KLF10 regulates colitis through mediating TGFb induction of FOXP3 in Treg cells.

描述（由申请人提供）：FOX3蛋白作用于对免疫调节重要的T细胞DNA。研究人员怀疑，这种关键的FOXP3+ T细胞至少在最常见的三种人类自身免疫性疾病和四种最致命的癌症中起着重要作用。由于有超过850万美国居民患有自身免疫性疾病，因此很容易理解理解这种关键的FOXP3+ T细胞发展背后机制的重要性。我们的长期目标是了解对肠道环境极其重要的细胞因子TGF如何调节肠道中FOXP3+ T细胞的产生。我们的实验室发现，小鼠中KLF家族成员的缺乏导致肠道FOXP3+ T细胞生成受阻，并倾向于发展类似于人类炎症性肠病的结肠炎。因此，我们的目的是确定KLF家族蛋白介导tgf依赖性Foxp3基因转录的机制，以及该途径的破坏如何导致结肠炎。为实现这一目标，我们设计了三个具体目标：(1)验证KLF10在T细胞中表达介导结肠炎抵抗机制的假设；(2)验证KLF10调节Foxp3不同基因组控制区的假设；(3)验证KLF10通过Foxp3激活所需的不同染色质重塑起作用的假设。我们将使用KLF10缺陷小鼠群体和免疫细胞室的过继转移来确定KLF10对预防结肠炎至关重要的精确细胞类型。后续的TCR转基因动物将用于确定KLF10调节肠道FOXP3+ T调节细胞发育的机制，该细胞对特定肠道抗原具有特异性。人类T细胞系和瞬时转染方法将用于表征Foxp3启动子功能所需的KLF10的特定调控域。最后，一种具有Foxp3启动子和荧光素酶报告基因的新型人类T细胞系将被用于表征Foxp3启动子激活所需的klf10依赖性染色质修饰。该项目意义重大，因为一旦得出结论，我们将了解KLF10在Foxp3调控中的作用，阐明慢性炎症和肿瘤发病机制的病理生物学信息。这反过来将刺激人类慢性炎症性疾病实验治疗的新领域。

DESCRIPTION (provided by applicant): The protein FOX3 acts on the DNA of T cells important to immune regulation. Researchers have suspected that this critical FOXP3+ T cell is important in at least the top three most common human autoimmune diseases and the four most deadly cancers. As there are over 8.5 million U.S. residents with an autoimmune disease, it is easy to appreciate the importance of understanding the mechanisms behind the development of this critical FOXP3+ T cell. Our long-term goal is to understand how the cytokine TGF, an extremely important cytokine to the intestinal environment, regulates the generation of these FOXP3+ T cells in the intestine. Our laboratory has discovered that the deficiency of a KLF family member in mice results in a block in intestinal FOXP3+ T cell generation and a tendency to develop colitis similar to human inflammatory bowel disease. Thus, our objective in this application is to determine the mechanism by which KLF family proteins mediate TGF-dependent Foxp3 gene transcription, and how disruption of this pathway leads to colitis. The three specific aims designed to achieve this objective include: (1) Test the hypothesis that KLF10 expression in T cells mediates a mechanism of resistance to colitis, (2) Test the hypothesis that KLF10 regulates distinct genomic control regions of Foxp3, and (3) Test the hypothesis that KLF10 works via distinct chromatin remodeling required for Foxp3 activation. We will use the KLF10-deficient mouse colony and adoptive transfer of immune cell compartments to determine the precise cell type in which KLF10 is critically required to prevent colitis. Subsequent TCR transgenic animals will be used to determine the mechanism by which KLF10 regulates the development of intestinal FOXP3+ T regulatory cells specific for a defined gut antigen. Human T cells lines and transient transfection methodology will be used to characterize the specific regulatory domains of KLF10 required for Foxp3 promoter function. Finally, a novel human T cell line with a defined Foxp3 promoter and luciferase reporter construct stably integrated into the host cell genome will be used to characterize KLF10-dependent chromatin modifications required for Foxp3 promoter activation. This project is significant because upon conclusion, we will understand the role for KLF10 in the regulation of Foxp3, elucidating pathobiological information into the pathogenesis of chronic inflammation and neoplasia. This in turn will stimulate new areas for experimental therapeutics in human chronic inflammatory diseases. PUBLIC HEALTH RELEVANCE: The public health burden of autoimmune disease is significant as these unregulated immune responses affect widely disparate organ systems causing such diseases as inflammatory bowel disease, rheumatoid arthritis and diabetes mellitus. This proposal addresses the mechanisms of development of T regulatory cells, cells expected to protect against autoimmune disease. Results from this proposal will stimulate new areas for experimental therapeutics in human chronic inflammatory diseases.