病毒性疾病是对公共卫生的主要威胁之一。了解影响病毒侵袭的因素对于抗病毒研究很重要。直到现在,已知大多数病毒具有非常低的噬斑形成单位(PFU)与颗粒的比率。然而,需要进一步调查以确定潜在因素。这里,使用定量单粒子分析方法,Semliki森林病毒(SFV)的入侵,日本脑炎病毒(JEV),和甲型流感病毒(IAV)附着在细胞表面,进入细胞,向细胞内部的运输,平行定量分析了与内体融合以释放核衣壳。发现对于具有约1:2的PFU与颗粒比率的SFV,约31%的进入效率限制了感染。对于JEV,PFU与颗粒的比例约为1:310,附着效率约为27%,进入效率为10%是限制其感染的主要因素。同时,对于PFU与颗粒比为1:8100的IAV,5%的附着效率,进入效率9%,53%的融合效率显着限制了其感染。这些结果表明,具有不同感染性的病毒在入侵过程中具有不同的有限步骤。此外,病毒之间的附着效率存在显著差异,强调附件在病毒入侵中的关键作用。还研究了病毒纯化方法对病毒入侵的影响。这项研究,第一次,报告病毒入侵不同阶段的效率,从而更好地了解病毒入侵,并提供定量分析病毒入侵效率的协议。
Viral diseases are among the main threats to public health. Understanding the factors affecting viral invasion is important for antiviral research. Until now, it was known that most viruses have very low plaque-forming unit (PFU)-to-particle ratios. However, further investigation is required to determine the underlying factors. Here, using quantitative single-particle analysis methods, the invasion of Semliki Forest virus (SFV), Japanese encephalitis virus (JEV), and influenza A virus (IAV) containing attachment to the cell surface, entry into the cell, transport towards the cell interior, and fusion with
endosomes to release nucleocapsids were quantitatively analysed in parallel. It was found that for SFV with an PFU-to-particle ratio of approximately 1:2, an entry efficiency of approximately 31% limited infection. For JEV, whose PFU-to-particle ratio was approximately 1:310, an attachment efficiency of approximately 27% and an entry efficiency of 10% were the main factors limiting its infection. Meanwhile, for IAV with PFU-to-particle ratios of 1:8100, 5% attachment efficiency, 9% entry efficiency, and 53% fusion efficiency significantly limited its infection. These results suggest that viruses with different infectivities have different limited steps in the invasion process. Moreover, there are significant differences in attachment efficiencies among viruses, emphasizing the pivotal role of attachment in viral invasion. The influence of the virus purification method on virus invasion was also investigated. This study, for the first time, reports the efficiencies of different stages of virus invasion, leading to a better understanding of virus invasion and providing a protocol to quantitatively analyse the virus invasion efficiency.