Establishment and evaluation of stable cell lines inhibiting foot-and-mouth disease virus by RNA interference.

RNA interference (RNAi) has been proved to be a powerful tool for foot-and-mouth disease virus FMDV inhibition in vitro and in vivo. We established five stable baby hamster kidney 21 cell lines (BHK-21) containing five short hairpin RNAs (shRNAs) expression plasmids (p3D1shRNA, p3D2shRNA, p3D3shRNA, p3D4shRNA, and p3D5shRNA) targeting 3D gene of FMDV. Immunofluorescent assay, virus titration, and real-time quantitative reverse transcription polymerase chain reaction (Q-RT-PCR) were conducted to detect the effect of shRNAs on FMDV replication. After challenged with FMDV of O/CHA/99, two cell lines (p3D1shRNA and p3D4shRNA) showed a significant reduction in the synthesis of viral protein and RNA, accompanied by a sharp decrease in viral yield, and the inhibition could last for at least thirty passages. We developed an efficient procedure for the establishment and evaluation of stable cell lines for anti-FMDV research based on RNAi technology, which can be a candidate method for anti-FMDV research.