Extended Data Fig. 1: Caspase-6 inhibition reduces coronavirus replication in different cell types.
From: Coronaviruses exploit a host cysteine-aspartic protease for replication
a MERS-CoV-infected Huh7 cells were treated with 100 μM z-VAD-fmk or DMSO. Cells were fixed at 24 hpi and immunolabeled with an in-house guinea pig immune serum against MERS-CoV N. The experiment was repeated two times independently with similar results. b Replication of human-pathogenic coronaviruses treated with 100 μM z-VAD-fmk or DMSO. Samples were harvested at 24 hpi and viral gene expression was quantified with RT-qPCR (n = 3). c BEAS2B, Calu3, Huh7, and BSC1 cells were treated with z-VAD-fmk at the indicated concentrations. Cell viability was quantified with CellTiter-Glo assays at 24 h post treatment (n = 6). d MDM, Caco2, Calu3, A549, and VeroE6 cells were infected with MERS-CoV at 1MOI and were treated with z-VEID-fmk, z-VAD-fmk, or DMSO. Cell lysate and supernatant samples were harvested at 24 hpi. MERS-CoV N gene copy was quantified with RT-qPCR (n = 3). e Huh7 cells were infected with SARS-CoV-2 Omicron BA.1 or BA.2 at 1MOI and were treated with z-VEID-fmk at the indicated concentrations. Cell lysate and supernatant samples were harvested at 24 hpi. SARS-CoV-2 RdRp gene copy was quantified with RT-qPCR (n = 3) and infectious titer was quantified with TCID50 assays (n = 3). f HFL, Calu3, Huh7, and BSC1 cells with or without infection with the indicated coronaviruses were treated with z-VEID-fmk. Cell viability was quantified with CellTiter-Glo assays at 24 h post treatment (n = 3). Data represented mean and standard deviations from the indicated number of biological repeats. Statistical significance between groups was determined with one way-ANOVA (c–e) or two-way ANOVA (b, f). Bars in (a) represented 20 μm.
