Deaf1 isoforms control changes in PTA expression in the NOD PLN during T1D pathog

Deaf1亚型控制T1D病理过程中NOD PLN中PTA表达的变化

基本信息

批准号：
8485528
负责人：
CHARLES GARRISON FATHMAN
金额：
$ 37.27万
依托单位：
STANFORD UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2010
资助国家：
美国
起止时间：
2010-07-01 至 2015-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8485528
关键词：
Address Age Age of Onset Alternative Splicing Antigens Autoantibodies Autoantigens Autoimmune Diseases Autoimmune Process Beta Cell Binding Biological Assay Biological Process Birth Blood Glucose Cells Cervical lymph node group ChIP-on-chip Collaborations Cytoplasm Data Defect Development Disease Disease Progression Dominant-Negative Mutation Down-Regulation Ectopic Expression Effector Cell Gene Expression Genes Genetic Genetic Transcription Histones Hormones Human Immunohistochemistry Immunophenotyping In Situ Hybridization Inbred NOD Mice Incidence Infiltration Inflammation Inflammatory Insulin Insulin-Dependent Diabetes Mellitus Islet Cell Islets of Langerhans Knock-out Knockout Mice Laboratories Lead Length Letters Lymph Node Tissue Lymphocyte Lymphoid Tissue Measures Mediating Microarray Analysis Modeling Molecular Mus Mutation Non obese Onset of illness Pancreas Pathogenesis Pathway interactions Patients Peptides Peripheral Phenotype Play Production Promoter Regions Protein Binding Protein Isoforms RNA Splicing Regulation Regulatory T-Lymphocyte Reporter Reporting Research Personnel Role Self Tolerance Severities Severity of illness Sorting - Cell Movement Spliced Genes Stromal Cells Structure of beta Cell of islet Syndrome T-Cell Development T-Lymphocyte Testing Thymus Gland Time Tissues Transcriptional Regulation Uveitis Variant age related autoreactive T cell base cell type congenic cytokine design diabetic diabetic patient lymph nodes mouse model nuclear factor 1 peripheral tolerance promoter public health relevance type I diabetic uveoretinitis

项目摘要

DESCRIPTION (provided by applicant): Type 1 diabetes (T1D) develops from the autoimmune destruction of pancreatic beta cells by self-reactive T cells. Potentially self-reactive T cells escaping elimination in the thymus may subsequently be deleted or tolerized in the periphery. Recently, stromal cells of lymph nodes were reported to control self-tolerance by inducing the ectopic expression of various peripheral tissue antigens (PTAs) and presenting them to T cells in a manner that induces tolerance (deletion or regulation). Currently, both the transcriptional control of PTA expression in lymph nodes and the dysregulation of peripheral tolerance in T1D are unclear. Our laboratory recently identified Deaf1 as a transcriptional regulator of PTA gene expression in peripheral lymph nodes. Our findings show that the gene expression of PTAs, including insulin and other beta cell antigens, are down- regulated in the pancreatic lymph nodes (PLN) of non-obese diabetic (NOD) mice at 12 weeks of age. This change in expression coincides in time with the onset of beta cell destruction by autoreactive T cells. Preliminary studies show that Deaf1 regulates the expression of multiple PTA genes in the PLN. Thus far, two forms of Deaf1, a full-length functional form and a non-functional variant (Deaf1-VAR) have been identified in the PLN of 12 week-old NOD mice. At this age, Deaf1-VAR expression is significantly higher and Deaf1 expression is significantly lower in the PLN of NOD compared to NOD.B10 mice. Deaf1-VAR is expressed in the cytoplasm, has little transcriptional activity of its own, and inhibits the transcriptional activity of Deaf1 by heterodimerizing with it and retaining it in the cytoplasm. Remarkably, we identified an equivalent alternatively spliced Deaf1 isoform in the PLN of T1D patients. This human variant which was ~20-fold more abundant in the PLN of T1D patients than controls, behaves like the mouse Deaf1-VAR. The high expression of this variant also correlated with the absence of insulin gene expression in the PLN of T1D patients. Based on these data, it is hypothesized that Deaf1 controls the expression of and maintains peripheral tolerance to certain pancreatic beta-cell antigens, including insulin, in the PLN, and that a change in Deaf1 splicing contributes to the pathogenesis of T1D. To examine this hypothesis, proposed studies address the following: 1) What cell type in the PLN expresses Deaf1, Deaf1-VAR and PTAs? 2) How does Deaf1 mediate PTA gene transcription on a molecular level? 3) Does inflammation of the PLN or various "genetic factors" regulate the splicing of Deaf1? 4) Will knock-out of Deaf1 expression in PTA-expressing cells exacerbate NOD disease, and if so, is this due to a lack of autoreactive T cell deletion or a lack of regulatory T cell development? Finally, do either mouse models of autoimmune uveoretinitis or human APS 1 patients have changes in Deaf1 that can be correlated with disease? The results of these studies will provide an overall understanding of how Deaf1 and its isoforms maintain peripheral tolerance and thus, how a change in the splicing of Deaf1 or a mutation in DEAF1 may contribute to the development of autoimmune disease.

