Herpesvirus of Turkey Recombinant Viruses Expressing Infectious Bursal Disease Virus (IBDV) VP2 Immunogen Induce Protection against an IBDV Virulent Challenge in Chickens

• Published in: Virology (New York, N.Y.) N.Y.), 1995-08, Vol.211 (2), p.481-490
• Main Authors: Darteil, Raphaël, Bublot, Michel, Laplace, Eliane, Bouquet, Jean-François, Audonnet, Jean-Christophe, Rivière, Michel
• Format: Article
• Language: English
• Subjects: animal viruses; Animals; antigene; antigenos; antigens; avian infectious bursitis; Base Sequence; Birnaviridae Infections - immunology; Birnaviridae Infections - prevention & control; Chick Embryo; Chickens; enfermedad de gumboro; Herpesviridae - genetics; Herpesviridae - immunology; herpetoviridae; infectious bursal disease virus; Infectious bursal disease virus - genetics; Infectious bursal disease virus - pathogenicity; Infectious bursal disease virus - physiology; maladie de gumboro; Marek Disease - immunology; Marek Disease - prevention & control; Molecular Sequence Data; pathogenicity; poder patogeno; pollo; poulet; pouvoir pathogene; Promoter Regions, Genetic; proteinas; proteine; proteins; synthetic vaccines; Transfection; Turkey; vaccin synthetique; vaccination; Vaccines, Synthetic - therapeutic use; vacuna sintetica; vacunacion; Viral Structural Proteins - genetics; Viral Structural Proteins - immunology; Virulence; virus de los animales; virus des animaux; Virus Replication
• ISSN: 0042-6822; 1096-0341
• DOI: 10.1006/viro.1995.1430

Two recombinant herpesviruses of turkey (HVT) expressing the VP2 protein of infectious bursal disease virus (IBDV or Gumboro disease virus) have been constructed vHVT001 and vHVT002. The VP2 open reading frame was inserted at the locus of the small subunit of ribonucleotide reductase gene (HSV-1 UL40 homolog) without any exogenous promoter in vHVT001 and at the locus of gl gene (HSV-1 US7 homolog) under the control of the human cytomegalovirus immediate-early promoter in vHVT002. The isolation of these recombinant viruses indicated that the deleted genes were not required for replication of HVT in chicken embryo fibroblasts. Efficacy of these recombinant viruses against IBDV strain 52/70 and Marek's disease virus (MDV strain RB1B) virulent challenges was evaluated in chickens vaccinated at 1 day of age. In the IBDV challenge, a good protection against mortality and bursal gross lesion was observed in vHVT002-vaccinated chickens: 100% with 105 PFU dose and 60% with 104 PFU dose; in contrast, only a weak level of protection was achieved after vaccination with vHVT001. Protection levels against MDV challenge obtained with vHVT001 and vHVTO02 were low (around 10%) compared to that induced by the parental HVT (84%). In spite of the low protection level against MDV, this is the first report which describes induction of full protection against IBDV with a single inoculation of a recombinant virus.