Supplementary table 4

Ticks are vectors of arboviruses in many parts of the world. The rising incidence and emergence of tick-borne arboviral infections across human populations indicates that further transmission control strategies including those based on vectors, will be required to reduce the burden of disease. However, arbovirus-tick interactions at the cellular level remain poorly understood in general, and particularly neglected for negative strand RNA arboviruses.In this study we developed a proteomics informed by transcriptomics approach to characterize the cellular response of <i>Rhipicephalus microplus-</i>derived cell cultures to infection with tick-borne severe fever with thrombocytopenia syndrome virus (SFTSV, <i>Phenuiviridae</i>). For this, we generated the first <i>de novo</i> transcriptomes and confirmed proteomes of infected and uninfected tick vector cells for SFTSV. Through comprehensive annotation of genes and proteins and pathway analysis, we identified core host responses and regulatory processes to SFTSV infection. Moreover, the viral nucleoprotein N interactome allowed us to integrate host responses with the analysis of cellular factors required for viral replication. The influence of specific genes on viral replication was assessed through dsRNA-mediated gene silencing, pinpointing two tick proteins, the RNA helicase DHX9 and the Up Frameshift Protein 1 (UPF1), as a critical antiviral tick protein controlling SFTSV. Collectively, our findings enrich the repository of resources available for understanding the antiviral response in <i>Rh. microplus</i> vector cells to SFTSV infection and pave the way for the development of novel vector control strategies.

蜱虫是全球多数地区虫媒病毒（arbovirus）的传播媒介。当前全球人群中蜱传虫媒病毒感染的发病率持续攀升且新发病例不断涌现，这表明亟需开发包括媒介防控在内的新型传播控制策略，以减轻此类疾病的负担。然而，目前学界对虫媒病毒与蜱细胞水平的互作机制仍缺乏深入认知，针对负链RNA虫媒病毒的相关研究更是严重不足。本研究采用转录组学辅助蛋白质组学（proteomics informed by transcriptomics）分析策略，解析了微小牛蜱（Rhipicephalus microplus）源细胞系感染蜱传发热伴血小板减少综合征病毒（SFTSV，白纤病毒科（Phenuiviridae））后的细胞应答反应。为此，我们首次构建了SFTSV感染与未感染蜱媒介细胞的从头转录组（de novo）与验证蛋白质组。通过对基因与蛋白质的全面注释及通路分析，我们鉴定出宿主针对SFTSV感染的核心应答与调控过程。此外，通过解析病毒核蛋白N的相互作用组，我们将宿主应答反应与病毒复制所需的宿主细胞因子关联分析相结合。我们通过双链RNA介导的基因沉默技术，评估了特定基因对病毒复制的影响，最终精准确定了两种蜱源蛋白——RNA解旋酶DHX9与上游移码蛋白1（UPF1）——是调控SFTSV复制的关键抗病毒蜱源蛋白。综上，本研究的发现丰富了针对微小牛蜱（Rh. microplus）媒介细胞抗SFTSV感染应答的研究资源库，为开发新型蜱媒防控策略奠定了坚实基础。