Fig. 3

Validation of the antiviral function of CaIRF1. The cells in this part of the assay were photographed under an inverted fluorescence microscope (Leica, D35578), camera model DFC3000G, with Leica application suite X. A Minimum G418 concentration screen to determine the minimal necessary to kill MDCK cells. The minimum concentration used in the study was determined to be 800 μg/mL. Scale bar, 75 μm. B Validation of MDCK cells stably expressing CaIRF1. An IFA was performed to identify cells that stably expressed CaIRF1. Adjustments of individual colour channels are sometimes necessary on merged images. The scale bar represents 138.8 μm. C MDCK-CaIRF1 protected cells against cytopathogenic lesions induced by VSV. The scale bar represents 100 μm. D Less VSV replicated in the MDCK-CaIRF1 cells than in the MDCK cells. E CPV-2 infection of MDCK cells inhibited the expression of CaIRF1 mRNA. F CaIRF1 inhibited the replication of CPV-2 in cells. G A CCK-8 assay was performed to determine the viability of si-CaIRF1- and si-NC-transfected MDCK cells (36 h). H and I Slightly increased replication of CPV-2 and VSV was found in CaIRF1-knockdown cells. The data shown in the figure represent the mean ± SD of three independent experiments, each experiment had three cell wells as technical replicates. * P < 0.05, ** P < 0.01, *** P < 0.001, **** P < 0.0001 compared with the empty vector transfection group. The enlarged versions of the cell images were shown in the Supplementary file 2