A transgenic plant cell‐suspension system for expression of epitopes on chimeric B amboo mosaic virus particles

We describe a novel strategy to produce vaccine antigens using a plant cell‐suspension culture system in lieu of the conventional bacterial or animal cell‐culture systems. We generated transgenic cell‐suspension cultures from N icotiana benthamiana leaves carrying wild‐type or chimeric B amboo mosaic virus ( B a MV ) expression constructs encoding the viral protein 1 ( VP 1) epitope of foot‐and‐mouth disease virus ( FMDV ). Antigens accumulated to high levels in B dT38 and B dT19 transgenic cell lines co‐expressing silencing suppressor protein P38 or P19. Ba MV chimeric virus particles ( CVP s) were subsequently purified from the respective cell lines (1.5 and 2.1 mg CVP s/20 g fresh weight of suspended biomass, respectively), and the resulting CVP s displayed VP 1 epitope on the surfaces. Guinea pigs vaccinated with purified CVP s produced humoral antibodies. This study represents an important advance in the large‐scale production of immunopeptide vaccines in a cost‐effective manner using a plant cell‐suspension culture system.