African swine fever virus(ASFV)is an important pathogen causing acute infectious disease in domestic pigs and wild boars that seriously endangers the global swine industry.As ASFV is structurally complex and encodes a...African swine fever virus(ASFV)is an important pathogen causing acute infectious disease in domestic pigs and wild boars that seriously endangers the global swine industry.As ASFV is structurally complex and encodes a large number of functional proteins,no effective vaccine has been developed to date.Thus,dissecting the mechanisms of immune escape induced by ASFV proteins is crucial.A previous study showed that the ASFV-encoded protein is an important factor in host immunity.In this study,we identified a negative regulator,MGF505-3R,that significantly downregulated cGAS/STING-and poly(dG:dC)-mediated IFN-βand interferon stimulation response element(ISRE)reporter activity and suppressed IFNB1 and IFIT2 mRNA levels.In addition,TBK1,IRF3 and IκBαphosphorylation levels were also inhibited.Mechanistically,MGF505-3R interacted with cGAS/TBK1/IRF3 and targeted TBK1 for degradation,thereby disrupting the cGAS-STING-mediated IFN-βsignaling pathway,which appears to be highly correlated with autophagy.Knockdown MGF505-3R expression enhanced IFN-βand IL-1βproduction.Taken together,our study revealed a negative regulatory mechanism involving the MGF505-3R-cGAS-STING axis and provided insights into an evasion strategy employed by ASFV that involves autophagy and innate signaling pathways.展开更多
African swine fever(ASF)is etiologically an acute,highly contagious and hemorrhagic disease caused by African swine fever virus(ASFV).Due to its genetic variation and phenotypic diversity,until now,no efficient commer...African swine fever(ASF)is etiologically an acute,highly contagious and hemorrhagic disease caused by African swine fever virus(ASFV).Due to its genetic variation and phenotypic diversity,until now,no efficient commercial vaccines or therapeutic options are available.The ASFV genome contains a conserved middle region and two flexible ends that code for five multigene families(MGFs),while the biological functions of the MGFs are not fully characterized.Here,ASFV MGF505-2R-deficient mutant ASFV-Δ2R was constructed based on a highly virulent genotype II field isolate ASFV CN/GS/2018 currently circulating in China.Transcriptomic profiling demonstrated that ASFV-Δ2R was capable of inducing a larger number of differentially expressed genes(DEGs)compared with ASFV CN/GS/2018.Hierarchical clustering of up-regulated DEGs revealed that ASFV-Δ2R induced the most dramatic expression of interferon-related genes and inflammatory and innate immune genes,as further validated by RT-qPCR.The GO and KEGG pathway analysis identified significantly enriched pathways involved in pathogen recognition and innate antiviral immunity.Conversely,pharmacological activation of those antiviral immune responses by exogenous cytokines,including type I/II IFNs,TNF-αand IL-1β,exerted combinatory effects and synergized in antiviral capacity against ASFV replication.Collectively,MGF505-2R is a newly identified inhibitor of innate immunity potentially implicated in immune evasion.展开更多
基金supported by the National Natural Science Foundation of China(31941018,32072888,U21A20261)China Agriculture Research System of MOF and MARA(CARS-35)+1 种基金Science and Technology Development Program of Jilin Province(YDZJ202102CXJD029,20190301042NY,20200402041NC)Science and Technology Development Program of Changchun City(21ZY42).
文摘African swine fever virus(ASFV)is an important pathogen causing acute infectious disease in domestic pigs and wild boars that seriously endangers the global swine industry.As ASFV is structurally complex and encodes a large number of functional proteins,no effective vaccine has been developed to date.Thus,dissecting the mechanisms of immune escape induced by ASFV proteins is crucial.A previous study showed that the ASFV-encoded protein is an important factor in host immunity.In this study,we identified a negative regulator,MGF505-3R,that significantly downregulated cGAS/STING-and poly(dG:dC)-mediated IFN-βand interferon stimulation response element(ISRE)reporter activity and suppressed IFNB1 and IFIT2 mRNA levels.In addition,TBK1,IRF3 and IκBαphosphorylation levels were also inhibited.Mechanistically,MGF505-3R interacted with cGAS/TBK1/IRF3 and targeted TBK1 for degradation,thereby disrupting the cGAS-STING-mediated IFN-βsignaling pathway,which appears to be highly correlated with autophagy.Knockdown MGF505-3R expression enhanced IFN-βand IL-1βproduction.Taken together,our study revealed a negative regulatory mechanism involving the MGF505-3R-cGAS-STING axis and provided insights into an evasion strategy employed by ASFV that involves autophagy and innate signaling pathways.
基金supported by grants from the National Key R&D Program of China(2021YFD1801300)the Key-Area Research and Development Program of Guangdong Province(grant number 2019B020211003)+2 种基金the Chinese Academy of Agricultural Science and Technology Innovation Project(grants number CAAS-ZDRW202006 and CAAS-ASTIP-2021-LVRI)Technology Major Projects of Gansu Province(20ZD7A006 and NCC0006)as well as funding from the director of Lanzhou Veterinary Research Institute(LVRI-SZJJ-202106).
文摘African swine fever(ASF)is etiologically an acute,highly contagious and hemorrhagic disease caused by African swine fever virus(ASFV).Due to its genetic variation and phenotypic diversity,until now,no efficient commercial vaccines or therapeutic options are available.The ASFV genome contains a conserved middle region and two flexible ends that code for five multigene families(MGFs),while the biological functions of the MGFs are not fully characterized.Here,ASFV MGF505-2R-deficient mutant ASFV-Δ2R was constructed based on a highly virulent genotype II field isolate ASFV CN/GS/2018 currently circulating in China.Transcriptomic profiling demonstrated that ASFV-Δ2R was capable of inducing a larger number of differentially expressed genes(DEGs)compared with ASFV CN/GS/2018.Hierarchical clustering of up-regulated DEGs revealed that ASFV-Δ2R induced the most dramatic expression of interferon-related genes and inflammatory and innate immune genes,as further validated by RT-qPCR.The GO and KEGG pathway analysis identified significantly enriched pathways involved in pathogen recognition and innate antiviral immunity.Conversely,pharmacological activation of those antiviral immune responses by exogenous cytokines,including type I/II IFNs,TNF-αand IL-1β,exerted combinatory effects and synergized in antiviral capacity against ASFV replication.Collectively,MGF505-2R is a newly identified inhibitor of innate immunity potentially implicated in immune evasion.
