Fig. 1

PEDV does not induce IFN-β production and inhibits poly (I:C)-mediated IFN-β induction. a IECs were cotransfected with IFN-β-Luc and phRL-TK, then infected with PEDV at an MOI of 1 and 0.1 for 24 h. Cells were retransfected with poly (I:C) as a positive control. After 12 h, the cells were harvested and subjected to a dual-luciferase assay. b IECs were infected with PEDV at an MOI of 1, mock-infected as a negative control, or transfected with poly (I:C) as a positive control. At the indicated time points, total RNA was extracted and IFN-β and β-actin mRNA were subjected to real-time PCR. RNA expression levels were normalized to β-actin. c In contrast to a, IECs were first mock-infected or infected with PEDV at an MOI of 1 for 12 h and then cotransfected with IFN-β-Luc and phRL-TK for 24 h. Cells were retransfected with or without poly (I:C) for an addition 12 h, harvested, and then subjected to a dual-luciferase assay. All data are expressed as means ± SD of 3 independent experiments. *p < 0.05; **p < 0.01 as compared with poly (I:C)