T regulatory cell subsets at the microbial interface: determinism and function

微生物界面的 T 调节细胞亚群：决定论和功能

• 批准号: 9892948
• 负责人: CHRISTOPHE O. BENOIST
• 金额: $ 42.38万
• 依托单位: HARVARD MEDICAL SCHOOL
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-04-01 至 2022-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9892948
• 关键词: ATAC-seq; Acute; Address; Affect; Agonist; Bar Codes; CD4 Positive T Lymphocytes; Cells; Characteristics; Chemicals; Chromatin; Chromatin Structure; Colitis; Colon; Complement; Equilibrium; FOXP3 gene; GATA3 gene; Gastrointestinal tract structure; Gene Expression Profile; Genetic Transcription; Human; Immune Tolerance; Immunoglobulin A; In Vitro; Infection; Inflammation; Inflammatory; Intestines; Investigation; Knock-out; Knockout Mice; Ligands; Location; LoxP-flanked allele; Maintenance; Microbe; Molecular; Mus; Outcome; Pathogenicity; Pathway interactions; Peripheral; Phenotype; Physiology; Play; Population; Population Control; Property; Regulatory T-Lymphocyte; Role; Shapes; Steroids; T-Lymphocyte; T-cell receptor repertoire; Testing; Thymus Gland; Time; Transgenes; Ursidae Family; combinatorial; commensal microbes; conditional knockout; congenic; experimental study; gut microbiota; in vivo; inflammatory disease of the intestine; intestinal barrier; microbial; microbiome; prevent; receptor; response; symbiont; synergism; tissue repair; transcription factor; transcriptome sequencing

Peaceful coexistence with the essential microbes that populate the mammalian gut requires a careful balance between tolerance of commensals, maintenance of barrier function, and avoidance of damaging inflammation. A key role is played by FoxP3+ T regulatory (Treg) cells, which help maintain immunologic tolerance and control inflammation in many organismal contexts. We have recently described the induction by several symbionts from the human gut of a unique population of FoxP3+ Treg cells that also express and require functionally the transcription factor RORg. This is paradoxal, as RORg is the master regulator of pro- inflammatory Th17 cells. Rorg+ Treg cells expand in response to gut symbionts, perhaps through local differentiation, and are functionally involved in the control of intestinal inflammation. They co-exist in the colon with more typical Helios+Gata3hi Tregs, likely of thymic origin. We propose to address several important questions opened by these observations, to explore the control, origin and function of Rorg+ Tregs. 1. How do FoxP3 and RORg synergize at the molecular level, and how does RORg function so differently in Th17 cells vs Rorg+ Tregs? This will be addressed by analyzing transcription and chromatin changes resulting from carefully controlled expression of FoxP3 and RORg in CD4+ T cells, modulated with other transcription factors that are differentially represented in Th17 and Tregs, or with oxysterol ligands of RORg. These inferences will be validated in vivo with conditional knockout mice, and their relevance to human physiology will be assessed by transducing human CD4+ T cells in parallel, and by low-input RNAseq analysis of Rorg+ Tregs we found in the human colon. 2. What are the cellular origin and differentiation pathways of Rorg+ Tregs? The origin and inter- relationships between colonic Treg subsets in the colon will be analyzed by transfer experiments, by lineage tracing after Treg-specific tagging, and by using TCR sequences as barcodes to assess relationships between Treg and Tconv populations in mice colonized by a single microbe 3. Relative roles of RORg+ and Helios+ colonic Tregs assessed by inducing Treg-specific knockouts in the key transcription that reciprocally control colonic Treg populations (Rorc, Gata3, Ikzf2). The effects of these perturbations will be assessed on colon inflammation at baseline, the control of chemical or bacterially- induced inflammation, intestinal barrier integrity, microbe-specific IgA repertoire and whether changes in Treg populations influence the balance of microbial phyla and species. These connected explorations will provide a unique mechanistic and functional understanding of these essential Treg populations, and will have profound implications on our understanding of the control of inflammation at the host/symbiont interface.

与充满哺乳动物肠道的必要微生物的和平共存需要谨慎 在共生的容忍度，障碍功能的维护和避免损害之间的平衡 炎。 FOXP3+ T调节性（TREG）细胞扮演关键角色，该细胞有助于维持免疫学 在许多生物环境中的耐受性和控制炎症。我们最近通过 来自人类肠道中的几个共生体，这些群体的foxp3+ treg细胞的独特群体也表达和 在功能上需要转录因子RORG。这是悖论，因为Rorg是Pro-的主要调节剂 炎症性Th17细胞。 Rorg+ Treg细胞会响应肠道共生体，也许是通过局部 分化，并在功能上与肠炎的控制有关。他们共存于结肠 具有更典型的Helios+Gata3hi Treg，可能是胸腺起源。我们建议解决一些重要的 这些观察结果开头的问题，以探索Rorg+ Tregs的控制，起源和功能。 1。Foxp3和Rorg如何在分子水平上协同作用，Rorg如何运作如此 在Th17细胞中与RORG+ Tregs不同？这将通过分析转录和染色质来解决 CD4+ T细胞中FOXP3和RORG经过精心控制的表达而产生的变化，该细胞调制了 在Th17和Tregs中差异表示的其他转录因子，或带有氧 罗格。这些推论将通过有条件的敲除小鼠在体内验证，它们与人的相关性 生理学将通过并行转导人CD4+ T细胞以及低输入RNASEQ分析来评估生理。 我们在人类结肠中发现的Rorg+ Treg。 2。rorg+ treg的细胞起源和分化途径是什么？起源和间 结肠中的结肠Treg子集之间的关系将通过转移实验分析，通过谱系 跟踪Treg特异性标签，并使用TCR序列作为条形码来评估 由单个微生物定居的小鼠中的Treg和TCONV种群 3。通过诱导Treg特异性敲除评估的Rorg+和Helios+结肠Treg的相对作用 在相互控制结肠Treg种群的关键转录中（Rorc，Gata3，ikzf2）。效果 这些扰动将在基线时对结肠炎症进行评估，对化学或细菌的控制 诱导的炎症，肠壁完整性，微生物特异性IgA库以及Treg的变化是否变化 种群影响微生物门和物种的平衡。 这些连接的探索将为这些提供独特的机械和功能理解 Treg的基本人口，将对我们对控制的理解产生深远的影响 主机/共生体接口处的炎症。