Plant Genetic Engineering

The advent of recombinant DNA techniques has launched a revolution in biotechnology by enabling the production of a diverse range of biopharmaceuticals in a variety of heterologous hosts. Among various categories of biopharmaceuticals, glycoproteins (including antibodies, blood factors, interferons, and vaccines) play an extremely important role in the diagnosis and treatment of human diseases.

The significance of glycoproteins in the pharmaceutical industry has attracted increasing attention. Despite soaring demand for biopharmaceutical products, progress in improving the production efficiency and expanding the production scale of conventional mammalian fermentation system is very slow. Increasing glycoprotein production poses even greater challenges because bacterial, yeast, plant, and insect cell expression systems cannot be used to produce human-like glycoproteins due to their different glycosylation patterns. Proper glycosylation is required for glycoprotein stability, action, and therapeutic effect. Currently, therapeutic glycoproteins are only produced using expensive mammalian systems.   

Plants are considered to be a promising expression platform for biopharmaceuticals because they offer many advantages, such as low cost and ease of scaling up in production. They are also free of mammalian pathogens. Plant-based expression systems have been widely used to produce various biopharmaceutical products.

For therapeutic glycoproteins, however, wild-type plants cannot be used directly because of their distinct glycosylation pattern is different from mammals. Therefore, plants need to be genetically engineered in order to be used to produce human-like glycoproteins. NCCU researchers are glycoengineering tobacco plants to produce humanized recombinant glycoproteins such as asialo-rhuEPO, which has neuroprotective effects, and an antibody against the Ebola virus. Clearly, plant genetic engineering promises to be a vital technology in the quest to improve human health.