An Insect Model of Molecular Host-Parasite Relationships

小行星9420638 本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，以实现在其宿主中的成功发展。 寄生虫抑制宿主的免疫系统，并逃避被识别为外来物。 在所研究的系统中，一种黄蜂寄生虫（称为拟寄生虫）在其宿主烟草天蛾的体腔中产卵，黄蜂发育成熟并杀死其宿主。 由于寄生蜂总是侵入其宿主，它们被有效地利用在许多毁灭性的昆虫害虫的生物防治。 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，是本研究的重点。 重要的是，在寄生过程中，聚集盘绒茧蜂将一种大的DNA病毒（称为多DNA病毒）注射到宿主的血淋巴中，并将卵沉积到血腔中。 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易感性。 宿主免疫抑制的机制，以及病毒对其的调节，将使用各种生化和分子技术进行探索。 遗传选择技术将被用来产生一个“难治”线的主机不支持寄生虫的发展，使我们能够澄清的生化机制的阻力。 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. ***