Current serum neutralization assays based on the inhibition of the cytopathic effect(Nt-CPE) need to ma nipulate live viruses, which are time-consuming, labor-intensive, and have the potential exposure to infectious...Current serum neutralization assays based on the inhibition of the cytopathic effect(Nt-CPE) need to ma nipulate live viruses, which are time-consuming, labor-intensive, and have the potential exposure to infectious agents, so a safe and objective assay via pseudovirus for the fast and efficient detection of enterovirus 71(EV71) neutralizing antibodies was developed. First, we generated EV71 pseudovirus containing firefly luciferase gene in place of the capsid gene P1 in EV71 genome. Vero cells infected with 200 CCID50(50% cell culture infective dose) of EV71 pseudovirus for 24 h were found to have the best performance. Seval sera were measured by EV71 pseudoparticle neutralization assay(Nt-PPN) and the conventional serological method Nt-CPE. Neutralizing antibody titers measured by Nt-PPN and those obtained by Nt-CPE demonstrate a high correlation between the two methods. Overall, the PPN assay represents a valid alternative to conventional serological methods for the evaluation of EV71 neutralizing anti bodies. This method can be used for detecting neutralizing antibodies of other picornaviruses, such as hepatitis A vi rus(HAV) and coxsackievirus 16(CVA16), and make it possible to determine whether there is cross-reactivity be tween EV71 and CVA16.展开更多
目的对比了解2022—2023年新冠疫情期间及疫情后广州市和佛山市手足口病流行病学及非肠道病毒71型(enterovirus 71,EV71)非柯萨奇病毒A组16型(Coxsaekievirus group A 16,CA16)病毒的分子流行病学特征,为治疗和防控提供依据。方法运用...目的对比了解2022—2023年新冠疫情期间及疫情后广州市和佛山市手足口病流行病学及非肠道病毒71型(enterovirus 71,EV71)非柯萨奇病毒A组16型(Coxsaekievirus group A 16,CA16)病毒的分子流行病学特征,为治疗和防控提供依据。方法运用荧光逆转录聚合酶链反应(RT-PCR)对2022—2023年疑似手足口病患者标本同时进行肠道病毒(enterovirus,EV)通用型、EV71、CA16检测,并选取EV71和CA16是阴性而EV通用型是阳性的标本进行型别鉴定,设计5′非编码区(UTR)引物,RT-PCR扩增后进行序列测定,序列用BLAST程序进行序列的EV型别确定。结果2022年,同时进行EV通用型、EV71、CA163种病毒检测的疑似手足口病例标本共362份,总阳性47份,阳性率为12.98%;其中EV71阳性0份;CA16阳性5份,占1.38%;非EV71非CA16的EV阳性标本42份,占11.60%。2023年,同时进行EV通用型、EV71、CA163种病毒检测的疑似手足口病标本有297份,总阳性100份,阳性率为33.67%,全年没有检出EV71,CA16全年检出率为2.36%(7/297),非EV71非CA16的EV阳性率为31.31%(93/297)。51份非EV71非CA16阳性标本的序列分析表明,2022—2023检出的非EV71非CA16的EV有9种型别,分别为:CA6、CA10、CA4、CA2、CA8、柯萨奇病毒B组5型(CB5)、CB2、CB3、埃可病毒30型(E30),其中CA6占主要,为27.45%(14/51),其次是CA10,占15.69%(8/51)。结论新冠疫情结束后的2023年比疫情期间的2022年EV阳性率高。2022—2023年手足口病主要以非EV71非CA16为主,序列分析表明非EV71非CA16病毒中以CA6和CA10为主,应加强对CA6、CA10为主要非EV71非CA16病毒进行研究及监测。展开更多
TANK-binding kinase 1(TBK1)is an essential protein kinase for activation of interferon regulatory factor 3(IRF3)and induction of the type I interferons(IFN-I).Although the biochemical regulation of TBK1 activation has...TANK-binding kinase 1(TBK1)is an essential protein kinase for activation of interferon regulatory factor 3(IRF3)and induction of the type I interferons(IFN-I).Although the biochemical regulation of TBK1 activation has been studied,little is known about how enterovirus 71(EV71)employs the deubiquitinases(DUBs)to regulate TBK1 activation for viral immune evasion.Here,we found that EV71 infection upregulated the expression of ubiquitinspecific protease 24(USP24).Further studies revealed that USP24 physically interacted with TBK1,and can reduce K63-linked polyubiquitination of TBK1.Knockdown of USP24 upregulated TBK1 K63-linked polyubiquitination,promoted the phosphorylation and nuclear translocation of IRF3,and in turn improved IFN-I production during EV71 infection.As a consequence,USP24 knockdown dramatically inhibited EV71 infection.This study revealed USP24 as a novel regulator of TBK1 activation,which promotes the understanding of immune evasion mechanisms of EV71 and could provide a potential strategy for treatment of EV71 infection.展开更多
