细胞和/或髓质胸皮上皮细胞。至关重要的是，开发胸腺细胞进入髓质并与其中的基质细胞相互作用以消除自动反应性细胞。从对自身免疫性多边形综合征-I患者以及该疾病的小鼠模型的研究，我们知道，如果延髓中的中央耐受性诱导会受到损害，则随之而来的是多器官自身免疫。根据我们以前的研究，胸腺细胞髓质进入需要GPCR信号传导。在此提案中，将评估候选GPCR在促进髓质进入和自我宽容中的作用。使用2光子显微镜，将成像缺乏候选GPCR的活胸腺细胞，以确定其进入髓质的能力是否会受损或与髓质基质细胞相互作用。在一系列互补的传统免疫学方法中，将测试缺乏候选GPCR的鼠模型，以实现明显的自身免疫性，以及无法诱导中央耐受性以模拟髓质自我抗原。最后，无偏的功能屏幕将确定促进胸腺细胞髓质进入和自我耐受性的其他分子候选物。这些研究将阐明分子机制，这些机制促进胸腺细胞迁移到髓质中，并与髓质基质细胞相互作用以促进中心耐受性，从而扩大我们对自身免疫性疾病病因的理解。