FOOT AND MOUTH DISEASE: EXPRESSION AND CHARACTERIZATION OF POLYPROTEIN P1 IN TRANSGENIC ALFALFA PLANTS

GOMEZ C; DUS SANTOS MJ; COMPAIRED D; RIOS R; FRANZONE P; ARDILA F; WIGDOROVITZ A

MONTREAL, CANADA

Congreso; CONFERENCE ON PLANT MADE PHARMACEUTICALS; 2005

Foot and mouth disease virus (FMDV) is the causative agent of an economically important disease affecting meat producing animals Current FMDV vaccines are based on the utilization of inactivated virus and, although they have proved to be effective tools for the prevention of the disease, their production is both costly and risky because of manipulation of massive amounts of virulent virus which could result in virus dissemination. Thus, it is important to develop new approaches that could provide practical alternatives to the current methodology of vaccine production The use of transgenic plants as vectors for the expression of viral and bacterial antigens has been increasingly tested as an alternative methodology for the production of experimental vaccines. However, an important limitation in most cases is the low concentration of the recombinant antigens in the plant tissues, which reduces the possibilities of practical applications. With that scope, we have focused on the use of strong promoters for conducting transgene expression. Previous results obtained by our group employing transient expression assays in alfalfa, showed that cassava vein mosaic virus (CsVMV) promoter presented higher transcriptional activity than 35S promoter. In this study, we propose the utilization of CsVMV promoter with the aim of increasing FMDV polyprotein (precursor of the viral structural proteins) expression in alfalfa plants. Transgenic alfalfa plants were obtained by the Agrobacterium tumefaciens methodology. The genetic construction placed P1 gene under the control of either CsVMV promoter or 35S promoter. Presence and transcriptional activity of the foreign gene was evaluated by PCR and RT-PCR respectively. Expression of polyprotein P1 was determinated by western blot and ELISA assays (showing a level of 134 ugr P1/ g fresh leaf). The results obtained demonstrated that CsVMV promoter had a better performance than 35S promoter for the expression of FMDV P1 in transgenic alfalfa plants.