Luo Jun, Shi Hehe, Tan Yeping, Niu Xuefeng, Long Teng, Zhao Jing, Tian Qin, Wang Yifei, Chen Hao, Guo Xiaofeng
College of Veterinary Medicine, South China Agricultural University, Guangzhou, China; Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, PR China.
Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Veterinary Biologicals Engineering and Technology, Ministry of Agriculture, National Center for Engineering Research of Veterinary Bio-products, Nanjing 210014, China.
Vaccine. 2016 Aug 17;34(37):4392-8. doi: 10.1016/j.vaccine.2016.07.020. Epub 2016 Jul 19.
Both rabies virus (RABV) and canine parvovirus (CPV) cause lethal diseases in dogs. In this study, both high egg passage Flury (HEP-Flury) strains of RABV and recombinant RABV carrying double RABV glycoprotein (G) gene were used to express the CPV virion protein 2 (VP2) gene, and were designated rHEP-VP2 and, rHEP-dG-VP2 respectively. The two recombinant RABVs maintained optimal virus titration according to their viral growth kinetics assay compared with the parental strain HEP-Flury. Western blotting indicated that G protein and VP2 were expressed in vitro. The expression of VP2 in Crandell feline kidney cells post-infection by rHEP-VP2 and rHEP-dG-VP2 was confirmed by indirect immunofluorescence assay with antibody against VP2. Immunogenicity of recombinant rabies viruses was tested in Kunming mice. Both rHEP-VP2 and rHEP-dG-VP2 induced high levels of rabies antibody compared with HEP-Flury. Mice immunized with rHEP-VP2 and rHEP-dG-VP2 both had a high level of antibodies against VP2, which can protect against CPV infection. A challenge experiment indicated that more than 80% mice immunized with recombinant RABVs survived after infection of challenge virus standard 24 (CVS-24). Together, this study showed that recombinant RABVs expressing VP2 induced protective immune responses to RABV and CPV. Therefore, rHEP-VP2 and rHEP-dG-VP2 might be potential combined vaccines for RABV and CPV.
狂犬病病毒（RABV）和犬细小病毒（CPV）均可引发犬类的致命疾病。在本研究中，RABV的高代鸡胚传代Flury（HEP-Flury）毒株以及携带双份RABV糖蛋白（G）基因的重组RABV均被用于表达CPV病毒粒子蛋白2（VP2）基因，分别命名为rHEP-VP2和rHEP-dG-VP2。与亲本毒株HEP-Flury相比，根据病毒生长动力学测定，这两种重组RABV保持了最佳病毒滴度。蛋白质免疫印迹法表明G蛋白和VP2在体外表达。用抗VP2抗体进行间接免疫荧光试验证实了rHEP-VP2和rHEP-dG-VP2感染后在Crandell猫肾细胞中VP2的表达。在昆明小鼠中测试了重组狂犬病病毒的免疫原性。与HEP-Flury相比，rHEP-VP2和rHEP-dG-VP2均诱导产生了高水平的狂犬病抗体。用rHEP-VP2和rHEP-dG-VP2免疫的小鼠均具有高水平的抗VP2抗体，可预防CPV感染。攻毒实验表明，用重组RABV免疫的小鼠在感染标准攻毒病毒24（CVS-24）后，超过80%存活。总之，本研究表明表达VP2的重组RABV诱导了对RABV和CPV的保护性免疫反应。因此，rHEP-VP2和rHEP-dG-VP2可能是RABV和CPV的潜在联合疫苗。
