Mechanisms of regulatory T cell processes by IL-2

自身免疫性疾病是美国年轻和中年妇女死亡的主要原因之一。 这些疾病是由自身反应性T细胞介导的，而自身反应性T细胞天然地包含在调节性T细胞中 （Tennis）. IL-2受体（IL-2 R）的非功能性突变导致Treg缺陷导致自身免疫 生存和功能。这一发现得到了体内小鼠模型的证实，导致了广泛的 结论IL-2对Treg的存活具有重要作用。然而，最近的数据表明，这是过于简单化。我们实验室 研究了一种小鼠模型，其中外周T细胞上IL-2 R的α链（CD 25）被条件性地 消融。CD 25基因敲除的TcR表现出中心TcR的不成比例的损失，其是长寿命的。 产生效应物以维持自身耐受性的循环TdR。批量敲除THEX还显示 关键Treg过程如增殖、存活、代谢和抑制功能的破坏。 此外，在IL-2 R突变动物中不存在高度抑制性终末分化的TcR， 表明IL-2可能调节维持外周血淋巴细胞增殖所需的高度抑制性T细胞因子的形成， 宽容鉴于这些发现，IL-2信号传导控制着预防糖尿病所必需的过程。 自身免疫和了解这一作用可以提供治疗途径来操纵这一群体。目的 1将确定IL-2对Treg亚群中的存活、增殖、功能和代谢的影响。 使用流式细胞术和体外测定，将对增殖、凋亡、存活、功能和代谢进行分析。 在有和没有IL-2信号传导的Tregs亚群中进行检查。这一目标将告知IL-2在多大程度上 调节T细胞亚群中的细胞过程，以进一步确定IL-2维持Treg的方式 人口。目的2探讨IL-2在调节性T细胞分化和异质性中的作用。由于缺陷 在IL-2的情况下，在TcG的分化中观察到，该目的将使用过继转移的Treg 具有和不具有IL-2信号传导的亚群，以确定IL-2如何调节从cT细胞的eT细胞的发展。 目的3将明确不同的IL-2依赖的转录和表观遗传过程中的cTGFAP与 电子邮件这一目标将利用高通量技术，如RNAseq和ATAC-seq， 在Treg亚群中，由于IL-2信号传导或缺乏IL-2信号传导而引起的表观遗传和转录变化。通过 定义IL-2依赖性途径和它们之间不同的细胞过程，这些发现将是 与目标1中的那些整合，以提供IL-2在调节每个Treg中的细胞过程中的明确作用。 子集这项研究的主要目标是确定IL-2驱动的过程协调Treg 与理解该细胞因子治疗应用密切相关的存活和稳态 并且与理解自身免疫性疾病广泛相关。

Autoimmune disease is one of the leading causes of death for young and middle-aged women in the US. These diseases are mediated by autoreactive T cells, which are naturally contained by T regulatory cells (Tregs). Non-functional mutations in the IL-2 receptor (IL-2R) lead to autoimmunity due to deficiencies in Treg survival and function. This finding is corroborated by in vivo mouse models, leading to the widespread conclusion that IL-2 is important for Treg survival. However, recent data indicates this is oversimplified. Our lab studies a mouse model in which the alpha chain (CD25) of the IL-2R on peripheral Tregs is conditionally ablated. CD25 knockout Tregs demonstrate a disproportionate loss of central Tregs, which are long-lived circulating Tregs that give rise to effectors to maintain self-tolerance. Bulk knockout Tregs also display disruptions in critical Treg processes such as proliferation, survival, metabolism and suppressive function. Additionally, there is an absence of highly suppressive terminally differentiated Tregs in IL-2R mutant animals, indicating IL-2 may regulate the development of highly suppressive Tregs required for maintain peripheral tolerance. Given these findings, IL-2 signaling controls processes that are essential for the prevention of autoimmunity and understanding this role can provide therapeutic avenues to manipulate this population. Aim 1 will determine the effects of IL-2 on survival, proliferation, function and metabolism in Treg subsets. Using flow cytometry and in vitro assays, proliferation, apoptosis, survival, function and metabolism will be examined in Tregs subsets with and without IL-2 signaling. This aim will inform the extent to which IL-2 regulates cellular processes in Tregs subsets to further define the way by which IL-2 maintains Treg populations. Aim 2 will evaluate the role of IL-2 in Treg differentiation and heterogeneity. Due to defects observed in the differentiation of Tregs in the setting of IL-2, this aim will use adoptively transferred Treg subsets with and without IL-2 signaling to determine how IL-2 regulates development of eTregs from cTregs. Aim 3 will define the distinct IL-2 dependent transcriptional and epigenetic processes in cTregs versus eTregs. This aim will harness high throughput techniques such as RNAseq and ATAC-seq to correlate epigenetic and transcriptional changes as a consequence of IL-2 signaling, or lack thereof, in Treg subsets. By defining IL-2-dependent pathways and cellular processes that differ between them, these findings will be integrated with those in aim 1 to provide a clear role for IL-2 in regulating the cellular processes in each Treg subset. The main objective of this fellowship research is to define IL-2 driven processes coordinating Treg survival and homeostasis that are acutely relevant for understanding therapeutic applications of this cytokine and broadly relevant for understanding autoimmune disease.