描述（由申请人提供）：1型糖尿病（T1D）从自身免疫性T细胞对胰腺β细胞的自身免疫性破坏而发展。随后可以在外围删除或耐受胸腺中消除消除的潜在自我反应性T细胞。最近，据报道，淋巴结的基质细胞通过诱导各种周围组织抗原（PTA）的异位表达来控制自耐受性，并以诱导耐受性（缺失或调节）的方式将其呈现给T细胞。当前，尚不清楚淋巴结中PTA表达的转录控制和T1D中外周耐受性的失调。我们的实验室最近将DEAF1确定为外周淋巴结中PTA基因表达的转录调节剂。我们的发现表明，在12周龄的非肥胖糖尿病（NOD）小鼠的胰腺淋巴结（PLN）中，PTA的基因表达，包括胰岛素和其他β细胞抗原。这种表达的变化与自动反应性T细胞破坏了β细胞破坏的及时。初步研究表明，DEAF1调节PLN中多个PTA基因的表达。到目前为止，已经在12周大的NOD小鼠的PLN中鉴定出了两种形式的聋人，一种全长功能形式和一种非功能变体（聋哑）。在这个年龄，与NOD.B10小鼠相比，NOD PLN的聋1-VAR表达显着更高，聋人表达显着降低。 Deaf1-Var在细胞质中表达，其自身的转录活性很小，并通过与其异构二聚并将其保留在细胞质中来抑制聋人的转录活性。值得注意的是，我们在T1D患者的PLN中确定了等效的脱聋1同工型。这种人类变体在T1D患者的PLN中比对照组的含量高约20倍，其表现像小鼠聋哑人。该变体的高表达也与T1D患者PLN中缺乏胰岛素基因表达相关。基于这些数据，假设聋人控制对某些胰腺β细胞抗原（包括胰岛素，包括胰岛素）的表达，并保持外围耐受性，并且聋哑剪接的变化有助于T1D的发病机理。为了检验这一假设，提出的研究解决了以下内容：1）PLN中的哪种细胞类型表达聋人，聋人1-VAR和PTA？ 2）聋人如何在分子水平上介导PTA基因转录？ 3）PLN的炎症或各种“遗传因素”是否调节聋人的剪接？ 4）在表达PTA的细胞中deaf1表达的敲除会加剧NOD疾病，如果是的，这是由于缺乏自身反应性T细胞缺失或缺乏调节性T细胞的发展所致吗？最后，自身免疫性葡萄膜炎的小鼠模型或人类APS 1患者的聋人变化可能与疾病相关吗？这些研究的结果将对聋人及其同工型如何保持外围耐受性提供总体上的理解，因此，聋人剪接的变化或聋哑1中突变的变化如何有助于自身免疫性疾病的发展。