Zhang Peng, Turnbull Matthew
Department of Biological Sciences, Clemson University, Clemson, SC 29631, USA.
Viruses. 2021 Aug 17;13(8):1621. doi: 10.3390/v13081621.
Polydnaviruses are dsDNA viruses associated with endoparasitoid wasps. Delivery of the virus during parasitization of a caterpillar and subsequent virus gene expression is required for production of an amenable environment for parasitoid offspring development. Consequently, understanding of Polydnavirus gene function provides insight into mechanisms of host susceptibility and parasitoid wasp host range. Polydnavirus genes predominantly are arranged in multimember gene families, one of which is the , which are virus homologues of insect gap junction genes, the . Previous studies of Ichnovirus Vinnexins using various heterologous systems have suggested the four encoded members may provide different functionality in the infected caterpillar host. Here, we expressed two of the members, and , using recombinant baculoviruses in susceptible host, the caterpillar . Following intrahemocoelic injections, we observed that >90% of hemocytes (blood cells) were infected, producing recombinant protein. Larvae infected with a -recombinant baculovirus exhibited significantly reduced molting rates relative to larvae infected with a control recombinant baculovirus and mock-infected larvae. Similarly, larvae infected with -recombinant baculoviruses were less likely to survive relative to controls and showed reduced ability to encapsulate chromatography beads in an immune assay. In most assays, the VnxG protein was associated with more severe pathology than VnxQ2. Our findings support a role for Vinnexins in CsIV and more broadly Ichnovirus pathology in infected lepidopteran hosts, particularly in disrupting multicellular developmental and immune physiology.
多DNA病毒是与内寄生蜂相关的双链DNA病毒。在寄生毛虫过程中传递病毒以及随后的病毒基因表达，是为寄生蜂后代发育创造适宜环境所必需的。因此，了解多DNA病毒基因功能有助于深入了解宿主易感性机制和寄生蜂的宿主范围。多DNA病毒基因主要排列在多成员基因家族中，其中之一是，它们是昆虫间隙连接基因的病毒同源物，即。先前使用各种异源系统对杆状病毒连接蛋白的研究表明，编码的四个成员可能在受感染的毛虫宿主中提供不同的功能。在这里，我们使用重组杆状病毒在易感宿主毛虫中表达了其中两个成员，即和。在进行血腔注射后，我们观察到超过90%的血细胞（血细胞）被感染，产生了重组蛋白。与感染对照重组杆状病毒的幼虫和模拟感染的幼虫相比，感染重组杆状病毒的幼虫蜕皮率显著降低。同样，与对照相比，感染重组杆状病毒的幼虫存活的可能性较小，并且在免疫测定中显示出包裹层析珠的能力降低。在大多数试验中，VnxG蛋白比VnxQ2与更严重的病理变化相关。我们的研究结果支持杆状病毒连接蛋白在杆状病毒中的作用，更广泛地说，支持杆状病毒在受感染鳞翅目宿主中的病理作用，特别是在破坏多细胞发育和免疫生理学方面。
