Plantibodies: Plants as an Alternate Production System towards Molecular Farming of Antibodies for Diverse Applications

Expression of antibodies in plants is one of the fields of plant genetic engineering, which was developed recently. It refers to the introduction and expression of the genes encoding antibodies or antibody fragments in plants. The most intriguing potential of expressing antibodies in plants is molecular farming i.e. inexpensive, large-scale production of antibodies for diverse applications. Expression and stability of antibodies in transgenic plants have been investigated and optimized by accumulation in different cellular compartments viz. cytosol, apoplastic space and endopasmic reticulum (ER). High-level expression of active recombinant single chain Fv antibodies (scFv's) was obtained by retention of these proteins in the lumen of the ER. This has been shown for leaves and seeds of tobacco as well as for potato tubers. Upscaling production in fermenters and subsequently its downstream processing can increase antibody production. Transgenic plants are attracting interests as bioreactors to provide almost unlimited amounts of recombinant antibodies, which have potential for use in diagnosis and therapy. In addition, altering traits is possible by manipulating plant metabolism using plantibodies. The immuno-modulation approach could also be applied to conferring pathogen resistance to plants and bioremediation of environmental pollutants. With these advances, it seems that molecular farming is becoming an economic and agricultural reality in the near future.