表达传染性法氏囊病病毒VP2基因的重组鸡痘病毒的构建及其免疫保护性研究

A Recombinant Fowlpox Virus Expressing IBDV VP2 Gene Induces Protection Against Lethal Effect of IBDV

以脂质体转染技术构建了表达鸡传染性法氏囊病病毒（ＩＢＤＶ）ＶＰ２基因的重组鸡痘病毒ＦＰＶ－ＶＰ２，该病毒在鸡胚成纤维细胞及鸡体内均能稳定产生子代病毒，经翅皮下５×１０５ＰＦＵ／羽免疫１日龄ＳＰＦ鸡，免疫后４周以１００ＬＤ５０／羽ＩＢＤＶ超强毒株Ｇ株攻毒，获得了５／６的保护，但不能有效预防临床发病及法氏囊受损萎缩。实验结果证明了ＶＰ２是ＩＢＤＶ的宿主保护性抗原，提示Ｔ细胞介导的免疫可能在ＩＢＤＶ的免疫中起着较为重要的作用。本研究为ＩＢＤＶ重组病毒疫苗研制进行了有益探索。

A recombinant fowlpox virus,FPV VP2,was constructed which expressed the host protective antigen VP2 of infectious bursal disease virus (IBDV)and conferred protection against IBDV G strain,a Chinese highly virulent strain of IBDV.The FPV VP2 contained the VP2 gene of IBDV under the control of fowlpox early/late promoter LP2EP2 AND the LacZ gene under the control of late promoter P11 of vaccinia virus inserted in a non essential region of FPV.Wing web inoculation of SPF chicken with FPV VP2 developed typical fowlpox lesions and induced low titre of antibody to IBDV.When challenged with IBDV G strain,5 out of 6 chickens vaccinated by FPV VP2 were protected,and the antibody levels increased rapidly as high as those in the group vaccinated by D78 strain,an attenuated vaccine strain of IBDV.