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to injury; simulation; stroke outcome; stroke therapy; therapeutic target; transcription factor; translational study; unpublished works; γδ T cells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.

项目摘要 中风是美国的一种毁灭性疾病，是美国的死亡和残疾原因。缺血性中风 导致众多免疫细胞的大量激活，这些免疫细胞会在血脑内屏障后会浸润大脑 分解。肠道菌群先前已被确定为影响结果和 临床研究和动物模型中缺血性中风的严重程度。但是，机制是 中风后菌群对免疫细胞的调节作用尚不清楚。树突状细胞（DC）充当 先天性和适应性免疫之间的桥梁，其能够从肠腔中采样材料和 形状T细胞响应。抗生素诱导的小鼠菌群改变导致中风神经保护 与携带的对照小鼠相比 常规的微生物群，经过类似的处理，但携带抗生素抗生素的微生物群，导致 微生物群类似于幼稚小鼠。这种效果归因于肠道和肠系膜的更大能力 携带“改变”微生物群的小鼠的淋巴结树突状细胞，以诱导小型T-调节细胞（Treg） 随后抑制破坏性的促炎性IL-17+γδT细胞的肠道流动到大脑 下风。使用我们的体外模型模拟肠道DC-T细胞相互作用，我们表明启动幼稚 来自含有“改变”或“常规”微生物群的小肠（SIC）的孤立含量的DC 随后与CD4细胞共培养同样会引起小鼠SIC的更大比例 与具有“常规”菌群的小鼠的SIC相比，携带“改变”的微生物群。该提议试图 阐明改变微生物群可能会导致模式识别受体的变化或 造成DC耐受性表型和Treg诱导的Toll样受体配体 小鼠的菌群改变。使用各种体外和体内方法，我旨在识别直流受体 以及负责感知这些腔内含量并产生耐受性表型的信号机制， 确定DC产生的信号/细胞因子诱导肠道的必要 中风神经保护症中的炎症IL-6与携带“改变”或“常规”的小鼠的中风结果 微生物群。总而言之，我试图了解肠道直流接收器如何依赖微生物群 可以充当肠道免疫和中风结果的调节剂，并确定潜在的治疗靶标。