H9N2禽流感病毒血凝素和神经氨酸酶DNA疫苗对小鼠的免疫保护研究

摘要

目的 检测H9N2禽流感病毒血凝素(hemagglutinin,HA)和神经氨酸酶(neuraminidase,NA)DNA疫苗保护小鼠抵抗致死量同源病毒感染的能力.方法 通过小鼠肺对肺传代,建立禽流感病毒A/chicken/Jiangsu/07/2002(H9N2)小鼠适应株.同时,构建病毒HA和NA DNA疫苗,以不同剂量电击法免疫小鼠1或2次,在初次免疫后4周或加强免疫后1周用致死量(40 LD50)鼠适应型病毒攻击小鼠.通过测定小鼠血清抗体滴度、小鼠存活率和肺部病毒滴度来评价疫占的效果.结果 HA或NADNA 10μg免疫1次或3μg免疫2次均可保护小鼠抵抗致死昔H9N2病毒的感染.结论 低剂量HA或NA DNA可为抗H9N2禽流感病毒感染提供有效的免疫保护.%Objective To test the protective ability of avian H9N2 virus hemagglutinin(HA)and neuraminidase(NA)DNA against lethal virus challenge in mice model.Methods Viral lung-to-lung passages in mice were used to obtain a mouse-adapted strain for avian H9N2 isolate A/chicken/Jiangsu/07/2002.DNA vaccines expressing H9N2 HA and NA,respectively,were constructed to immunize mice by electroporation.Mice were immunized once or twice(at a 3-week interval)with various dosages of DNA vaccine and were then challenged with a lethal dose(40 LD50)of mouse-adapted virus.The effectiveness of the two DNAs was evaluated by serum specific antibody titers of mice,survival rates and lung virus titers.Results Immunization once with HA or NA DNA at a dosage of 10 μg or twice at a dosage of 3 μg provided protection for mice against lethal virus challenge.Conclusion Either H9N2 virus HA or NA DNA can be effective in defending avian influenza virus infection.