UMR INRA-ENVT Microbiologie moléculaire, École vétérinaire, 23, chemin des Capelles, 31076 Toulouse Cedex
Myxoma virus is a member of the poxvirus family, which are amongst the largest animal viruses. Its genome of 160 kb codes for over 150 proteins, including factors that help evade the host response to infection. Myxoma virus produces virokines, viral equivalents of host cytokines, and viroceptors, non-functional cytokine receptors. These decoys prevent the infected cell from communicating with its environment. Moreover, myxoma virus codes for anti-apoptotic molecules. A better knowledge of how these virulence factors function help construct avirulent mutant viruses. All poxviruses can host large fragments of foreign DNA in their genome ; being exclusively intracytoplasmic they are fairly safe vectors widely used as vaccines. The authors present how myxoma virus has been engineered to express the major capsid protein of rabbit viral haemorrhagic disease (RVHD) virus, thus generating a vaccine against both myxomatosis and RVHD. Myxoma virus could also be used as a non-replicative vector on non-host species.