Objective:To estimate the potential causal impact of Enterovirus A71(EV71)vaccination program on the reduction of EV71-infected hand,foot,and mouth disease(HFMD)in Zhejiang Province.Methods:We utilized the longitudina...Objective:To estimate the potential causal impact of Enterovirus A71(EV71)vaccination program on the reduction of EV71-infected hand,foot,and mouth disease(HFMD)in Zhejiang Province.Methods:We utilized the longitudinal surveillance dataset of HFMD and EV71 vaccination in Zhejiang Province during 2010-2019.We estimated vaccine efficacy using a Bayesian structured time series(BSTS)model,and employed a negative control outcome(NCO)model to detect unmeasured confounding and reveal potential causal association.Results:We estimated that 20,132 EV71 cases(95%CI:16,733,23,532)were prevented by vaccination program during 2017-2019,corresponding to a reduction of 29%(95%CI:24%,34%).The effectiveness of vaccination increased annually,with reductions of 11%(95%CI:6%,16%)in 2017 and 66%(95%CI:61%,71%)in 2019.Children under 5 years old obtained greater benefits compared to those over 5 years.Cities with higher vaccination coverage experienced a sharper EV71 reduction compared to those with lower coverage.The NCO model detected no confounding factors in the association between vaccination and EV71 cases reduction.展开更多
Enterovirus 71(EV71)poses a serious threat to human health,with scattered outbreaks worldwide.There are several vaccines against a few EV71 strains but no efficient drug for the treatment of EV71 infection.Therefore,i...Enterovirus 71(EV71)poses a serious threat to human health,with scattered outbreaks worldwide.There are several vaccines against a few EV71 strains but no efficient drug for the treatment of EV71 infection.Therefore,it is urgent and of significance to develop anti-EV71 drugs.Here,we found that PLX8394,a RAF inhibitor,possesses high antiviral activity against EV71 in vitro,being superior to the traditional clinical drug ribavirin.Moreover,PLX8394 exhibits broad-spectrum antiviral activity against enteroviruses.Notably,in a suckling mouse model,PLX8394 provided a 70%protection rate for EV71-infected mice,reduced the viral load in liver and heart tissues,and relieved the inflammatory response.A mechanistic study showed that PLX8394 inhibited EV71 by suppressing the RAF/MEK/ERK signaling pathway.Thus,PLX8394 lays a foundation for the development of new drugs against EV71.展开更多
Enterovirus 71(EV71)infection is more likely to cause hand,foot and mouth disease(HFMD)in children,which can lead to neurogenic complications and higher mortality.As a commonly used clinical medicine,Reduning injectio...Enterovirus 71(EV71)infection is more likely to cause hand,foot and mouth disease(HFMD)in children,which can lead to neurogenic complications and higher mortality.As a commonly used clinical medicine,Reduning injection(RDN)helps to shorten the symptoms of patients with HFMD and facilitate the early recovery of children.However,the regulatory mechanism of RDN on the HFMD immune system disorder caused by EV71 remains to be discussed.This study collected detailed treatment data of56 children with HFMD who entered the affiliated Children’s Hospital of Nanjing Medical University during 2019.Retrospective analysis of clinical data showed that the symptoms of the RDN treatment group were improved compared with the untreated group.To explore its mechanism,the relevant detection indicators were detected by flow cytometry,enzyme-linked immunosorbent assay and realtime quantitative PCR.It was found that the number and function of innate immune(ILCs)and adaptive immunity(Th1,Th2 and secreted cytokines)were reduced,suggesting that RDN plays a role by regulating cellular immunity.The in vitro differentiation inhibition test further confirmed that RDN affected Th1 differentiation by inhibiting the expression of transcription factors on the basis of Th1 cell differentiation in vitro.展开更多
