USE OF Lactuca sativa l. (LETTUCE) FOR THE EXPRESSION OF RECOMBINANT PROTEINS OF VACCINAL INTEREST AGAINST Toxoplasma gondii

SANCHEZ, EDWIN F; RADONIC, LAURA; CORIGLIANO, MARIANA G; RIVERA, MAXIMILIANO; ALBARRACÍN, ROMINA M; SANDER, VALERIA A; BENGOA LUONI, SOFIA A; LÓPEZ, MABEL; CLEMENTE MARINA

Santiago de Chile

Congreso; FLAP XXIV Congreso Latinoamericano de Parasitología; 2017

Sociedad Chilena de Parasitología (SOCHIPA)

Advances in biotechnology have allowed plants to beconceived as bioreactors to produce proteins of immunological interest. In thisway, proteins are expressed in plant tissues to be used as oral vaccines and toinduce a protective immune response in the host. The production of proteins inlettuce showed some advantages making it a convenient system to producevaccines, such as low cost of production, the possibility of achieving optimalexpression levels and free-animal and free-human pathogens proteins. In thissense and due to its medical importance, toxoplasmosis is presented as a goodmodel to study the antigenic properties of proteins expressed in this system.Therefore, we proposed to develop a plant system to produce T. gondii antigens to produce a vaccine.SAG1 is the main surface antigen of this parasite and a promising candidate todevelop a vaccine. Therefore, we worked with the construction of the matureprotein (SAG1) fused to the 90 kDa heat shock protein of N. benthamiana (NbHsp90.3) as an adjuvant. This construction wascloned into the binary vector pK7WGR. The genetic transformation of GrandRapids variety was carried out using the strain LBA4404 of A. tumefaciens. The shoots that showed root development in thepresence of the selective agent were taken to the greenhouse for acclimation,growth and subsequent analysis by PCR. The expression of the protein wasevaluated by western blot in 11 transgenic lines, observing expression in 7 ofthem, but only 2 lines showed the highest levels of expression, around 30 μg/mg of lyophilized leaf. Finally, the antigenic propertieswere evaluated by western blot. We observed that the protein expressed inlettuce were recognized by IgG antibodies from seropositive human patients,indicating that SAG1 fused to NbHsp90.3 is recognized by antibodies generatedduring natural infections and would act as a promising candidate to develop avaccine. Our results show that lettuce plants can be an attractive platform forthe expression of antigens since they are able to maintain its antigenicproperties.