They spliced a gene encoding an HBV surface protein into Agrobacterium . Invading the tobacco cells, the Agrobacterium directed the cells to produce the HBV antigen. The researchers regenerated the cells into tobacco plants. It was incredible. To be honest, I almost expected the plants to degrade the antigen.
Plants usually do that to nonuseful proteins.
And here we come along, putting in a protein of a human pathogen . . . Arntzen and colleagues next crushed the tobacco plants' leaves, extracted the HBV antigen, and injected it into mice. Sure enough, the mice developed antibodies to the antigen. Using their modified HBV antigen, the researchers added a DNA sequence that causes proteins to be expressed in potato tubers. Although injecting plant-produced vaccines in mice is a good way to test the concept, researchers really want animals to gain immunity by eating a vaccine in food.