【摘要】 以传染性法氏囊病病毒 (IBDV) VP2蛋白基因表达质粒 DNA为免疫原 ,以 Cp G的寡核苷酸 (Cp G- ODN)为免疫佐剂 ,肌肉注射于 14日龄 SPF鸡 ,1周后加强免疫 1次 ,2次免疫后 15 d和 2 1d分别测定血清 EL ISA抗体效价 ,并于免疫后 2 1d用 IBDV99J1强毒株攻毒和进行病理学观察。结果显示 ,(1) VP2基因重组质粒 DNA与 Cp G共同免疫组的 EL ISA抗体水平明显高于 VP2重组质粒免疫组 ;(2 ) IBD弱毒苗与 VP2重组质粒免疫组抗体水平明显高于 VP2重组质粒免疫组 ,且比 VP2基因重组质粒 DNA与 Cp G共同免疫组略高 ;(3) VP2基因重组质粒 DNA与 Cp G共同免疫组及 IBD弱毒苗与 VP2重组质粒免疫组可明显降低 IBDV强毒攻击后引起的急性发病率和死亡率。由此表明 ,Cp G寡核苷酸对 IBDV VP2蛋白基因真核表达质粒免疫具有明显增强作用 ,有很大的应用前景。更多还原

【Abstract】 The present study was conducted to investigate the feasibility of two plasmids DNA carrying VP2 genes of the very virulent strain of IBDV(vvIBDV),pcDNA3.1-VP2 and pCI-VP2,and CpG ODN to protect chickens against infectious bursal disease virus(IBDV) infection.Fourteen-day-old chickens were intramuscularly injected with the plasmids alone or plus commercial attenuated IBD vaccine or synthetic CpG ODN twice at weekly intervals.Chickens at 5 weeks old were orally inoculated with vvIBDV strain 99J1 and observed for 7 days after challenge.Immunization with plasmid plus commercial attenuated IBD vaccine or CpG ODN conferred protection for 70% and 75% of chickens,respectively,as evidenced by the absence of clinical signs,mortality and bursal atrophy.About 10%-25% chickens vaccinated with commercial attenuated IBD vaccine or plasmid pcDNA3.1-VP2 or pCI-VP2 alone had clinical signs and died after challenge.The survived chickens exhibited varying degree of bursal atrophy.Enzyme-linked immunosorbent assay(ELISA) antibody titers in chickens vaccinated the constructs DNA plus live vaccine or CpG ODN were significantly higher than those inoculated with the constructs or the live vaccine alone.These results suggest that co-administration of the constructed plasmid pcDNA3.1-VP2 or pCI-VP2 with CpG ODN or commercial attenuated IBD vaccine could protect efficiently the chicken from direct vvIBDV challenge.更多还原