Porcine epidemic diarrhea virus (PEDV) is a
member of the coronaviridae family, which can cause acute
and highly contagious enteric disease of swine characterized
by severe entero-pathogenic diarrhea in piglets. Currently,
the vaccines of PEDV are only partially effective
and there is no specific drug available for treatment of
PEDV infection. To exploit the possibility of using RNA
interference (RNAi) as a strategy against PEDV infection,
five shRNA-expressing plasmids targeting the N, M, and S
genes of PEDV were constructed and transfected into Vero
cells. The cytopathic effect and MTS assays demonstrated
that two shRNAs (pSilencer4.1-M1 and pSilencer4.1-N)
were capable of protecting cells against PEDV invasion
with very high specificity and efficiency. The two shRNA
expression plasmids were also able to inhibit the PEDV
replication significantly, as shown by detection of virus
titers (TCID50/mL). A real-time quantitative RT-PCR further
confirmed that the amounts of viral RNAs in cell
cultures pre-transfected with these two plasmids were
reduced by 95.0 %. Our results suggest that RNAi might be
a promising new strategy against PEDV infection.