H5N1亚型高致病性禽流感病毒A/goose/Guangdong/1/96株反向基因操作系统的建立

Establishment of Reverse Genetics System of Highly Pathogenic H5N1 Avian Influenza Virus A/goose/Guangdong/1/96

A/goose/Guangdong/1/96(GSGD/1/96)是中国分离的第1株H5N1亚型禽流感病毒,它不仅是97香港感染并致人死亡的H5N1亚型流感病毒HA基因供体株,而且是中国目前已报到的H5亚型流感病毒分离株的共同祖先。本研究建立了该病毒的8质粒反向基因操作系统,并通过细胞转染成功拯救了该病毒(R-GSGD/1/96)。R-GSGD/1/96在对SPF鸡和Balb/c小鼠的致病性方面保持了与亲本野毒(W-GSGD/1/96)一致的生物学特性,即对鸡都是高致病性毒株,R-GSGD/1/96与W-GSGD/1/96的静脉致病指数分别为2.01和2.10;救获病毒与野生病毒一样,尽管106EID50经鼻腔感染小鼠后1～2d内能从肺脏检测到低滴度的病毒,但不能在小鼠体内成功复制。GSGD/1/96反向基因操作系统的成功建立为进一步开展中国高致病性禽流感病毒分离株的生物学特性、遗传衍化及结构与其功能关系研究奠定了基础。

A/goose/Guangdong/l/96（GSGD/l/96） is the first highly pathogenic H5N1 avian influenza virus isolated from the mainland of China. It is the HA gene donor of the Hong Kong 97 H5N1 viruses and the ancestor of current H5NI viruses circulating in the mainland of China. In the present study, the authors have established an eight-plasmid reverse genetics system and rescued GSGD/I/96 （R-GSGD/1/96） through cell transfection. Animal studies confirmed that the rescued virus maintained the biological properties of the wild type GSGD/1/96 virus （W-GSGD/1/96）. Both R-GSGD/1/96 virus and W-GSGD/1/96 are highly pathogenic for chickens with intravenous pathogenecity index （IVPI） of 2.01 and 2.10, respectively. The viruses could not replicate in mice, though lower titer viruses could be recovered from the lungs of few mice 1-2 days after inoculated intranasally with 10^6EID50 of the viruses. The successfully establishment of the reverse genetics system of GSGD/1/96 will enable us to conduct extensive studies of the molecular basis of the evolution of H5N1 avian influenza viruses.