A novel population of PLZF+CD8+ regulatory T cells: phenotype and function

调节性T细胞(Treg)介导的免疫耐受在控制炎症和 自身免疫性疾病。由于缺乏CD8 Treg的分子标记，目前尚缺乏CD8 Treg的详细生物学研究 它们与传统的CD8+T细胞(CD8conv)不同，因为Foxp3的表达是针对CD4 Treg。我们有 发现早幼粒细胞白血病锌指(PLZF)转录因子与 其他标记将新的、非传统的CD8 Treg群体与其他CD8conv以及 非常规T细胞。虽然CD8 Treg在幼稚小鼠的肝脏中丰富，但在其他动物中也存在 淋巴组织和人外周血单个核细胞，并显示激活/记忆表型和先天类似的属性 T细胞。我们的长期目标是研究CD8 Treg在小鼠和人类中的生物学特性，并了解 CD8Treg所采用的限制过度免疫刺激的负反馈调节机制(S)。 这些研究意义重大，因为它们不仅有可能揭示CD8 Treg介导的关键 分子机制(S)参与了免疫动态平衡的研究，也将对 自身免疫性疾病的新免疫疗法的发展。这笔赠款的目的是将 CD8-Treg的转录组特征、发育、激活/扩增及其调控机制 也是为了确定它们在人类中的分子和抑制功能。中环 假设PLZF转录程序允许获得CD8中的先天类似和记忆特征 Treg，使他们能够通过靶向迅速有效地控制炎症性自身免疫反应 活化的T细胞和APC。基于我们关键的初步数据，这些数据表明了一种独特的表型 CD8Treg(PLZF+TCRαβ+CD8Treg+)，我们提出了以下具体目标：目的1.确定它们的唯一性 转录程序和分子途径，单细胞RNA测序分析CD8 Treg亚群将 在外周和发炎的中枢神经系统都可以进行。将使用骨髓嵌合方法来 确定PLZF转录因子在其发育和功能中的作用；目的2.确定关键的 交叉呈递机制在遗传缺陷小鼠CD8 Treg生理诱导中的作用 将使用CDC1.在PLZFF/F小鼠中CD8 Treg的基因缺失将破译它们在恢复和恢复中的作用 实验性自身免疫性脑脊髓炎的抵抗力。对调节分子来说是一个关键角色， 包括CD200和Fgl2，在抑制DC功能和/或诱导Th1/Th17方面将被阐明； 3.研究人CD8Treg的转录信号和抑制机制(S)， 从健康人的外周血液中分离的细胞将被使用。总而言之，我们建议的研究将有 在非常规T细胞新兴领域和CD8 Treg介导的调节中的重大影响 机制(S)参与了免疫耐受的维持。

Immune tolerance mediated by regulatory T cells (Treg) is important in the control of inflammatory and autoimmune diseases. The detailed biology of CD8 Treg is lacking due to the absence of molecular markers to distinguish them from conventional CD8+ T cells (CD8conv), as Foxp3 expression is for CD4 Treg. We have discovered that the expression of the promyelocytic leukemia zinc finger (PLZF) transcription factor together with other markers distinguishes a novel, unconventional CD8 Treg population from other CD8conv as well as unconventional T cells. Though, CD8 Treg are enriched in liver of naïve mice, they are also present in other lymphoid tissues and in human PBMC and display an activated/memory phenotype and attributes of innate-like T cells. Our long-term goal is to characterize the biology of CD8 Treg in both mice and humans and to understand the negative feedback regulatory mechanism(s) employed by CD8 Treg that limits excessive immune stimulation. These studies are highly significant as they will have potential to not only uncover a key CD8 Treg-mediated molecular mechanism(s) involved in immune homeostasis, but also will have major implications for the development of new immune therapies in autoimmune diseases. The objective of this grant is to characterize the transcriptome signature, development, activation/expansion and mechanism of regulation of CD8 Treg in murine models and also to determine their molecular and suppressive functions in humans. The central hypothesis is that the PLZF transcription program allows acquisition of innate-like and memory features in CD8 Treg that enables them to control promptly and effectively inflammatory autoimmune responses by targeting activated T cells as well as APCs. Based upon our critical preliminary data that indicate a unique phenotype of CD8 Treg (PLZF+TCRαβ+CD8αα+), we propose the following specific aims: Aim 1. To determine their unique transcriptional program and molecular pathways, single cell RNA sequencing analysis of CD8 Treg subsets will be carried out in both the periphery and in the inflamed CNS. A bone marrow chimeric approach will be used to determine the role of PLZF transcription factor in their development and function; Aim 2. To determine the critical role of the cross-presentation mechanism in the physiological induction of CD8 Treg, mice genetically lacking cDC1 will be used. Genetic depletion of CD8 Treg in PLZFF/F mice will decipher their role in the recovery and resistance from experimental autoimmune encephalomyelitis. A critical role for the regulatory molecules, including CD200 and Fgl2, in the inhibition of DC function and/or Th1/Th17 induction will be elucidated; and Aim 3. To characterize the transcriptional signature and suppressive mechanism(s) involved in human CD8 Treg, sorted cells from peripheral blood of healthy individuals will be used. Collectively, our proposed studies will have a major impact in the emerging field of unconventional T cells and in the CD8 Treg-mediated regulatory mechanism(s) involved in the maintenance of immune tolerance.