Enterovirus 71(EV71) caused hand, foot and mouth disease(HFMD) is a serious threat to the health of young children. Although type I interferon(IFN-I) has been proven to control EV71 replication, the key downstream IFN...Enterovirus 71(EV71) caused hand, foot and mouth disease(HFMD) is a serious threat to the health of young children. Although type I interferon(IFN-I) has been proven to control EV71 replication, the key downstream IFNstimulated gene(ISG) remains to be clarified and investigated. Recently, we found that 2’-5’-oligoadenylate synthetases 3(OAS3), as one of ISG of IFN-β1b, was antagonized by EV71 3C protein. Here, we confirm that OAS3is the major determinant of IFN-β1b-mediated EV71 inhibition, which depends on the downstream constitutive RNase L activation. 2’-5’-oligoadenylate(2-5A) synthesis activity deficient mutations of OAS3 D816A, D818A,D888A, and K950A lost resistance to EV71 because they could not activate downstream RNase L. Further investigation proved that EV71 infection induced OAS3 but not RNase L expression by IFN pathway. Mechanically, EV71 or IFN-β1b-induced phosphorylation of STAT1, but not STAT3, initiated the transcription of OAS3 by directly binding to the OAS3 promoter. Our works elucidate the immune regulatory mechanism of the host OAS3/RNase L system against EV71 replication.展开更多
Similar to that of other enteroviruses, the replication of enterovirus 71(EV71) occurs on rearranged membranous structures called replication organelles(ROs). Phosphatidylinositol 4-kinase Ⅲ(PI4KB), which is required...Similar to that of other enteroviruses, the replication of enterovirus 71(EV71) occurs on rearranged membranous structures called replication organelles(ROs). Phosphatidylinositol 4-kinase Ⅲ(PI4KB), which is required by enteroviruses for RO formation, yields phosphatidylinositol-4-phosphate(PI4P) on ROs. PI4P then binds and induces conformational changes in the RNA-dependent RNA polymerase(Rd Rp) to modulate Rd Rp activity. Here, we targeted 3D polymerase, the core enzyme of EV71 ROs, and found that the host factor Annexin A2(ANXA2) can interact with 3 D polymerase and promote the replication of EV71. Then, an experiment showed that the annexin domain of ANXA2, which possesses membranebinding capacity, mediates the interaction of ANXA2 with EV71 3 D polymerase. Further research showed that ANXA2 is localized on ROs and interacts with PI4KB. Overexpression of ANXA2 stimulated the formation of PI4P, and the level of PI4P was decreased in ANXA2-knockout cells. Furthermore, ANXA2, PI4KB, and 3D were shown to be localized to the viral RNA replication site, where they form a higher-order protein complex, and the presence of ANXA2 promoted the PI4 KB-3D interaction. Altogether, our data provide new insight into the role of ANXA2 in facilitating formation of the EV71 RNA replication complex.展开更多
The Enterovirus 71(EV71)VP4 is co-translationally linked to myristic acid at its amino-terminal glycine residue.However,the role of this myristoylation in the EV71 life cycle remains largely unknown.To investigate thi...The Enterovirus 71(EV71)VP4 is co-translationally linked to myristic acid at its amino-terminal glycine residue.However,the role of this myristoylation in the EV71 life cycle remains largely unknown.To investigate this issue,we developed a myristoylation-deficient virus and reporter(luciferase)pseudovirus with a Gly-to-Ala mutation(G2A)on EV71 VP4.When transfecting the EV71-G2 A genome encoding plasmid in cells,the loss of myristoylation on VP4 did not affect the expression of viral proteins and the virus morphology,however,it did significantly influence viral infectivity.Further,in myristoylation-deficient reporter pseudovirus-infected cells,the luciferase activity and viral genome