MOLECULAR BIOLOGY OF PNEUMOCYSTIS CARINII

卡氏肺囊虫的分子生物学

• 批准号: 3141241
• 负责人: JEFFREY C EDMAN
• 金额: $ 14.77万
• 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/3141241
• 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的主要肺部病原体 患有获得性免疫缺陷综合征(艾滋病)。研究：关于 这种有机体的基本生物学因缺乏一种 适宜的体外培养体系。为了开发新的 重组DNA文库--该生物的研究方法 已经从大鼠肺孢子虫中制备出来，使分离 肺孢子虫核酸序列的核酸和 抗体筛查。这个库将被用来解决 肺孢子虫生物学的以下几个方面： 1.卡氏肺孢子虫的分类地位 辩论的主题。大多数调查人员得出的结论是， 一种原生动物，然而有几个人认为它是一种真菌。 在本实验室，通过对大鼠肺孢子虫的系统发育分析 小亚基rRNA序列，我们已经证明肺孢子虫是一种 与酵母密切相关的真菌(见下文)。我们计划 通过分离和测序来扩展和改进这种分析 几个大鼠和人的肺孢子虫基因。通过比较rRNA 和几个肺孢子虫分离株的抗原基因，将是 确定是否存在菌株或种类的肺孢子虫。 肺孢子虫的菌株或种类的存在可能会 对儿童精神分裂症的获得和治疗的重要意义 疾病。 2.宿主细胞与肺孢子虫的特异性相互作用 似乎是致病所必需的。这一过程必须包括 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 肺孢子虫蛋白谱系。有两种主要的抗原 这两种蛋白似乎都是表面糖蛋白。 这些抗原将通过对一株肺孢子虫的筛选来克隆 表达文库的初步研究 专一性。结构和功能角色，这些角色 蛋白质的作用将通过在酵母菌中表达来研究 鹿角。依附于I型肺泡细胞，可能是第一个 在发病机制方面，将通过测试能力进行调查 表达肺孢子虫抗原的葡萄球菌与 培养中的肺泡细胞。 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。分类学分析是发展的关键 控制和治疗PCP的新策略。此外, 这一信息将对定义无菌方法非常重要。 肺孢子虫的培养及其流行病学研究 肺孢子虫感染。系统的结构和功能分析 肺孢子虫抗原将有助于流行病学研究和 开始定义那些刺激肺孢子虫的决定因素 一种免疫反应。对免疫应答有清晰的认识 要开始研究肺孢子虫有什么缺陷？ 艾滋病患者和营养不良的婴儿有共同之处。