Coronaviruses have developed various measures to evade innate immunity, We have previously shown that severe acute respiratory syndrome （SARS） coronavirus M protein suppresses type I interferon （IFN） production by...Coronaviruses have developed various measures to evade innate immunity, We have previously shown that severe acute respiratory syndrome （SARS） coronavirus M protein suppresses type I interferon （IFN） production by impeding the formation of functional TRAF3-containing complex. In this study, we demonstrate that the IFN-antagonizing activity is specific to SARS coronavirus M protein and is mediated through its first transmembrane domain （TM 1） located at the N terminus. M protein from human coronavirus HKU 1 does not inhibit IFN production. Whereas N-linked glycosylation of SARS coronavirus M protein has no influence on IFN antagonism, TM1 is indispensable for the suppression of IFN production. TM 1 targets SARS coronavirus M protein and heterologous proteins to the Golgi apparatus, yet Golgi localization is required but not sufficient for IFN antagonism. Mechanistically, TM 1 is capable of binding with RIG-I, TRAF3, TBK1 and IKK~, and preventing the interaction of TRAF3 with its downstream effectors. Our work defines the molecular architecture of SARS coronavirus M orotein reouired for suooression of innate antiviral re^nnn^e.展开更多
Tripartite motif(TRIM)family proteins are important effectors of innate immunity against viral infections.Here we identified TRIM35 as a regulator of TRAF3 activation.Deficiency in or inhibition of TRIM35 suppressed t...Tripartite motif(TRIM)family proteins are important effectors of innate immunity against viral infections.Here we identified TRIM35 as a regulator of TRAF3 activation.Deficiency in or inhibition of TRIM35 suppressed the production of type I interferon(IFN)in response to viral infection.777m35-deficient mice were more susceptible to influenza A virus(IAV)infection than were wild-type mice.TRIM35 promoted the RIG-Imediated signaling by catalyzing Lys63-linked polyubiquitination of TRAF3 and the subsequent formation of a signaling complex with VISA and TBK1.IAV PB2 polymerase countered the innate antiviral immune response by impeding the Lys63-linked polyubiquitination and activation of TRAF3.TRIM35 mediated Lys48-linked polyubiquitination and proteasomal degradation of IAV PB2,thereby antagonizing its suppression of TRAF3 activation.Our in vitro and in vivo findings thus reveal novel roles of TRIM35,through catalyzing Lys63-or Lys48-linked polyubiquitination,in RIG-I antiviral immunity and mechanism of defense against IAV infection.展开更多
Psoriasis is a common chronic inflammatory skin disease characterized by inflammatory cell infiltration and epidermal hyperplasia.However,the regulatory complexity of cytokine and cellular networks still needs to be i...Psoriasis is a common chronic inflammatory skin disease characterized by inflammatory cell infiltration and epidermal hyperplasia.However,the regulatory complexity of cytokine and cellular networks still needs to be investigated.Here,we show that the expression of FXYD3,a member of the FXYD domain-containing regulators of Na+/K+ATPases family,is significantly increased in the lesional skin of psoriasis patients and mice with imiquimod(IMQ)-induced psoriasis.IL-17A,a cytokine important for the development of psoriatic lesions,contributes to FXYD3 expression in human primary keratinocytes.FXYD3 deletion in keratinocytes attenuated the psoriasis-like phenotype and inflammation in an IMQ-induced psoriasis model.Importantly,FXYD3 promotes the formation of the IL-17R-ACT1 complex by competing with IL-17R for binding to TRAF3 and then enhances IL-17A signaling in keratinocytes.This promotes the activation of the NF-κB and MAPK signaling pathways and leads to the expression of proinflammatory factors.Our results clarify the mechanism by which FXYD3 serves as a mediator of IL-17A signaling in keratinocytes to form a positive regulatory loop to promote psoriasis exacerbation.Targeting FXYD3 may serve as a potential therapeutic approach in the treatment of psoriasis.展开更多
