Gene gun-mediate DNA vaccination against foot-and-mouth disease virus.

Foot-and-mouth disease (FMD) is one of the most dangerous diseases of cloven-hoofed animals and is a constant threat in the Middle-East and other regions throughout the world despite intensive vaccination programs. In this work, we describe the ability of FMDV expression constructs to protect pigs from FMDV challenge when used as a vaccine. The construct consists of encephalomyocarditis virus (EMCV) internal ribosome entry site (IRES), the entire P1 and 2A together with 3CD sequences, all in the same reading frame. Another plasmid that was tested, carries the serotype O1 (G) VP1, Asia1 VP1 and O1 (G) 3C. Between each of the genes the 3C cleavage sequences were inserted. All constructs carried the cytomegalo virus (CMV) promoter. Using immunofluorescent and immunoblot techniques, we could show the expression and processing of viral proteins. Following the application of FMDV expression constructs into pigs skin by 'Gene Gun', pigs were partially protected from FMDV challenge.