促进禽流感病毒变异的因素

项目名称： 促进禽流感病毒变异的因素

项目编号： No.31472206

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 水产学、兽医学

项目作者： 李泽君

作者单位： 中国农业科学院上海兽医研究所

项目金额： 88万元

中文摘要： 禽流感病毒的致病性、跨宿主传播、抗原变异、耐药性产生与其变异速率息息相关。不同亚型禽流感病毒的变异速率差异很大、甚至相同亚型不同毒株的变异速率也不尽相同，变异快的禽流感病毒造成的危害更严重,更容易出现跨宿主传播、抗原变异和耐药性，目前还不清楚哪些因素可以加速禽流感的变异。本项目将利用流感病毒反向遗传操作技术，拯救一系列表达GFP的HA缺失病毒，用这些病毒感染表达HA蛋白的MDCK-HA2细胞系，利用cDNA文库测序和深度测序方法确定病毒携带的GFP和NS1基因序列，计算病毒在MDCK-HA2细胞上的变异速率, 明确重组、点突变等在促进禽流感病毒加速变异中的作用，通过小鼠实验验证这些因素是否真正能够促进禽流感病毒适应性突变；此外，利用表达GFP蛋白的H9N2病毒感染不同细胞或动物组织来测定宿主因素对病毒变异的影响。确定促进禽流感病毒变异的主要因素，将从新的角度进一步认识禽流感病毒进化规律。

中文关键词： 禽流感病毒；变异促进因素；宿主；病毒

英文摘要： The pathogenicity, interspecies transmission, antigenic variation and drug resistance mutation of avian influenza viruses (AIVs) are highly related with their mutation rates. The mutation rates of AIVs vary dramatically among the subtypes, even among the virus isolates of the same subtype. The AIVs with high mutation rates are more dangerous and prone to interspecies transmission, antigenic variation and drug resistance. However, little is known about the determinants which may promote the mutation of AIVs. To explore viral mutation-promoting factors, the reverse genetics technology of influenza virus will be used to develop HA-deleted GFP-expressing reassortant and single-site-mutation viruses. These viruses will be used to infected HA-expressing cells (MDCK-HA2) and the sequences of GFP and NS1 genes will be determined by deep sequencing, or by construction of their cDNA libraries and partial sequence analysis. The mutation rate of each recombinant virus will be calculated and the viral mutation-promoting factors of AIVs will be clarified. The adaptability of the recombinant viruses with mutation-promoting factors will be tested on mice to prove their high mutation rate. On the other hand, a GFP-expressing H9N2 influenza virus will be used to infected different cells and different animal tissues. The mutation rate of the virus in different hosts will be calculated for exploration of the host's mutation-promoting factors. These knowledge about viral and host's mutation-promoting factors of AIVs will provide new insight into AIV evolution.

英文关键词： Avian influenza virus;mutation-promoting factor;host;viral