As a major component of the viral ribonucleoprotein(vRNP)complex in influenza A virus(IAV),nucleoprotein(NP)interacts with isoforms of importinαfamily members,leading to the import of itself and vRNP complex into the...As a major component of the viral ribonucleoprotein(vRNP)complex in influenza A virus(IAV),nucleoprotein(NP)interacts with isoforms of importinαfamily members,leading to the import of itself and vRNP complex into the nucleus,a process pivotal in the replication cycle of IAV.In this study,we found that BinCARD1,an isoform of Bcl10-interacting protein with CARD(BinCARD),was leveraged by IAV for efficient viral replication.BinCARD1 promoted the nuclear import of the vRNP complex and newly synthesized NP and thus enhanced vRNP complex activity.Moreover,we found that BinCARD1 interacted with NP to promote NP binding to importinα7,an adaptor in the host nuclear import pathway.However,we also found that BinCARD1 promoted RIG-I-mediated innate immune signaling by mediating Lys63-linked polyubiquitination of TRAF3,and that TBK1 appeared to degrade BinCARD1.We showed that BinCARD1 was polyubiquitinated at residue K103 through a Lys63 linkage,which was recognized by the TBK1-p62 axis for autophagic degradation.Overall,our data demonstrate that IAV leverages BinCARD1 as an important host factor that promotes viral replication,and two mechanisms in the host defense system are triggered—innate immune signaling and autophagic degradation—to mitigate the promoting effect of BinCARD1 on the life cycle of IAV.展开更多
Innate immunity represents one of the main host responses to viral infection.1,2,3 STING(Stimulator of interferon genes),a crucial immune adapter functioning in host cells,mediates cGAS(Cyclic GMP-AMP Synthase)sensing...Innate immunity represents one of the main host responses to viral infection.1,2,3 STING(Stimulator of interferon genes),a crucial immune adapter functioning in host cells,mediates cGAS(Cyclic GMP-AMP Synthase)sensing of exogenous and endogenous DNA fragments and generates innate immune responses.4 Whether STING activation was involved in infection and replication of enterovirus remains largely unknown.In the present study,we discovered that human enterovirus A71(EV-A71)infection triggered STING activation in a cGAS dependent manner.EV-A71 infection caused mitochondrial damage and the discharge of mitochondrial DNA into the cytosol of infected cells.However,during EV-A71 infection,cGAS-STING activation was attenuated.EV-A71 ^(pro)teins were screened and the viral ^(pro)tease 2A^(pro) had the greatest capacity to inhibit cGAS-STING activation.We identified TRAF3 as an important factor during STING activation and as a target of 2A^(pro).Supplement of TRAF3 rescued cGAS-STING activation suppression by 2A^(pro).TRAF3 supported STING activation mediated TBK1 phosphorylation.Moreover,we found that 2A^(pro) ^(pro)tease activity was essential for inhibiting STING activation.Furthermore,EV-D68 and CV-A16 infection also triggered STING activation.The viral ^(pro)tease 2A^(pro) from EV-D68 and CV-A16 also had the ability to inhibit STING activation.As STING activation prior to EV-A71 infection generated cellular resistance to EV-A71 replication,blocking EV-A71-mediated STING suppression represents a new anti-viral target.展开更多
To date,EV71 infection still poses a great challenge to the health of infants and young children.1 Much established evidence suggests that EV71 infection depends on a wide variety of host factors,including cell surfac...To date,EV71 infection still poses a great challenge to the health of infants and young children.1 Much established evidence suggests that EV71 infection depends on a wide variety of host factors,including cell surface receptors for EV71 entry,innate immune response,miRNAs,and lncRNAs.2,3 It is thought that diverse signaling pathways are required for EV71 to escape the host immune response.4 Innate immunity serves as the first line of defense against pathogens.Tumor necrosis factor receptor-associated factor(TRAF)proteins are essential components of signaling pathways activated by Toll-like receptor(TLR)or RIG-I-like receptor(RLR)family members.TRAF3 is widely expressed by many cell types,including all nucleated immune cells,in which it plays many roles in the regulation of immune functions.5 TRAF3 plays a significant role in regulating the functions of B and T lymphocytes.TRAF3 is a highly versatile regulator that positively controls type I interferon and cytokine production through interferon regulatory factors(IRFs)and nuclear factor-κB(NF-κB).6 A recent study indicated that EV71-induced ubiquitin-specific protease 19(USP19)negatively regulates type I IFN signaling by targeting TRAF3.展开更多
