Influenza viruses not only cause respiratory illness,but also have been reported to elicit neurological manifestations following acute viral infection.The central nervous system(CNS)has a specific defense mechanism ag...Influenza viruses not only cause respiratory illness,but also have been reported to elicit neurological manifestations following acute viral infection.The central nervous system(CNS)has a specific defense mechanism against pathogens structured by cerebral microvasculature lined with brain endothelial cells to form the blood–brain barrier(BBB).To investigate the response of human brain microvascular endothelial cells(hBMECs)to the Influenza A virus(IAV),we inoculated the cells with the A/WSN/33(H1N1)virus.We then conducted an RNAseq experiment to determine the changes in gene expression levels and the activated disease pathways following infection.The analysis revealed an effective activation of the innate immune defense by inducing the pattern recognition receptors(PRRs).Along with the production of proinflammatory cytokines,we detected an upregulation of interferons and interferon-stimulated genes,such as IFN-β/λ,ISG15,CXCL11,CXCL3 and IL-6,etc.Moreover,infected hBMECs exhibited a disruption in the cytoskeletal structure both on the transcriptomic and cytological levels.The RNAseq analysis showed different pathways and candidate genes associated with the neuroactive ligand-receptor interaction,neuroinflammation,and neurodegenerative diseases,together with a predicted activation of the neuroglia.Likewise,some genes linked with the mitochondrial structure and function displayed a significantly altered expression.En masse,this data supports that hBMECs could be infected by the IAV,which induces the innate and inflammatory immune response.The results suggest that the influenza virus infection could potentially induce a subsequent aggravation of neurological disorders.展开更多
Avian H9N2 viruses have wide host range among the influenza A viruses.However,knowledge of H9N2 mammalian adaptation is limited.To explore the molecular basis of the adaptation to mammals,we performed serial lung pass...Avian H9N2 viruses have wide host range among the influenza A viruses.However,knowledge of H9N2 mammalian adaptation is limited.To explore the molecular basis of the adaptation to mammals,we performed serial lung passaging of the H9N2 strain A/chicken/Hunan/8.27 YYGK3W3-OC/2018(3W3)in mice and identified six mutations in the hemagglutinin(HA)and polymerase acidic(PA)proteins.Mutations L226Q,T511I,and A528V of HA were responsible for enhanced pathogenicity and viral replication in mice;notably,HA-L226Q was the key determinant.Mutations T97I,I545V,and S594G of PA contributed to enhanced polymerase activity in mammalian cells and increased viral replication levels in vitro and in vivo.PA-T97I increased viral polymerase activity by accelerating the viral polymerase complex assembly.Our findings revealed that the viral replication was affected by the presence of PA-97I and/or PA-545V in combination with a triple-point HA mutation.Furthermore,the double-and triple-point PA mutations demonstrated antagonistic effect on viral replication when combined with HA-226Q.Notably,any combination of PA mutations,along with double-point HA mutations,resulted in antagonistic effect on viral replication.We also observed antagonism in viral replication between PA-545V and PA-97I,as well as between HA-528V and PA-545V.Our findings demonstrated that several antagonistic mutations in HA and PA proteins affect viral replication,which may contribute to the H9N2 virus adaptation to mice and mammalian cells.These findings can potentially contribute to the monitoring of H9N2 field strains for assessing their potential risk in mammals.展开更多
The matrix protein 2 (M2) is a preferred target for developing a universal vaccine against the influenza A virus (IAV). This study aimed to develop a method for assessing antibody-dependent cell-mediated cytotoxicity ...The matrix protein 2 (M2) is a preferred target for developing a universal vaccine against the influenza A virus (IAV). This study aimed to develop a method for assessing antibody-dependent cell-mediated cytotoxicity (ADCC) associated with M2-based immunization in mice. We first established a stable cell line derived from mouse lymphoma cells (YAC-1) expressing M2 of H3N2. This cell line, designated as YAC-1-M2, was generated using a second-generation lentiviral tricistronic plasmid system to transduce the M2 gene into YAC-1 cells. The ADCC effect induced by polyclonal antibodies targeting matrix protein 2 ectodomain (M2e) was demonstrated by YAC-1-M2 cell lysis by natural killer cells (NK) derived from mice, in the presence of anti-M2 antibodies obtained from mice immunized with an mRNA vaccine based on M2e. This ADCC effect was found to be stronger compared to the effect induced by monoclonal antibodies (14C2) against M2. Moreover, the ADCC effect was enhanced as the effector-to-target ratio of NK to YAC-1-M2 cells increased. In conclusion, we established a novel method to detect ADCC of M2 of IAV, which paves the way for the development of an M2-based universal vaccine against IAV and an in-depth analysis of its mechanism of broad-spectrum immune protection in mice.展开更多
