Intrinsic modulators of Treg lineage commitment and immunoregulation post-transplantation

同种异体移植排斥反应是由受体对供体抗原的免疫反应介导的， 它由CD 4 + T细胞启动和协调，但也涉及其他复杂的问题，包括 次级淋巴器官内和移植物本身内的适应性反应。CD4+Foxp3+ 调节性T细胞（Treg）是维持自身耐受性的核心，调节免疫应答， 过度的免疫反应，实验性疗法使用它们的免疫调节作用， 抑制同种异体免疫和诱导对 同种异体移植然而，基于Treg的疗法受到其不稳定性和其潜在的免疫抑制作用的阻碍。 去分化成可以引发/引起排斥的效应细胞。我们以前的研究 表明DEPTOR由CD 4 + Treg细胞表达，在有丝分裂原刺激后显著降低， 激活，并且DEPTOR的持续表达通过激活而稳定谱系定型。 Foxp 3启动子的表观遗传调控和增加氧化代谢。体内，诱导 在胸腺内的DEPTOR表达足以促进免疫调节并抑制心脏收缩。 同种异体移植排斥反应。该提议检验了DEPTOR是Treg的中心调节剂的假设 亚群稳态和功能，以及维持免疫调节和耐受性是必要的 移植后。它还将测试DEPTOR是否通过一种新的调节信号发挥作用 网络和/或与不同Treg谱系或子集内的靶基因的新型相互作用。的 方法分为三个具体目标：第一，研究DEPTOR功能的机制， DEPTOR活性的TdR和mTOR非依赖性靶点;第二，系统地发现 增强Treg功能和谱系的扩展DEPTOR诱导的调节信号网络 第三，鉴定调节DEPTOR蛋白表达的小分子， 下游靶基因和/或调节信号传导活性作为潜在的促致耐受性治疗剂 毒品在K99的指导阶段，拟议研究的结果将确定新的 DEPTOR在Treg亚群中的作用，并发现DEPTOR对Treg的mTOR非依赖性作用 生物学这些研究将启动独立研究的R 00阶段， Treg亚群中负调节剂和/或靶基因的网络的机制功能，和 开发一种药理学筛选试验，以确定有潜力作为 诱导对同种异体移植物的免疫耐受性和/或作为治疗 自身免疫性疾病这项工作的更广泛的含义涉及到生物学的重要性， Treg靶向作为肿瘤免疫治疗的组成部分。

Allograft rejection is mediated by the recipient’s immunological response to donor antigen that is initiated and coordinated by CD4+ T cells, but it also involves other complex issues including adaptive responses within secondary lymphoid organs and within the graft itself. CD4+Foxp3+ regulatory T cells (Treg) are central to the maintenance of self-tolerance, the regulation of excessive immune responses, and experimental therapies use their immunoregulatory properties to suppress alloimmunity and to induce immunological tolerance towards the allograft. However, Treg based therapies are hindered by their instability and their potential to dedifferentiate into effector cells that can initiate/cause rejection. Our previous studies demonstrated that DEPTOR is expressed by CD4+ Treg cells, is markedly reduced upon mitogen activation, and that sustained expression of DEPTOR stabilizes lineage commitment via the epigenetic regulation of the Foxp3 promoter and by augmenting oxidative metabolism. In vivo, induced DEPTOR expression within Tregs is sufficient to promote immunoregulation and inhibit cardiac allograft rejection. This proposal tests the hypothesis that DEPTOR is a central modulator of Treg subset homeostasis and function, and that it is essential to maintain immunoregulation and tolerance following transplantation. It will also test whether DEPTOR functions via a novel regulatory signaling network and/or novel interactions with target genes within distinct Treg lineages or subsets. The approach is divided into three specific aims to: first, investigate mechanisms of DEPTOR function in Tregs and mTOR-independent targets of DEPTOR activity; second, systematically discover the extended DEPTOR-induced modulatory signaling network that enhances Treg function and lineage commitment; and third, identify small molecules that modulate DEPTOR protein expression, its downstream target genes and/or regulatory signaling activity as potential pro-tolerogenic therapeutic drugs. During the mentored phase of the K99, the results of the proposed studies will identify new roles for DEPTOR in Treg subsets and discover mTOR-independent effects of DEPTOR on Treg biology. These studies will launch the R00 phase of independent research to investigate the mechanistic function of the network of negative modulators and/or target genes in Treg subsets, and develop a pharmacological screening assay to identify small molecules that have potential as therapeutic drugs to induce immunological tolerance towards allografts and/or as a treatment for autoimmune disease. The broader implication of this work relates to the biological importance of Treg targeting as a component of tumor immunotherapy.