tailieunhanh - Báo cáo khoa học: "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-g"

Tuyển tập các báo cáo nghiên cứu khoa học quốc tế về bệnh thú y đề tài: 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-g | J. Vet. Sci. 2009 10 2 131-139 DOI JOURNAL OF Veterinary Science 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-Y Jeong Ho Park Haan Woo Sung Byung Il Yoon Hyuk Moo Kwon Laboratory of Veterinary Microbiology School of Veterinary Medicine and Institute of Veterinary Science Kangwon National University Chuncheon 200-701 Korea 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-Y 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-Y ChIFN-Y 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-Y did not enhance protective immunity. In the ConA-induced lymphocyte proliferation assay of peripheral blood lymphocyte collected 10 days post-challenge there was .