Subunit vaccine transgenic plants

In order to overcome environmental concerns in particular, some companies are investigating the use of engineered plant cell lines as opposed to intact transgenic plants in the context of biopharmaceutical production. One company (DowAgroSciences) gained approval in 2006 for a veterinary subunit vaccine against Newcastle disease in poultry produced by such means. 

In 1990, the first plant-made vaccines were performed via expression of Streptococcus mutans surface protein A in transgenic tobacco, followed by oral immunization of mice with the same plant material (Fischer and Emans, 2000). This transgenic plant material was later shown to successfully induce an antibody response through a demonstration that serum from immunized mice could react with intact S. mutans. Plants were also developed that expressed Escherichia coli enterotoxin B subunit (LT-B) and that exhibited successful inducement of both mucosal and serum antibody responses (Tacket, 2005). These initial experiments led to a cornucopia of studies involving generations of plant-made vaccines and therapeutic proteins and their applications in medicine. 

Awram, P., et ah. The potential of plant viral vectors and transgenic plants for subunit vaccine production. Adv Vims Res, 2002 58 81-124. 

Tab. 9.2 Vaccine antigens expressed in plant systems subunit antigen expression in transgenics... 

The first system used to produce vaccines was potato plants and transgenic tubers have being employed in some clinical trials. Expression of vaccines is also reported in other hosts such as tomato, banana, carrot, lettuce, maize, alfalfa, white clover and Arabidospis. Hepatitis B surface antigen was successfully expressed in cherry tomatillo and potato. Expression of human cholera toxin p subunit was achieved in tomato and tobacco plants. ... 

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