MOLECULAR BIOLOGY OF PNEUMOCYSTIS CARINII

卡氏肺囊虫的分子生物学

• 批准号: 3141243
• 负责人: JEFFREY C EDMAN
• 金额: $ 14.18万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-07-01 至 1992-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3141243
• 关键词: AIDS; Pneumocystis; Saccharomyces cerevisiae; fungal antigens; genetic library; human immunodeficiency virus 1; human subject; laboratory rat; molecular biology; molecular cloning; molecular pathology; monoclonal antibody; protein structure function; secondary infection; systematic biology; tissue /cell culture

Pneumocystis carinii is the major pulmonary pathogen in patients with the acquired immunodeficiency sysndrome (AIDS). Studies on the basic biology of the organism have been hampered by lack of an adequate in vitro cultivation system. In order to develop new approaches to the study of this organism, a recombinant DNA library has been prepared from rat Pneumocystis which enables the isolation of Pneumocystis nucleic acid sequences via nucleic acid and antibody screening. This library will be utilized to address the following aspects of Pneumocystis biology: 1. The taxonomic position of Pneumocystis carinii has long been a subject of debate. Most investigators have concluded that it is a protozoan, however several have suggested that it is a fungus. In this laboratory, by phylogenetic analysis of rat pneumocystis small-subunit rRNA sequence, we have shown that pneumocystis is a fungus closely related to the yeasts (see below). We plan to extend and refine this analysis by isolation and sequencing of several rat and human Pneumocystis genes. By comparison of rRNA and antigen genes for several isolates of Pneumocystis, it will be determined whether or not strains or species of pneumocystis exist. The existence of strains or species of Pneumocystis may have important implications in the acquisition and therapy of the disease. 2. Specific interactions between host cells and Pneumocystis appear to be required for pathogenesis. This process must involve Pneumocystis proteins that recognize the surface of lung epithelial cells. Recent studies have shown that the host reacts to a limited repertoire of Pneumocystis proteins. Two major antigens have been recognized, both of which appear to be surface glycoproteins. These antigens will be cloned by screening of a Pneumocystis expression library with monoclonal antibodies of defined specificity. The structural and functional roles which these proteins play will be studied by expression in Saccharomyces cerevisae. Attachment to type I pneumocytes, presumably the first step in pathogenesis, will be investigated by testing the ability of S. cerevisae expressing pneumocystis antigens to attach to pulmonary alveolar cells in culture. The long term-goal this project is a better understanding of this important human pathogen. Taxonomic analysis is crucial to develop new strategies for the control and therapy of PCP. In addition, this information will be important for defining methods of axenic cultivation of Pneumocystis and epidemiologic studies of Pneumocystis infection. Analysis of the structure and function of Pneumocystis antigens will aid in the epidemiologic studies and begin to define those determinants on Pneumocystis which stimulate an immune response. A clear understanding of the immune response to Pneumocystis is necessary to begin to study what defect that AIDS patients and malnourished infants have in common.

卡氏肺孢子虫是患者肺部的主要病原体 获得性免疫缺陷综合征（AIDS）。 研究 生物体的基本生物学受到缺乏 适当的体外培养系统。 为了开发新 研究这种生物的方法，重组DNA文库 从大鼠肺孢子虫中制备， 肺孢子虫核酸序列通过核酸和 抗体筛选 该库将用于解决 肺孢子虫生物学的以下方面： 1. 卡氏肺孢子虫的分类地位长期以来一直是 争论的话题 大多数调查人员得出结论， 一种原生动物，但有些人认为它是一种真菌。 本实验室通过对大鼠肺孢子虫的系统发育分析， 小亚基rRNA序列，我们已经表明，肺孢子虫是一个 与酵母菌密切相关的真菌（见下文）。 我们计划 通过分离和测序来扩展和完善这项分析 几个大鼠和人类肺孢子虫基因。 通过rRNA的比较 和几个肺孢子虫分离株的抗原基因，它将是 确定是否存在肺孢子虫的菌株或种类。 肺孢子虫菌株或种属的存在可能 重要的影响，在收购和治疗的 疾病 2. 宿主细胞与肺孢子虫的特异性相互作用 似乎是发病所必需的。 这个过程必须包括 识别肺上皮细胞表面的肺孢子虫蛋白 细胞 最近的研究表明，宿主对有限的 肺孢子虫蛋白的所有组成部分。 两种主要的抗原已经被 这两种蛋白似乎都是表面糖蛋白。 这些抗原将通过筛选肺孢子虫 具有定义的单克隆抗体的表达文库 的特异性 这些结构和功能的作用， 蛋白质发挥将通过在酵母中表达来研究 啤酒。 附着在I型肺细胞上，可能是第一个 在发病机制的步骤，将通过测试的能力进行调查， 色葡萄表达肺孢子虫抗原的酿酒酵母， 培养的肺泡细胞。 这个项目的长期目标是更好地理解这一点 重要的人类病原体 分类学分析对于开发 控制和治疗PCP的新策略。 此外，本发明还提供了一种方法， 这一信息对于确定无菌方法将是重要的。 肺孢子虫的培养和肺孢子虫的流行病学研究 肺孢子虫感染。 结构与功能分析 肺孢子虫抗原将有助于流行病学研究， 开始确定肺孢子虫的决定因素， 免疫反应 对免疫反应的清晰理解 肺孢子虫是必要的，开始研究什么缺陷， 艾滋病患者和营养不良的婴儿有共同点。