Packaging of Rift Valley fever virus pseudoviruses and establishment of a neutralization assay method

Li, Yuetao; Zhao, Yongkun; Wang, Cuiling; Zheng, Xuexing; Wang, Hualei; Gai, Weiwei; Jin, Hongli; Yan, Feihu; Qiu, Boning; Gao, Yuwei; Li, Nan; Yang, Songtao; Xia, Xianzhu

Recently, pseudovirus technology has become a very effective tool in scientific research [6, 7, 14] and has demonstrated several unique application advantages. For example, in experimental studies, pseudoviruses can be used to replace high-risk viruses with greater pathogenicity and infectivity, with RVFV being a typical example. Compared with natural viruses, pseudovirus particles have similar patterns of cell infection, and pseudoviruses can also effectively simulate the early cell infection process of natural viruses. Additionally, free viral DNA or reporter genes (i.e., EGFP and LacZ) can be artificially introduced into pseudoviruses, and this approach is conducive to rapid and timely detection and analysis in a clinic. Furthermore, pseudoviruses exhibit defective replication (ensuring safe manipulation), avoid the risk of infection posed by high-risk viruses, and eliminate the risk of serious safety concerns such as release from the laboratory. Therefore, pseudoviruses can be used in studies of the mechanism underlying viral infection of host cells. More importantly, pseudoviruses can be used to replace the natural viruses used in traditional virus neutralization assays. Currently, neutralization assays incorporating pseudoviruses are becoming a new, effective route for the detection of neutralizing antibodies. The many types of currently established pseudoviruses available both domestically and internationally include Middle East respiratory syndrome coronavirus (MERS-CoV), EBOV, hepatitis C virus, and SARS-CoV [4, 12, 20] . Some pseudoviruses have been successfully applied in drug screening, neutralizing antibody activity detection, and the evaluation of vaccine effects [3, 9] .