Flaviviruses,which include globally impactful pathogens,such as West Nile virus,yellow fever virus,Zika virus,Japanese encephalitis virus,and dengue virus,contribute significantly to human infections.Despite the ongoi...Flaviviruses,which include globally impactful pathogens,such as West Nile virus,yellow fever virus,Zika virus,Japanese encephalitis virus,and dengue virus,contribute significantly to human infections.Despite the ongoing emergence and resurgence of flavivirus-mediated pathogenesis,the absence of specific therapeutic options remains a challenge in the prevention and treatment of flaviviral infections.Through the intricate processes of fusion,transcription,replication,and maturation,the complex interplay of viral and host metabolic interactions affects pathophysiology.Crucial interactions involve metabolic molecules,such as amino acids,glucose,fatty acids,and nucleotides,each playing a pivotal role in the replication and maturation of flaviviruses.These viral-host metabolic molecular interactions hijack and modulate the molecular mechanisms of host metabolism.A comprehensive understanding of these intricate metabolic pathways offers valuable insights,potentially unveiling novel targets for therapeutic interventions against flaviviral pathogenesis.This review emphasizes promising avenues for the development of therapeutic agents that target specific metabolic molecules,such as amino acids,glucose,fatty acids,and nucleotides,which interact with flavivirus replication and are closely linked to the modulation of host metabolism.The clinical limitations of current drugs have prompted the development of new inhibitory strategies for flaviviruses based on an understanding of the molecular interactions between the virus and the host.展开更多
Flaviviruses,such as dengue virus(DENV),Zika virus(ZIKV),and Japanese encephalitis virus(JEV),represent a substantial public health challenge as there are currently no approved treatments available.Here,we investigate...Flaviviruses,such as dengue virus(DENV),Zika virus(ZIKV),and Japanese encephalitis virus(JEV),represent a substantial public health challenge as there are currently no approved treatments available.Here,we investigated the antiviral effects of bis-benzylisoquinoline alkaloids(BBAs)on flavivirus infections.We evaluated five specific BBAs—berbamine,tetrandrine,iso-tetrandrine,fangchinoline,and cepharanthine—and found that they effectively inhibited infections by ZIKV,DENV,or JEV by blocking virus entry and genome replication stages in the flavivirus life cycle.Furthermore,we synthesized a fluorophore-conjugated BBA and showed that BBAs targeted endolysosomes,causing lysosomal pH alkalization.Mechanistic studies on inhibiting ZIKV infection by BBAs revealed that these compounds blocked TRPML channels,leading to lysosomal dysfunction and reducing the expression of NCAM1,a key receptor for the entry of ZIKV into cells,thereby decreasing cells susceptibility to ZIKV infection.Additionally,BBAs inhibited the fusion of autophagosomes and lysosomes,significantly reducing viral RNA replication.Collectively,our results suggest that BBAs inhibit flavivirus entry and replication by compromising endolysosomal trafficking and autophagy,respectively,underscoring the potential of BBAs as therapeutic agents against flavivirus infections.展开更多
The family of flaviviruses is one of the most medically important groups of emerging arthropod-borne viruses. Host cell cytoskeletons have been reported to have close contact with flaviviruses during virus entry, intr...The family of flaviviruses is one of the most medically important groups of emerging arthropod-borne viruses. Host cell cytoskeletons have been reported to have close contact with flaviviruses during virus entry, intracellular transport, replication, and egress process, although many detailed mechanisms are still unclear. This article provides a brief overview of the function of the most prominent flaviviruses-induced or-hijacked cytoskeletal structures including actin, microtubules and intermediate filaments, mainly focus on infection by dengue virus, Zika virus and West Nile virus. We suggest that virus interaction with host cytoskeleton to be an interesting area of future research.展开更多
