DIFFERENTIAL ADHERENCE AND INVASION OF CELLS BY NOCARDIA

诺卡氏菌对细胞的差异粘附和侵袭

基本信息

批准号：
6170890
负责人：
BLAINE L BEAMAN
金额：
$ 17.23万
依托单位：
UNIVERSITY OF CALIFORNIA AT DAVIS
依托单位国家：
美国
项目类别：
财政年份：
1998
资助国家：
美国
起止时间：
1998-09-30 至 2001-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/6170890
关键词：
Actinomycetales adhesions bacteria infection mechanism bacterial genetics bacterial proteins cytotoxicity electron microscopy gene expression gene mutation host organism interaction microfilaments molecular cloning nucleic acid sequence phagocytes tissue /cell culture

项目摘要

DESCRIPTION (Adapted from the applicant's abstract): Current research focuses on the pathogenesis of Mycobacterium. The closely related N. asteroides is emerging as an important pathogen in patients with immunodeficiencies and in healthy people; yet, Nocardia species have received little research attention. N. asteroides GUH-2 (GUH-2) is an ideal model for research because its pathogenesis has been studied extensively both in vivo and in vitro. It produces substances important for differential adherence to and invasion of the lungs and brain, alteration of phagocyte function, abrogation of microbicidal activities of phagocytes, and cellular cytotoxicity. The molecular and genetic mechanisms which control these activities are not known. Our hypothesis is that filament tip associated proteins on the surface of log phase organisms adhere selectively to surface receptors and trigger invasion by the induction of a particular signaling process within these host cells. The following specific aims are proposed to test this hypothesis: (1) To determine the filament tip associated proteins involved in differential adherence to specific host cell surfaces, and identify the genes that encode for these surface proteins. (2) To determine whether these filament tip proteins facilitate invasion and dissemination. To achieve these goals, filament tip associated proteins of GUH-2 that bind to the surface of host cells, promote invasion, and dissemination will be determined. The genes which encode for these substances will be identified, cloned, sequenced and expressed in either N. asteroides GUH-2, N. lactamdurans, or E. coli. Adherence and invasion of these recombinants will be studied in vitro and in vivo by biochemical, immunological, light and electron microscopic, and microbiological methods. This will identify components involved in adherence to and invasion of host cells resulting in an understanding of mechanisms for organ specificity and dissemination. These studies should lead to improved diagnosis, treatment, and prevention of nocardiosis.

描述（改编自申请人的摘要）：当前研究重点研究分枝杆菌的发病机制。密切相关的N. asteroides 正在成为患有以下疾病的患者的重要病原体免疫缺陷和健康人；然而，诺卡氏菌属物种很少受到研究关注。 N. asteroides GUH-2 (GUH-2) 是一个理想的研究模型，因为其发病机制已被广泛研究体内和体外。它产生重要的物质对肺和脑的不同粘附和侵袭，改变吞噬细胞功能，吞噬细胞杀菌活性的消除，以及细胞的细胞毒性。控制的分子和遗传机制这些活动尚不清楚。我们的假设是，丝尖相关蛋白在表面对数期生物选择性地粘附在表面受体上并触发通过诱导这些细胞内的特定信号传导过程来入侵宿主细胞。提出以下具体目标来检验这一假设：（1）确定参与差异的丝尖相关蛋白粘附到特定的宿主细胞表面，并识别编码的基因对于这些表面蛋白。 (2) 判断这些细丝尖端是否蛋白质促进入侵和传播。为了实现这些目标，GUH-2 的丝尖相关蛋白结合到达宿主细胞表面，促进侵袭和传播决定。编码这些物质的基因将被识别，在 N. asteroides GUH-2、N. asteroides GUH-2、N. asteroides 中进行克隆、测序和表达。内酰胺类，或大肠杆菌。这些重组体的粘附和入侵将通过生化、免疫学、光和化学等方法进行体外和体内研究电子显微镜和微生物学方法。这将识别参与宿主细胞粘附和侵袭的成分，导致了解器官特异性和传播机制。这些研究应能改善诊断、治疗和预防诺卡氏菌病。