Introduction: Plant viruses can be employed as versatile vectors for produc-tion of vaccines by expressing immunogenic epitopes on the surface of chi-meric viral particles. Although several viruses, including tobacco mosaicvirus, potato virus X and cowpea mosaic virus, have been developed as vectors, we aimed to develop a new viral vaccine delivery system, a bamboomosaic virus (BaMV), that carries larger transgene loads, and generates better immunity in the target animals with fewer adverse environmental effects.Methods: We engineered the BaMV as a vaccine vector expressing the anti-genic epitope(s) of the capsid protein VP1 of foot-and-mouth disease virus(FMDV). The recombinant BaMV plasmid (pBVP1) was constructed by replacing DNA encoding the 35 N-terminal amino acid residues of the BaMV coat protein with that encoding 37 amino acid residues (T128-N164)of FMDV VP1.Results: The pBVP1 infected host plants and generated a chimeric virionBVP1 expressing VP1 epitopes in its coat protein. Immunization of swine with BVP1 virions resulted in the production of anti-FMDV neutralizing antibodies and VP1-specific IFN-c. Furthermore, all BVP1-immunized swinewere protected against FMDV challenge. Conclusions: Chimeric BaMV virions that express partial sequence of FMDV VP1 effectively induced not only humoral and cell-mediated immune responses but also full protection against FMDV in target animals. This BaMV-based vector technology may be applied to other vaccines that require correct expression of antigens on chimeric viral particles.
