Yoshii Kentaro, Ikawa Ayae, Chiba Yumiko, Omori Yuki, Maeda Junko, Murata Ryo, Kariwa Hiroaki, Takashima Ikuo
Laboratory of Public Health, Graduate School of Veterinary Medicine, Hokkaido University, Kita-18 Nishi-9, Kita-ku, Sapporo, Hokkaido, Japan.
J Virol Methods. 2009 Oct;161(1):173-6. doi: 10.1016/j.jviromet.2009.05.016. Epub 2009 May 27.
Previously, a system for packaging tick-borne encephalitis virus (TBEV) subgenomic replicon RNAs into single-round infectious virus-like particles (VLPs) was developed. In the present study, VLPs were applied to measuring the levels of neutralizing antibodies against TBEV as an alternative to performing neutralization tests with live virus. As markers of VLP infection, the genes for GFP and luciferase were inserted into the TBEV replicon, which was then packaged into VLPs. The reporter genes were expressed in cells that were infected with the VLPs, and this infection was inhibited by neutralizing antibodies to TBEV. Serum samples from wild rodents were used to evaluate the neutralization test using VLPs. All the sera that were positive in the conventional neutralization test were also found to be positive in the neutralization test using VLPs, and there were highly significant correlations between the neutralization titres obtained using the native virus and those using VLPs. These results indicate that VLPs that express reporter genes represent a useful and safe alternative to conventional neutralization testing using live virus.
此前，已开发出一种将蜱传脑炎病毒（TBEV）亚基因组复制子RNA包装到单轮感染性病毒样颗粒（VLP）中的系统。在本研究中，VLP被用于测量针对TBEV的中和抗体水平，作为用活病毒进行中和试验的替代方法。作为VLP感染的标志物，绿色荧光蛋白（GFP）和荧光素酶的基因被插入到TBEV复制子中，然后将其包装到VLP中。报告基因在感染VLP的细胞中表达，并且这种感染被针对TBEV的中和抗体所抑制。来自野生啮齿动物的血清样本被用于评估使用VLP的中和试验。在传统中和试验中呈阳性的所有血清在使用VLP的中和试验中也呈阳性，并且使用天然病毒获得的中和效价与使用VLP获得的中和效价之间存在高度显著的相关性。这些结果表明，表达报告基因的VLP是使用活病毒进行传统中和试验的一种有用且安全的替代方法。
