Objective In China, 24 cases of human infection with highly pathogenic avian influenza(HPAI) H5 N6 virus have been confirmed since the first confirmed case in 2014. Therefore, we developed and assessed two H5 N6 candi...Objective In China, 24 cases of human infection with highly pathogenic avian influenza(HPAI) H5 N6 virus have been confirmed since the first confirmed case in 2014. Therefore, we developed and assessed two H5 N6 candidate vaccine viruses(CVVs).Methods In accordance with the World Health Organization(WHO) recommendations, we constructed two reassortant viruses using reverse genetics(RG) technology to match the two different epidemic H5 N6 viruses. We performed complete genome sequencing to determine the genetic stability. We assessed the growth ability of the studied viruses in MDCK cells and conducted a hemagglutination inhibition assay to analyze their antigenicity. Pathogenicity attenuation was also evaluated in vitro and in vivo.Results The results showed that no mutations occurred in hemagglutinin or neuraminidase, and both CVVs retained their original antigenicity. The replication capacity of the two CVVs reached a level similar to that of A/Puerto Rico/8/34 in MDCK cells. The two CVVs showed low pathogenicity in vitro and in vivo, which are in line with the WHO requirements for CVVs.Conclusion We obtained two genetically stable CVVs of HPAI H5N6 with high growth characteristics,which may aid in our preparedness for a potential H5N6 pandemic.展开更多
The highly pathogenic avian influenza (HPAI) H5N1 virus has caused several outbreaks in domestic poultry. Despite great efforts to control the spread of this virus, it continues to evolve and poses a substantial thr...The highly pathogenic avian influenza (HPAI) H5N1 virus has caused several outbreaks in domestic poultry. Despite great efforts to control the spread of this virus, it continues to evolve and poses a substantial threat to public health because of a high mortality rate. In this study, we sequenced whole genomes of eight H5N1 avian influenza viruses isolated from domestic poultry in eastern China and compared them with those of typical influenza virus strains. Phylogenetic analyses showed that all eight genomes belonged to clade 2.3.2.1 and clade 7.2, the two main circulating clades in China. Viruses that clustered in clade 2.3.2.1 shared a high degree of homology with H5N1 isolates located in eastern Asian. Isolates that clustered in clade 7.2 were found to circulate throughout China, with an east-to-west density gradient. Pathogenicity studies in mice showed that these isolates replicate in the lungs, and clade 2.3.2.1 viruses exhibit a notably higher degree of virulence compared to clade 7.2 viruses. Our results contribute to the elucidation of the biological characterization and pathogenicity of HPAI H5N1 viruses.展开更多
A novel Clade 2.3.2.1c H5N1 reassortant virus caused several outbreaks in wild birds in some regions of China from late 2014 to 2015.Based on the genetic and phylogenetic analyses,the viruses possess a stable gene con...A novel Clade 2.3.2.1c H5N1 reassortant virus caused several outbreaks in wild birds in some regions of China from late 2014 to 2015.Based on the genetic and phylogenetic analyses,the viruses possess a stable gene constellation with a Clade 2.3.2.1c HA,a H9N2-derived PB2 gene and the other six genes of Asian H5N1-origin.The Clade 2.3.2.1c H5N1 reassortants displayed a high genetic relationship to a human H5N1 strain(A/Alberta/01/2014).Further analysis showed that similar viruses have been circulating in wild birds in China,Russia,Dubai(Western Asia),Bulgaria and Romania(Europe),as well as domestic poultry in some regions of Africa.The affected areas include the Central Asian,East Asian-Australasian,West Asian-East African,and Black Sea/Mediterranean flyways.These results show that the novel Clade 2.3.2.1c reassortant viruses are circulating worldwide and may have gained a selective advantage in migratory birds,thus posing a serious threat to wild birds and potentially humans.展开更多
Highly pathogenic avian influenza H5N 1 epidemics are a significant public health hazard. Genetically engineered H5N 1 viruses with mammalian transmission activity highlight the potential risk of a human influenza H5N...Highly pathogenic avian influenza H5N 1 epidemics are a significant public health hazard. Genetically engineered H5N 1 viruses with mammalian transmission activity highlight the potential risk of a human influenza H5N 1 pandemic. Understanding the underlying principles of the innate immune system in response to influenza H5N 1 viruses will lead to improved prevention and control of these potentially deadly viruses, γδT cells act as the first line of defense against microbial infection and help initiate adaptive immune responses during the early stages of viral infection. In this study, we investigated the molecular mechanisms of γδ T cells in response to influenza H5N1 viral infection, We found that recombinant hemagglutinin (rHA) derived from three different strains of influenza H5N 1 viruses elicited the activation of γδ T cells cultured in peripheral blood mononuclear cells (PBMCs). Both the cell surface expression of CD69, an early activation marker on γδ T cells, and the production of interferon-y (IFN-y) were significantly increased. Notably, the rHA protein-induced γδ T-cell activation was not mediated by TCRγδ, NKG2D or pattern recognition receptors (PRRs) or NKp46 receptors. The interaction of rHA proteins with sialic acid receptors may play a critical role in γδ T-cell activation. Our data may provide insight into the mechanisms underlyingγδT-cell activation in response to infection with H5N1 viruses.展开更多
基金This study was supported by the National Major Science and Technology Project for Control and Prevention of Major Infectious Diseases in China[No.2018ZX10711001,2018ZX10305409-004-002]Emergency Prevention and Control Project of Ministry of Science and Technology of China[No.10600100000015001206].