Background: Sertoli cells(SCs) create a specialized environment to support and dictate spermatogenesis.MicroRNAs(miRNAs), a kind of ~ 22 nt small noncoding RNAs, have been reported to be highly abundant in mouse SCs a...Background: Sertoli cells(SCs) create a specialized environment to support and dictate spermatogenesis.MicroRNAs(miRNAs), a kind of ~ 22 nt small noncoding RNAs, have been reported to be highly abundant in mouse SCs and play critical roles in spermatogenesis. However, the miRNAs of porcine SCs remain largely unknown.Methods: We isolated porcine SCs and conducted small RNA sequencing. By comparing miRNAs in germ cells, we systematically analyzed the miRNA expression pattern of porcine SCs. We screened the highly enriched SC miRNAs and predicted their functions by Gene Ontology analysis. The dual luciferase assay was used to elucidate the regulation of tumor necrosis factor receptor(TNFR)-associated factor 3(TRAF3) by ssc-miR-149.Results: The analysis showed that 18 miRNAs were highly expressed in SCs and 15 miRNAs were highly expressed in germ cells. These miRNAs were predicted to mediate SC and germ cell functions. In addition, ssc-miR-149 played critical roles in SCs by targeting TRAF3.Conclusion: Our findings provide novel insights into the miRNA expression pattern and their regulatory roles of porcine SCs.展开更多
SARS coronavirus （SARS-CoV） develops an antagonis- tic mechanism by which to evade the antiviral activities of interferon （IFN）. Previous studies suggested that SARS-CoV papain-like protease （PLpro） inhibits act...SARS coronavirus （SARS-CoV） develops an antagonis- tic mechanism by which to evade the antiviral activities of interferon （IFN）. Previous studies suggested that SARS-CoV papain-like protease （PLpro） inhibits activa- tion of the IRF3 pathway, which would normally elicit a robust IFN response, but the mechanism（s） used by SARS PLpro to inhibit activation of the IRF3 pathway is not fully known. In this study, we uncovered a novel mechanism that may explain how SARS PLpro effi- ciently inhibits activation of the IRF3 pathway. We found that expression of the membrane-anchored PLpro domain （PLpro-TM） from SARS-CoV inhibits STING/ TBKl/IKKE-mediated activation of type I IFNs and dis- rupts the phosphorylation and dimerization of IRF3, which are activated by STING and TBKI. Meanwhile, we showed that PLpro-TM physically interacts with TRAF3, TBK1, IKK~, STING, and IRF3, the key components that assemble the STING-TRAF3-TBK1 complex for activa- tion of IFN expression. However, the interaction between the components in STING-TRAF3-TBK1 complex is dis- rupted by PLpro-TM. Furthermore, SARS PLpro-TM reduces the levels of ubiquitinated forms of RIG-I, STING, TRAF3, TBK1, and IRF3 in the STING-TRAF3- TBK1 complex. These results collectively point to a new mechanism used by SARS-CoV through which PLpro negatively regulates IRF3 activation by interaction withSTING-TRAF3-TBK1 complex, yielding a SARS-CoV countermeasure against host innate immunity.展开更多
文摘Coronaviruses have developed various measures to evade innate immunity, We have previously shown that severe acute respiratory syndrome （SARS） coronavirus M protein suppresses type I interferon （IFN） production by impeding the formation of functional TRAF3-containing complex. In this study, we demonstrate that the IFN-antagonizing activity is specific to SARS coronavirus M protein and is mediated through its first transmembrane domain （TM 1） located at the N terminus. M protein from human coronavirus HKU 1 does not inhibit IFN production. Whereas N-linked glycosylation of SARS coronavirus M protein has no influence on IFN antagonism, TM1 is indispensable for the suppression of IFN production. TM 1 targets SARS coronavirus M protein and heterologous proteins to the Golgi apparatus, yet Golgi localization is required but not sufficient for IFN antagonism. Mechanistically, TM 1 is capable of binding with RIG-I, TRAF3, TBK1 and IKK~, and preventing the interaction of TRAF3 with its downstream effectors. Our work defines the molecular architecture of SARS coronavirus M orotein reouired for suooression of innate antiviral re^nnn^e.
