A natural host model for microsporidia pathogenesis in the intestine

描述（由申请人提供）：该项目的主要目标是了解微孢子虫是如何引起疾病的。微孢子虫是真核细胞内病原体，可感染多种宿主，但对其了解甚少。这些病原体可引起严重的人类感染，特别是艾滋病患者。了解微孢子虫的致病特性与NIH的使命有关，因为它有望帮助减轻人类疾病的负担。微孢子虫与宿主肠细胞之间的分子相互作用知之甚少，尽管一些观察表明它们之间存在密切的动态关系。我们的长期目标是更好地了解微孢子虫利用宿主肠道细胞的策略，以及宿主用来控制这些感染的策略。本研究的目的是研究秀丽隐杆线虫及其天然微孢子虫病原体巴黎新丝虫之间的分子相互作用。巴黎奈瑟菌感染秀丽隐杆线虫的肠细胞，肠细胞是透明的，便于直接成像。秀丽隐杆线虫的肠细胞与哺乳动物的肠细胞有许多共同的特征，比如手指状的微绒毛，它们被固定在一个叫做终端网的细胞骨架结构中。有趣的是，巴黎N. isii可以特别操纵终端网络，可能是作为退出策略的一部分。该建议的中心假设是寄主和病原体之间存在特定的分子相互作用，使巴黎奈丝虫能够直接靶向寄主细胞成分，并使秀丽隐杆线虫能够调节对感染的抵抗力。我们将追求两个具体目标来解决这一假设：1)确定巴黎奈瑟氏菌重组和修饰秀丽隐杆线虫肠细胞的机制；2)确定对巴黎奈瑟虫感染的抗性/易感性调控的重要途径。为了实现第一个目标，我们将在秀丽隐杆线虫肠道中表达荧光标记的细胞骨架和亚细胞标记物的动物中使用巴黎奈瑟虫感染的体内成像。这些研究将辅以对感染后果的生理和生化分析。在第二个目标下，我们将结合使用遗传和基因组技术来确定哪些途径对控制巴黎奈瑟菌感染是重要的。该方法具有创新性，因为它利用自然宿主/病原体模型，提供遗传、分子和成像工具，以更好地了解微孢子虫与其宿主之间的分子相互作用。这项拟议的研究意义重大，因为它有望为微孢子虫与其人类宿主之间的分子相互作用提供见解。

DESCRIPTION (provided by applicant): The primary goal of this project is to understand how microsporidia cause disease. Microsporidia are eukaryotic intracellular pathogens that can infect a wide variety of hosts but are poorly understood. These pathogens can cause serious infections in humans, particularly in AIDS patients. Understanding the pathogenic properties of microsporidia is relevant to the NIH's mission because it promises to help reduce the burden of human illness. Very little is known about the molecular interactions between microsporidia and their host intestinal cells, although several observations suggest that there is an intimate dynamic between them. Our long-term goal is to better understand the strategies that microsporidia use to exploit host intestinal cells, as well as the strategies hosts use to control these infections. The objective of this proposal is to investigate the molecular interactions between the nematode C. elegans and its natural microsporidian pathogen, N. parisii. N. parisii infects C. elegans intestinal cells, which are transparent, facilitating direct imaging of the infection. C. elegans intestinal cells share many features with mammalian intestinal cells, such as finger-like microvilli, which are anchored into a cytoskeletal structure called the terminal web. Intriguingly, N. parisii can specifically manipulate the terminal web, probably as part of an exit strategy. The central hypothesis of this proposal is that there are specific molecular interactions between host and pathogen that allow N. parisii to directly target host cell components, and that allow C. elegans to regulate resistance to infection. We will pursue two specific aims to address this hypothesis: 1) determine the mechanisms used by N. parisii to restructure and modify C. elegans intestinal cells; and 2) identify the pathways that are important for regulating resistance/susceptibility to N. parisii infection. To accomplish the first aim we will use in vivo imaging of N. parisii infection in animals expressing fluorescently-labeled cytoskeletal and subcellular markers in the C. elegans intestine. These studies will be complemented with physiological and biochemical analyses of the consequences of infection. Under the second aim we will use a combination of genetic and genomic techniques to identify which pathways are important for control of N. parisii infection. The approach is innovative because it utilizes a natural host/pathogen model that offers genetic, molecular, and imaging tools to better understand molecular interactions between microsporidia and their hosts. The proposed research is significant because it is expected to provide insights into the molecular interactions between microsporidia and their human hosts.