Transgenic plants as factories for biopharmaceuticals
Nature Biotechnology Nov00 v.18, n.11

Glynis Giddings, Gordon Allison, Douglas Brooks & Adrian Carter
 
Institute of Biological Sciences, University of Wales, Aberystwyth, Cledwyn Building, Aberystwyth Ceredigion SY23 3DD, UK.
Correspondence should be addressed to G Giddings. e-mail: gdg@aber.ac.uk

Plants have considerable potential for the production of biopharmaceutical proteins and peptides because they are easily transformed and provide a cheap source of protein. Several biotechnology companies are now actively developing, field testing, and patenting plant expression systems, while clinical trials are proceeding on the first biopharmaceuticals derived from them. One transgenic plant-derived biopharmaceutical, hirudin, is now being commercially produced in Canada for the first time. Product purification is potentially an expensive process, and various methods are currently being developed to overcome this problem, including oleosin-fusion technology, which allows extraction with oil bodies. In some cases, delivery of a biopharmaceutical product by direct ingestion of the modified plant potentially removes the need for purification. Such biopharmaceuticals and edible vaccines can be stored and distributed as seeds, tubers, or fruits, making immunization programs in developing countries cheaper and potentially easier to administer. Some of the most expensive biopharmaceuticals of restricted availability, such as glucocerebrosidase, could become much cheaper and more plentiful through production in transgenic plants.