中文摘要：

目的去除B8R对外源抗原免疫原性的影响，为降低载体的免疫优势从而提高疫苗的有效性提供参考。方法利用针对痘苗病毒的pSCll质粒，构建插入OVA的质粒pSC11－OVA，在CV－1细胞中与去除B8R的痘苗病毒重组，筛选纯化获得重组病毒。利用体外培养细胞，检测B8R缺失和外源抗原插入对病毒感染复制特性的影响；利用感染小鼠模型，检测重组病毒诱发的针对OVA的细胞免疫应答和免疫记忆效应；采用体征及神经行为学评分系统，检测重组病毒的毒力。结果B8R缺失和OVA导入对痘苗病毒的生物学特性无明显影响；去除B8R后，外源性OVA成为显性表位，针对OVA的细胞免疫应答和免疫记忆效应明显增强；去除B8R还可显著降低痘苗病毒的毒力。结论去除B8R可有效降低痘苗病毒的免疫优势效应，增加外源性抗原的免疫原性。去除痘苗病毒本身的显性表位，可为疫苗和基因治疗提供更为有效的载体。

英文摘要：

Objective Toinvestigatevtheantigenicity of foreign antigen in recombinant vaccinia virus （VACV） after elimination of BSR, and provide help to improve the efficacy of VACV-based vaccines, and provide guidance for vaccine design. Methods Transfer vector pSCll-OVA was generated, and OVA gene was inserted into VACV with B8R deletion. The biological characteristics of recombinant VACV was investigated in vitro, and the immune responses against OVA were tested in vivo. Results The plague phenotypes and growth of recombinant VACV and its parental strains were essentially identical. Cellular immune response against OVA was augmented in mice infected with BSR-deleted recombinant VACV when compared with those infected with BSR-intact recombinant VACV. Conclusion Deletion of BSR and insertion of OVA does not affect the biological characteristics of VACV. Immunogenicity of exogenous target antigens can be improved in VACV with B8R deficiency. Deletion of dominant epitopes may provide a vector with more efficiency for vaccines and gene therapy.