RNA decreased significantly as compared to that of wild type virus;however,cytopathic effect and viral capsid proteins were not detected in myristoylation-deficient virus-infected cells.Also,although myristoylation-deficient viral RNA and proteins were detected in the second blind passage of infection,they were much fewer in number compared to that of the wild type virus.The replication of genomic RNA and negative-strand viral RNA were both blocked in myristoylation-deficient viruses,suggesting that myristoylation affects viral genome RNA release from capsid to cytoplasm.Besides,loss of myristoylation on VP4 altered the distribution of VP4-green fluorescent protein protein,which disappeared from the membrane structure fraction.Finally,a liposome leakage assay showed that EV71 myristoylation mediates the permeability of the model membrane.Hence,the amino-terminal myristoylation of VP4 is pivotal to EV71 infection and capsidmembrane structure interaction.This study provides novel molecular mechanisms regarding EV71 infection and potential molecular targets for antiviral drug design.展开更多
Virus identification is a prerequisite not only for the early diagnosis of viral infectious diseases but also for the effective prevention of epidemics.Successful cultivation is the gold standard for identifying a vir...Virus identification is a prerequisite not only for the early diagnosis of viral infectious diseases but also for the effective prevention of epidemics.Successful cultivation is the gold standard for identifying a virus,according to the Koch postulates.However,this requires screening for a permissive cell line,which is traditionally time-,reagent-and labor-intensive.Here,a simple and easy-to-operate microfluidic chip,formed by seeding a variety of cell lines and culturing them in parallel,is reported for use in virus cultivation and virus-permissive host-cell screening.The chip was tested by infection with two known viruses,enterovirus 71(EV71)and influenza virus H1N1.Infection with EV71 and H1N1 caused significant cytopathic effects(CPE)in RD and MDCK cells,respectively,demonstrating that virus cultivation based on this microfluidic cell chip can be used as a substitute for the traditional plate-based culture method and reproduce the typical CPE caused by virus infection.Using this microfluidic cell chip method for virus cultivation could make it possible to identify an emerging virus in a highthroughput,automatic,and unprecedentedly fast way.展开更多
基金Supported by the National Natural Science Foundation of China(No.20872048)
文摘Current serum neutralization assays based on the inhibition of the cytopathic effect(Nt-CPE) need to ma nipulate live viruses, which are time-consuming, labor-intensive, and have the potential exposure to infectious agents, so a safe and objective assay via pseudovirus for the fast and efficient detection of enterovirus 71(EV71) neutralizing antibodies was developed. First, we generated EV71 pseudovirus containing firefly luciferase gene in place of the capsid gene P1 in EV71 genome. Vero cells infected with 200 CCID50(50% cell culture infective dose) of EV71 pseudovirus for 24 h were found to have the best performance. Seval sera were measured by EV71 pseudoparticle neutralization assay(Nt-PPN) and the conventional serological method Nt-CPE. Neutralizing antibody titers measured by Nt-PPN and those obtained by Nt-CPE demonstrate a high correlation between the two methods. Overall, the PPN assay represents a valid alternative to conventional serological methods for the evaluation of EV71 neutralizing anti bodies. This method can be used for detecting neutralizing antibodies of other picornaviruses, such as hepatitis A vi rus(HAV) and coxsackievirus 16(CVA16), and make it possible to determine whether there is cross-reactivity be tween EV71 and CVA16.