Influenza A virus(IAV)genome comprises eight negative-sense RNA segments,of which the replication is well orchestrated and the delicate balance of multiple segments are dynamically regulated throughout IAV life cycle....Influenza A virus(IAV)genome comprises eight negative-sense RNA segments,of which the replication is well orchestrated and the delicate balance of multiple segments are dynamically regulated throughout IAV life cycle.However,previous studies seldom discuss these balances except for functional hemagglutinin-neuraminidase balance that is pivotal for both virus entry and release.Therefore,we attempt to revisit IAV life cycle by highlighting the critical role of“genome balance”.Moreover,we raise a“balance regression”model of IAV evolution that the virus evolves to rebalance its genome after reassortment or interspecies transmission,and direct a“balance compensation”strategy to rectify the“genome imbalance”as a result of artificial modifications during creation of recombinant IAVs.This review not only improves our understanding of IAV life cycle,but also facilitates both basic and applied research of IAV in future.展开更多
Influenza A virus(IAV),responsible for seasonal epidemics and recurring pandemics,represents a global threat to public health.Given the risk of a potential IAV pandemic,it is increasingly important to better understan...Influenza A virus(IAV),responsible for seasonal epidemics and recurring pandemics,represents a global threat to public health.Given the risk of a potential IAV pandemic,it is increasingly important to better understand virushost interactions and develop new anti-viral strategies.Here,we reported nonmuscle myosin IIA(MYH9)-mediated regulation of IAV infection.MYH9 depletion caused a profound inhibition of IAV infection by reducing viral attachment and internalization in human lung epithelial cells.Surprisingly,overexpression of MYH9 also led to a significant reduction in viral productive infection.Interestingly,overexpression of MYH9 retained viral attachment,internalization,or uncoating,but suppressed the viral ribonucleoprotein(vRNP)activity in a minigenome system.Further analyses found that excess MYH9 might interrupt the formation of vRNP by interacting with the viral nucleoprotein(NP)and result in the reduction of the completed vRNP in the nucleus,thereby inhibiting subsequent viral RNA transcription and replication.Together,we discovered that MYH9 can interact with IAV NP protein and engage in the regulation of vRNP complexes,thereby involving viral replication.These findings enlighten new mechanistic insights into the complicated interface of host-IAV interactions,ultimately making it an attractive target for the generation of antiviral drugs.展开更多
基金the financial support provided by the National Program on Key Research Project of China(2016YFD0500406)the National Natural Sciences Foundation of China(Grant No.31872455)+1 种基金the Fundamental Research Funds for the Central Universities(2662018PY016)the Start-up Research Fund from Huazhong Agricultural University.
文摘Influenza viruses not only cause respiratory illness,but also have been reported to elicit neurological manifestations following acute viral infection.The central nervous system(CNS)has a specific defense mechanism against pathogens structured by cerebral microvasculature lined with brain endothelial cells to form the blood–brain barrier(BBB).To investigate the response of human brain microvascular endothelial cells(hBMECs)to the Influenza A virus(IAV),we inoculated the cells with the A/WSN/33(H1N1)virus.We then conducted an RNAseq experiment to determine the changes in gene expression levels and the activated disease pathways following infection.The analysis revealed an effective activation of the innate immune defense by inducing the pattern recognition receptors(PRRs).Along with the production of proinflammatory cytokines,we detected an upregulation of interferons and interferon-stimulated genes,such as IFN-β/λ,ISG15,CXCL11,CXCL3 and IL-6,etc.Moreover,infected hBMECs exhibited a disruption in the cytoskeletal structure both on the transcriptomic and cytological levels.The RNAseq analysis showed different pathways and candidate genes associated with the neuroactive ligand-receptor interaction,neuroinflammation,and neurodegenerative diseases,together with a predicted activation of the neuroglia.Likewise,some genes linked with the mitochondrial structure and function displayed a significantly altered expression.En masse,this data supports that hBMECs could be infected by the IAV,which induces the innate and inflammatory immune response.The results suggest that the influenza virus infection could potentially induce a subsequent aggravation of neurological disorders.
