Delivering stabilised mRNA to cells for antigen production

The current Covid-19 pandemic has highlighted the continuing need to protect populations from emerging disease threats. One of the most efficient ways of achieving this is through vaccination. Since the nature of a new threat is not known in advance, it is critical that vaccines can be produced quickly and distributed efficiently to combat it. This requires the development of generic technologies which can be rapidly deployed to combat a new threat as soon as it has been identified. One method that has come to prominence recently is the use of RNA vaccines which are designed to produce the proteins necessary to stimulate immunity within the body. The great advantage of this approach is that RNA molecules have a similar overall structure regardless of their origin. Thus, new types of RNA molecules can be rapidly made using previously developed technology making the approach highly responsive. The major drawback of the approach, particularly in less developed regions of the world, is that RNA is inherently unstable, and vaccines based on it have to be stored and distributed a low temperature. Thus, there is a need to develop methods for stabilising RNA molecules prior to deployment.

Researchers at the John Innes Institute (JIC) and Leaf Expression Systems (LES), both based on Norwich Research Park, UK, has shown that surrounding RNAs with the coat protein shell of a plant virus greatly stabilises them. Such shells containing the required RNA can be produced easily in plants in about one week and they can be highly purified using standard procedures. The project involves basing these stabilised RNAs from organisms that cause diseases of importance to low- and middle-income countries so that can be widely distributed without the need for refrigeration. In collaboration with the University of Leeds (UoL), UK, We will therefore test the ability of the protected RNAs to be taken up by cells and then used within the cells to produce proteins that are able to stimulate an immune response. In this way, we intend to make RNA-based vaccines available to regions of the world where refrigeration to low temperatures is either very difficult or impossible. Thus, the project will make a contribution to the control of diseases in poorer regions of the world and will provide means of rapidly responding to new disease threats.