Fig. 1. A VSV-based non-gain-of-function system was developed to predict SARS-CoV-2 3CLpro mutations.
(A) 3CLpro from SARS-CoV-2 and mouse hepatitis virus (MHV) were tested in a gain-of-signal assay. Data are presented as individual points of n = 3 biologically independent replicates per condition for SARS-CoV-2 3CLpro and n = 2 for MHV 3CLpro, average values are represented by histogram bars. (B) Replication kinetics are shown for wild-type (wt) VSV-G-3CLpro-L and GC376-selected F305L variant. Data are presented as SD of n = 2 biologically independent replicates per condition. (C) GC376 and nirmatrelvir dose responses are shown for wild-type (wt) VSV-G-3CLpro-L and GC376-selected F305L variant. Data are presented as means of n = 2 (GC376) and n = 3 (Nirmatrelvir) biologically independent replicates per condition. (D) Sequence alignment of C-terminal autocleavage sites is shown for SARS-CoV-2 3CLpro and related coronaviruses.