In order to establish double antibody sandwich enzyme-linked immunosorbent assay （DAS-ELISA） for detection of duck or goose flavivirus, polyclonal antibody against the flavivirus strain JS804 in geese and monoclonal...In order to establish double antibody sandwich enzyme-linked immunosorbent assay （DAS-ELISA） for detection of duck or goose flavivirus, polyclonal antibody against the flavivirus strain JS804 in geese and monoclonal antibody against the E protein of flavivirus strain JS804 in geese were used as the capture antibody and detection antibody, respectively. The optimal dilution of the capture antibody and detecting antibody capable of detecting the flavivirus strain JS804 in geese were 1：3 200 and 1：160 in the check-board titration, respectively. The reaction time of sample was 1 h, and the optimal working dilution of HRP-labeled goat-anti-mouse IgG was 1：10 000. The positive standard value was 0.247 （OD450.m）. The geese flavivirus could be detected at a minimal concentration of 1.875 μg mL^-1. The ELISA had no cross-reaction with Newcastle disease virus （NDV）, Avian influenza virus （AIV）, Infectious bronchitis virus （IBV）, Infectious bursal disease virus （IBDV）, Duck hepatitis virus （DHV）, and Gosling plague virus （GPV）. Twenty clinical samples were detected by the DAS-ELISA and RT-PCR respectively, with the agreement rate of 75%. The results revealed that the DAS-ELISA possessed favorable specificity and higher sensitivity, indicating a suitable method for rapid detection of the duck or goose flavivirus.展开更多
Many flaviviruses are significant human pathogens causing considerable disease burdens,including encephalitis and hemorrhagic fever,in the regions in which they are endemic.A paucity of treatments for flaviviral infec...Many flaviviruses are significant human pathogens causing considerable disease burdens,including encephalitis and hemorrhagic fever,in the regions in which they are endemic.A paucity of treatments for flaviviral infections has driven interest in drug development targeting proteins essential to flavivirus replication,such as the viral protease.During viral replication,the flavivirus genome is translated as a single polyprotein precursor,which must be cleaved into individual proteins by a complex of the viral protease,NS3,and its cofactor,NS2B.Because this cleavage is an obligate step of the viral life-cycle,the flavivirus protease is an attractive target for antiviral drug development.In this review,we will survey recent drug development studies targeting the NS3 active site,as well as studies targeting an NS2B/NS3interaction site determined from flavivirus protease crystal structures.展开更多
Many flaviviruses are emerging and reemerging pathogens, such as West Nile virus （WNV）, dengue virus （DENV）, yellow fever virus （YFV）, and Japanese encephalitis virus. Serological assay is the dominant method fo...Many flaviviruses are emerging and reemerging pathogens, such as West Nile virus （WNV）, dengue virus （DENV）, yellow fever virus （YFV）, and Japanese encephalitis virus. Serological assay is the dominant method for diagnosis of flavivirus infections in human. Because antibodies generated during flavivirus infections cross-react with other flavivirus members, plaque reduction neutralization test （PRNT） is the only available assay to determine the infecting flavivirus type. Since PRNT requires culturing raw viruses, it must be performed in biosafety levet-3 or level-4 containment for many flaviviruses, and takes more than ten days to complete. To overcome these problems, we have developed flavivirus viral-like particles （VLPs） that could be used to replace raw viruses in the neutralization assay. The VLPs were prepared by trans packaging a luciferase-reporting replicon with viral structural proteins. This novel assay involves three simple steps： （i） VLPs from a panel of flaviviruses are incubated with flavivirus-infected sera at 37℃ for 1 h; （ii）the neutralized VLPs are used to infect Vero cells; and （iii） the infected cells are measured for luciferase activities at 22 h post-infection. The virus type whose VLP is most efficiently neutralized by the serum specimen （as quantified by the luciferase activities） is the etiologic agent. As a proof-of-concept, we show that a WNV-infected mouse serum neutralized the WNV VLP more efficiently and selectively than the DENV and YFV VLPs. Our results demonstrate that the VLP neutralization assay maintains the ＂gold standard＂ of the classic PRNT; importantly, it shortens the assay time from 〉10 days to 〈1 day, and can be performed in biosafety level-2 facility.展开更多
