IFN-Gamma Gene Regulation in T Cells and NK Cells

T 细胞和 NK 细胞中的 IFN-γ 基因调控

基本信息

批准号：
7791178
负责人：
Thomas M. Aune
金额：
$ 16.15万
依托单位：
VANDERBILT UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2000
资助国家：
美国
起止时间：
2000-07-15 至 2014-11-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7791178
关键词：
3-Dimensional Address Affect Autoimmune Diabetes Autoimmune Diseases Autoimmunity Bacterial Artificial Chromosomes Cell Differentiation process Cells Cellular Immunity Characteristics Chromosome Deletion Code Complex DNA Defect Development Disease Distal Effector Cell Elements Ensure Epigenetic Process Exhibits Failure Functional RNA Gene Activation Gene Expression Gene Expression Regulation Gene Transfer Techniques Genes Genetic Genetic Code Genetic Transcription Genomics Histone Acetylation Histone Code Histones Human Humoral Immunities Hypersensitivity IFNG gene Immune response Immune system Insulin-Dependent Diabetes Mellitus Interferon Type II Link Methylation Modeling Modification Molecular Conformation Mus Natural Killer Cells Non obese Nuclear Onset of illness Organism Pathogenesis Pattern Play Positioning Attribute Process Production Proliferating Property Regulation Regulatory Element Role Staging Stimulus Structure T-Lymphocyte Th2 Cells Tissues Transcriptional Activation Transcriptional Regulation Transgenic Mice arm cell type cytokine developmental plasticity diabetic extracellular gene repression histone modification human disease pathogen programs promoter public health relevance success

项目摘要

DESCRIPTION (provided by applicant): The histone code hypothesis proposes that cell fate decisions are achieved through creation of stable epigenetic histone marks at gene loci. These marks can be localized to promoters and transcribed regions of genes or can extend many kilobases beyond these boundaries. Although it is well established that certain histone marks are associated with transcriptional activation and other histone marks are associated with transcriptional repression, the precise mechanisms by which histone marks activate or repress transcription is incompletely understood. Further, it is becoming increasingly apparent that both activating and repressive marks are formed at loci of developmentally regulated genes and it is thought that these dual marks ensure developmental plasticity. For example, the Ifng gene exhibits complex activating and repressive patterns of epigenetic modifications that cover a region spanning over 50 kb of upstream and downstream genomic DNA in cells that express or silence Ifng. Given the critical role epigenetic marks play in normal development, it is becoming increasingly apparent that epigenetic defects also contribute to disease processes, including autoimmunity. Our results also demonstrate that failure to properly establish this long-range histone code may contribute to the characteristic over-production of IFN-3 by proliferating T cells from mice that develop autoimmune diabetes. To investigate these questions, we plan a three-pronged approach. First, we will prepare and analyze functional properties of transgenic mice with a wild-type human bacterial artificial chromosome (BAC) containing the IFNG gene and approximately 100 kb of flanking upstream and downstream sequence and BAC transgenic mice with various large (20-40 kb) and small (1kb) deletions within the 200 kb BAC. Second, we will perform detailed structure-function and nuclear positioning analyses to identify genomic sequences critical for these essential processes. Third, we will use several approaches to manipulate the formation stable long-range epigenetic histone marks across the IFNG locus and evaluate alterations in transcription, chromosomal conformation and nuclear positioning of the IFNG locus. Together, these studies will provide direct links between the function of the genetic code and the epigenetic code. They will also identify defects in the epigenetic code that may contribute to autoimmune disease. PUBLIC HEALTH RELEVANCE: The histone code hypothesis proposes that cell fate decisions are achieved through creation of stable epigenetic histone marks at gene loci. In this proposal, we plan to elucidate mechanisms underlying formation of long range histone marks across the Ifng locus in developing effector Th1 and Th2 cells and functional consequences created by these marks. Increasing evidence suggests that imbalance in the histone code may contribute to disease onset or pathogenesis, including autoimmune diseases, and it may be possible to affect the course of disease by altering the epigenetic code through increasing levels of activating histone acetylation marks or decreasing levels of inhibitory histone methylation marks, either generally or at specific genomic loci.

描述（由申请人提供）：组蛋白代码假设提出，通过在基因基因座的创建稳定的表观遗传组蛋白标记来实现细胞命运决策。这些标记可以定位于启动子和基因的转录区域，也可以将许多千叠酶扩展到这些边界之外。尽管已经很好地确定某些组蛋白标记与转录激活相关，而其他组蛋白标记与转录抑制相关，但组蛋白标记激活或抑制转录的确切机制不完全理解。此外，越来越明显的是，在发育调节的基因的基因座形成了激活和抑制性痕迹，并且人们认为这些双重标记确保了发育可塑性。例如，IFNG基因表现出复杂的表观遗传修饰的激活和抑制模式，这些模式涵盖了超过50 kb上游和下游基因组DNA的区域，在表达或沉默的IFNG的细胞中。鉴于表观遗传标记在正常发育中起着关键作用，因此越来越明显的是，表观遗传缺陷也有助于疾病过程，包括自身免疫性。我们的结果还表明，未正确建立这种长期组蛋白代码可能会通过从患有自身免疫性糖尿病的小鼠中增殖的T细胞增殖而导致IFN-3的特征过量产生。为了调查这些问题，我们计划了三管齐下的方法。首先，我们将使用含有IFNG基因的野生型人工染色体（BAC）来准备和分析转基因小鼠的功能特性，该染色体（BAC）含有IFNG基因和大约100 kb的上游和下游序列和BAC转基因小鼠，以及具有各种大型（20-40 kb）的BAC转基因小鼠，以及各种大型（20-40 kb）的删除（1kb）和200 kb中的dacb。其次，我们将执行详细的结构功能和核定位分析，以识别这些基本过程至关重要的基因组序列。第三，我们将使用几种方法来操纵IFNG基因座的稳定的远程表观遗传组蛋白标记，并评估IFNG基因座的转录，染色体构象和核位置的改变。这些研究将共同提供遗传密码功能与表观遗传密码之间的直接联系。他们还将确定可能导致自身免疫性疾病的表观遗传密码中的缺陷。公共卫生相关性：组蛋白代码假设提出，通过在Gene基因座创建稳定的表观遗传组蛋白标记来实现细胞命运决策。在此提案中，我们计划阐明在发展效应子Th1和Th2细胞中，跨IFNG基因座的远距离组蛋白标记的基础机制以及这些标记产生的功能后果。越来越多的证据表明，组蛋白代码中的不平衡可能导致疾病发作或发病机理，包括自身免疫性疾病，并且可能通过增加激活组蛋白乙酰化标记或降低抑制性甲基化甲基化水平的抑制性基因型基因组或在特定基因上的抑制性甲基化水平来改变表观遗传密码来影响疾病的过程。