Robust neutralization assay based on SARS-CoV-2 S-bearing vesicular stomatitis virus (VSV) pseudovirus and ACE2-overexpressed BHK21 cells

Hualong Xiong; Yangtao Wu; Jiali Cao; Ren Yang; Jian Ma; Xiaoyang Qiao; Xiangyang Yao; Baohui Zhang; Yali Zhang; Wangheng Hou; Yang Shi; Jingjing Xu; Liang Zhang; Shaojuan Wang; Baorong Fu; Ting Yang; Shengxiang Ge; Jun Zhang; Quan Yuan; Baoying Huang; Zhiyong Li; Tianying Zhang; Ningshao Xia

The pseudovirus system provides a convenient tool for the research of RG-3 viruses, it makes the evaluation of inhibitors for viral entry, neutralizing antibodies and immunized-serum much easier. Retrovirus and VSV are both common used pseudovirus system, but the pseudotype virus titer obtained with VSVdG system is generally higher than that of the retrovirus system [10] . Furthermore, infection of CoV-2 and Huh7 cell, the reporter gene firefly luciferase was used to indicate the infection of pseudotyped virus [12] . Noteworthy, the truncation of the cytoplasmic tail . CC-BY-NC-ND 4.0 International license author/funder. It is made available under a The copyright holder for this preprint (which was not peer-reviewed) is the . https://doi.org/10.1101/2020.04.08.026948 doi: bioRxiv preprint may increase fusion activity, which is consistent with the study of SIV-MuLV chimeric envelope protein [17] . Enhanced syncytia arising from the fusion may contribute to the improved packaging efficiency. The pseudotyped VSV with C- The copyright holder for this preprint (which was not peer-reviewed) is the . https://doi.org/10.1101/2020.04.08.026948 doi: bioRxiv preprint 12 h post infection to calculate the inhibit ratio. The IC50 was analysed by nonlinear regression. The copyright holder for this preprint (which was not peer-reviewed) is the . https://doi.org/10.1101/2020.04.08.026948 doi: bioRxiv preprint Figure 1 .