基金The work was supported by the National Key Research and Development Program of China(2016YFD0500205)the National Natural Science Foundation of China(NSFC)(Grant Nos.31521005,31672582,31422054,and 31472215)+1 种基金the Natural Science Foundation of Heilongjiang Province(JQ2019C005)by the Central Public-Interest Scientific Institution Basal Research Fund(No.Y2017JC35).
文摘Tripartite motif(TRIM)family proteins are important effectors of innate immunity against viral infections.Here we identified TRIM35 as a regulator of TRAF3 activation.Deficiency in or inhibition of TRIM35 suppressed the production of type I interferon(IFN)in response to viral infection.777m35-deficient mice were more susceptible to influenza A virus(IAV)infection than were wild-type mice.TRIM35 promoted the RIG-Imediated signaling by catalyzing Lys63-linked polyubiquitination of TRAF3 and the subsequent formation of a signaling complex with VISA and TBK1.IAV PB2 polymerase countered the innate antiviral immune response by impeding the Lys63-linked polyubiquitination and activation of TRAF3.TRIM35 mediated Lys48-linked polyubiquitination and proteasomal degradation of IAV PB2,thereby antagonizing its suppression of TRAF3 activation.Our in vitro and in vivo findings thus reveal novel roles of TRIM35,through catalyzing Lys63-or Lys48-linked polyubiquitination,in RIG-I antiviral immunity and mechanism of defense against IAV infection.
基金Supported by Shenzhen Science and Technology Project(JCYJ20180306173022502)Shenzhen Strategic Emerging and Future Industrial Development Funds(20170426231005389)。
基金the National Natural Science Foundation of China(91842103,31870907,81930041)the Natural Science Foundation of Zhejiang Province(Z19H100001).
文摘Psoriasis is a common chronic inflammatory skin disease characterized by inflammatory cell infiltration and epidermal hyperplasia.However,the regulatory complexity of cytokine and cellular networks still needs to be investigated.Here,we show that the expression of FXYD3,a member of the FXYD domain-containing regulators of Na+/K+ATPases family,is significantly increased in the lesional skin of psoriasis patients and mice with imiquimod(IMQ)-induced psoriasis.IL-17A,a cytokine important for the development of psoriatic lesions,contributes to FXYD3 expression in human primary keratinocytes.FXYD3 deletion in keratinocytes attenuated the psoriasis-like phenotype and inflammation in an IMQ-induced psoriasis model.Importantly,FXYD3 promotes the formation of the IL-17R-ACT1 complex by competing with IL-17R for binding to TRAF3 and then enhances IL-17A signaling in keratinocytes.This promotes the activation of the NF-κB and MAPK signaling pathways and leads to the expression of proinflammatory factors.Our results clarify the mechanism by which FXYD3 serves as a mediator of IL-17A signaling in keratinocytes to form a positive regulatory loop to promote psoriasis exacerbation.Targeting FXYD3 may serve as a potential therapeutic approach in the treatment of psoriasis.
