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

描述（由申请人提供）：蛋白FOX3作用于对免疫调节重要的T细胞的DNA。研究人员怀疑这种关键的FOXP3+ T细胞在至少三种最常见的人类自身免疫性疾病和四种最致命的癌症中很重要。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FOXP3+ T细胞发展背后的机制的重要性。我们的长期目标是了解细胞因子TGF（一种对肠道环境非常重要的细胞因子）如何调节肠道中这些FOXP3+ T细胞的生成。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，本申请的目的是确定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。为实现这一目标而设计的三个具体目标包括：（1）检验T细胞中KLF10表达介导结肠炎抗性机制的假设，（2）检验KLF10调节Foxp3不同基因组控制区域的假设，以及（3）检验KLF10通过Foxp3激活所需的不同染色质重塑发挥作用的假设。我们将使用KLF10缺陷小鼠集落和免疫细胞隔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。随后的TCR转基因动物将用于确定KLF10调节特定肠道抗原特异性肠道FOXP3+ T调节细胞发育的机制。将使用人T细胞系和瞬时转染方法来表征Foxp3启动子功能所需的KLF10的特异性调控结构域。最后，一种新的人T细胞系与一个确定的Foxp3启动子和荧光素酶报告构建体稳定整合到宿主细胞基因组将被用来表征KLF10依赖性染色质修饰所需的Foxp3启动子激活。该项目意义重大，因为在结论中，我们将了解KLF10在Foxp3调节中的作用，阐明慢性炎症和肿瘤发病机制的病理生物学信息。这反过来又将刺激人类慢性炎症性疾病实验疗法的新领域。 公共卫生相关性：自身免疫性疾病的公共卫生负担是显著的，因为这些不受调节的免疫应答影响广泛不同的器官系统，引起诸如炎性肠病、类风湿性关节炎和糖尿病的疾病。该提案解决了T调节细胞的发展机制，这些细胞有望防止自身免疫性疾病。这一提议的结果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.