Therapeutic application of RNA interference against foot-and-mouth disease virus in vitro and in vivo.
ABSTRACT Foot-and-mouth disease (FMD) is an economically important animal disease because of the speed of its transmission. Routine vaccination may not be effective for early protection in an outbreak situation. Small interfering RNA (siRNA) can be used in a rapid and effective antiviral approach. However, siRNA has limitations when used in disease prevention, such as a short duration of action. In this study, we have demonstrated that treatment with siRNA after FMD virus (FMDV) infection has an antiviral effect and could be effective in control of FMDV. We applied adenoviruses expressing siRNA both before and after FMDV infection in vitro and in vivo. Treatment after FMDV infection gave effective viral inhibition, but a combination of treatment before and after FMDV infection gave the best results in IBRS-2 cells. We obtained high survival rates in suckling mice by the use of therapeutic injections following challenge. The results of this study suggest that treatment with siRNA could enhance antiviral effects and may be helpful in the control of FMDV in an outbreak.
Article: Identification of an effective siRNA target site and functional regulatory elements, within the hepatitis B virus posttranscriptional regulatory element.[show abstract] [hide abstract]
ABSTRACT: Infection with hepatitis B virus (HBV) is major public health concern. The limitations of available antiviral drugs require development of novel approaches to inhibit HBV replication. This study was conducted to identify functional elements and new siRNA target sites within the highly conserved regions of the 533 base post-transcriptional regulatory element (PRE) of HBV RNAs. Computational analysis of the PRE sequence revealed several conserved regulatory elements that are predicted to form local secondary structures some of these within known regulatory regions. A deletion analysis showed that sub-elements of the PRE have different effects on the reporter activity suggesting that the PRE contains multiple regulatory elements. Conserved siRNA targets at nucleotide position 1317-1337 and 1329-1349 were predicted. Although the siRNA at the position 1329-1349 had no effect on the expression of reporter gene, the siRNA target site at the position 1317-1337 was observed to significantly decrease expression of the reporter protein. This siRNA also specifically reduced the level of cccDNA in transiently HBV infected cells. The HBV PRE is likely to contain multiple regulatory elements. A conserved target within this region at 1317-1337 is an effective siRNA target.Virology Journal 01/2010; 7:216. · 2.34 Impact Factor
Article: Effective inhibition of foot-and-mouth disease virus (FMDV) replication in vitro by vector-delivered microRNAs targeting the 3D gene.[show abstract] [hide abstract]
ABSTRACT: Foot-and-mouth disease virus (FMDV) causes an economically important and highly contagious disease of cloven-hoofed animals. RNAi triggered by small RNA molecules, including siRNAs and miRNAs, offers a new approach for controlling viral infections. There is no report available for FMDV inhibition by vector-delivered miRNA, although miRNA is believed to have more potential than siRNA. In this study, the inhibitory effects of vector-delivered miRNAs targeting the 3D gene on FMDV replication were examined. Four pairs of oligonucleotides encoding 3D-specific miRNA of FMDV were designed and selected for construction of miRNA expression plasmids. In the reporter assays, two of four miRNA expression plasmids were able to significantly silence the expression of 3D-GFP fusion proteins from the reporter plasmid, p3D-GFP, which was cotransfected with each miRNA expression plasmid. After detecting the silencing effects of the reporter genes, the inhibitory effects of FMDV replication were determined in the miRNA expression plasmid-transfected and FMDV-infected cells. Virus titration and real-time RT-PCR assays showed that the p3D715-miR and p3D983-miR plasmids were able to potently inhibit the replication of FMDV when BHK-21 cells were infected with FMDV. Our results indicated that vector-delivered miRNAs targeting the 3D gene efficiently inhibits FMDV replication in vitro. This finding provides evidence that miRNAs could be used as a potential tool against FMDV infection.Virology Journal 01/2011; 8:292. · 2.34 Impact Factor