基金supported by the National Key Research and Development Program of China(NKPs)(2022YFC2604101)the National Science and Technology Major Project of China(2020ZX10001016-002)。
文摘Avian H9N2 viruses have wide host range among the influenza A viruses.However,knowledge of H9N2 mammalian adaptation is limited.To explore the molecular basis of the adaptation to mammals,we performed serial lung passaging of the H9N2 strain A/chicken/Hunan/8.27 YYGK3W3-OC/2018(3W3)in mice and identified six mutations in the hemagglutinin(HA)and polymerase acidic(PA)proteins.Mutations L226Q,T511I,and A528V of HA were responsible for enhanced pathogenicity and viral replication in mice;notably,HA-L226Q was the key determinant.Mutations T97I,I545V,and S594G of PA contributed to enhanced polymerase activity in mammalian cells and increased viral replication levels in vitro and in vivo.PA-T97I increased viral polymerase activity by accelerating the viral polymerase complex assembly.Our findings revealed that the viral replication was affected by the presence of PA-97I and/or PA-545V in combination with a triple-point HA mutation.Furthermore,the double-and triple-point PA mutations demonstrated antagonistic effect on viral replication when combined with HA-226Q.Notably,any combination of PA mutations,along with double-point HA mutations,resulted in antagonistic effect on viral replication.We also observed antagonism in viral replication between PA-545V and PA-97I,as well as between HA-528V and PA-545V.Our findings demonstrated that several antagonistic mutations in HA and PA proteins affect viral replication,which may contribute to the H9N2 virus adaptation to mice and mammalian cells.These findings can potentially contribute to the monitoring of H9N2 field strains for assessing their potential risk in mammals.
基金the National Key Research and Development Program of China(2021YFC2300101).
文摘The matrix protein 2 (M2) is a preferred target for developing a universal vaccine against the influenza A virus (IAV). This study aimed to develop a method for assessing antibody-dependent cell-mediated cytotoxicity (ADCC) associated with M2-based immunization in mice. We first established a stable cell line derived from mouse lymphoma cells (YAC-1) expressing M2 of H3N2. This cell line, designated as YAC-1-M2, was generated using a second-generation lentiviral tricistronic plasmid system to transduce the M2 gene into YAC-1 cells. The ADCC effect induced by polyclonal antibodies targeting matrix protein 2 ectodomain (M2e) was demonstrated by YAC-1-M2 cell lysis by natural killer cells (NK) derived from mice, in the presence of anti-M2 antibodies obtained from mice immunized with an mRNA vaccine based on M2e. This ADCC effect was found to be stronger compared to the effect induced by monoclonal antibodies (14C2) against M2. Moreover, the ADCC effect was enhanced as the effector-to-target ratio of NK to YAC-1-M2 cells increased. In conclusion, we established a novel method to detect ADCC of M2 of IAV, which paves the way for the development of an M2-based universal vaccine against IAV and an in-depth analysis of its mechanism of broad-spectrum immune protection in mice.
基金supported by National Natural Science Foundation of China(No.82104134)Key Technology Research and Development Program of Shandong,China(No.2020CXGC010505)The Social Benefiting Technology Program of Qingdao,China(No.21-1-4-rkjk-15-nsh).
文摘Influenza A virus(IAV)genome comprises eight negative-sense RNA segments,of which the replication is well orchestrated and the delicate balance of multiple segments are dynamically regulated throughout IAV life cycle.However,previous studies seldom discuss these balances except for functional hemagglutinin-neuraminidase balance that is pivotal for both virus entry and release.Therefore,we attempt to revisit IAV life cycle by highlighting the critical role of“genome balance”.Moreover,we raise a“balance regression”model of IAV evolution that the virus evolves to rebalance its genome after reassortment or interspecies transmission,and direct a“balance compensation”strategy to rectify the“genome imbalance”as a result of artificial modifications during creation of recombinant IAVs.This review not only improves our understanding of IAV life cycle,but also facilitates both basic and applied research of IAV in future.
基金supported by the National Natural Science Foundation of China(82071788,81901598,81771704,and 82041015)National Key R&D Program of China(2022YFC2604100).
文摘Influenza A virus(IAV),responsible for seasonal epidemics and recurring pandemics,represents a global threat to public health.Given the risk of a potential IAV pandemic,it is increasingly important to better understand virushost interactions and develop new anti-viral strategies.Here,we reported nonmuscle myosin IIA(MYH9)-mediated regulation of IAV infection.MYH9 depletion caused a profound inhibition of IAV infection by reducing viral attachment and internalization in human lung epithelial cells.Surprisingly,overexpression of MYH9 also led to a significant reduction in viral productive infection.Interestingly,overexpression of MYH9 retained viral attachment,internalization,or uncoating,but suppressed the viral ribonucleoprotein(vRNP)activity in a minigenome system.Further analyses found that excess MYH9 might interrupt the formation of vRNP by interacting with the viral nucleoprotein(NP)and result in the reduction of the completed vRNP in the nucleus,thereby inhibiting subsequent viral RNA transcription and replication.Together,we discovered that MYH9 can interact with IAV NP protein and engage in the regulation of vRNP complexes,thereby involving viral replication.These findings enlighten new mechanistic insights into the complicated interface of host-IAV interactions,ultimately making it an attractive target for the generation of antiviral drugs.
