An Insect Model of Molecular Host-Parasite Relationships

9420638 Beckage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其宿主的成功发育。寄生虫抑制宿主的免疫系统，逃避被认为是外来的。在所研究的系统中，黄蜂寄生虫(称为寄生虫)在其宿主烟草角虫的体腔内产卵，黄蜂发育到成熟并杀死其宿主。由于寄生蜂总是入侵它们的寄主，它们被有效地利用来生物防治许多毁灭性的害虫。寄生蜂和寄主之间的免疫相互作用很重要，因为它们决定了寄生蜂的寄主范围，而这些生理相互作用是本研究的重点。重要的是，在寄生和将卵子沉积到血腔的过程中，寄生的聚集绒茧蜂会将一种大型DNA病毒(称为多聚核糖核酸病毒)注入宿主的血淋巴中。病毒的作用是抑制宿主的免疫反应，就像艾滋病病毒抑制哺乳动物的免疫反应一样，使宿主对其他寄生虫和病原体表现出更强的敏感性。将使用各种生化和分子技术来探索宿主免疫抑制的机制以及病毒对其的调节。基因选择技术将被用来产生一个不支持寄生虫发育的“难耐”寄主品系，使我们能够阐明抗药性的生化机制。这项研究为破译寄生虫如何成功感染宿主提供了一个很好的框架，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领域提供基本重要的数据。***

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. ***