Robust immune tolerance conferred by Foxp3 transcriptional regulation

Foxp3转录调控产生强大的免疫耐受 调节性T(Treg)细胞主动抑制导致多种自身免疫的自杀性T细胞 疾病。尽管取得了重大进展，但基于Treg的治疗明显受限于有限的方法 提高Treg抑制能力。我们的目标是剖析Treg诱导和谱系的机制过程。 维护以揭示赋予强大免疫抑制功能的因素和机制。Treg细胞 是由传递给分化T细胞的环境线索的汇聚引起的 变异，导致随机Treg发展。此外，遗传要素的DNA序列 调节Treg血统的身份也因个体而异。鉴于T细胞抗原的巨大多样性 受体(TCR)和靶的特异性，Treg细胞的诱导有许多不确定性。一旦承诺，特雷格 命运由细胞内在和外在因素维持着延长的抑制功能，不断地 波动。所有这些不确定性都提出了一个问题，即Treg细胞如何赋予强大的免疫耐受性。 对Treg主调控子Foxp3的研究为解决这个问题提供了一种独特的方法，因为Foxp3 表达中心是Treg命运的决定和功能。我们假设有足够的缓冲能力 由高效的Treg发育和血统稳定授予的反对遗传变异和免疫 微扰。为了验证这一假设，我们研究了决定Treg诱导和谱系的Foxp3增强子 稳定性。已知单个Foxp3增强子在Foxp3的诱导或维持中发挥阶段特异性的作用。 然而，携带其个别突变的小鼠即使有明显的免疫失调，也会出现轻微的免疫失调 Treg发育或血统稳定性存在缺陷。为了解开这个谜团，我们研究了表观遗传机制。 介导Foxp3表达并假设Foxp3增强子协同作用可有效诱导Treg 或稳定的血统认同，以获得足够的Treg缓冲能力。 我们产生了新的小鼠品系来测试我们的假设，并发现两个相互作用的Foxp3的缺失 增强剂导致致命性自身免疫性疾病并伴有严重的Treg诱导或谱系缺陷 稳定性。这一结果与其他研究一起描绘了获得的Treg缓冲容量的全谱 通过协调Foxp3增强子。在这项拟议的研究中，我们将充分揭示 Treg诱导或谱系稳定性严重降低的小鼠的后果。我们将开发新的算法 并使用单细胞RNA测序来评估Treg谱系的多样性和谱系稳定性以推断Treg缓冲 容量。我们还将使用我们新开发的小鼠遗传工具来确定连续胸腺的作用 Treg诱导以维持Treg缓冲容量。 总体而言，我们的研究将揭示Foxp3所赋予的Treg抑制能力的全谱 转录调控。这将提高我们对Treg相关自身免疫性疾病的基本理解。

Robust immune tolerance conferred by Foxp3 transcriptional regulation Regulatory T (Treg) cells actively suppress self-destructive T cells that cause a variety of autoimmune diseases. Despite significant progress, Treg-based treatment is significantly constrained by limited methods to improve Treg suppressive capacity. We aim to dissect the mechanistic processes of Treg induction and lineage maintenance to uncover the factors and mechanisms conferring robust immune suppressive function. Treg cells are induced by the convergence of environmental cues delivered to differentiating T cells with considerable variations, resulting in stochastic Treg development. Besides, the DNA sequences of the genetic elements regulating Treg lineage identity also vary among individuals. Given the enormously diverse T cell antigen receptors (TCRs) and target specificities, Treg cells are induced with many uncertainties. Once committed, Treg fate is maintained for extended suppressive function by cell-intrinsic and -extrinsic factors that constantly fluctuate. All these uncertainties raise a question about how robust immune tolerance is conferred by Treg cells. Study of Treg master regulator Foxp3 offers a unique approach to address this question, because Foxp3 expression centers Treg fate determination and function. We hypothesize that an adequate buffering capacity conferred by efficient Treg development and lineage stability opposes the genetic variations and immune perturbations. To test this hypothesis, we examined the Foxp3 enhancers that dictate Treg induction and lineage stability. Individual Foxp3 enhancers were known to play stage-specific roles in Foxp3 induction or maintenance. However, mice bearing their individual mutations develop mild if any immune dysregulation despite significant defects in Treg development or lineage stability. To solve this mystery, we examined the epigenetic mechanisms mediating Foxp3 expression and hypothesize that Foxp3 enhancers coordinate to enable efficient Treg induction or stable lineage identity for adequate Treg buffering capacity. We generated new mouse strains to test our hypotheses and found that deletion of two interacting Foxp3 enhancers caused fatal autoimmune diseases accompanied with severe defects of Treg induction or lineage stability. This result together with other studies delineates a full spectrum of Treg buffering capacity acquired through coordinating Foxp3 enhancers. In the proposed study, we will fully uncover the immunological consequences of mice with severely reduced Treg induction or lineage stability. We will develop new algorithms and use single cell RNA sequencing to assess Treg repertoire diversity and lineage stability to infer Treg buffering capacity. We will also use our newly developed mouse genetic tools to determine the role of continuous thymic Treg induction in maintaining the Treg buffering capacity. Overall, our study will uncover a full spectrum of Treg suppressive capacity conferred by Foxp3 transcriptional regulation. It will improve our basic understanding of Treg-related autoimmune diseases.