Expression of immunogenic poliovirus Sabin type 1 VP proteins in transgenic tobacco

One of the milestones of vaccinology is the depletion of the global impact of Poliomyelitis. The current vaccines to deal with Polio comprise the Sabin and Salk formulations. The main limitation of the former is the use of attenuated viruses that can revert into pathogenic forms, whereas the latter is more expensive and induces no protection in the intestinal tract; the site of virus replication. Genetically engineered plants cope with such limitations. In addition, they offer a low-cost alternative for production, storage and delivery of vaccines. This technology has been narrowly applied in the development of Polio vaccines. Herein, we explored the ability of tobacco cells to express the immunogenic VP1, VP2, VP3, and VP4 Polio antigens, which are relevant for vaccine development. Evidence on the expression of the plant-made Polio VPs is presented and an immunogenicity assessment proved their capacity to induce local and systemic humoral responses when administered by subcutaneous and oral routes. The plant-made VPs will be useful in the development of low-cost vaccine formulations able to induce effective mucosal immunity without the risks associated to the use of attenuated viruses; therefore there is a potential for this technology to contribute toward Polio eradication.

Keywords: Molecular farming; Mucosal immunity; Oral vaccine; Plant-made vaccine; Poliomyelitis; Subunit vaccine.