Fig. 6

–VACV gene expression, cytopathic effects and viral replication in ATF6α-KO MEFs. A Representative Phase-Contrast micrographs of VACV-induced CPE on confluent monolayers of ATF6α-KO or WT MEFs. Cells were infected with MOI 10 and visualized at 24 h post infection. Scale bars indicate 100 µm. B ATF6-KO or ATF6-WT MEFs were infected at MOI 0.01 of VACV WR strain for 48 h. Plaque phenotypes were visualized by immunostaining with VACV hyperimmune serum followed by protein-A-HRP and 3, 3′-diaminobenzidine incubation. Representative images are shown. The areas of 50 plaques per infected cell type were measured using ImageJ, and the average ± standard deviation is graphically indicated above each image. C Cells were infected with VACV at a MOI of 10 and harvested at 3, 6, 12, 24 or 48 hpi; viral yield was quantified by viral plaque assay in BSC40 cells. Data are means of triplicate experiments ± SD. D cells were infected with VACV at a MOI of 0.01 and harvested at 0, 24, 48 or 72 hpi, and viral yield was quantified by viral plaque assay in BSC40 cells. Data are representative of at least three independent experiments. E ATF6α-KO MEFs were transfected with pEGFP-ATF6 expression plasmid or empty vector and infected with VACV-WR for 24 h before harvested for virus growth analysis. Virus titers were determined by viral plaque assay in BSC40 cells. Results were plotted as mean ± SEM from duplicate samples and from two independent experiments. F Total DNA was extracted from transfected infected-cells and used to quantify VACV genome copy number by qPCR. The data were mean from two independent experiments. ** or *** indicate statistical significant differences between groups (p < 0.01 or p < 0.001, respectively) as determined by ANOVA followed by Bonferroni’s test. G MEFs were infected with VACV WR at MOI of 10, incubated for 24 h, processed and visualized by transmission electron microscopy (TEM). Scale bars are represented bellow each panel