宿主RNA结合蛋白参与口蹄疫病毒复制的机制研究

Host RNA-binding proteins (RBPs) play essential roles in virus replication and cell fate. Foot-and-mouth disease virus (FMDV), as one of the animal viruses, seriously affects the development of animal husbandry. Hence, exploring the strategies employed by FMDV to harness RBPs and efficiently promote viral replication is pivotal for understanding the viral pathogenesis after endocytosis. We recently found that RBPs interacting with FMDV internal ribosome entry site (IRES) not only regulate the IRES-mediated translation, but also involve in stress granules and innate immune antiviral responses. However, whether there exist other RBPs involved in FMDV replication and antiviral response is not well understood. Therefore, using an RNA pull-down assay and proteomics approaches, we will further identify the RBPs interacting with FMDV 5'UTR/3'UTR, and delineate the RBPs modulation of FMDV replication during infection, specifically on viral replication cycle (including IRES-dependent translation, viral RNA synthesis, and switch from translation to replication) and host antiviral response and viral countermeasures. Elucidation of FMDV-RBPs interaction not only facilitates our understanding the pathogenesis of FMDV, but also provides an opportunity for the therapeutic application of broad-spectrum antiviral drugs and genetically modified viruses.

RNA结合蛋白（RBPs）在病毒复制和细胞生物学过程中发挥重要功能，追踪口蹄疫病毒（FMDV）如何劫持RBPs为自身服务对理解病毒入胞后的复制机理至关重要。前期研究FMDV内部核糖体进入位点（IRES）-蛋白复合体（翻译相关复合体）时，发现特定RBPs不仅介导病毒蛋白翻译活性的调控，还参与应激颗粒形成和抗病毒免疫反应。是否还存在其他RBPs参与调控FMDV复制及宿主的抗病毒反应？因此，本项目将利用RNA亲和捕捉法结合生物质谱的方法，继续开展FMDV 5'UTR/3'UTR-蛋白复合体的鉴定工作，并从FMDV的复制周期（包括蛋白翻译、蛋白翻译向基因组合成转换、基因组合成）以及宿主的抗病毒反应和病毒颉抗对策两个层面，全方位探讨RBPs调控FMDV复制的机制。研究结果将为揭示FMDV的致病机理提供科学资料，亦将为设计抗小RNA病毒的广谱药物和高效疫苗的种毒改造提供思路。

RNA结合蛋白（RBPs）在病毒复制和细胞生物学过程中发挥重要功能，追踪口蹄疫病毒（FMDV）如何劫持RBPs为自身服务，对理解病毒入胞后的复制机理至关重要。本项目利用RNA亲和捕捉法结合生物质谱的方法，分别对FMDV5'UTR和核糖体进入位点（IRES）与宿主RBPs组成的蛋白复合体进行分离鉴定，并筛选出大量潜在影响FMDV复制的RBPs。随后我们分别选择核仁素Nucelolin、解旋酶DDX3和核糖体蛋白RPL13三个候选RBPs进行了深入研究，研究结果显示（1）核仁蛋白nucleolin通过增强翻译起始复合体的组装来促进FMDV-IRES依赖性翻译起始；（2）解旋酶DDX3和核糖体蛋白RPL13协同促进FMDV-IRES依赖性翻译；（3）核糖体蛋白RPL13参与FMDV诱导的先天免疫反应。研究结果不仅为揭示FMDV的致病机理提供关于RBPs的科学资料，亦将为设计抗小RNA病毒的广谱药物和高效疫苗的种毒改造提供思路。