一株对小鼠具有高致病性的H5N1亚型禽流感病毒的拯救

禽流感病毒(Avianinfluenzavirus)正在逐渐获得突破种间屏障感染哺乳动物的能力,揭示其获得此种能力的分子机制已经成为禽流感病毒的研究热点。A/Chicken/Guangdong/04(H5N1)是一株高致病性禽流感病毒,同时对BALB/c小鼠也具有高致病力。实验通过反向遗传操作技术对该病毒进行拯救,获得了拯救毒R-A/Chicken/Guangdong/04(R-CG)。R-CG与其亲本毒A/Chicken/Guangdong/04(W-CG)在胚半数感染量(EID50)、细胞培养半数感染量(TCID50)、对SPF鸡和BALB/c小鼠致病力等生物学特性保持一致。即R-CG与W-CG对鸡都为高致病力,静脉接种指数分别为2.88和2.91;R-CG与W-CG一样,以106EID50鼻腔感染BALB/c小鼠后,均能引起小鼠死亡,在小鼠脑、肺、肾和脾脏中都能分离到病毒,说明拯救的病毒与亲本毒一样,都可在小鼠体内有效复制,对小鼠具有高致病性。本实验成功地拯救了A/Chicken/Guangdong/04,拯救病毒R-CG可作为背景毒株,为研究禽流感病毒突破种间屏障感染哺乳动物的分子机制奠定了实验基础。

Rescue of H5N1 Subtype Influenza Virus which Is Lethal to Mice

Avian influenza virus is acquiring the ability to cross the species barrier between the avian and mammal. However, the genetic mechanism of this ability has not been well known. Influenza A virus A/Chicken/Guangdong/04(H5N1) which was highly pathogenic to both SPF chicken and BALB/c mice, was successfully rescued by a plasmid-based reverse genetics. The rescued virus R- A/Chicken/Guangdong/04(R-CG) and the wild type A/Chicken/Guangdong/04(W-CG) shared similar biological properties such as in titers of 50% embryo infective dose(EID50), 50% tissue culture infective dose(TCID50) and intravenous pathogenecity index(IPVI). Both the R-CG and the W-CG viruses are highly pathogenic to chickens, and the IVPI are 2.88 and 2.91, respectively. R-CG, like that of W-CG, was highly pathogenic in mice post natural route infection. Both the R-CG and W-CG viruses could be isolated from multiple organs of mice such as brain, lung, kidney and spleen. As a result, the constructed R-CG reverse genetic system can be used as a tool in the investigation of molecular mechanism of the mammalian host infected by avian influenza virus.