A plant-produced SARS-CoV-2 spike protein elicits heterologous immunity in hamsters
Abstract
Molecular farming of vaccines has been heralded as a cheap, safe and scalable
production platform. In reality, however, differences in the plant biosynthetic
machinery, compared to mammalian cells, can complicate the production of
viral glycoproteins. Remodelling the secretory pathway presents an opportunity
to support key post-translational modifications, and to tailor aspects of
glycosylation and glycosylation-directed folding. In this study, we applied an
integrated host and glyco-engineering approach, NXS/T Generation™, to
produce a SARS-CoV-2 prefusion spike trimer in Nicotiana benthamiana as a
model antigen from an emerging virus. The size exclusion-purified protein
exhibited a characteristic prefusion structure when viewed by transmission
electron microscopy, and this was indistinguishable from the equivalent
mammalian cell-produced antigen.