Growth, replication, and gene expression in infected, parental, and ACE2/TMPRSS2-expressing A549 cells.

(A) Virus growth was quantified in parental and ACE2/TMPRSS2-expressing A549 cells infected at an MOI of 0.01. Supernatant collected at the respective time points was titrated by plaque assay on Vero E6 cells. Growth kinetic experiments were performed once in triplicates. (B) Expression of cell-associated envelope was determined in parental and ACE2/TMPRSS2-expressing A549 cells at 24 and 48 hours postinfection by Q-RT-PCR. (C) Expression of cell-associated sgN in Calu-3 cells at 24 and 48 hours postinfection was determined by Q-RT-PCR. TBP was used for normalization. (D) Expression of the indicated genes was determined by Q-RT-PCR. Shown is the mean fold change +/− SD of 3 biologically independent experiments that were each conducted in quadruplicates. RVFV cl.13, which is devoid of its IFN antagonist NSs, was included for the analysis of expression of IFNs and ISGs. A+/T+, ACE2/TMPRSS2-expressing A549 cells; GE, genome equivalents; par, parental; IFN, interferon; MOI, multiplicity of infection; Q-RT-PCR, quantitative real-time PCR; RVFV cl.13, Rift Valley Fever Virus clone 13; sgN, subgenomic nucleocapsid; TBP, TATA-binding protein. See S1 Data. (TIF)