文摘目的对比了解2022—2023年新冠疫情期间及疫情后广州市和佛山市手足口病流行病学及非肠道病毒71型(enterovirus 71,EV71)非柯萨奇病毒A组16型(Coxsaekievirus group A 16,CA16)病毒的分子流行病学特征,为治疗和防控提供依据。方法运用荧光逆转录聚合酶链反应(RT-PCR)对2022—2023年疑似手足口病患者标本同时进行肠道病毒(enterovirus,EV)通用型、EV71、CA16检测,并选取EV71和CA16是阴性而EV通用型是阳性的标本进行型别鉴定,设计5′非编码区(UTR)引物,RT-PCR扩增后进行序列测定,序列用BLAST程序进行序列的EV型别确定。结果2022年,同时进行EV通用型、EV71、CA163种病毒检测的疑似手足口病例标本共362份,总阳性47份,阳性率为12.98%;其中EV71阳性0份;CA16阳性5份,占1.38%;非EV71非CA16的EV阳性标本42份,占11.60%。2023年,同时进行EV通用型、EV71、CA163种病毒检测的疑似手足口病标本有297份,总阳性100份,阳性率为33.67%,全年没有检出EV71,CA16全年检出率为2.36%(7/297),非EV71非CA16的EV阳性率为31.31%(93/297)。51份非EV71非CA16阳性标本的序列分析表明,2022—2023检出的非EV71非CA16的EV有9种型别,分别为:CA6、CA10、CA4、CA2、CA8、柯萨奇病毒B组5型(CB5)、CB2、CB3、埃可病毒30型(E30),其中CA6占主要,为27.45%(14/51),其次是CA10,占15.69%(8/51)。结论新冠疫情结束后的2023年比疫情期间的2022年EV阳性率高。2022—2023年手足口病主要以非EV71非CA16为主,序列分析表明非EV71非CA16病毒中以CA6和CA10为主,应加强对CA6、CA10为主要非EV71非CA16病毒进行研究及监测。
基金support was provided by the National Natural Science Foundation of China(81572052 and 82102473)Changzhou science and technology support plan(CE20225036,CJ20210141)Young Talent Development Plan of Changzhou Health Commission(2020-233).
文摘TANK-binding kinase 1(TBK1)is an essential protein kinase for activation of interferon regulatory factor 3(IRF3)and induction of the type I interferons(IFN-I).Although the biochemical regulation of TBK1 activation has been studied,little is known about how enterovirus 71(EV71)employs the deubiquitinases(DUBs)to regulate TBK1 activation for viral immune evasion.Here,we found that EV71 infection upregulated the expression of ubiquitinspecific protease 24(USP24).Further studies revealed that USP24 physically interacted with TBK1,and can reduce K63-linked polyubiquitination of TBK1.Knockdown of USP24 upregulated TBK1 K63-linked polyubiquitination,promoted the phosphorylation and nuclear translocation of IRF3,and in turn improved IFN-I production during EV71 infection.As a consequence,USP24 knockdown dramatically inhibited EV71 infection.This study revealed USP24 as a novel regulator of TBK1 activation,which promotes the understanding of immune evasion mechanisms of EV71 and could provide a potential strategy for treatment of EV71 infection.
基金supported the grants from National Key R&D Program of China (2022YFC2305305)by grants from consultancy project (2022-JB-06)by the Chinese Academy of Engineering (CAE)the Bill&Melinda Gates Foundation[Grant Number:INV-016826].
文摘Objective:To estimate the potential causal impact of Enterovirus A71(EV71)vaccination program on the reduction of EV71-infected hand,foot,and mouth disease(HFMD)in Zhejiang Province.Methods:We utilized the longitudinal surveillance dataset of HFMD and EV71 vaccination in Zhejiang Province during 2010-2019.We estimated vaccine efficacy using a Bayesian structured time series(BSTS)model,and employed a negative control outcome(NCO)model to detect unmeasured confounding and reveal potential causal association.Results:We estimated that 20,132 EV71 cases(95%CI:16,733,23,532)were prevented by vaccination program during 2017-2019,corresponding to a reduction of 29%(95%CI:24%,34%).The effectiveness of vaccination increased annually,with reductions of 11%(95%CI:6%,16%)in 2017 and 66%(95%CI:61%,71%)in 2019.Children under 5 years old obtained greater benefits compared to those over 5 years.Cities with higher vaccination coverage experienced a sharper EV71 reduction compared to those with lower coverage.The NCO model detected no confounding factors in the association between vaccination and EV71 cases reduction.
基金supported by grants from the National Key Research and Development Plan of China(Grant No.2021YFC2300700)the China Postdoctoral Science Foundation(No.2021M693363)the grants from Hubei Health Commission(No.WJ2021M027).
