Figure 2: Changes in SAMHD1 expression in porcine macrophages and MARC-145 cells infected with HP-PRRSV.

(A,B) PAMs and MARC-145 cells were infected with HP-PRRSV at an MOI of 5 and harvested at the indicated times. RT-qPCR (A) and western blot analysis of SAMHD1 expression (B) in HP-PRRSV infected cells. β-actin was used as a loading control. (C) The cell lysates of PAMs incubated with UV-inactivated HP-PRRSV for 12 h and 16 h were collected for western blot analysis of SAMHD1 protein expression. (D) The expression of IFN-α determined by ProcartaPlex Multiplex Immunoassays. PAMs were infected with HP-PRRSV for 12, 24, 36, 48, 60 and 72 h. The medium from mock infected cells served as a negative control. (E) PAMs were first pretreated with IFN-alpha-IFNAR-IN-1 or mock pretreated with medium containing DMSO for 2 h. The cells were then infected with the HP-PRRSV virus at an MOI of 5 or mock-infected with DMEM for 12 h and 16 h, respectively. The cell lysates were collected and analyzed by western blot. The fold change of SAMHD1 protein is expressed as densitometric units of the band normalized to the β-actin level relative to the uninfected control. The error bar represents standard deviation from three independent experiments. The asterisks indicate a significant difference compared to mock infection (NS, not significant: p > 0.05; *p < 0.05; **p < 0.01). Uncropped images of blots are shown in Supplementary Figure 2.