Point mutations in an infectious bovine viral diarrhoea virus type 2 cDNA transcript that yields an attenuated and protective viral progeny.
An infectious cDNA clone of the hypervirulent bovine viral diarrhoea virus (BVDV) strain 890 (isolate 256) was produced by a streamlined PCR procedure. As compared to the published sequence of strain 890, the nucleotide sequencing of cloned cDNA corresponding to isolate 256 revealed several mutations seven of which were attributed to the cloning procedure. The infectious transcript was transfected into permissive cells and led to viral multiplication (AvrII+ strain). In vitro, viral titres reached by the parental strain exceed those of the AvrII+ strain by more than one order of magnitude. The latter was clearly less virulent to young calves as indicated by clinical, haematological and virological parameters. Thirty-four days after inoculation with AvrII+ strain, calves were challenged with the virulent parental strain. The animals were protected as compared to unvaccinated controls. Therefore, our approach led to the production of an attenuated strain with potential use as a vaccine strain and will be useful for studies of virulence determinants in BVDV-2.
Dehan
P
P
Department of Infectious and Parasitic Diseases, Immunology and Virology, Faculty of Veterinary Medicine, University of Liège, Boulevard de Colonster, 20 B43b, B-4000 Liège, Belgium.
Couvreur
B
B
Hamers
C
C
Lewalle
P
P
Thiry
E
E
Kerkhofs
P
P
Pastoret
P-P
PP
D000818:Animals; D001912:Bovine Virus Diarrhea-Mucosal Disease / Q000276:immunology / Q000517:prevention & control*; D002417:Cattle; D018076:DNA, Complementary / Q000235:genetics*; D001908:Diarrhea Viruses, Bovine Viral / Q000235:genetics* / Q000276:immunology / Q000472:pathogenicity; D017354:Point Mutation; D014611:Vaccination / Q000662:veterinary; D014613:Vaccines, Attenuated / Q000008:administration & dosage* / Q000276:immunology; D014765:Viral Vaccines / Q000008:administration & dosage* / Q000276:immunology; D014774:Virulence
D018076:DNA, Complementary; D014613:Vaccines, Attenuated; D014765:Viral Vaccines