【摘要】 为评价鸡传染性法氏囊病病毒(IBDV)VP5缺失病毒株rHLJ0504HT△VP5的生物学特性,本研究首先对该缺失病毒与其亲本病毒rHLJ0504HT(vvIBDV HLJ0504 253/284双位点突变细胞适应病毒)进行了体外复制动力学比较研究。结果表明,VP5缺失病毒复制滴度明显低于亲本病毒(p<0.05)。动物实验结果表明,该缺失病毒可以诱导机体产生良好的免疫应答反应,免疫后10 d,其抗体水平与亲本病毒相当;并能够抵抗同源或异源超强毒的攻击,为免疫鸡提供100%保护。此外,该缺失病毒对免疫鸡无明显的致病性;VP5缺失病毒免疫组与未免疫组禽流感血凝抑制效价相当,不存在明显差异(p>0.05),表明该病毒对免疫鸡无免疫抑制作用,不影响其它疫苗的免疫效果。而且,VP5的缺失可以作为鉴定该缺失病毒的生物学标记。以上结果表明,rHLJ0504HT△VP5是一株安全有效的IBDV标记候选疫苗株。更多还原

【Abstract】 To evaluate the characteristics of the VP5-deficient(rHLJ0504HT △VP5) infectious bursal disease virus(IBDV),the replication of the deficient virus was determined and compared with its parental virus in vitro. The results indicated that the VP5-deficient virus demonstrated significantly lower viral titers than the parental virus of rHLJ0504 HT strain(p<0.05). Animal experiments showed that the deficient virus induced high level of immune responses in chickens and conferred full protection against homogeneous and heterogenous vvIBDV challenge. In addition, the VP5-deficient virus had no pathogenicity in SPF chickens. The rHLJ0504 HT △VP5-inoculated group caused no immunosuppression on the AIV inactivated vaccine by showing similar AIV-HI titers with the mock-inoculated group. Our data demonstrated that the VP5-deficient virus rHLJ0504 HT △VP5could be used as a potential marked vaccine with priming efficacy and safety for the prevention of vvIBDV infection.更多还原