A recent study, published in Nature Communications, has described how a candidate synthetic vaccine for polio has been developed with a method grown in plants that use virus like particles (VLPs).
Stop polio
The method employed in the study involves infiltration into plant tissues by genes that carry information to produce VLPs — empty shells that trick the immune system into a protective reaction. The host plant then reproduces large quantities of VLPs via protein expression mechanisms.
To confirm the structure of the empty shells, the team used cryo-electron microscopy at Diamond’s Electron Bio-Imaging Centre (eBIC). With this they were also able to demonstrate the external features of the synthetic vaccine were identical to the live virus one.
Dave Rowlands, Emeritus professor of Virology at the University of Leeds and principal investigator on this project, said: “Small scale laboratory tests demonstrated that the ground-breaking synthetic vaccine provided animals with immunity from the disease similar to the existing widely used vaccine. Although this is still early results, it does provide evidence that this can be taken to the next stage with input of pharmaceutical industry collaborators.
“The results of our research pave the way towards production of a novel synthetic vaccine to help bring about the global elimination of poliomyelitis. Such a vaccine would be quicker, easier and safer to produce, without the inherent danger of accidental release of virus associated with the production of current vaccines.”
This breakthrough was made by employing technology that helped in the design of a new synthetic vaccine to combat the foot and mouth disease virus (FMDV) to target the virus that causes polio.
“We were inspired by the successful synthetic vaccine for foot-and-mouth disease, also investigated at Diamond as part of UK research collaboration,” explained Dave Stuart, director of Life Sciences at Diamond Light Source and professor of Structural Biology at University of Oxford. “By using Diamond’s visualisation capabilities and the expertise of Oxford University in structural analysis and computer simulation, we were able to visualise something a billion times smaller than a pinhead and further enhance the design atom by atom of the empty shells. Through information gained at Diamond, we also verified that these have essentially the same structure as the native virus to ensure an appropriate immune response.”
“This is an incredible collaboration involving plant science, animal virology and structural biology. The question for us now is how to scale it up — we don’t want to stop at a lab technique,” added Prof. Lomonossoff, from the John Innes Centre. “The beauty of this system of growing non-pathogenic virus mimics in plants, is that it boosts our ability to scale-up the production of vaccine candidates to combat emerging threats to human health.”
The consortium was funded by the World Health Organisation and the Bill & Melinda Gates Foundation which are seeking alternative vaccines that avoid use of the live polio virus as part of an international drive to completely eradicate the disease worldwide.