Research: The Plant-Based Vaccine Project
Plant-based vaccine and pharmaceutical protein production platforms have overtaken traditional systems based on fungi, bacteria, yeast, insects, mammalian cells, and transgenic mammals as a method of choice for large-scale production of vaccines and pharmaceutical recombinant proteins. This is because plants have several advantages over other production systems including: (1) low cost of production, (2) production of multimeric proteins, such as antibodies, (3) they are safer, not being hosts of human pathogens, and (4) they glycosylate making vaccines stable. These advantages not withstanding, several limitations need to be examined before the use of plants as bioreactors can become more widespread: (1) protein quality and homogeneity, (2) good manufacturing practice conditions, and (3) biosafety concerns. Each requires detailed science-based studies.
Our efforts are directed at optimizing plant-based production systems by targeting vaccine and pharmaceutical proteins to specific compartments of the cell and reducing the effect of gene silencing. The plant species we currently use is a wild tobacco, Nicotiana benthamiana. Human immunodeficiency virus type 1 (HIV-1) and Respiratory syncytial virus (RSV) candidate vaccines are being used to develop our technology and we will be extending this study to vaccines and pharmaceutical proteins of other diseases. We are targeting the proteins to the plasma membrane (PM), endomembranes, especially the endoplasmic reticulum (ER) and chloroplast, where clinically useful specific posttranslational modifications (example glycosylation and folding) occur. We are also producing transgenic plants with enhanced recombinant protein yield and superior immunogenicity qualities.
