Expression of Antibody Fragments in Plant Cells

Abstract

Stable expression of active antibodies and antibody fragments has been achieved in plant cells. It has been shown for complete antibodies, Fab fragments, scFv’s and single VH domains (for review see Conrad and Fiedler 1998). Production of antibodies in transgenic plants and plant cells is generally of interest if high quantities of a specific antibody fragment are needed, i.e. therapeutic antibodies in human medicine. Other fields of application are monitoring of diseases and purification of specific products. Plant organs and especially storage organs like seeds and tubers are traditionally used as human and animal food. Therefore, a direct application by feeding the plant material containing the therapeutic antibody fragments could force the development of new passive vaccination strategies in human and veterinary medicine. A general advantage of plant expression systems are the relatively low production costs. Specific media and sterile conditions are avoided if the plants are grown in soil. Furthermore, human and animal pathogens such as viruses and bacteria can be excluded per se. A main advantage is the possibility to produce in specific plant storage organs that are normally used in nutrition. Growing and harvesting technologies for such basic plant products have already been developed and have only to be adapted for the development of new plantibodies for passive immunization.