REGULATION AND MEDIATION OF THE IMMUNE/INFLAMMATORY RESPONSE BY PGE2

前列腺素E2（PGE 2）是前列腺增生症中重要的环氧合酶代谢物， 肺，调节平滑肌张力以及免疫/炎症 应答 了解哪些PGE 2受体亚型介导这些 反应是不完整的，一个孤立的细胞效应的整合 免疫/过敏性疾病的多细胞病理生理学， 甚至更不被理解。 细胞内cAMP的增加已经被证实是 参与PGE 2介导的抗炎作用。 近期 克隆四种不同的前列腺素E受体亚型，命名为EP 1， EP 2、EP 3和EP 4与药理学研究相结合，将允许更多的 完全理解参与的信号转导途径 这些免疫调节作用。 这个项目的主要假设是 EP受体亚型与不同的效应系统结合， 差异调节特性;因此不同EP的表达 单个炎症细胞类型上的受体亚型决定了 在每个靶细胞中诱发对PGE 2的生理反应。 根据我们 根据文献中的初步数据和研究，我们假设EP 2 受体是PGE 2抗炎作用的主要决定因素。 为了检验这些相关假设，提出了以下具体目标： 在具体目标1中，我们将确定EP的表达模式， 相关人和鼠免疫/炎症细胞上的受体亚型 包括单核细胞、嗜酸性粒细胞、肺泡巨噬细胞、鼠辅助性T细胞 (Th)1以及Th 2淋巴细胞克隆和肥大细胞。 由于EP的丰富 受体通常是相当低的，敏感的逆转录聚合酶 将采用链反应（RT-PCR）和RNA酶保护测定。 将对EP受体基因表达阳性的细胞进行配体分析 结合，第二信使的产生和功能反应， 亚型选择性配体。 在具体目标2中，我们将讨论EP 2和受体的重要性。 通过气道过敏或病毒性炎症模型的研究， 和嗜酸性粒细胞积聚以及全身过敏反应。 我们已经分离出 编码鼠EP 2受体的基因以及鼠EP 2 受体cDNA 在具体目标3中，如果根据具体目标中的调查结果， 目的1和2，我们确定EP 2受体确实位于 靶向细胞，以支持其在PGE 2诱发的抗肿瘤中的作用。 炎症反应，我们将产生EP 2受体缺陷小鼠， 标准基因靶向方法，从同源重组开始 在胚胎干细胞中。 这只EP 2缺陷小鼠将被用作一种工具， 用于研究EP 2受体功能。 这些研究将阐明 EP 2受体功能在炎症性肺病中的作用， 鉴定这种受体亚型作为开发的治疗靶点， 用于治疗这些疾病的新型配体。

Prostaglandin E2 (PGE2) is an important cyclooxygenase metabolite in the lung where it regulates smooth muscle tone as well as immune/inflammatory responses. Understanding of which PGE2 receptor subtypes mediate these responses is incomplete, an the integration of isolated cellular effects into the multicellular pathophysiology of immunologic/allergic diseases is even less well understood. Increases in intracellular cAMP have been implicated in the PGE2 mediated anti-inflammatory effect. The recent cloning of four distinct prostaglandin E receptor subtypes designated, EP1, EP2, EP3 and EP4, combined with pharmacologic studies, will allow a more complete understanding of the signal transduction pathways participating in these immuno-regulatory actions. The main hypothesis of this project is that EP receptor subtypes couple to different effector systems and display differential regulatory properties; thus expression of different EP receptor subtypes on individual inflammatory cell types determines the physiologic response to PGE2 evoked in each target cell. Based upon our preliminary data and studies in the literature, we hypothesize that the EP2 receptor is a major determinant of the anti-inflammatory effects of PGE2. To test these related hypotheses the following specific aims are propose; In specific aim 1, we will determine the pattern of expression of EP receptor subtypes on relevant human and murine immune/inflammatory cells including monocytes, eosinophils, alveolar macrophages, murine T-helper (Th)1 and Th2 lymphocyte clones and mast cells. Since the abundance of EP receptors usually is quite low, sensitive reverse transcription-polymerase chain reaction (RT-PCR) and RNAse protection assays will be employed. Cells positive for EP receptor gene expression will be analyzed for ligand binding, second messenger generation and functional responses using subtype-selective ligands. In specific aim 2, we will address the importance of EP2 and receptor subtypes through studies of models of airway allergic or viral inflammation and eosinophil accumulation, and systemic anaphylaxis. We have isolated the gene encoding the murine EP2 receptor as well as the murine EP2 receptor cDNA. In specific aim 3, if based upon the findings in specific aims 1 and 2, we establish that the EP2 receptor is indeed localized on target cells in such a way as to support its role in PGE2 evoked anti- inflammatory response, we will generate EP2 receptor-deficient mice by standard gene targeting methodology, starting with homologous recombination in embryonic stem cells. This EP2 deficient mouse will be used as a tool for the study of EP2 receptor function. These studies will elucidate the role of EP2 receptor function in inflammatory lung disease and possibly identify this receptor subtype as a therapeutic target for the development of novel ligands for the treatment of these disorders.