The plasmid constructs producing shRNA corresponding to the conserved 3D polymerase of Foot and Mouth Disease virus protects guinea pigs against challenge virus.

RNA interference (RNAi) has been used as an effective antiviral strategy for its specific silencing of viral gene expression in mammalian cells. In this study, shRNA targeting two regions of Foot and Mouth Disease Virus (FMDV) i.e. 3D and 5'UTR which are very essential in virus replication were evaluated. The constructs were made using h7K RNA polymerase III promoter. We investigated in vivo inhibitory effect of shRNA on FMDV replication in BHK-21 cells and guinea pigs. The results showed that transfection of 3D shRNA could reduce virus growth by three folds when cells were challenged with 10(2) TCID(50) of FMDV. Pretreated guinea pigs with 3DshRNA were protected 80% with 10(3) GPID(50) of FMDV. As a first report in guinea pigs which are recognized animal model for FMD vaccine potency testing, the study suggests that shRNA could be a viable therapeutic approach to control severity of FMD infection and spread.

Calcium phosphate nanoparticle prepared with foot and mouth disease virus P1-3CD gene construct protects mice and guinea pigs against the challenge virus.

Calcium phosphate nanoparticles provide safe and easily manufactured vaccine adjuvant and delivery system for DNA vaccines. In the present study FMDV "O" P1-3CD DNA vaccine was encapsulated in calcium phosphate nanoparticles of size 50-100 nm diameters. The maximum loading and entrapment efficiency of nanoparticles were studied by spectrophotometer, as well as agarose gel electrophoresis. In vitro transfection efficiency of these calcium phosphate nanoparticles was found to be as good as commercial transfecting reagent lipofectamine. In vivo analysis of the calcium phosphate nanoparticle P1-3CD (CaPNP1-3CD) FMDV "O" vaccine in mice and guinea pigs could induce significant cell mediated and humoral immune response. Also, immunized mice and guinea pigs were protected against the challenge virus.