Figure 4
Comparison of time-dependent reporter gene expression in ACE2-TMPRSS2-293T cells transduced by VEE-SARS-CoV-2 vectors and SC2-VLPs. (A) Luciferase gene expression level and (B) folds of luciferase mRNA change in ACE2-TMPRSS2-293T cells after transduction by VEE-SARS-COV-2-Luc vectors and SC2-Luc-VLP. Transduced cells were harvested at the indicated times, and luciferase assay and real-time qPCR analysis were performed. The fold change was normalized to the first time point determined (2 h post-transduction). GAPDH was used as the internal control. Data are presented as the mean ± SD of independent triplicates. (C) GFP expression in ACE2-TMPRSS2-293T cells transduced with VEE-SARS-CoV-2-GFP vectors or SC2-GFP VLPs at 48 h post-transduction. (D) Time-dependent GFP expression in ACE2-TMPRSS2-293T cells transduced by VEE-SARS-CoV-2-GFP vectors. Transduced cells were passaged every 4 days and GFP expression was recorded under a fluorescence microscope and cell density was photographed under regular microscope at the indicated times. Scale bar = 200 μm.
