Abstract:
Foot-and-mouth disease (FMD) is a highly contagious viral disease affecting cloven-hoofed animals. One of the issues related to this disease is the persistence of its causative agent, foot-and-mouth disease virus (FMDV). While the mechanisms of FMDV persistence remain unclear, there are clues that it may be related to protein-protein interactions (PPI) between viral proteins and cellular proteins involved in the interferon (IFN) response. Since FMDV persistence has been described in cattle, sheep and goats but not in swine, we screened PPI involving FMDV proteins and sixteen major type-I IFN pathway proteins from these four species by nanoluciferase-2-hybrid complementation assay, in order to identify new PPI and determine their host specificity. As the results concerning the 3Dpol were the most interesting in view of the limited data concerning its role in immune escape, we decided to focus particularly on this protein. The identified PPI were confirmed by GST pull-down. We identified PPI between 3Dpol and seven IFN pathway proteins, namely, IKKα, IKKε, IRF3, IRF7, NEMO, MDA5 and MAVS. These PPI are conserved among the four studied species, with the exception of the one between 3Dpol and MAVS, which was only found with the swine protein. We also showed, using luciferase reporter assays, that 3Dpol could inhibit the induction phase of the IFN pathway. These results demonstrate, for the first time, a putative role for 3Dpol in FMDV innate immune escape.
摘要:
口蹄疫(FMD)是一种高度传染性的病毒性疾病,影响偶蹄动物。与这种疾病有关的问题之一是其致病因子的持续存在,口蹄疫病毒(FMDV)。虽然FMDV持续存在的机制尚不清楚,有线索表明,它可能与病毒蛋白和参与干扰素(IFN)反应的细胞蛋白之间的蛋白-蛋白相互作用(PPI)有关。由于已经在牛中描述了FMDV的持久性,绵羊和山羊,但不是猪,我们筛选了PPI涉及FMDV蛋白和16个主要的I型IFN途径蛋白从这四个物种通过纳米荧光素酶-2-杂交互补试验,以鉴定新的PPI并确定其宿主特异性。由于关于3Dpol在免疫逃逸中的作用的数据有限,因此有关3Dpol的结果是最有趣的,我们决定特别关注这种蛋白质。确定的PPI通过GST拉低得到确认。我们鉴定了3Dpol和7种IFN途径蛋白之间的PPI,即,IKKα,IKKε,IRF3,IRF7,NEMO,MDA5和MAVS。这些PPI在四个研究物种中是保守的,除了3Dpol和MAVS之间的一个,只在猪蛋白中发现。我们还展示了,使用荧光素酶报告基因测定,3Dpol可以抑制IFN途径的诱导阶段。这些结果表明,第一次,3Dpol在FMDV先天免疫逃逸中的推定作用。