MOLECULAR PATHOLOGY OF PNEUMOCYSTIS PNEUMONIA

描述：卡氏肺孢子虫感染宿主的肺泡巨噬细胞 吞噬功能缺陷和转录因子的表达 这些细胞中的GATA-2基因表达严重下调。介绍一种 正常人肺泡巨噬细胞中GATA-2特异性反义寡核苷酸的研究 未感染的动物也导致吞噬活性下降。 这些细胞。在这项拟议的研究中，将进行实验以进一步 探讨GATA-2在肺泡巨噬细胞吞噬功能中的作用。A GATA-2 将表达载体导入肺炎链球菌肺泡巨噬细胞。 感染Carinii的宿主调查GATA-2过表达是否会 纠正缺陷。为进一步了解GATA-2在肺炎中的作用。 Carinii的发病机制，单核细胞中受GATA-2调控的基因将是 已确认身份。DNA微阵列将用标记的野生型和 GATA-2基因敲除单核细胞。杂交后的微阵列将被分析以 确定哪些基因受GATA-2调控。实验也将是 以确定编码MMR、MIP-1α、 单核细胞趋化蛋白-1、白介素6和肿瘤坏死因子-α与肺泡功能的关系 巨噬细胞受GATA-2调节。卡氏肺孢子虫引起 我们将探索GATA-2在肺泡巨噬细胞中的下调作用。正常 肺泡巨噬细胞直接或间接与活体或死体孵育 以确定卡氏肺孢子虫的蛋白质是否与 下调GATA-2转录导致细胞内 肺泡巨噬细胞的吞噬活性。蛋白质，如Vitronectin， 纤维连接蛋白、表面活性蛋白A和D以及卡氏肺孢子虫主要表面 糖蛋白是已知与肺泡巨噬细胞相互作用的蛋白。 卡氏杆菌感染，也将进行检查。这些蛋白质将被孵化 单独或与正常巨噬细胞结合以确定 它们对GATA-2的下调有任何影响。不同分数的 卡氏肺孢子虫感染肺的支气管肺泡灌洗液也将 测试过。卡氏肺孢子虫或宿主蛋白被发现有能力 下调的GATA-2表达将通过测序确定 蛋白质。

DESCRIPTION: Alveolar macrophages from Pneumocystis carinii-infected hosts are defective in phagocytosis, and the expression of the transcription factor GATA-2 in these cells is severely down-regulated. Introduction of a GATA-2-specific antisense oligonuceotide into alveolar macrophages from normal uninfected animals also resulted in a decrease in the phagocytic activity of these cells. In this proposed study, experiments will be performed to further investigate the role of GATA-2 in alveolar macrophage phagocytosis. A GATA-2 expression vector will be introduced into alveolar macrophages from P. carinii-infected hosts to investigate whether GATA-2 over-expression could correct the defect. To further understand the involvement of GATA-2 in P. carinii pathogenesis, genes that are regulated by GATA-2 in monocytes will be identified. DNA microarrays will be probed with labeled cDNA from wild type and GATA-2 knockout monocytes. The hybridized microarrays will then be analyzed to determine which genes are regulated by GATA-2. Experiments will also be performed to determine whether genes such as those encoding MMR, MIP-1alpha, MCP-1, IL6 and TNF-alpha that are associated with functions of alveolar macrophages are regulated by GATA-2. The mechanisms by which P. carinii causes down regulation of GATA-2 in alveolar macrophages will be explored. Normal alveolar macrophages will be incubated directly or indirectly with live or dead P. carinii organisms to determine whether a P. carinii protein is responsible for down regulation of GATA-2 transcription leading to a reduction in the phagocytic activity of alveolar macrophages. Proteins such as vitronectin, fibronectin, surfactant proteins A and D, and P. carinii major surface glycoprotein, which are known to interact with alveolar macrophages during P. carinii infection, will also be examined. These proteins will be incubated either alone or in combination with normal macrophages to determine whether they have any effect on GATA-2 down regulation. Different fractions of bronchoalveolar lavage fluids from P. carinii-infected lung will also be tested. Any P. carinii or host protein that is found to have the ability to down regulate GATA-2 expression will be identified by sequencing a portion of the protein.