The new vaccine produced by the infectious cDNA : Development of rabies oral vaccine reinforced gene.

为了利用反向遗传学技术生产新一代动物用狂犬病疫苗，本研究构建了日本狂犬病疫苗生产用狂犬病病毒RC-HL株的感染性cDNA，回收了重组狂犬病病毒RRC-HL(RRC-HL)及其与亲本西原株的嵌合病毒。此外，我们还检测了每个被拯救的菌株对小鼠的免疫原性。结果如下：1)构建了携带rc-HL株基因组全长c DNA的质粒和含有rc-HL株N、P、L基因完整开放阅读框的辅助载体。将其导入BHK-21细胞后，获得了与野生型RC-HL株生物学特性基本相同的传染性狂犬病病毒。利用RC-HL株的反向遗传学系统，我们获得了一株嵌合病毒R(G)株，其G基因的开放阅读框来自亲本西原株，其余的基因组区域来自RC-HL株。2)嵌合病毒R(G)株在神经性NA细胞和非神经性BHK-21细胞中的生长曲线与野生型和RRC-HL株相似。R(G)株对小鼠的免疫原性明显优于RC-HL株，与西原株相似，是研制下一代动物疫苗的候选毒株。

In this study, to produce the new generational rabies vaccine for animal by reverse genetics, we constructed the infectious cDNA for the RC-HL strain of rabies virus used for the production of animal vaccine in Japan and rescued the recombinant RC-HL (rRC-HL) and the chimeric virus of the RC-HL and the parent Nishigahara strains. In addition, we determined immunogenicity of each rescued strain for mice. The results run as follows :1) The full-length genome plasmid carrying comlete genomic cDNA of the RC-HL strain, and the helper plasmids which contained cDNAs of complete open reading frame of the N, P and L genes from the RC-HL strain, respectively, were constructed. After transfection of these plasmids into BHK-21 cells, infectious rabies virus which had almost the same biological properties as the wild type RC-HL strain, was rescued. Using this reverse genetics system of the RC-HL strain, we produced a chimeric virus, R (G) strain with the open reading frame of the G gene from the parent Nishigahara strain and the remainning genomic regions from the RC-HL strain.2) The growth curves of the chimeric virus, R (G) strain in neuronal NA cells and non-neuronal BHK-21 cells were similar to those of the wild and rRC-HL strains. The immunogenicity of the R (G) strain for mice was apparently superior to that of the RC-HL strain and was similar to the Nishigahara strain.From these results, it was saggested that the R (G) strain was a candidate for the production of the next generational vaccine for animal.