Transient expression techniques will be used to temporarily stimulate plants into over-producing proteins, which can subsequently be assessed for their value as vaccines. Plants have been used to produce pharmaceuticals in this way before but technical constraints mean their value has not been fully realised. A few candidates with proven vaccine ability have been produced and, although these proteins are effective at preventing disease, they have limited commercial use as they compete with existing conventional products. They have, however, shown that plant-based vaccines production and assessment is possible, and safe.
The PLAPROVA consortium will exploit transient expression systems recently developed by the partners that can produce amounts of protein suitable for testing within weeks, rather than in months. This means that large-scale screening for candidate vaccines is now within reach, allowing products for which there is no conventional counterpart to be produced. Initially, the consortium will concentrate on diseases of importance to farming in both the EU and Russia, which includes Avian influenza, blue tongue, foot and mouth disease and porcine reproductive and respiratory syndrome. Proteins identified through this screening programme will be developed for large-scale production and ultimately low-cost production of effective vaccines.
Organization and Objectives
The technological objectives of the project will be:
The work plan is divided into 11 Workpackages, which include the scaling up of the expression systems and the management of the consortium. The overall strategy of the project is initially to use high-yielding transient expression systems which have already been developed by some of the partners, such as the CPMV HT system based on the Cowpea Mosaic Virus. Starting with the expression of simple VLPs, the work will then focus on the production of protein complexes and on the processing of polyproteins in planta.
|Innoculation of plants in the John Innes Centre greenhouse. Top: Paolo Lenzi and Yulia Meshcheriakova; Bottom: George Lomonossoff and Keith Saunders|