基金This investigation was funded by a grant from the Laboratory of Lingnan Modern Agriculture Project(NT2021007 to HC and CL)the National Natural Science Foundation of China(NSFC)(32192453 to CL,32172847 to LJ)+2 种基金the National Key Research and Development Program of China(2021YFD1800203 to HC,2021YFD1800204 to CL)the Natural Science Foundation of Heilongjiang Province(JQ2019C005 to CL)the Central Public-Interest Scientific Institution Basal Research Fund(Y2017JC35 to GT).
文摘As a major component of the viral ribonucleoprotein(vRNP)complex in influenza A virus(IAV),nucleoprotein(NP)interacts with isoforms of importinαfamily members,leading to the import of itself and vRNP complex into the nucleus,a process pivotal in the replication cycle of IAV.In this study,we found that BinCARD1,an isoform of Bcl10-interacting protein with CARD(BinCARD),was leveraged by IAV for efficient viral replication.BinCARD1 promoted the nuclear import of the vRNP complex and newly synthesized NP and thus enhanced vRNP complex activity.Moreover,we found that BinCARD1 interacted with NP to promote NP binding to importinα7,an adaptor in the host nuclear import pathway.However,we also found that BinCARD1 promoted RIG-I-mediated innate immune signaling by mediating Lys63-linked polyubiquitination of TRAF3,and that TBK1 appeared to degrade BinCARD1.We showed that BinCARD1 was polyubiquitinated at residue K103 through a Lys63 linkage,which was recognized by the TBK1-p62 axis for autophagic degradation.Overall,our data demonstrate that IAV leverages BinCARD1 as an important host factor that promotes viral replication,and two mechanisms in the host defense system are triggered—innate immune signaling and autophagic degradation—to mitigate the promoting effect of BinCARD1 on the life cycle of IAV.
基金This work was supported,in part,by following fundings:the National Natural Science Foundation of China(number 31970151,92169203,81701988,31900133,82172239,82102384,32041006,81772169)the National Natural Science Foundation of Zhejiang Province(LQ21C010001 and LY22C080002,)the Leading innovative and Entrepreneur Team Introduction Program of Zhejiang(2019R01007).We thank Yifei Shi kindly provided key reagents.
文摘Innate immunity represents one of the main host responses to viral infection.1,2,3 STING(Stimulator of interferon genes),a crucial immune adapter functioning in host cells,mediates cGAS(Cyclic GMP-AMP Synthase)sensing of exogenous and endogenous DNA fragments and generates innate immune responses.4 Whether STING activation was involved in infection and replication of enterovirus remains largely unknown.In the present study,we discovered that human enterovirus A71(EV-A71)infection triggered STING activation in a cGAS dependent manner.EV-A71 infection caused mitochondrial damage and the discharge of mitochondrial DNA into the cytosol of infected cells.However,during EV-A71 infection,cGAS-STING activation was attenuated.EV-A71 ^(pro)teins were screened and the viral ^(pro)tease 2A^(pro) had the greatest capacity to inhibit cGAS-STING activation.We identified TRAF3 as an important factor during STING activation and as a target of 2A^(pro).Supplement of TRAF3 rescued cGAS-STING activation suppression by 2A^(pro).TRAF3 supported STING activation mediated TBK1 phosphorylation.Moreover,we found that 2A^(pro) ^(pro)tease activity was essential for inhibiting STING activation.Furthermore,EV-D68 and CV-A16 infection also triggered STING activation.The viral ^(pro)tease 2A^(pro) from EV-D68 and CV-A16 also had the ability to inhibit STING activation.As STING activation prior to EV-A71 infection generated cellular resistance to EV-A71 replication,blocking EV-A71-mediated STING suppression represents a new anti-viral target.
基金funded by the National Natural Science Foundation of China(No.81172740 and No.81573205 to G.C.D.)Project founded by China Postdoctoral Science Foundation(No.2019M662543 to Y.F.J.)High-level Talent Start-up Funding of Zhengzhou University(No.141-32340042 to W.G.Z.).
