Natural Killer Cell Functions in Lymphangioleiomyomatosis

项目摘要。淋巴管肌瘤病(LAM)是一种罕见的女性肺部疾病。 增殖的平滑肌细胞携带获得性突变的TSC1或TSC2基因转移 不明来源并渗入肺部。增殖的平滑肌细胞导致血管的破坏 周围肺组织囊性重塑和器官衰竭。不幸的是，医生通常会诊断 LAM在疾病显著进展后。我们报告了关于免疫功能的关键发现[特别是， 自然杀伤(NK)细胞]在LAM患者的这一疾病阶段，但仍有未得到满足的需求，以进一步 明确这些细胞在疾病晚期和疾病早期的作用。早期事件可能是 使用最能反映导致LAM的病理过程的动物模型进行有效研究。我们的 检查LAM患者和LAM小鼠模型的初步数据显示，LAM的肌瘤形成和 肺中TSC2缺失的结节表明NK细胞功能存在器官特异性改变 可能与LAM的发病机制有关。具体地说，循环和肺中存在独特的NK细胞亚群 在细胞毒性和细胞因子反应性方面表现为“高反应性”的组织。我们 还使用子宫特异性TSC2缺失的小鼠模型检查了疾病的早期阶段 发展为LAM的显著特征包括平滑肌瘤的形成和肺积聚 由携带TSC2缺失的平滑肌细胞组成的结节。我们发现肌瘤表达 NKG2D激活受体的高水平配体，也精心设计了高水平的可溶性配体， 可能下调NKG2D的表达，损害NK细胞的功能。初步数据显示， 在整个发病过程中，NK细胞表型和功能的动态塑造。这样做的目的是 建议在LAM和LAM患者中确定NK细胞和NKG2D的表型、功能和作用 样本和动物模型。为了实现这一目标，我们将1)确定独特的NK细胞的功能意义 在LAM的人口。2)明确VEGFD扩增的NK细胞活化机制。3)定义函数 NK细胞和Nkg2d在LAM发生发展中的作用。和4)定义以下各项的功效和好处 循环中可溶性Nkg2d配体的治疗抑制。这些研究很有可能成功完成 对我们理解LAM的发病机制有很高的影响。细胞毒性淋巴细胞的作用 NK细胞在疾病的多个阶段是明确的，例如控制肿瘤的生长和组织 改建。我们将确定这些细胞在疾病多个阶段的作用，确定NK的机制 细胞反应性和免疫监视的崩溃，并检查治疗的潜力 针对可溶性NKG2D配体的干预。几种旨在调节NK细胞功能的疗法包括 慢性感染、自身免疫性疾病和癌症的发展中。我们希望这些特工能 在不久的将来，在现有治疗方法的基础上，为LAM提供新的治疗选择。

Project Summary. Lymphangioleiomyomatosis (LAM) is a rare lung disease of women in which abnormally proliferating smooth muscle cells carrying acquired mutations in the TSC1 or TSC2 genes metastasize from an unknown source and infiltrate the lung. The proliferating smooth muscle cells lead to destruction of surrounding lung tissue, cystic remodeling, and organ failure. Unfortunately, physicians typically diagnose LAM after significant disease progression. We reported key findings regarding immune function [specifically, natural killer (NK) cells] at this stage of disease in LAM patients, but there is still an unmet need to further define the role of these cells in advanced disease as well as early stages of disease. Early events can be effectively studied using animal models that best reflect the pathological processes leading to LAM. Our preliminary data examining LAM patients and a mouse model of LAM featuring leiomyoma formation and Tsc2-null nodules in the lungs demonstrate the existence of organ-specific alterations in NK cell function that likely contribute to LAM pathogenesis. Specifically, unique subsets of NK cells exist in circulation and lung tissue that are characterized as “hyperresponsive” in terms of cytotoxicity and cytokine responsiveness. We also examined earlier stages of disease using a mouse model employing a uterine specific Tsc2 deletion which develop hallmark features of LAM including leiomyoma formation and accumulation of pulmonary nodules consisting of smooth muscle cells carrying Tsc2 deletions. We show that the leiomyomas express high levels of ligands for the NKG2D activating receptor but also elaborate high levels of soluble ligands that likely downregulate NKG2D expression and impaired NK cell function. The preliminary data demonstrates a dynamic shaping of NK cell phenotype and function throughout the arc of pathogenesis. The goal of this proposal is to define the phenotype, function, and role of NK cells and NKG2D in LAM using both LAM patient samples and animal models. Towards this goal, we will 1) Define the functional significance of unique NK cell populations in LAM. 2) Define the mechanism of VEGFD-amplified NK cell activation. 3) Define the function of NK cells and Nkg2d in the initiation and progression of LAM. And 4) Define the efficacy and benefits of therapeutic inhibition of circulating soluble Nkg2d ligands. The successful completion of these studies is likely to have a high impact on our understanding of LAM pathogenesis. The role of cytotoxic lymphocytes such as NK cell are clear in terms of the multiple stages of disease such as the control of tumor growth and tissue remodeling. We will identify the role of these cells at multiple stages of disease, identify mechanisms of NK cell responsiveness and breakdown of immune surveillance, and examine the potential for therapeutic intervention targeting soluble NKG2D ligands. Several therapeutics aimed at modulating NK cell function are in development for chronic infections, autoimmune diseases, and cancer. Our hope is that these agents will provide new options for therapy, in addition to existing therapies for LAM, in the near future.