EXPRESSION OF THE POTYVIRUS COAT PROTEIN-MEDIATED BY RECOMBINANT VACCINIA VIRUS AND ASSEMBLY OF POTYVIRUS-LIKE PARTICLES IN MAMMALIAN-CELLS

The coat protein of the potyvirus, Johnsongrass mosaic virus (JGMV), w as expressed using a recombinant vaccinia virus (VV) system. Ultra-thi n section electron microscopy demonstrated that the coat protein assem bled into potyvirus-like particles (PVLPs) in recombinant VV infected cells. Infection of cells with two additional VV recombinants expressi ng coat protein plus N-terminal and N- and C-terminal extensions also resulted in the formation of PVLPs. These results suggest that the abi lity of VV to express the potyvirus coat protein at sufficient levels to allow PVLP formation in vitro, could make VV a suitable vector for the delivery of PVLPs displaying vaccine antigens in vivo without the need for particle purification and/or inclusion of adjuvant. Use of su ch a vaccine strategy would also benefit from the proven advantages of poxviruses as vaccines such as stability in a freeze dried form, resi stance to environmental factors and the potential for oral administrat ion.