文摘Enterovirus 71(EV71)poses a serious threat to human health,with scattered outbreaks worldwide.There are several vaccines against a few EV71 strains but no efficient drug for the treatment of EV71 infection.Therefore,it is urgent and of significance to develop anti-EV71 drugs.Here,we found that PLX8394,a RAF inhibitor,possesses high antiviral activity against EV71 in vitro,being superior to the traditional clinical drug ribavirin.Moreover,PLX8394 exhibits broad-spectrum antiviral activity against enteroviruses.Notably,in a suckling mouse model,PLX8394 provided a 70%protection rate for EV71-infected mice,reduced the viral load in liver and heart tissues,and relieved the inflammatory response.A mechanistic study showed that PLX8394 inhibited EV71 by suppressing the RAF/MEK/ERK signaling pathway.Thus,PLX8394 lays a foundation for the development of new drugs against EV71.
基金supported by the National Natural Science Foundation of China(Nos.81973221 and 81603647)the Innovation Team of the“Double-First Class”Disciplines(No.CPU2018GF08)+2 种基金the Medical Science and Technology Development Foundation of Nanjing Medical University(No.2017NJMUZD055)High-Level Talents in Six Industries in Jiangsu(No.SWYY010)Young and Middle-aged Academic Leader for Universities of Qinglan Project of Jiangsu(No.1170040009)。
文摘Enterovirus 71(EV71)infection is more likely to cause hand,foot and mouth disease(HFMD)in children,which can lead to neurogenic complications and higher mortality.As a commonly used clinical medicine,Reduning injection(RDN)helps to shorten the symptoms of patients with HFMD and facilitate the early recovery of children.However,the regulatory mechanism of RDN on the HFMD immune system disorder caused by EV71 remains to be discussed.This study collected detailed treatment data of56 children with HFMD who entered the affiliated Children’s Hospital of Nanjing Medical University during 2019.Retrospective analysis of clinical data showed that the symptoms of the RDN treatment group were improved compared with the untreated group.To explore its mechanism,the relevant detection indicators were detected by flow cytometry,enzyme-linked immunosorbent assay and realtime quantitative PCR.It was found that the number and function of innate immune(ILCs)and adaptive immunity(Th1,Th2 and secreted cytokines)were reduced,suggesting that RDN plays a role by regulating cellular immunity.The in vitro differentiation inhibition test further confirmed that RDN affected Th1 differentiation by inhibiting the expression of transcription factors on the basis of Th1 cell differentiation in vitro.
基金supported by funding from the National Key R&D Program of China (2021YFC2301900 and 2301904)National Natural Science Foundation of China (81930062)+2 种基金Science and Technology Department of Jilin Province (YDZJ202201ZYTS590)Health Commission of Jilin Province (2020J059)the Key Laboratory of Molecular Virology,Jilin Province (20102209)
文摘Enterovirus 71(EV71) caused hand, foot and mouth disease(HFMD) is a serious threat to the health of young children. Although type I interferon(IFN-I) has been proven to control EV71 replication, the key downstream IFNstimulated gene(ISG) remains to be clarified and investigated. Recently, we found that 2’-5’-oligoadenylate synthetases 3(OAS3), as one of ISG of IFN-β1b, was antagonized by EV71 3C protein. Here, we confirm that OAS3is the major determinant of IFN-β1b-mediated EV71 inhibition, which depends on the downstream constitutive RNase L activation. 2’-5’-oligoadenylate(2-5A) synthesis activity deficient mutations of OAS3 D816A, D818A,D888A, and K950A lost resistance to EV71 because they could not activate downstream RNase L. Further investigation proved that EV71 infection induced OAS3 but not RNase L expression by IFN pathway. Mechanically, EV71 or IFN-β1b-induced phosphorylation of STAT1, but not STAT3, initiated the transcription of OAS3 by directly binding to the OAS3 promoter. Our works elucidate the immune regulatory mechanism of the host OAS3/RNase L system against EV71 replication.
