Protection of chicken against very virulent IBDV provided by in ovo priming with DNA vaccine and boosting with killed vaccine and the adjuvant effects of plasmid-encoded chicken interleukin-2 and interferon-gamma.
10.4142/jvs.2009.10.2.131
- Author:
Jeong Ho PARK
1
;
Haan Woo SUNG
;
Byung Il YOON
;
Hyuk Moo KWON
Author Information
1. Laboratory of Veterinary Microbiology, School of Veterinary Medicine and Institute of Veterinary Science, Kangwon National University, Chuncheon 200-701, Korea. kwonhm@kangwon.ac.kr
- Publication Type:Original Article ; Research Support, Non-U.S. Gov't
- Keywords:
adjuvant;
DNA vaccine;
IBDV;
prime-boost vaccination
- MeSH:
Adjuvants, Immunologic/pharmacology;
Animals;
Antibodies, Viral/blood;
Birnaviridae Infections/immunology/prevention & control/*veterinary/virology;
Body Weight/immunology;
Bursa of Fabricius/immunology;
Chick Embryo;
*Chickens;
Histocytochemistry/veterinary;
Immunization/*veterinary;
Infectious bursal disease virus/genetics/*immunology;
Interferon-gamma/pharmacology;
Interleukin-2/pharmacology;
Organ Size/immunology;
Poultry Diseases/immunology/*prevention & control/virology;
RNA, Viral/chemistry/genetics;
Random Allocation;
Reverse Transcriptase Polymerase Chain Reaction/veterinary;
Specific Pathogen-Free Organisms;
Vaccines, DNA/*administration & dosage/immunology;
Vaccines, Inactivated/administration & dosage/immunology;
Viral Vaccines/*administration & dosage/immunology
- From:Journal of Veterinary Science
2009;10(2):131-139
- CountryRepublic of Korea
- Language:English
-
Abstract:
The aim of this study was to examine the efficacy of in ovo prime-boost vaccination against infectious bursal disease virus (IBDV) using a DNA vaccine to prime in ovo followed by a killed-vaccine boost post hatching. In addition, the adjuvant effects of plasmid-encoded chicken interleukin-2 and chicken interferon-gamma were tested in conjunction with the vaccine. A plasmid DNA vaccine (pcDNA-VP243) encoding the VP2, VP4, and VP3 proteins of the very virulent IBDV (vvIBDV) SH/92 strain was injected into the amniotic sac alone or in combination with a plasmid encoding chicken IL-2 (ChIL-2) or chicken IFN-gamma (ChIFN-gamma) at embryonation day 18, followed by an intramuscular injection of a commercial killed IBD vaccine at 1 week of age. The chickens were orally challenged with the vvIBDV SH/92 strain at 3 weeks of age and observed for 10 days. In ovo DNA immunization followed by a killed-vaccine boost provided significantly better immunity than the other options. No mortality was observed in this group after a challenge with the vvIBDV. The prime-boost strategy was moderately effective against bursal damage, which was measured by the bursa weight/body weight ratio, the presence of IBDV RNA, and the bursal lesion score. In ovo DNA vaccination with no boost did not provide sufficient immunity, and the addition of ChIL-2 or ChIFN-gamma did not enhance protective immunity. In the ConA-induced lymphocyte proliferation assay of peripheral blood lymphocyte collected 10 days post-challenge, there was greater proliferation responses in the DNA vaccine plus boost and DNA vaccine with ChIL-2 plus boost groups compared to the other groups. These findings suggest that priming with DNA vaccine and boosting with killed vaccine is an effective strategy for protecting chickens against vvIBDV.
