口蹄疫病毒自身核酸片段对病毒样颗粒组装的促进作用

Promotion of self-nucleic acid fragments on the assembly of foot-and-mouth disease virus-like particles

摘要:

选取能够与口蹄疫病毒结构蛋白相互作用且有特殊结构的核酸片段5′非翻译区 (5′ UTR) 和内部核糖体进入位点 (Internal ribosome entry site，IRES) 作为支架，进行病毒样颗粒组装的研究。通过对组装产物进行粒径、表面电位、凝胶阻滞、核酸酶消化、尺寸排阻色谱、透射电镜、圆二色光谱等检测，结果表明，核酸片段5′ UTR和IRES能与口蹄疫病毒样颗粒共组装并形成病毒样颗粒。通过统计学分析发现VLPs-5′UTR的75S颗粒的组装效率显著高于单纯VLPs组 (P<0.001) 和VLPs-IRES (P<0.01)，而VLPs-IRES的12S颗粒的组装效率显著高于单纯VLPs组 (P<0.000 1) 和VLPs-5′UTR (P<0.000 1)，表明口蹄疫病毒自身核酸片段5′ UTR更有利于口蹄疫病毒样颗粒的组装。该研究对促进口蹄疫病毒样颗粒组装提出了新的思路和优化策略，有助于病毒样颗粒疫苗的研发。

Abstract:

The special nucleic acid fragments, 5′ untranslated region (5′ UTR) and internal ribosome entry site (IRES) of foot-and-mouth disease virus (FMDV), which interact with the capsid proteins, were selected as scaffolds to investigate the assembly efficiency of foot-and-mouth disease (FMD) virus-like particles (VLPs). The assembled product was characterized by evaluation of particle size, surface potential, gel retardation assay, nuclease digestion experiments, size-exclusion chromatography, transmission electron microscopy and circular dichroism analysis. The results confirmed that the 5′ UTR and IRES of FMDV co-assembled with the FMD VLPs and facilitated the assembly efficiency of FMD-VLPs. It demonstrates that the assembly efficiency of 75S particles of VLPs-5′UTR was significantly higher than those of the VLPs (P<0.001) and VLPs-IRES group (P<0.01). Comparatively the assembly efficiency of 12S particles of VLPs-IRES was significantly higher than those of the VLPs (P<0.000 1) and VLPs-5′UTR (P<0.000 1). It showed that the 5′ UTR represented more effective in facilitating the assembly of VLPs. This study proposes an optimized strategy for improving the assembly efficiency of VLPs for the development of VLPs vaccine.