The H9N2 subtype avian influenza virus(AIV)inactivated vaccine has been used extensively in poultry farms,but it often fails to stimulate a sufficiently high immune response in poultry in the field,although it works w...The H9N2 subtype avian influenza virus(AIV)inactivated vaccine has been used extensively in poultry farms,but it often fails to stimulate a sufficiently high immune response in poultry in the field,although it works well in laboratory experiments;hence,the virus still causes economic damage every year and poses a potential threat to public health.Based on surveillance data collected in the field,we found that broilers with high levels of maternal-derived antibodies(MDAs)against H9N2 virus did not produce high levels of antibodies after vaccination with a commercial H9N2 inactivated vaccine.In contrast,specific pathogen-free(SPF)chickens without MDAs responded efficiently to that vaccination.When MDAs were mimicked by administering passively transferred antibodies(PTAs)into SPF chickens in the laboratory,similar results were observed:H9N2-specific PTAs inhibited humoral immunity against the H9N2 inactivated vaccine,suggesting that H9N2-specific MDAs might hinder the generation of antibodies when H9N2 inactivated vaccine was used.After challenge with homologous H9N2 virus,the virus was detected in oropharyngeal swabs of the vaccinated and unvaccinated chickens with PTAs but not in the vaccinated chickens without PTAs,indicating that H9N2-specific MDAs were indeed one of the reasons for H9N2 inactivated vaccine failure in the field.When different titers of PTAs were used to mimic MDAs in SPF chickens,high(HI=12 log2)and medium(HI=log 9 log2)titers of PTAs reduced the generation of H9N2-specific antibodies after the first vaccination,but a booster dose would induce a high and faster humoral immune response even of PTA interference.This study strongly suggested that high or medium titers of MDAs might explain H9N2 inactivated vaccine failure in the field.展开更多
NAS preparation, a kind of Chinese herbal medicine found by the Yunnan Eco-agricultural Research Institute, has potential antiviral activity. In this paper, the inhibiting effect of NAS preparation on H9N2 subtype Avi...NAS preparation, a kind of Chinese herbal medicine found by the Yunnan Eco-agricultural Research Institute, has potential antiviral activity. In this paper, the inhibiting effect of NAS preparation on H9N2 subtype Avian influenza virus (AIV) was investigated in vivo. Chickens infected with H9N2 virus were treated with NAS preparation for 4 days. The virus was then detected by hemoagglutination (HA) test and reverse transcription polymerase chain reaction (RT-PCR). The results showed that no H9N2 virus could be detected at the 7th day when the chickens were treated with 0.2g/kg/d or 0.1g/kg/d of NAS preparation. However the virus could be detected in other chickens without NAS preparation treatment. This result suggested that NAS preparation may be a potential drug candidate to control infection of H9N2 subtype AIV in chickens.展开更多
应用反向遗传技术将含有1998年中国大陆分离株H9N2亚型禽流感病毒(Avianinfluenzavirus,AIV)的8个基因片段的质粒共转染COS_1细胞,产生了与野生病毒生物学特性相同的H9N2亚型AIV。将A Chicken Shanghai F 98(CK SH F 98)株H9N2亚型AIV的...应用反向遗传技术将含有1998年中国大陆分离株H9N2亚型禽流感病毒(Avianinfluenzavirus,AIV)的8个基因片段的质粒共转染COS_1细胞,产生了与野生病毒生物学特性相同的H9N2亚型AIV。将A Chicken Shanghai F 98(CK SH F 98)株H9N2亚型AIV的8个基因组cDNA分别克隆到polⅠ_polⅡ转录 表达载体pHW2 0 0 0中,构建成8个转录表达载体重组质粒。将这8个质粒共转染COS_1细胞,2 4h后收获细胞及上清接种SPF鸡胚,4 8h后收取鸡胚尿囊液继续进行鸡胚传代,产生能致死鸡胚的病毒。经血凝、血凝抑制试验、序列分析和电镜观察,证实产生了CK SH F 98(H9N2 )株AIV。展开更多
基金This study was supported by grants from the National Key Research and Development Plan(Nos.2016YFD0500204 and 2017YFD0500800)National Natural Science Foundation of China(Nos.31772753,31572543,31700136 and 31702237)+1 种基金Shanghai Municipal Natural Science Foundation(No.17ZR1437400)the Project of the Shanghai Science and Technology Commission(No.17391901700).
文摘The H9N2 subtype avian influenza virus(AIV)inactivated vaccine has been used extensively in poultry farms,but it often fails to stimulate a sufficiently high immune response in poultry in the field,although it works well in laboratory experiments;hence,the virus still causes economic damage every year and poses a potential threat to public health.Based on surveillance data collected in the field,we found that broilers with high levels of maternal-derived antibodies(MDAs)against H9N2 virus did not produce high levels of antibodies after vaccination with a commercial H9N2 inactivated vaccine.In contrast,specific pathogen-free(SPF)chickens without MDAs responded efficiently to that vaccination.When MDAs were mimicked by administering passively transferred antibodies(PTAs)into SPF chickens in the laboratory,similar results were observed:H9N2-specific PTAs inhibited humoral immunity against the H9N2 inactivated vaccine,suggesting that H9N2-specific MDAs might hinder the generation of antibodies when H9N2 inactivated vaccine was used.After challenge with homologous H9N2 virus,the virus was detected in oropharyngeal swabs of the vaccinated and unvaccinated chickens with PTAs but not in the vaccinated chickens without PTAs,indicating that H9N2-specific MDAs were indeed one of the reasons for H9N2 inactivated vaccine failure in the field.When different titers of PTAs were used to mimic MDAs in SPF chickens,high(HI=12 log2)and medium(HI=log 9 log2)titers of PTAs reduced the generation of H9N2-specific antibodies after the first vaccination,but a booster dose would induce a high and faster humoral immune response even of PTA interference.This study strongly suggested that high or medium titers of MDAs might explain H9N2 inactivated vaccine failure in the field.
基金Key Technologies Research and Development Program (2004BA519A26)
文摘NAS preparation, a kind of Chinese herbal medicine found by the Yunnan Eco-agricultural Research Institute, has potential antiviral activity. In this paper, the inhibiting effect of NAS preparation on H9N2 subtype Avian influenza virus (AIV) was investigated in vivo. Chickens infected with H9N2 virus were treated with NAS preparation for 4 days. The virus was then detected by hemoagglutination (HA) test and reverse transcription polymerase chain reaction (RT-PCR). The results showed that no H9N2 virus could be detected at the 7th day when the chickens were treated with 0.2g/kg/d or 0.1g/kg/d of NAS preparation. However the virus could be detected in other chickens without NAS preparation treatment. This result suggested that NAS preparation may be a potential drug candidate to control infection of H9N2 subtype AIV in chickens.
文摘应用反向遗传技术将含有1998年中国大陆分离株H9N2亚型禽流感病毒(Avianinfluenzavirus,AIV)的8个基因片段的质粒共转染COS_1细胞,产生了与野生病毒生物学特性相同的H9N2亚型AIV。将A Chicken Shanghai F 98(CK SH F 98)株H9N2亚型AIV的8个基因组cDNA分别克隆到polⅠ_polⅡ转录 表达载体pHW2 0 0 0中,构建成8个转录表达载体重组质粒。将这8个质粒共转染COS_1细胞,2 4h后收获细胞及上清接种SPF鸡胚,4 8h后收取鸡胚尿囊液继续进行鸡胚传代,产生能致死鸡胚的病毒。经血凝、血凝抑制试验、序列分析和电镜观察,证实产生了CK SH F 98(H9N2 )株AIV。
