An Insect Model of Molecular Host-Parasite Relationships

分子宿主-寄生虫关系的昆虫模型

• 批准号: 9420638
• 负责人: Nancy Beckage
• 金额: $ 28.15万
• 依托单位: University of California-Riverside
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-04-01 至 1999-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9420638&HistoricalAwards=false
• 关键词: Insect; Model; Molecular; Host; Parasite

9420638 Beckage The goal of this project is to determine how parasites exploit biochemical mechanisms of host interaction to achieve successful development in their host. Parasites suppress the immune system of the host, and escape being recognized as foreign. In the system under study, a wasp parasite (called a parasitoid) lays its eggs in the body cavity of its host, the tobacco hornworm, and the wasp develops to maturity and kills its host. Because parasitoids invariably invade their hosts, they are effectively exploited in the biological control of many devastating insect pests. The immunological interactions between parasitoids and hosts are important because they determine the host range of the parasitoid, and these physiological interactions are the focus of this study. Importantly, the parasitoid Cotesia congregata injects a large DNA virus (termed a polydnavirus) into the hemolymph of the host during parasitization and deposition of eggs into the hemocoel. The role of the virus is to suppress the host's immune response, much like the AIDS virus depresses the mammalian immune response making the host show enhanced susceptibility to other parasites and pathogens. The mechanisms of host immunosuppression, and their regulation by the virus, will be explored using a variety of biochemical and molecular techniques. Genetic selection techniques will be utilized to generate a "refractory" line of hosts which do not support development of the parasite, allowing us to clarify the biochemical mechanisms of resistance. The research provides an excellent framework for deciphering how parasites work to achieve successful infection of their host, and will provide data of fundamental importance to the fields of immunology, physiology, parasitology, virology, entomology, epidemiology, and evolutionary biology. ***

这个项目的目标是确定寄生虫如何利用宿主相互作用的生化机制来实现在宿主体内的成功发育。寄生虫抑制宿主的免疫系统，从而避免被识别为外来物。在研究中的系统中，寄生蜂（称为拟寄生蜂）在其寄主烟草角虫的体腔中产卵，然后寄生蜂发育成熟并杀死寄主。由于寄生蜂不可避免地侵入寄主，它们被有效地利用在许多破坏性害虫的生物防治中。寄生蜂与寄主之间的免疫相互作用决定了寄生蜂的寄主范围，这些生理相互作用是本研究的重点。重要的是，在寄主寄生和卵沉积到血腔的过程中，寄生蜂将一个大的DNA病毒（称为多DNA病毒）注射到宿主的血淋巴中。这种病毒的作用是抑制宿主的免疫反应，很像艾滋病病毒抑制哺乳动物的免疫反应，使宿主对其他寄生虫和病原体表现出更强的易感性。宿主免疫抑制的机制，以及病毒对其的调控，将利用各种生化和分子技术进行探索。利用遗传选择技术产生不支持寄生虫发育的“耐药”寄主系，使我们能够阐明抗性的生化机制。该研究为解释寄生虫如何成功感染宿主提供了一个极好的框架，并将为免疫学、生理学、寄生虫学、病毒学、昆虫学、流行病学和进化生物学等领域提供重要的基础数据。＊＊＊