Inhibition on replication of infectious bursal disease virus by siRNA targeting VP1 gene

Three short interfering RNA(siRNA) sequences,named VP1-siRNA668,VP1-siRNA1034 and VP1-siRNA2250 based on conserved regions in the VP1 gene of the infectious bursal disease virus(IBDV) were selected and synthesized via in vitro transcription.The chicken embryo fibroblast(CEF) was transfected with the 3 siRNA and then infected with IBDV,respectively.The viral titers of CEF cultures were 102.75,102.00 and 101.75 TCID50/0.1 mL in CEF cultures transfected with VP1-siRNA668,VP1-siRNA1034 and VP1-siRNA2250,respectively,which were significantly lower than 106TCID50/0.1 mL in siRNACON and IBDV control groups.As compared to the control,the inhibitory rates were 73.10%,81.79% and 90.28% in the real-time fluorescence quantitative RT-PCR assay for detecting VP1 gene,respectively.The results indicated that the 3 siRNA could effectively inhibit IBDV replication in vitro,in which 2 250 the highest site of the siRNA inhibitory effect,suggesting that is a major functional region of VP1 gene and an important target for designing novel drug and vaccine against IBDV.