中文摘要：

为研究鸡传染性支气管炎病毒（IBV）作为载体表达外源基因的可行性,本研究以IBV疫苗株H120为病毒载体,在其非结构蛋白5a编码区上游插入鸡γ-干扰素（Ch IFN-γ）基因,通过反向遗传操作技术构建重组病毒。经RT-PCR和测序鉴定表明拯救获得重组病毒（r H120-c IFNγ/5a）。生物学特性研究结果表明,r H120-c IFNγ/5a感染鸡胚后能够引起特征性病变,但与其亲本病毒株H120相比,病毒的毒价及其在鸡胚中的复制能力有所下降。将r H120-c IFNγ/5a在鸡胚中连续传代,采用RT-PCR进行检测,结果表明Ch IFN-γ基因在病毒传至第9代时仍保持稳定,至第12代Ch IFN-γ基因出现部分或完全丢失现象。本研究结果为进一步研制以IBV为载体的新型基因重组疫苗奠定了基础。

英文摘要：

To investigate the feasibility of avian infectious bronchitis virus （IBV） as a vector for expressing exogenous gene, we used vaccine strain H120 of IBV as a vector to express the chicken IFN-y （ChlFN-y） gene. Then, the ChlFN-y gene was amplified by RT-PCR and inserted into the upstream of 5a gene by reverse genetic techniques. Rescued recombinant virus （rH120-clFNy/5a） expressing ChlFN-y gene was rescued and identified by RT-PCR and sequencing. The results of biological characteristics showed that rH120-clFNy/5a was still able to lead to chicken embryo dwarf. However, compared with the wild-type strain H120, the viral titer and replication rate of recombinant virus were reduced relatively. In addition, the rH120-clFNy/5a remained stable after the ninth passages in SPF embryonated eggs for continuous passages, but ChlFN-y gene in the recombinant virus lost partly or completely by passaged in chick embryo more than twelve passages. These results laid a foundation for further development of new recombinant IBV vaccine.