Xing Longsheng, Yuan Chuanfei, Wang Manli, Lin Zhe, Shen Benchang, Hu Zhihong, Zou Zhen
From the ‡State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101.
§University of Chinese Academy of Sciences, Beijing 100049.
Mol Cell Proteomics. 2017 Jun;16(6):1009-1028. doi: 10.1074/mcp.M116.062547. Epub 2017 Apr 12.
Over the past decades, nucleopolyhedrovirus (HearNPV) has been widely used for biocontrol of cotton bollworm, which is one of the most destructive pest insects in agriculture worldwide. However, the molecular mechanism underlying the interaction between HearNPV and host insects remains poorly understood. In this study, high-throughput RNA-sequencing was integrated with label-free quantitative proteomics analysis to examine the dynamics of gene expression in the fat body of larvae in response to challenge with HearNPV. RNA sequencing-based transcriptomic analysis indicated that host gene expression was substantially altered, yielding 3,850 differentially expressed genes (DEGs), whereas no global transcriptional shut-off effects were observed in the fat body. Among the DEGs, 60 immunity-related genes were down-regulated after baculovirus infection, a finding that was consistent with the results of quantitative real-time RT-PCR. Gene ontology and functional classification demonstrated that the majority of down-regulated genes were enriched in gene cohorts involved in energy, carbohydrate, and amino acid metabolic pathways. Proteomics analysis identified differentially expressed proteins in the fat body, among which 76 were up-regulated, whereas 373 were significantly down-regulated upon infection. The down-regulated proteins are involved in metabolic pathways such as energy metabolism, carbohydrate metabolism (CM), and amino acid metabolism, in agreement with the RNA-sequence data. Furthermore, correlation analysis suggested a strong association between the mRNA level and protein abundance in the fat body. More importantly, the predicted gene interaction network indicated that a large subset of metabolic networks was significantly negatively regulated by viral infection, including CM-related enzymes such as aldolase, enolase, malate dehydrogenase, and triose-phosphate isomerase. Taken together, transcriptomic data combined with proteomic data elucidated that baculovirus established systemic infection of host larvae and manipulated the host mainly by suppressing the host immune response and down-regulating metabolism to allow viral self-replication and proliferation. Therefore, this study provided important insights into the mechanism of host-baculovirus interaction.
在过去几十年中，核型多角体病毒（HearNPV）已被广泛用于棉铃虫的生物防治，棉铃虫是全球农业中最具破坏性的害虫之一。然而，HearNPV与宿主昆虫之间相互作用的分子机制仍知之甚少。在本研究中，高通量RNA测序与无标记定量蛋白质组学分析相结合，以研究幼虫脂肪体中基因表达响应HearNPV攻击的动态变化。基于RNA测序的转录组分析表明，宿主基因表达发生了显著改变，产生了3850个差异表达基因（DEG），而在脂肪体中未观察到全局转录关闭效应。在这些DEG中，60个免疫相关基因在杆状病毒感染后下调，这一发现与实时定量RT-PCR结果一致。基因本体论和功能分类表明，大多数下调基因富集于参与能量、碳水化合物和氨基酸代谢途径的基因群组中。蛋白质组学分析鉴定了脂肪体中的差异表达蛋白质，其中76个上调，而373个在感染后显著下调。下调的蛋白质参与能量代谢、碳水化合物代谢（CM）和氨基酸代谢等代谢途径，这与RNA序列数据一致。此外，相关性分析表明脂肪体中mRNA水平与蛋白质丰度之间存在强关联。更重要的是，预测的基因相互作用网络表明，很大一部分代谢网络受到病毒感染的显著负调控，包括醛缩酶、烯醇酶、苹果酸脱氢酶和磷酸丙糖异构酶等CM相关酶。综上所述，转录组数据与蛋白质组数据阐明了杆状病毒在宿主幼虫中建立全身感染，并主要通过抑制宿主免疫反应和下调代谢来操纵宿主，以实现病毒的自我复制和增殖。因此，本研究为宿主-杆状病毒相互作用机制提供了重要见解。
