Human Pharmaceuticals Produced in Plants

Genetically engineered agricultural plants with improved traits (e.g. herbicide and pest resistance) have yielded significant agricultural revenues over the past 5 years. In addition, numerous immunotherapeutic proteins, antibodies and vaccines have been successfully produced using plant “bioreactors”(Arakawa et al., 1998); however, only a limited number have made their way into clinical trials. The most advanced product in human clinical trials is a secretory IgA antibody comprised of four polypeptide chains that inhibits the binding to teeth of Streptococcus mutans, the major causal agent of tooth decay. This chapter will summarize recent work demonstrating the potential of plants to synthesize and assemble complex proteins suitable for human therapeutic use.