Expression of Multiple Taenia Solium Immunogens in Plant Cells Through a Ribosomal Skip Mechanism

Abstract

Taenia solium cysticercosis is a major parasitic disease that affects the human health and the economy in underdeveloped countries. Porcine cysticercosis, an obligatory stage in the parasite life cycle, is a suitable target for vaccination. While several recombinant and synthetic antigens proved to be effective as vaccines, the cost and logistic difficulties have prevented their massive use. Taking this into account, a novel strategy for developing a multi-epitope low-cost vaccine is herein explored. The S3Pvac vaccine components (KETc1, KETc12, KETc7, and GK1 [KETc7]) and the protective HP6/TSOL18 antigen were expressed in a Helios2A polyprotein system, based on the 'ribosomal skip' mechanism mediated by the 2A sequence (LLNFDLLKLAGDVESNPG-P) derived from the Foot-and-mouth disease virus, which induces self-cleavage events at a translational level. This protein arrangement was expressed in transgenic tobacco cells. The inserted sequence and its transcript were detected in several Helios2A lines, with some lines showing recombinant protein accumulation levels up to 1.3 µg/g of fresh weight in leaf tissues. The plant-derived Helios2A vaccine was recognized by antibodies in the cerebral spinal fluid from neurocysticercosis patients and elicited specific antibodies in BALB/c immunized mice. These evidences point to the Helios2A polyprotein as a promising system for expressing multiple antigens of interest for vaccination and diagnosis in one single construction.

Plant‐made oral vaccines against human infectious diseases—Are we there yet?

“…Plant-derived Helios2A accumulated up to 1.3 lg/g FW in transgenic tobacco leaf tissue and was recognized by antibodies in the cerebrospinal fluid from patients with NCC in a functional assay. Further, orally immunized mice elicited an immune response, but antibody titres were not reported (Monreal-Escalante et al, 2015).…”

Structures and Corresponding Functions of Five Types of Picornaviral 2A Proteins

“…Moreover, the F2A-mediated heterogeneous glycosylphosphatidylinositol-anchored proteins co-displaying yeast system is an effective method for improving the efficiency of enzyme-displaying yeast biocatalysts (Sun et al, 2012). In addition, F2A has been used to co-express five Taenia solium (pork tapeworm) immunogens in plant cells (Monreal-Escalante et al, 2015). The 2A protein of PTV-1 has also been successfully used to co-express multi-proteins in parasites (Tang et al, 2016).…”

What Does Plant-Based Vaccine Technology Offer to the Fight against COVID-19?

“…Given that plant systems have been successfully adopted for the production of multiepitope proteins, the generation of such vaccines against COVID-19 is considered highly viable [88][89][90]. Besides expressing chimeric proteins, multiple antigen expression can be achieved by transplastomic technologies (operon-like expression) or at the nuclear level using the picornaviral 2A sequence that allows releasing individual antigens from a single coding gene [91].…”