Intestinal Microbiota Affect Stroke Outcome by Modulating the Dendritic Cell-regulatory T Cell Axis

肠道微生物群通过调节树突状细胞调节 T 细胞轴影响中风结果

• 批准号: 10751249
• 负责人: Emma O'Cinneide
• 金额: $ 4.77万
• 依托单位: WEILL MEDICAL COLL OF CORNELL UNIV
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-01 至 2025-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10751249
• 关键词: Adaptive Immune System; Affect; Alteplase; Amoxicillin; Animal Model; Anti-Inflammatory Agents; Antibiotic Resistance; Antibiotics; Bacteria; Blood - brain barrier anatomy; Brain; CD4 Positive T Lymphocytes; Cause of Death; Cell Communication; Cell Separation; Cells; Clinical Research; Coculture Techniques; Coupled; Data; Dendritic Cells; Diet; Diffusion; Disease; Equilibrium; Exhibits; Functional disorder; Gastrointestinal Diseases; Goals; IL17 gene; Immune; Immunity; In Vitro; Incubated; Infection; Infiltration; Inflammatory; Innate Immune System; Interleukin-6; Intervention; Intestinal Content; Intestines; Ischemic Brain Injury; Ischemic Stroke; Ligands; Link; Mediating; Mediator; Middle Cerebral Artery Occlusion; Modeling; Molecular; Mus; NF-kappa B; Natural Immunity; Outcome; Pathology; Pathway interactions; Patients; Pattern recognition receptor; Phenotype; Predisposition; Prevalence; Production; Prognostic Factor; Property; Public Health; Publishing; Receptor Cell; Regulatory T-Lymphocyte; Research; Role; Sampling; Severities; Shapes; Signal Transduction; Small Intestines; Stroke; Study models; T cell response; T-Lymphocyte; Tissues; Toll-like receptors; United States; adaptive immunity; comparison control; cytokine; disability; gut microbiota; immunoregulation; improved; in vitro Model; in vivo; insight; ischemic injury; mesenteric lymph node; microbial composition; microbiota; neuroprotection; pathogen; polarized cell; programs; response; response to injury; simulation; stroke outcome; stroke therapy; therapeutic target; transcription factor; translational study; unpublished works; γδ T cells

PROJECT SUMMARY Stroke is a devastating disease and leading cause of death and disability in the United States. Ischemic stroke results in massive activation of numerous immune cells that can infiltrate the brain following blood-brain-barrier breakdown. The gut microbiota has previously been identified as a significant factor affecting outcome and severity of ischemic stroke in clinical studies and animal models. However, mechanisms underlying the modulatory role of microbiota on immune cells following stroke remain unclear. Dendritic cells (DCs) act as the bridge between innate and adaptive immunity, with their ability to sample material from the intestinal lumen and shape T-cell responses. Antibiotic-induced alteration of microbiota in mice results in stroke neuroprotection in mice following middle cerebral artery occlusion model of ischemic stroke compared to control mice carrying conventional microbiota, which are similarly treated but carry antibiotic-resistant microbiota resulting in microbiota similar to that of naïve mice. This effect is attributed to the greater capacity of intestinal and mesenteric lymph node dendritic cells of mice carrying “altered” microbiota to induce T-regulatory cells (Tregs) in the small intestine which subsequently suppress destructive pro-inflammatory IL-17+ γδ T cells that traffic to the brain following stroke. Using our in vitro model to simulate intestinal DC-T cell interactions, we show that priming naïve DCs with isolated contents from the small intestine (SIC) of mice carrying “altered” or “conventional” microbiota and subsequent co-culture with CD4 cells similarly induces greater proportions of Tregs following SIC from mice carrying “altered” microbiota compared to SIC from mice with “conventional” microbiota. This proposal seeks to elucidate the mechanism by which altering microbiota may result in changes in pattern-recognition receptors or toll-like receptor ligands that are responsible for a DC-tolerizing phenotype and Treg induction observed with microbiota alteration in mice. Using a variety of in vitro and in vivo approaches, I aim to identify the DC receptors and signaling machinery responsible for sensing these luminal contents and producing a tolerogenic phenotype, determine DC-produced signals/cytokines necessary for intestinal Treg induction, and establish the role of pro- inflammatory IL-6 in stroke neuroprotection vs poor stroke outcome in mice carrying “altered” or “conventional” microbiota. In summary, I seek to understand how intestinal DC receptor ligands that are microbiota-dependent can act as regulators of intestinal immunity and stroke outcome, as well as identify potential therapeutic targets.

项目概要 中风是一种毁灭性的疾病，也是美国缺血性中风导致死亡和残疾的主要原因。 导致大量免疫细胞被激活，这些免疫细胞可以通过血脑屏障渗透到大脑中 肠道微生物群的分解先前已被确定为影响结果和的重要因素。 临床研究和动物模型中缺血性中风的严重程度然而，其背后的机制。 微生物群对中风后免疫细胞的调节作用仍不清楚。 先天性免疫和适应性免疫之间的桥梁，能够从肠腔中采样物质并 抗生素诱导的小鼠微生物群改变可导致中风神经保护。 缺血性中风大脑中动脉闭塞模型小鼠与对照组小鼠相比 传统微生物群，经过类似处理，但携带抗生素抗性微生物群，导致 微生物群与幼鼠相似，这种效应归因于肠道和肠系膜容量更大。 携带“改变的”微生物群的小鼠的淋巴结树突状细胞可在小细胞中诱导 T 调节细胞 (Treg) 随后抑制输送至大脑的破坏性促炎性 IL-17+ γδ T 细胞 使用我们的体外模型来模拟肠道 DC-T 细胞相互作用，我们证明了初始启动（priming naïve）。 含有从携带“改变的”或“传统”微生物群的小鼠小肠 (SIC) 中分离出的 DC 随后与 CD4 细胞共培养同样会在小鼠 SIC 后诱导更大比例的 Tregs 与具有“传统”微生物群的小鼠的 SIC 相比，携带“改变的”微生物群该提案旨在 阐明改变微生物群可能导致模式识别受体变化的机制或 Toll 样受体配体负责 DC 耐受表型和 Treg 诱导 我的目标是利用各种体外和体内方法来鉴定小鼠体内微生物群的变化。 和负责感知这些管腔内容物并产生耐受表型的信号机制， 确定 DC 产生的肠道 Treg 诱导所需的信号/细胞因子，并确定 pro- 炎性 IL-6 在中风神经保护中与携带“改变”或“传统”小鼠的不良中风结果 总之，我试图了解肠道 DC 受体配体如何依赖于微生物群。 可以作为肠道免疫和中风结果的调节剂，并确定潜在的治疗靶点。