Autoreactive CD4 Tscm Development in Type 1 Diabetes

项目摘要 自身免疫性1型糖尿病（T1 D）是由T细胞介导的胰岛β细胞的破坏引起的， 导致对外源性胰岛素的终身依赖和危及生命的血糖事件的风险。因此，在本发明中， 胰岛自身反应性T细胞的缺失或免疫偏离是预防和治疗糖尿病的主要治疗目标， T1 D的治疗具有干细胞特性的记忆T细胞（Tscm）的存在提出了这样一种可能性， 它们在T1 D中充当自身反应性T细胞的持续储存库。然而，人们对它的存在知之甚少。 胰岛特异性CD 4 Tscm细胞在T1 D。我们发现了一个新的现象， 与健康供体相比，T1 D患者外周血中CD 4 T细胞区室中的Tscm （HD）.重要的是，我们还检测到外周血中具有Tscm表型的胰岛特异性CD 4 T细胞增加。 T1 D受试者的血液相对于HD，包括诊断后即刻和长达7年。转录物分析 的胰岛特异性CD 4 T细胞显示TCR、Wnt-β-catenin和IL-7信号传导基因集的表达增加 在来自T1 D受试者的细胞中，与HD相比，已知在CD 4 Tscm发育中起核心作用的途径。 需要进一步研究来证实T1 D中胰岛特异性CD 4 Tscm具有功能性Tscm特性， 确定导致T1 D中Tscm细胞频率增加的机制。我们假设胰岛特异性 T1 D中的CD 4 Tscm具有自我更新和分化为中枢和效应记忆的能力 在T1 D中，由于TCR、Wnt-β-连环蛋白和/或细胞因子信号传导的升高而增加。我们将 在两个具体目标中阐述我们的假设。目的1：研究T1 D患者胰岛特异性CD 4 Tscm细胞是否与T1 D相关， 受试者具有记忆干细胞群的表型和功能特性。我们将评估 转录谱、端粒长度、存活率以及胰岛特异性细胞自我更新和分化的潜力。 CD 4 Tscm与总CD 4初治、Tscm、中枢记忆（Tcm）和效应记忆（Tem）人群的比较 在T1 D患者的外周血中。CD 8 Tscm细胞的特性将作为参考。作为 为了控制疾病，我们将比较总CD 4幼稚，Tscm，Tcm和Tem的转录谱和功能， 来自匹配HD的外周血中的群体。目标2将检验信号通路 与HD相比，T1 D受试者中的Tscm升高，有助于增加 胰岛特异性CD 4 Tscm细胞。我们将比较TCR、Wnt-β-catenin和IL-7 R通路的表达， 来自T1 D受试者和HD的CD 4幼稚T细胞中的信号传导。同时，我们将确定这些途径 有助于T1 D受试者中CD 4 Tscm细胞的上级分化或存活，与HD相比， 在Wnt抑制剂/激动剂和IL-7的存在或不存在下，肽或多克隆刺激。拟议 这项研究适用于R21机制，因为它是对一种新的自身反应机制的探索性研究。 T1 D的细胞类型这些结果将为靶向自身反应性以预防和治疗T1 D开辟新的研究领域。

PROJECT SUMMARY Autoimmune type 1 diabetes (T1D) results from T cell-mediated destruction of pancreatic beta cells in the islet, leading to lifelong dependence on exogenous insulin and risk of life-threatening glycemic events. As a result, deletion or immune deviation of islet-autoreactive T cells is a major therapeutic goal in the prevention and treatment of T1D. The existence of memory T cells with stem cell properties (Tscm) raises the possibility that they serve as an ongoing reservoir of autoreactive T cells in T1D. However, little is known about the presence of islet-specific CD4 Tscm cells in T1D. We have made the novel observation that there is an increased frequency of Tscm within the CD4 T cell compartment in peripheral blood from T1D patients compared with healthy donors (HD). Importantly, we also detected increased islet-specific CD4 T cells with a Tscm phenotype in the peripheral blood of T1D subjects relative to HD, both immediately and up to 7 years following diagnosis. Transcript analysis of islet-specific CD4 T cells showed increased expression of TCR, Wnt-β-catenin, and IL-7 signaling gene sets in cells from T1D subjects compared to HD, pathways known to play a central role in CD4 Tscm development. Further study is required to confirm that islet-specific CD4 Tscm in T1D have functional Tscm properties and to determine the mechanism leading to increased Tscm cell frequency in T1D. We hypothesize that islet-specific CD4 Tscm in T1D have the capacity for self-renewal and differentiation into central and effector memory T cells, and are increased in T1D due to elevated TCR, Wnt-β-catenin, and/or cytokine signaling. We will address our hypothesis in two specific aims. Aim 1 will investigate whether islet-specific CD4 Tscm cells in T1D subjects have phenotypic and functional properties of a memory stem cell population. We will evaluate the transcript profile, telomere length, survival, and the potential for self-renewal and differentiation of islet-specific CD4 Tscm compared to total CD4 naïve, Tscm, central memory (Tcm) and effector memory (Tem) populations in peripheral blood from T1D patients. The characteristics of CD8 Tscm cells will serve as a reference. As a control for disease, we will compare transcript profiles and function of total CD4 naïve, Tscm, Tcm, and Tem populations in peripheral blood from matched HD. Aim 2 will test the hypothesis that signaling pathways supporting the development of CD4 Tscm are elevated in T1D subjects versus HD, contributing to increased islet-specific CD4 Tscm cells in T1D. We will compare TCR, Wnt-β-catenin, and IL-7R pathway expression and signaling in CD4 naïve T cells from T1D subjects and HD. In parallel, we will determine if these pathways contribute to superior differentiation or survival of CD4 Tscm cells in T1D subjects vs. HD in response to islet peptides or polyclonal stimulation in the presence or absence of Wnt inhibitors/agonists and IL-7. The proposed study is appropriate for the R21 mechanism because it is an exploratory investigation of a novel autoreactive cell type in T1D. The results will open new areas of inquiry for targeting autoreactivity to prevent and treat T1D.