DISRUPTION OF HOST IMMUNE RESPONSE BY A PARASITIC WASP

由于昆虫传播了人类和动物的许多疾病，因此理解 寄生虫与它们的昆虫宿主之间的相互作用是一种 重要的研究领域。昆虫的免疫系统起着至关重要的作用 在保护昆虫免受入侵生物体侵害方面的作用，以及在 度量定义了给定物种是否为给定物种的合适宿主 寄生虫或病原体。昆虫的血细胞(血细胞)常常被消灭 单细胞病原体，如细菌，通过吞噬而多细胞， 后生动物的寄生虫是通过封装杀死的。反过来，也有一些 病原体和寄生虫通过破坏血细胞来避免消除 功能。我们之前的研究表明，寄生虫微粒炎 拆解器破坏其寄主拟丛枝孢霉的封装反应 包括通过一种名为M.破碎者的共生病毒的作用 多聚核糖核酸病毒(MdPDV)。MDPDV诱导一类人白血病细胞的凋亡 在呈现另一类血细胞的同时，P. 不能附着在寄生虫身上。基于这些观察，我们 建议确定导致这些疾病的病毒基因 宿主血细胞的变化，以及宿主如何免疫 系统对病毒感染做出反应。这项提议的具体目标是 特征：1)参与诱导细胞凋亡的MDPDV基因 和破坏血细胞黏附；2)MdPDV如何与 宿主细胞的凋亡途径；3)MDPDV如何影响 血细胞黏附，以及；4)宿主血细胞群体如何应对 寄生虫和病毒感染。血细胞效应器的功能有 在无脊椎动物分类群中保存。我们在这项研究中学到的东西将 提供有关调控因素的重要比较信息 节肢动物的抗寄生虫和抗病毒防御。

Since insects vector many diseases of humans and animals, understanding the interactions between parasites and their insect hosts is an important area of study. The insect immune system plays an essential role in defending insects against invading organisms, and in large measure defines whether a given species is a suitable host for a given parasite or pathogen. Insect blood cells (hemocytes) often eliminate unicellular pathogens like bacteria by phagocytosis while multicellular, metazoan parasites are killed by encapsulation. Reciprocally, some pathogens and parasites avoid elimination by disrupting hemocyte function. Our previous studies revealed that the parasite Microplitis demolitor disrupts the encapsulation response of its host, Pseudoplusia includens, through the actions of a symbiotic virus called M. demolitor polydnavirus (MdPDV). MdPDV induces the apoptosis of one class of hemocytes in P. includens while rendering another class of blood cells incapable of adhering to the parasite. Based on these observations, we propose to identify the viral genes responsible for inducing these alterations in host hemocytes, and to characterize how the host immune system responds to viral infection. Specific aims for this proposal are to characterize: 1) the MdPDV genes involved in induction of apoptosis and disruption of hemocyte adhesion; 2) how MdPDV interacts with the apoptotic pathway of host cells; 3) how MdPDV affects mediators of hemocyte adhesion, and; 4) how host hemocyte populations respond to parasitism and viral infection. Hemocyte effector functions are conserved across invertebrate taxa. What we learn in this study will provide important comparative information on the factors regulating anti-parasitic and anti-viral defenses in arthropods.