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的病原体，可以感染多种宿主，但人们对此知之甚少。这些病原体可能会对人类造成严重感染，特别是对艾滋病患者。了解微孢子虫的致病特性与NIH的任务相关，因为它有望帮助减轻人类疾病的负担。人们对微孢子虫与其宿主肠道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用来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。这项建议的目的是研究线虫与其天然微孢子虫病原体N.parisii之间的分子相互作用。Nparisii感染线虫肠道细胞，这些细胞是透明的，便于直接成像感染。线虫的肠道细胞与哺乳动物的肠道细胞有许多共同的特征，例如手指状的微绒毛，它们固定在一种称为末端网的细胞骨架结构中。有趣的是，N.parisii可以专门操纵终端网络，这可能是退出战略的一部分。这一建议的中心假设是，寄主和病原体之间存在特定的分子相互作用，允许parisii直接靶向宿主细胞成分，并允许线虫调节对感染的抵抗力。我们将追求两个特定的目标来解决这一假设：1)确定parisii线虫重组和修饰线虫肠道细胞所使用的机制；2)确定对调节对N.parisii感染的抵抗力/敏感性至关重要的途径。为了实现第一个目标，我们将使用体内成像技术，对线虫肠道中表达荧光标记的细胞骨架和亚细胞标记的动物进行细小线虫感染的体内成像。这些研究将辅之以对感染后果的生理和生化分析。在第二个目标下，我们将使用遗传和基因组技术相结合的方法来确定哪些途径对于控制细小核线虫感染是重要的。这种方法是创新的，因为它利用了一个自然的宿主/病原体模型，提供了遗传、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。这项拟议的研究具有重要意义，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.