The single-cell non- pathogenic parasite – Trypanosoma melophagium - naturally found in sheep and goats is being utilized by Roslin Technologies to develop a vaccine vehicle for application in these animals. The ultimate aim being to use the parasite to develop a method of immunizing sheep and goats against a wide range of pathogens.
University of Edinburgh scientists isolated the parasite from wild Soay sheep on St Kilda an island off the Scottish Outer Hebrides. T melophagium is spread by wingless insects called sheep keds.
The vaccine vehicle can be manipulated to host proteins for a wide range of diseases, be they transmitted via a virus, bacterium or parasite. Initial investigations are targeting a vaccine to tackle peste des petits of ruminants.
The engineered vehicle expresses the candidate vaccine proteins. The efficiency of T. melophagium in spreading throughout the sheep or goat aids the delivery of candidate proteins to the host’s immune system. The potential persistency of the parasite could actually help reduce the number of booster vaccinations common in existing delivery methods.
The vaccine vehicle will also be used as a platform for expressing target proteins for vaccines that require improvement and for emerging diseases. It could also benefit diseases that are problematic at present for vaccinology to be a tool of management.
Roslin claims the vehicle is quick and easy to reengineer, and as such, it should be straightforward to target new antigen expression where strain variations in pathogens emerge. The potency of the technology and its ability to sustain long-term immunity will be useful to farmers in remote areas or in developing countries, where vaccine interventions are not practical and too costly.
The project is being supported by funding from the UK’s Biotechnology and Biological Sciences Research Council’s Impact Accelerator Account. Roslin will work with the University of Edinburgh’s School of Biological Sciences to develop the technology.