Based on the Culex flavivirus (CxFV) E gene sequences in GenBank, CxFV-specific primers and probes were designed for real-time reverse transcription-polymerase chain reaction (RT-qPCR). The specificity test revealed t...Based on the Culex flavivirus (CxFV) E gene sequences in GenBank, CxFV-specific primers and probes were designed for real-time reverse transcription-polymerase chain reaction (RT-qPCR). The specificity test revealed that CxFV could be detected using RT-qPCR with the specific CxFV primers and probes; other species of arboviruses were not detected. The stability test demonstrated a coefficient of variation of <1.5%. A quantitative standard curve for CxFV RT-qPCR was established. Quantitative standard curve analysis revealed that the lower detection limit of the RT-qPCR system is 100 copies/mu L. Moreover, RT-qPCR was used to detect CxFV viral RNA in mosquito pool samples. In conclusion, we established a real-time RT-PCR assay for CxFV detection, and this assay is more sensitive and efficient than general RT-PCR. This technology may be used to monitor changes in the environmental virus levels.展开更多
Flaviviruses are a genus of mostly arthropod-borne RNA viruses that cause a range of pathologies in humans.Basic knowledge on flaviviruses is rapidly expanding,partly due to their status as frequent emerging or re-eme...Flaviviruses are a genus of mostly arthropod-borne RNA viruses that cause a range of pathologies in humans.Basic knowledge on flaviviruses is rapidly expanding,partly due to their status as frequent emerging or re-emerging pathogens.Flaviviruses include the dengue,Zika,West Nile,tick-borne encephalitis and yellow fever viruses(DENV,ZIKV,WNV,TBEV and YFV,respectively).As is the case with other families of viruses,the success of productive infection of human cells by flaviviruses depends in part on the antiviral activity of a heterogeneous group of cellular antiviral proteins called restriction factors.Restriction factors are the effector proteins of the cell-autonomous innate response against viruses,an immune pathway that also includes virus sensors as well as intracellular and extracellular signal mediators such as type I interferons(IFN-I).In this review,I summarize recent progress toward the identification and characterization of flavivirus restriction factors.In particular,I focus on IFI6,Schlafen 11,FMRP,OAS-RNase L,RyDEN,members of the TRIM family of proteins(TRIM5α,TRIM19,TRIM56,TRIM69 and TRIM79α)and a new mechanism of action proposed for viperin.Recent and future studies on this topic will lead to a more complete picture of the flavivirus restrictome,defined as the ensemble of cellular factors with demonstrated anti-flaviviral activity.展开更多
Flaviviruses, ss(+) RNA viruses, include many of mankind's most important pathogens. Their pathogenicity derives from their ability to infect many types of cells including neurons, to replicate, and eventually to ...Flaviviruses, ss(+) RNA viruses, include many of mankind's most important pathogens. Their pathogenicity derives from their ability to infect many types of cells including neurons, to replicate, and eventually to kill the cells. Flaviviruses can activate tumor necrosis factor α and both intrinsic(Bax-mediated) and extrinsic pathways to apoptosis. Thus they can use many approaches for activating these pathways. Infection can lead to necrosis if viral load is extremely high or to other types of cell death if routes to apoptosis are blocked. Dengue and Japanese Encephalitis Virus can also activate autophagy. In this case the autophagy temporarily spares the infected cell, allowing a longer period of reproduction for the virus, and the autophagy further protects the cell against other stresses such as those caused by reactive oxygen species. Several of the viral proteins have been shown to induce apoptosis or autophagy on their own, independent of the presence of other viral proteins. Given the versatility of these viruses to adapt to and manipulate the metabolism, and thus to control the survival of, the infected cells, we need to understand much better how the specific viral proteins affect the pathways to apoptosis and autophagy. Only in this manner will we be able to minimize the pathology that they cause.展开更多
Flaviviruses are a group of positive-stranded RNA viruses that cause a broad spectrum of severe illnesses in humans worldwide.Clinical manifestations of flavivirus infections range from mild febrile illness to hemorrh...Flaviviruses are a group of positive-stranded RNA viruses that cause a broad spectrum of severe illnesses in humans worldwide.Clinical manifestations of flavivirus infections range from mild febrile illness to hemorrhage,shock,and neurological manifestations.Flavivirus infections cause a substantial global health impact,with an estimated more than 400 million cases of infections annually.Hence,an understanding of flavivirus-host interaction is urgently needed for new antiviral therapeutic strategies.In recent years,many aspects concerning epigenetic therapy for viral infections have been addressed,including methylation of the genome,acetylation/deacetylation of histone complex and microRNA regulation.In this context,we surveyed and reviewed the literature and summarized the epigenetic effects of resveratrol,a natural polyphenol with potential anti-viral properties,on flavivirus infections.展开更多