文摘To date,EV71 infection still poses a great challenge to the health of infants and young children.1 Much established evidence suggests that EV71 infection depends on a wide variety of host factors,including cell surface receptors for EV71 entry,innate immune response,miRNAs,and lncRNAs.2,3 It is thought that diverse signaling pathways are required for EV71 to escape the host immune response.4 Innate immunity serves as the first line of defense against pathogens.Tumor necrosis factor receptor-associated factor(TRAF)proteins are essential components of signaling pathways activated by Toll-like receptor(TLR)or RIG-I-like receptor(RLR)family members.TRAF3 is widely expressed by many cell types,including all nucleated immune cells,in which it plays many roles in the regulation of immune functions.5 TRAF3 plays a significant role in regulating the functions of B and T lymphocytes.TRAF3 is a highly versatile regulator that positively controls type I interferon and cytokine production through interferon regulatory factors(IRFs)and nuclear factor-κB(NF-κB).6 A recent study indicated that EV71-induced ubiquitin-specific protease 19(USP19)negatively regulates type I IFN signaling by targeting TRAF3.
基金supported in part by the National Natural Science Foundation of China (Grant No. 31572401, 31772605) to W.Z。
文摘Background: Sertoli cells(SCs) create a specialized environment to support and dictate spermatogenesis.MicroRNAs(miRNAs), a kind of ~ 22 nt small noncoding RNAs, have been reported to be highly abundant in mouse SCs and play critical roles in spermatogenesis. However, the miRNAs of porcine SCs remain largely unknown.Methods: We isolated porcine SCs and conducted small RNA sequencing. By comparing miRNAs in germ cells, we systematically analyzed the miRNA expression pattern of porcine SCs. We screened the highly enriched SC miRNAs and predicted their functions by Gene Ontology analysis. The dual luciferase assay was used to elucidate the regulation of tumor necrosis factor receptor(TNFR)-associated factor 3(TRAF3) by ssc-miR-149.Results: The analysis showed that 18 miRNAs were highly expressed in SCs and 15 miRNAs were highly expressed in germ cells. These miRNAs were predicted to mediate SC and germ cell functions. In addition, ssc-miR-149 played critical roles in SCs by targeting TRAF3.Conclusion: Our findings provide novel insights into the miRNA expression pattern and their regulatory roles of porcine SCs.
文摘SARS coronavirus （SARS-CoV） develops an antagonis- tic mechanism by which to evade the antiviral activities of interferon （IFN）. Previous studies suggested that SARS-CoV papain-like protease （PLpro） inhibits activa- tion of the IRF3 pathway, which would normally elicit a robust IFN response, but the mechanism（s） used by SARS PLpro to inhibit activation of the IRF3 pathway is not fully known. In this study, we uncovered a novel mechanism that may explain how SARS PLpro effi- ciently inhibits activation of the IRF3 pathway. We found that expression of the membrane-anchored PLpro domain （PLpro-TM） from SARS-CoV inhibits STING/ TBKl/IKKE-mediated activation of type I IFNs and dis- rupts the phosphorylation and dimerization of IRF3, which are activated by STING and TBKI. Meanwhile, we showed that PLpro-TM physically interacts with TRAF3, TBK1, IKK~, STING, and IRF3, the key components that assemble the STING-TRAF3-TBK1 complex for activa- tion of IFN expression. However, the interaction between the components in STING-TRAF3-TBK1 complex is dis- rupted by PLpro-TM. Furthermore, SARS PLpro-TM reduces the levels of ubiquitinated forms of RIG-I, STING, TRAF3, TBK1, and IRF3 in the STING-TRAF3- TBK1 complex. These results collectively point to a new mechanism used by SARS-CoV through which PLpro negatively regulates IRF3 activation by interaction withSTING-TRAF3-TBK1 complex, yielding a SARS-CoV countermeasure against host innate immunity.
