Activation, Phenotype and Function of CD4 T Cells in Schistosoma-Pulmonary Hypertension

摘要/摘要 炎症在肺动脉高压(PAH)的发病机制中起着重要作用，但 炎症是因果的，是另一种触发机制的放大，还是尚不清楚的附带现象。 以前在这一领域的研究主要集中在先天免疫、不育模型和单一细胞因子或细胞。 在缺乏明确的病理生物学背景的情况下--不能解决适应性疾病的各个方面的方法 免疫或先天适应性免疫串扰导致血管疾病。要解决这些问题 局限性，我们课题组研究的是血吸虫寄生虫，其中血吸虫病的病因可能是最多的 全球流行的多环芳烃形式。使用血吸虫-肺动脉高压(PH)小鼠模型，研究 前一阶段确定了一系列对PH发生至关重要的机械性事件：Th2激活 肺中的CD4T细胞；它将CCR2+Ly6c+单核细胞招募到外膜间隙，表达 血栓反应蛋白-1(TSP-1)；TSP-1在功能上激活潜在的转化生长因子-β，导致血管重构。 这个建议建立在这个基础上，现在通过询问适应性和先天免疫接口，我们 认为有必要对血吸虫-PH的发病机制进行研究。我们将研究扩展到翻译分析 人类生物菌群，寻找与重症高危人群中多环芳烃存在相关的蛋白质 血吸虫病。这一提议将检验肺内树突状细胞(DC)存在的假设 血吸虫抗原作用于支持Th2极化的CD4T细胞，导致间质激活 巨噬细胞(IM)，释放CCR2配体CCLS 2、7和12，推动TSP-1+单核细胞募集， 转化生长因子-β的激活和PH。我们还假设，增加PAH风险的关键蛋白-包括CCL2， 在人血浆中可以检测到CCL7、CCL12和TSP-1-。我们提出了四个目标。目标1将决定 在血吸虫-PH中，T细胞激活需要由特定DC亚群cDC2s提呈抗原。目标2 将确定Th1/Th2炎症平衡是否驱动单核/巨噬细胞和PH表型 血吸虫-PH。AIM 3将确定TSP1+单核细胞需要IMS释放CCL2/7/12 在血吸虫中的招募-PH。AIM 4将确定受试者中与PAH发展相关的血浆蛋白 患有血吸虫病。这一翻译目标将通过开发和描述两个队列来实现 从巴西4个临床中心招募的受试者：有血吸虫病前驱症状的受试者 超声心动图筛查不太可能有PAH的肝脾疾病(SchHSD)， 右心插管证实为PAH的SchHSD受试者。完成这些研究后， 了解先天免疫和获得性免疫在血吸虫-PAH发展中的作用，以及 为诊断和潜在治疗这种疾病的全新方法创造机会。我们建议 识别血液中与疾病存在相关的机制蛋白，促进高危筛查 低资源地区的受试者。

Summary/Abstract Inflammation has important roles in the pathogenesis of pulmonary arterial hypertension (PAH), but whether inflammation is causal, an amplifier of alternative triggering mechanisms, or an epiphenomenon remains unclear. Prior studies in this area have largely focused on innate immunity, sterile models, and single cytokines or cells in the absence of a well-defined pathobiological context—approaches that cannot address aspects of adaptive immunity or innate-adaptive immunity crosstalk which contribute to vascular disease. To address these limitations, our group studies the parasite Schistosoma, the cause of schistosomiasis which may be the most prevalent form of PAH worldwide. Using a Schistosoma-pulmonary hypertension (PH) murine model, studies in the prior period identified a series of mechanistic events which are critical for PH development: Th2-activation of CD4 T cells in the lungs; which recruit of CCR2+ Ly6c+ monocytes to the adventitial space that express thrombospondin-1 (TSP-1); and the TSP-1 functionally activates latent TGF-β, causing vascular remodeling. This proposal builds on this foundation by now interrogating adaptive and innate immune interfaces that we believe to be necessary to Schistosoma-PH pathogenesis. We extend our studies to translational analysis of human biospecimens, seeking proteins that correlate with PAH presence in an at-risk group with severe schistosomiasis. This proposal will test the hypothesis that intrapulmonary dendritic cells (DCs) present Schistosoma antigen to CD4 T cells which support Th2 polarization, causing activation of interstitial macrophages (IMs), who release the CCR2 ligands CCLs 2, 7 and 12, driving TSP-1+ monocyte recruitment, TGF-β activation, and PH. We also hypothesize that key proteins that increase risk of PAH—including CCL2, CCL7, CCL12, and TSP-1—can be detected in human plasma. We propose 4 Aims. Aim 1 will determine that antigen presentation by a specific DC subset, cDC2s, is required for T cell activation in Schistosoma-PH. Aim 2 will determine if the balance of Th1 to Th2 inflammation drives monocyte/macrophage and PH phenotypes in Schistosoma-PH. Aim 3 will determine that CCL2/7/12 release by IMs is required for TSP1+ monocyte recruitment in Schistosoma-PH. Aim 4 will identify plasma proteins associated with PAH development in subjects with schistosomiasis. This translational Aim will be achieved by developing and characterizing two cohorts of subjects recruited from 4 clinical centers in Brazil: subjects with the precursor condition schistosomiasis hepatosplenic disease (SchHSD) who are unlikely to have PAH on the basis of echocardiography screening, and subjects with SchHSD who have right heart catheterization-confirmed PAH. Completion of these studies will lead to understanding the role of innate and adaptive immunity in the development of Schistosoma-PAH, and create opportunities for entirely novel approaches to diagnosing and potentially treating this disease. We propose to identify mechanistic proteins which correlate with disease presence in blood, facilitating screening of at-risk subjects in low-resource areas.