Microbiota Control Lung Th17 Cell Response and Plasticity Leading to Autoimmune Lung Disease

项目摘要。 肺部并发症是类风湿关节炎（RA）患者常见的主要死亡原因。 治疗是有限的，关节炎调节药物实际上可以恶化类风湿关节炎患者的肺部疾病，但很少 关于RA相关的肺发病机制是已知的。很明显，肠道和肠道微生物群具有强烈的 影响许多肺部疾病。从机制上讲，这种被称为肠-肺轴的现象， 定义了我们报道了通过肠肺通讯，一种肠寄生的，分节的丝状细菌 (SFB)能够扩增表达双重T细胞受体（TCR）的辅助性T细胞17（Th 17）细胞，导致肺 三级淋巴结构（TLS），病变往往与自身免疫性患者的预后不良。到 了解肠肺轴，我们建议解决的机制利用SFB促进Th 17细胞 反应、肠-肺迁移和肺TLS形成。缺氧诱导因子-1 α（HIF-1α）感知O2， 缺氧组织，例如肠和发炎组织，并且已知其增强糖酵解并促进Th 17细胞 分化最近的研究报道了组织培养室中T细胞的再氧合大大增强了T细胞的增殖。 HIF-1a诱导。重要的是，肠道（缺氧）来源的T细胞进入肺（常氧）可能面临类似的O2 变化我们假设并将测试肠道微生物群是否与肺复氧相结合- 调节肠源性肺CD 4 + T细胞中HIF-1α的表达，促进其糖酵解活性和Th 17细胞 承诺和肺部疾病恶化。使用KikGR光转换模型追踪T细胞从肠道到 肺，我们的新数据支持我们的假设，显示KikR（肠道来源）中的HIF-1α水平高于KikG CD 4 + SFB+小鼠的肺而非脾中存在T细胞。CCR 6由Th 17细胞高度表达。我们的新数据显示， 2型肺泡上皮细胞（AEC 2）产生丰富的CCL 20，CCL 20是自身免疫前炎症中的CCR 6配体。 疾病阶段。我们将测试肺微生物群和先天信号是否是AEC 2的CCL 20所必需的。 通过使用AEC 2特异性MyD 88和CCL 20消耗来检测Th 17细胞表达和Th 17细胞募集。最近，Gut 微生物群已显示局部诱导共表达Rorγt+和Foxp 3+的有趣的肠道T细胞类型， Th 17细胞和T细胞的主要调节因子。然而，肠道微生物群是否以及如何远程调节T 肺中的细胞可塑性仍然未知。我们的新数据表明，IL-17+ Foxp 3+细胞的独特群体 在SFB+小鼠的肺中比SFB−小鼠显著增加。我们将通过调节性T细胞的命运来检查T细胞的可塑性。 映射，并使用单细胞TCR分析来分析微生物群偏斜的双TCR库是否允许 Foxp 3 + T细胞以获得Th 17样表型。最后，我们将使用Cre-loxP系统来解决“好 IL-17+ Foxp 3 + T细胞在肺自身免疫中的“或恶”功能。通过采用一种独特的方法来追踪肠肺 串扰，这一建议允许研究，以揭示病因学的肠肺轴，有助于铺平道路， 设计未来的治疗方法，以对抗肠-肺轴相关疾病。

Project Summary. Lung complications are a common and major cause of death in patients with rheumatoid arthritis (RA). Therapies are limited, and arthritis modulating drugs can actually worsen lung disease in RA patients, yet little is known regarding RA-related lung pathogenesis. It is evident that the gut and gut microbiota have a strong influence in many lung diseases. Mechanistically, this phenomenon known as the gut-lung axis, is poorly defined. We reported that through gut-lung communication, a gut commensal, segmented filamentous bacteria (SFB) are able to expand dual T cell receptor (TCR)-expressing T helper 17 (Th17) cells, leading to lung tertiary lymphoid structures (TLS), lesions often associated with poor prognosis in autoimmune patients. To understand gut-lung axis, we propose addressing the mechanisms utilized by SFB to promote a Th17 cell response, gut-lung migration, and lung TLS formation. Hypoxia-inducible factor-1α (HIF-1α) senses O2 in hypoxic tissues, e.g. the gut and inflamed tissues, and is known to enhance glycolysis and promote Th17 cell differentiation. Recent studies reported reoxygenation of T cells in tissue culture chambers greatly enhances HIF-1a induction. Importantly, gut (hypoxic)-derived T cells entering the lung (normoxic) may face similar O2 changes. We hypothesize and will test whether the gut microbiota in combination with lung reoxygenation up- regulate HIF-1α expression in gut-derived lung CD4+ T cells, promoting their glycolytic activity and Th17 cell commitment, and worsening lung disease. Using the KikGR-photoconvertible model to trace T cells from gut to lung, our new data favor our hypothesis by showing a higher HIF-1α level in KikR (gut-derived) than KikG CD4+ T cells in lung but not spleen of SFB+ mice. CCR6 is highly expressed by Th17 cells. Our new data show that type 2 alveolar epithelial cells (AEC2) produce abundant CCL20, the CCR6 ligand in the pre-autoimmune disease phase. We will test whether lung microbiota and innate signaling are required for AEC2s’ CCL20 expression and Th17 cell recruitment by using AEC2-specific MyD88 and CCL20 depletions. Recently, gut microbiota have been shown to locally induce an intriguing gut T cell type co-expressing Rorγt+ and Foxp3+, master regulators of Th17 cells and Tregs. However, whether and how gut microbiota can remotely regulate T cell plasticity in the lung remains unknown. Our new data show that a unique population of IL-17+Foxp3+ cells is significantly increased in lung of SFB+ over SFB− mice. We will examine T cell plasticity by Treg fate mapping, and use single cell TCR analysis to analyze whether a microbiota-skewed dual TCR repertoire allows Foxp3+ T cells to acquire a Th17-like phenotype. Finally, we will use the Cre-loxP system to address the “good or evil” function of IL-17+Foxp3+ T cells in lung autoimmunity. By taking a unique approach of tracking gut-lung crosstalk, this proposal permits studies to reveal the etiology of gut-lung axis, helping to pave the way for the designing of future therapies to combat gut-lung axis-related diseases.