Open Access Methodology article

Development of an improved polykaryon-based influenza virus rescue system

Vincent Bourret123*, Jon Lyall4, Mariette F Ducatez23, Jean-Luc Guérin23 and Laurence Tiley4

Author Affiliations

1 Cambridge Infectious Disease Consortium, Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge, CB3 0ES, UK

2 INRA, UMR 1225, IHAP, Toulouse, F-31076, France

3 Université de Toulouse, INP, ENVT, Toulouse, F-31076, France

4 Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge, CB3 0ES, UK

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BMC Biotechnology 2012, 12:69  doi:10.1186/1472-6750-12-69

Published: 25 September 2012



Virus rescue from transfected cells is an extremely useful technique that allows defined viral clones to be engineered for the purpose of rational vaccine design or fundamental reverse genetics studies. However, it is often hindered by low primary rescue success rates or yields, especially with field-derived viral strains.


We investigated the possibility of enhancing influenza virus rescue by eliciting cell fusion to increase the chances of having all necessary plasmids expressed within the same polykaryon. To this end we used the Maedi-Visna Virus envelope protein which has potent fusion activity in cells from a wide range of different species.


Co-transfecting cells with the eight plasmids necessary to rescue influenza virus plus a plasmid expressing the Maedi-Visna Virus envelope protein resulted in increased rescue efficiency. In addition, partial complements of the 8-plasmid rescue system could be transfected into two separate populations of cells, which upon fusion led to live virus rescue.


The simple modification described here has the potential to improve the efficiency of the virus rescue process and expand the potential applications for reverse genetic studies.

Influenza; Virus rescue; Cell fusion; Reverse genetics