Control of dysfunctional Tregs

项目摘要 排斥反应仍然是长期移植存活的主要障碍，我们渴望揭示 阻碍同种异体移植物稳定存活的基本机制。在上一个资助期内，我们研究了 Treg功能障碍的机制，并将BATF和BATF 3鉴定为Foxp 3的有效阻遏物， 抑制Foxp 3表达和Treg诱导。这些研究也导致了DHX 15的发现。 解旋酶作为Foxp 3 + TcR的关键调节因子，因为TcR中Dhx 15的条件性缺失导致 外周和致命性自身免疫性疾病中Tcl 3的严重消耗。从本质上讲，DHX 15是一个 RNA解旋酶（一种RNA结合马达蛋白），传统上认为与RNA加工有关.其 在控制TdR中的作用是出乎意料的，并清楚地揭示了TdR以前未知的新方面 与目前已知的机制不同，而揭示这些机制是中心目标 这个提议。 我们的工作假设是DHX 15控制外周部位的Treg身份和/或存活， 缺乏导致它们回复到Teff或死于细胞凋亡。我们推测DHX 15也可能 控制移植部位的THP，在那里它们必须克服炎症环境以施加抑制性作用。 功能协调发展的我们提出了3个目的来测试这个假设在这个应用程序中：第一个目的是测试是否 DHX 15通过充当RNA剪接因子，加工编码调节性T细胞的mRNA， Foxp 3或Foxp 3控制的标签分子，第二个目的是解决DHX 15 通过调节IL-2信号复合物来控制TcR的存活，使得TcR在其细胞凋亡中死亡。 第三个目的是检查DHX 15是否对移植部位的THP特别重要 在最需要它们的地方促进移植耐受性。DHX 15是第一个RNA解旋酶， 到目前为止，已经确定了控制Tibet的基因，以及转基因模型和尖端技术。 我们开发的方法使我们处于一个独特的位置，可以机械地剖析DHX 15 解旋酶在调节Treg中起作用，Treg是基础Treg生物学和Treg生物学中相当重要的领域。 基础疗法。

Project Summary Rejection remains a major hurdle to long lasting transplant survival and we aspire to uncover the fundamental mechanisms that hinder stable allograft survival. In the last funding period, we studied the mechanisms of Treg dysfunctions and identified BATF and BATF3 as potent repressors of Foxp3, suppressing Foxp3 expression and Treg induction. These studies also led to the discovery of the DHX15 helicase as a critical regulator of Foxp3+Tregs, as conditional deletion of Dhx15 in Tregs resulted in a profound depletion of Tregs in the periphery and lethal autoimmune diseases. In essence, DHX15 is an RNA helicase (an RNA binding motor protein) and traditionally thought to be involved in RNA processing. Its roles in the control of Tregs are unexpected and clearly reveal novel previously unknown aspects of Tregs that are different from currently known mechanisms, and uncovering those mechanisms is the central goal of this proposal. Our working hypothesis is that DHX15 controls Treg identity and/or survival at peripheral sites and that its deficiency results in either their reversion to Teff or die of apoptosis. We surmise that DHX15 may also control Tregs at the graft site, where they must overcome the inflammatory milieu to exert suppressive functions. We proposed 3 Aims to test this hypothesis in this application: the first Aim is to test whether DHX15 controls Treg identity by acting as an RNA splicing factor, processing mRNAs that encode the Foxp3 or Foxp3 controlled signature molecules in Tregs, the second Aim is to address whether DHX15 controls Tregs survival by regulating the IL-2 signaling complex, such that Tregs die of apoptosis in its absence, and the third Aim is to examine whether DHX15 is especially important for Tregs at graft sites where they are needed the most in promoting transplant tolerance. Overall, DHX15 is the first RNA helicase identified thus far that controls Tregs, and the genetically modified models as well as cutting-edge approaches we have developed put us in a unique position in dissecting mechanistically how the DHX15 helicase acts in regulating Tregs, an area of considerable importance in both basic Treg biology and Treg- based therapies.