Molecular Farming in Plants: An Overview

Abstract

Protein-based biopharmaceuticals have become increasingly important due to a combination of their bioreactivity, specificity, safety and overall success rate. Escherichia coli, yeast and animal cells have traditionally been used as heterologous expression systems for production of pharmaceutical proteins. However, these conventional expression systems are often limited by high production costs, potential risks of product contamination, and the complexity and difficulty of scale-up to industrial production. Plants have emerged as a promising alternative expression system for production of pharmaceutical proteins because they offer several potential advantages, including low production costs, ease of scale-up to commercial quantities of production and reduced risk of product contamination by mammalian viruses or toxins. Plants are already being used to produce antibodies, vaccines, growth factors and many other proteins of pharmaceutical importance. The use of plants as factories for production of recombinant pharmaceutical proteins, including industrial enzymes, is now more commonly referred to as molecular farming. In this chapter, we discuss the technological basis of molecular farming in plants, with a focus on host systems and approaches/strategies developed to maximize protein yields and to ensure efficient recovery and purification of plant-made recombinant products.