4 - Non-food interventions: Exploring plant biotechnology applications to therapeutic protein production

Abstract

Antibody-based therapeutics and molecular farming are currently being tested in an increasingly diverse range of therapeutic modalities. Many different engineered formats for the antibody molecule and multiple methods for raising and tailoring binding specificities are currently available. Plant cells can express recombinant secretory IgA (sIgA). Transgenic soybeans are capable of producing humanized antibodies against herpes simplex virus HSV-2. GM corn is capable of producing human antibodies at yields of up to 1kg per hectare and has been demonstrated to preserve antibody function through 5 years of storage under ordinary conditions. For seed production, a plant optimized for large seed and high protein production is clearly preferred. Transgenic tobacco chloroplasts can produce human somatotropin or interferons at protein levels over a 100-fold higher than their nuclear transgenic counterparts, with production of somatotropin representing 7% of the total plant protein production. In this chapter, an overview will be provided to recent advances in production in plants of useful therapeutic molecules, such as acid β-glucosidase (GCase) and human acid maltase.