REPLICONS OF PESTIVIRUSES THAT DO NOT EXPRESS C AND OR E1 PROTEIN AND INFECTIOUS VIRAL PARTICLES CONTAINING SAME, THAT CAN BE USED IN VACCINES

摘要

The present invention provides new Pestiviral RNA genomes (replicons) that areable to replicate, and can be packaged into infectious viral particles incells that complement the missing protein(s), but do not produce infectiousprogeny virus. Such replicons can be useful for vaccine purposes. Thereplicons encode most, preferably all, envelop proteins of the virus, while,on the other hand, it would not be capable of producing infectious progenyvirus. The present invention provides a Pestiviral replicon, preferably fromthe Bovine Viral Diarrhea Virus (BVDV), which expresses all structuralproteins except for a functional C or E1 protein. Preferably at least part ofthe coding sequence of the E1 or C protein has been deleted from saidreplicon. The present inventors proved for the first time, that both C and E1structural proteins are essential for the formation of infectiouspestiviruses. Furthermore it was shown that deletion of C and E1 does notimpact the ability of RNA self-replication. By using cell lines constitutivelyexpressing pestiviral structural proteins, Capsid- or E1-proteins can beefficiently trans-complemented. The resulting virions are able to infectbovine target cells and to transfer the replicons without generatingreplication-competent virus progeny. In other words, no infectious progenyvirus is produced. The complemented virions are indistinguishable from wild-type Pestivirus.in virus neutralization experiments. Recombinations yieldinginfectious wild-type virus were not detected in any of the complementationexperiments. The complemented viruses may be used for the safe and efficaciousimmunization against BVDV.