文摘Objective In China, 24 cases of human infection with highly pathogenic avian influenza(HPAI) H5 N6 virus have been confirmed since the first confirmed case in 2014. Therefore, we developed and assessed two H5 N6 candidate vaccine viruses(CVVs).Methods In accordance with the World Health Organization(WHO) recommendations, we constructed two reassortant viruses using reverse genetics(RG) technology to match the two different epidemic H5 N6 viruses. We performed complete genome sequencing to determine the genetic stability. We assessed the growth ability of the studied viruses in MDCK cells and conducted a hemagglutination inhibition assay to analyze their antigenicity. Pathogenicity attenuation was also evaluated in vitro and in vivo.Results The results showed that no mutations occurred in hemagglutinin or neuraminidase, and both CVVs retained their original antigenicity. The replication capacity of the two CVVs reached a level similar to that of A/Puerto Rico/8/34 in MDCK cells. The two CVVs showed low pathogenicity in vitro and in vivo, which are in line with the WHO requirements for CVVs.Conclusion We obtained two genetically stable CVVs of HPAI H5N6 with high growth characteristics,which may aid in our preparedness for a potential H5N6 pandemic.
基金supported in part by the funding from the National Natural Scientific Foundation(81370518)the National High Technology Research and Development Program of China(2015AA020924 and 2013ZX10004003)supported by a grant from the Beijing Nova Program(No.Z141107001814054)
文摘The highly pathogenic avian influenza (HPAI) H5N1 virus has caused several outbreaks in domestic poultry. Despite great efforts to control the spread of this virus, it continues to evolve and poses a substantial threat to public health because of a high mortality rate. In this study, we sequenced whole genomes of eight H5N1 avian influenza viruses isolated from domestic poultry in eastern China and compared them with those of typical influenza virus strains. Phylogenetic analyses showed that all eight genomes belonged to clade 2.3.2.1 and clade 7.2, the two main circulating clades in China. Viruses that clustered in clade 2.3.2.1 shared a high degree of homology with H5N1 isolates located in eastern Asian. Isolates that clustered in clade 7.2 were found to circulate throughout China, with an east-to-west density gradient. Pathogenicity studies in mice showed that these isolates replicate in the lungs, and clade 2.3.2.1 viruses exhibit a notably higher degree of virulence compared to clade 7.2 viruses. Our results contribute to the elucidation of the biological characterization and pathogenicity of HPAI H5N1 viruses.
基金supported by grants from the National Natural Science Foundation of China (31311120063,81470096,31570026,31471253)the Ministry of Education and Science of the Russian Federation (Chinese-Russian project:RFMEFI61315X0045)+3 种基金the intramural special grant for influenza virus research from the Chinese Academy of Sciences (KJZD-EW-L09)the IDRCAPEIR program (106915-001)Special Project of Ministry of Science and Technology (2013FY113500)supported by the “Taishan Scholar” project of Shandong Province
文摘A novel Clade 2.3.2.1c H5N1 reassortant virus caused several outbreaks in wild birds in some regions of China from late 2014 to 2015.Based on the genetic and phylogenetic analyses,the viruses possess a stable gene constellation with a Clade 2.3.2.1c HA,a H9N2-derived PB2 gene and the other six genes of Asian H5N1-origin.The Clade 2.3.2.1c H5N1 reassortants displayed a high genetic relationship to a human H5N1 strain(A/Alberta/01/2014).Further analysis showed that similar viruses have been circulating in wild birds in China,Russia,Dubai(Western Asia),Bulgaria and Romania(Europe),as well as domestic poultry in some regions of Africa.The affected areas include the Central Asian,East Asian-Australasian,West Asian-East African,and Black Sea/Mediterranean flyways.These results show that the novel Clade 2.3.2.1c reassortant viruses are circulating worldwide and may have gained a selective advantage in migratory birds,thus posing a serious threat to wild birds and potentially humans.
基金This workwas supported by two grants, No. CHB1-31056-BE-11 from the US Civilian Research & Development Foundation from the National Institute of Allergy and Infectious Diseases and No. 31070785 from the National Natural Science Foundation of China. We thank Dr Jianmin Zhang and Dr Austin Cape for critical reading of the manuscript.
文摘Highly pathogenic avian influenza H5N 1 epidemics are a significant public health hazard. Genetically engineered H5N 1 viruses with mammalian transmission activity highlight the potential risk of a human influenza H5N 1 pandemic. Understanding the underlying principles of the innate immune system in response to influenza H5N 1 viruses will lead to improved prevention and control of these potentially deadly viruses, γδT cells act as the first line of defense against microbial infection and help initiate adaptive immune responses during the early stages of viral infection. In this study, we investigated the molecular mechanisms of γδ T cells in response to influenza H5N1 viral infection, We found that recombinant hemagglutinin (rHA) derived from three different strains of influenza H5N 1 viruses elicited the activation of γδ T cells cultured in peripheral blood mononuclear cells (PBMCs). Both the cell surface expression of CD69, an early activation marker on γδ T cells, and the production of interferon-y (IFN-y) were significantly increased. Notably, the rHA protein-induced γδ T-cell activation was not mediated by TCRγδ, NKG2D or pattern recognition receptors (PRRs) or NKp46 receptors. The interaction of rHA proteins with sialic acid receptors may play a critical role in γδ T-cell activation. Our data may provide insight into the mechanisms underlyingγδT-cell activation in response to infection with H5N1 viruses.