Regulatory T Cell Modulation of the Alveolar Epithelium in Acute Lung Injury

描述(由申请者提供)：NRSA个人奖学金申请的全球目标是促进基本技能的发展，使应聘者能够成为一名学术内科医生-科学家。这位候选人和他的导师已经设计了一个培训计划，其中将包括一个严格的研究部分，以及建立成功职业发展所必需的思维过程和原则的教学指导。急性肺损伤(ALI)和更为严重的急性呼吸窘迫综合征(ARDS)是以低氧血症、毛细血管渗漏、水肿和上皮细胞损伤为特征的弥漫性肺部疾病。这些过程每年在美国造成巨大的发病率和死亡率。尽管对ALI发病机制进行了数十年的研究，但死亡率仍然很高。关于ALI的溶解阶段知之甚少；然而，在ALI的小鼠内毒素(LPS)给药模型中，调节性T细胞(Treg)已被证明在ALI的溶解中起重要作用。此外，在ARDS患者的支气管肺泡液中检测到Tregs增加，这表明它们可能在人类对ALI的免疫反应中起重要作用。在急性或慢性损伤中，肺上皮不能再生在急性肺损伤、肺炎、肺纤维化、癌症、慢性阻塞性肺病和衰老等过程中起作用。最近，人们对参与修复的细胞类型以及调节这些过程的决定因素进行了相当大的兴趣。候选人有初步数据表明，Tregs的存在或不存在调节肺泡上皮修复。这一新发现的Treg对肺泡上皮的调节以前没有被描述过。这项建议的重点是进一步研究ALI缓解过程中Treg对肺泡上皮细胞的影响，希望确定可能导致ALI患者潜在治疗选择的新机制。提出的具体目标将利用体内和体内 体外技术研究Treg与肺泡上皮的相互作用。在具体目标1中，将单独检测Tregs在ALI消退过程中对肺泡上皮屏障的影响，并使用多色流式细胞术和免疫组织化学方法对肺泡上皮进行评估，以定量体内上皮的变化。在特定目标2中，Tregs对肺泡上皮细胞表型和功能的影响将通过II型肺泡上皮细胞和Tregs的体外共培养来确定。这些实验将探索有关ALI期间肺泡上皮Treg调节的新观察，最终目标是改善这种往往是致命疾病的患者的预后。 公共卫生相关性：急性肺损伤(ALI)是一种常见的肺部疾病，发病率和死亡率都很高。调节性T细胞(Tregs)在ALI的消退中起重要作用，但它们在肺泡上皮损伤和修复中的相互作用和调节作用尚不清楚。我们建议研究Treg对肺泡上皮细胞的调节，以期确定新的机制，最终可能导致这种疾病的新的治疗选择。

DESCRIPTION (provided by applicant): The global objective of this NRSA Individual Fellowship Application is to facilitate development of essential skills that will allow the candidae to become an academic physician-scientist. The candidate and his mentor have designed a training plan that will include a rigorous research component along with didactic instruction to establish the thought processes and principles necessary for successful career development. Acute lung Injury (ALI) and the more severe Acute Respiratory Distress Syndrome (ARDS) are diffuse lung diseases characterized by hypoxemia, capillary leakage, edema, and epithelial cell damage. These processes cause tremendous morbidity and mortality in the United States each year. Despite decades of research into the pathogenesis underlying the development of ALI, mortality remains high. There is a paucity of information known about the resolution phase of ALI; however, Regulatory T cells (Tregs) have been demonstrated to be important in ALI resolution in a mouse endotoxin (LPS) administration model of ALI. Furthermore, Tregs have been detected to increase in bronchoalveolar fluid of patients with ARDS, suggesting that they may be important in the human immunological response to ALI. In acute or chronic injury the failure to regenerate the lung epithelium plays a role in such processes as acute lung injury, pneumonia, pulmonary fibrosis, cancer, COPD, and aging. Recently there has been considerable interest in investigating the cells types involved in repair along with the determinants which regulate these processes. The candidate has preliminary data demonstrating that the presence or absence of Tregs modulates alveolar epithelial repair. This novel finding of Treg modulation of the alveolar epithelium has not been previously described. The focus of this proposal is to further examine Treg effects on the alveolar epithelium during ALI resolution with the hope of identifying novel mechanisms that may lead to potential treatment options in patients with ALI. The specific aims proposed will utilize both in vivo and in vitro techniques to study Treg-alveolar epithelium interactions. In Specific Aim 1, examination of the effect of Tregs on the alveolar epithelial barrier during ALI resolution will be performed alon with evaluation of the alveolar epithelium using multi-color flow cytometry and immunohistochemistry to quantify in vivo epithelial changes. In Specific Aim 2, the impact Tregs exert on alveolar epithelial properties of phenotype and function will be determined through in vitro co-cultures of type II alveolar epithelial cells and Tregs. These experiments will explore new observations concerning Treg modulation of the alveolar epithelium during ALI with the ultimate goal of improving patient outcomes in this oftentimes fatal disease. PUBLIC HEALTH RELEVANCE: Acute lung injury (ALI) is a common pulmonary disease with high morbidity and mortality. Regulatory T Cells (Tregs) have been shown to be important in the resolution of ALI but their potential interaction and modulation of the alveolar epithelium in damage and repair is unknown. We propose to study Treg modulation of alveolar epithelial cells with the hope of identifying novel mechanisms that may ultimately lead to new therapeutic options for this disease.