基金This study was supported by the National Science Foundation of China(81971976,81772236)Major Project of Technology Innovation Program of Hubei Province(2018ACA123)。
文摘Similar to that of other enteroviruses, the replication of enterovirus 71(EV71) occurs on rearranged membranous structures called replication organelles(ROs). Phosphatidylinositol 4-kinase Ⅲ(PI4KB), which is required by enteroviruses for RO formation, yields phosphatidylinositol-4-phosphate(PI4P) on ROs. PI4P then binds and induces conformational changes in the RNA-dependent RNA polymerase(Rd Rp) to modulate Rd Rp activity. Here, we targeted 3D polymerase, the core enzyme of EV71 ROs, and found that the host factor Annexin A2(ANXA2) can interact with 3 D polymerase and promote the replication of EV71. Then, an experiment showed that the annexin domain of ANXA2, which possesses membranebinding capacity, mediates the interaction of ANXA2 with EV71 3 D polymerase. Further research showed that ANXA2 is localized on ROs and interacts with PI4KB. Overexpression of ANXA2 stimulated the formation of PI4P, and the level of PI4P was decreased in ANXA2-knockout cells. Furthermore, ANXA2, PI4KB, and 3D were shown to be localized to the viral RNA replication site, where they form a higher-order protein complex, and the presence of ANXA2 promoted the PI4 KB-3D interaction. Altogether, our data provide new insight into the role of ANXA2 in facilitating formation of the EV71 RNA replication complex.
基金supported by the National Natural Science Foundation of China(Grant No.31770184)
文摘The Enterovirus 71(EV71)VP4 is co-translationally linked to myristic acid at its amino-terminal glycine residue.However,the role of this myristoylation in the EV71 life cycle remains largely unknown.To investigate this issue,we developed a myristoylation-deficient virus and reporter(luciferase)pseudovirus with a Gly-to-Ala mutation(G2A)on EV71 VP4.When transfecting the EV71-G2 A genome encoding plasmid in cells,the loss of myristoylation on VP4 did not affect the expression of viral proteins and the virus morphology,however,it did significantly influence viral infectivity.Further,in myristoylation-deficient reporter pseudovirus-infected cells,the luciferase activity and viral genome RNA decreased significantly as compared to that of wild type virus;however,cytopathic effect and viral capsid proteins were not detected in myristoylation-deficient virus-infected cells.Also,although myristoylation-deficient viral RNA and proteins were detected in the second blind passage of infection,they were much fewer in number compared to that of the wild type virus.The replication of genomic RNA and negative-strand viral RNA were both blocked in myristoylation-deficient viruses,suggesting that myristoylation affects viral genome RNA release from capsid to cytoplasm.Besides,loss of myristoylation on VP4 altered the distribution of VP4-green fluorescent protein protein,which disappeared from the membrane structure fraction.Finally,a liposome leakage assay showed that EV71 myristoylation mediates the permeability of the model membrane.Hence,the amino-terminal myristoylation of VP4 is pivotal to EV71 infection and capsidmembrane structure interaction.This study provides novel molecular mechanisms regarding EV71 infection and potential molecular targets for antiviral drug design.
基金the Scientific Instrument Developing Project of the Chinese Academy of Sciences(No.YJKYYQ20190057)the National Nature Science Foundation of China(No.81827804)+1 种基金the CAS Emergency Project of ASF Research(No.KJZDSW-L06-02)Applied Basic Research Program of Wuhan(No.2018060401011327)。
文摘Virus identification is a prerequisite not only for the early diagnosis of viral infectious diseases but also for the effective prevention of epidemics.Successful cultivation is the gold standard for identifying a virus,according to the Koch postulates.However,this requires screening for a permissive cell line,which is traditionally time-,reagent-and labor-intensive.Here,a simple and easy-to-operate microfluidic chip,formed by seeding a variety of cell lines and culturing them in parallel,is reported for use in virus cultivation and virus-permissive host-cell screening.The chip was tested by infection with two known viruses,enterovirus 71(EV71)and influenza virus H1N1.Infection with EV71 and H1N1 caused significant cytopathic effects(CPE)in RD and MDCK cells,respectively,demonstrating that virus cultivation based on this microfluidic cell chip can be used as a substitute for the traditional plate-based culture method and reproduce the typical CPE caused by virus infection.Using this microfluidic cell chip method for virus cultivation could make it possible to identify an emerging virus in a highthroughput,automatic,and unprecedentedly fast way.