Regulatory Tissue Polymorphonuclear Leukocytes Determinants of Ocular Immune Responses

 描述（由申请人提供）：多形核白细胞（PMNL）在眼部免疫反应的病因学或发病机制中很大程度上被忽视。PMNL假定的眼部作用是宿主防御，并且它们被认为是引起下游附带组织损伤的次级募集促炎细胞。然而，一个单一的原始炎性PMNL细胞类型的教条正在迅速发展，在其他器官系统和不同的群体PMNL现在被认为是调节淋巴细胞功能。其发病机理由效应T细胞的异常活化引发的免疫驱动的眼部疾病是水性泪液缺乏性干眼病，其是最常见的眼部疾病之一，并且在女性中具有惊人的患病率。PMNL在干眼病中的作用尚未研究。PMNL的主要功能是类花生酸的形成和释放，这些脂质介质的受体在淋巴细胞中表达。然而，类花生酸调节淋巴细胞是一个相对未开发的免疫调节领域。除了驱动宿主防御，PMNL也是产生抗炎类花生酸脂氧素A4（LXA 4）的限速细胞类型。 我们最近提供了第一个证据，表明人类和小鼠角膜损伤反应存在显著的性别特异性差异，并确定雌激素下调上皮LXA 4回路是女性伤口愈合延迟的机制。在初步研究中，我们在健康男性和女性的角膜利姆布斯、泪腺和颈部淋巴结中发现了一种新的产生LXA 4的组织-PMNL群体。与炎性PMNL不同，这种组织-PMNL表达高度放大的LXA 4回路，并且在免疫驱动的干眼病期间受到动态和性别特异性调节。最显著的性别特异性差异是，与男性不同，女性的干燥应激引发了淋巴结PMNL数量的显着减少，这些淋巴结PMNL数量在干眼病期间仍然受到抑制。女性淋巴结PMNL的抑制与LXA 4形成的减少和活化的CD 4 + T细胞的早期增加以及干眼发病机制直接相关。重要的是，我们确定了LXA 4受体ALX在引流淋巴结T细胞中的动态表达。这些突破性的发现激发了三个具体目标：一。确定LXA 4产生组织-PMNL和LXA 4在眼表和引流淋巴结中在免疫驱动的干眼病中的作用。二.使用新型ALX KO-GFP启动子报告小鼠系阐明组织-PMNL和LXA 4受体（ALX）介导的效应T细胞活化抑制的机制。三.研究性类固醇在雌性特异性调节LXA 4产生中的作用 通过蛋白质组学和脂质组学方法，确定招募这种新型PMNL人群的因素。该项目的目标是研究组织-PMNL，LXA 4及其受体在免疫驱动的干眼病中的作用，并建立其性别特异性调节作为异常效应T细胞活化和女性眼部疾病起始的重要因素和治疗靶点。

 DESCRIPTION (provided by applicant): Polymophonuclear leukocytes (PMNL) have largely been ignored in the etiology or pathogenesis of ocular immune responses. PMNL presumed ocular role is host defense and they are considered secondary recruited pro-inflammatory cells that cause downstream collateral tissue damage. However, the dogma of a single primitive inflammatory PMNL cell type is rapidly evolving in other organ systems and distinct populations of PMNL are now recognized that regulate lymphocyte function. An immune-driven ocular disease, whose pathogenesis is initiated by aberrant activation of effector T cells, is aqueous tear deficient Dry Eye Disease, which is one of the most frequent ocular morbidities and has a striking female prevalence. The role of PMNL in Dry Eye Disease has not been investigated. A primary function of PMNL is formation and release of eicosanoids and receptors for these lipid mediators are expressed in lymphocytes. However, eicosanoid regulation of lymphocytes is a relatively unexplored area of immune regulation. In addition to driving host defense, PMNL are also the rate limiting cell type for generating the anti-inflammatory eicosanoid lipoxin A4 (LXA4). We recently provided the first evidence for marked sex-specific differences in corneal injury responses in both humans and mice and identified estrogen downregulation of an epithelial LXA4 circuit as a mechanism for delayed wound healing in females. In pilot studies, we discovered a novel LXA4-producing tissue-PMNL population in corneal limbus, lacrimal glands and cervical lymph nodes of healthy males and females. This tissue-PMNL, unlike inflammatory-PMNL, express a highly amplified LXA4 circuit and are dynamically and sex- specifically regulated during immune-driven Dry Eye Disease. The most striking sex-specific differences was that desiccating stress in females, unlike in males, triggered a remarkable decrease in lymph node PMNL numbers that remained depressed during Dry Eye Disease. Depressed lymph node PMNL in females correlated directly with decreased LXA4 formation and an early increase in activated CD4+ T cells and dry eye pathogenesis. Importantly, we identified dynamic expression of the LXA4 receptor, ALX, in T cells from draining lymph nodes. These ground breaking findings inspired three specific aims: I. Establish the role of LXA4- producing tissue-PMNL and LXA4 in the ocular surface and draining lymph nodes in immune-driven Dry Eye Disease. II. Elucidate the mechanism for tissue-PMNL and LXA4 receptor (ALX) mediated suppression of effector T cell activation using a novel ALX KO-GFP promoter reporter mouse line. III. Investigate the role of sex steroids in the female specific regulation of LXA4-producing PMNL and identify factors that recruit this novel PMNL population by proteomic and lipidomic approaches. The goals of the project are to investigate the role of tissue-PMNL, LXA4 and its receptors in immune-driven Dry Eye Disease and establish their sex-specific regulation as a significant factor and therapeutic target in aberrant effector T cell activation and initiation of ocular disease in females.