[ Objective] Aim to establish a kind of efficient detection method for duck flavivirus（DFV）. E Method] The method of nested PCR based on flavivirus universal primers which were designed according to the GeneBank fla...[ Objective] Aim to establish a kind of efficient detection method for duck flavivirus（DFV）. E Method] The method of nested PCR based on flavivirus universal primers which were designed according to the GeneBank flavivirus gene sequence. [ Result] The degenerate universal prim ers Flav P1 -Flav P4 were designed by genome comparison to target NS5 gene conserved area. The system could only amplify flavivirus purpose gene and the sensitivity was 90 copies/iJL, higher than the ordinary PCR 1 000 times. Homology and evolutionary analysis showed that duck flavivirus belonged to mosquito-born flavivirus, NTAV group, similar with Tembusu and BYD virus. [ Conclusion] Primers of the nested PCR system had good universality and specificity and method had high sensitivity. This system successfully detected flavivirus and clarified the evolution station of DFV.展开更多
Flaviviruses are important arthropod-borne pathogens that represent an immense global health problem.Their unprecedented epidemic rate and unpredictable clinical features underscore an urgent need for antiviral interv...Flaviviruses are important arthropod-borne pathogens that represent an immense global health problem.Their unprecedented epidemic rate and unpredictable clinical features underscore an urgent need for antiviral interventions.Dehydroepiandrosterone(DHEA)is a natural occurring adrenal-derived steroid in the human body that has been associated in protection against various infections.In the present study,the plaque assay based primary screening was conducted on 32 synthetic derivatives of DHEA against Japanese encephalitis virus(JEV)to identify potent anti-flaviviral compounds.Based on primary screening,HAAS-AV3026 and HAAS-AV3027 were selected as hits from DHEA derivatives that exhibited strong antiviral activity against JEV(IC_(50)=2.13 and 1.98μmol/L,respectively)and Zika virus(ZIKV)(IC_(50)=3.73 and 3.42μmol/L,respectively).Mechanism study indicates that HAAS-AV3026 and HAAS-AV3027 do not exhibit inhibitory effect on flavivirus binding and entry process,while significantly inhibit flavivirus infection at the replication stage.Moreover,indirect immunofluorescence assay,Western blot analyses,and quantitative reverse transcription-PCR(qRT-PCR)revealed a potent antiviral activity of DHEA derivatives hits against JEV and ZIKV in terms of inhibition of viral infection,protein production,and viral RNA synthesis in Vero cells.Taken together,our results may provide a basis for the development of new antivirals against flaviviruses.展开更多
[ Objective] This experiment aimed to find out the origin and genetic evolution relationship of chicken flavivirus （CFV） CJD05 strain in Fujian Province. [Method] A pair of primers were designed and synthesized acco...[ Objective] This experiment aimed to find out the origin and genetic evolution relationship of chicken flavivirus （CFV） CJD05 strain in Fujian Province. [Method] A pair of primers were designed and synthesized according to the sequences of E gene from Duck flavivirus （DFV） iso- late BYD-1. E gene of CFV isolate CJD05 was specially amplified and its sequences were analyzed. [Result] The target bar which was cloned from CFV isolate C, JD05 was I 503 bp. Homology analysis was conducted to compare E gene nucleotide sequence of CFV isolate CJD05 with DFV iso- late BYD-I and goose flavivirus （GFV） isolate JS804. Results indicated that isolate nuclectide homologies were 99.2% and 99.3%, and amino acid homologies were 99.0% and 98.6% respectively. [Conclusion] CFV isolate C, JD05, DFV isolate BYD-1 and GFV isolate JS804 were highly homologous. The homology of CFV isolate CJD05 with Tembusu virus （TMUV） was higher than with other arthropod-borne flaviviruses.展开更多
A severe egg-drop disease caused by the infection of a novel duck flavivirus outbroke successively in many provinces in southeastern China since 2010.It was identified as a duck Tembusu virus（DTMUV）and named by Chin...A severe egg-drop disease caused by the infection of a novel duck flavivirus outbroke successively in many provinces in southeastern China since 2010.It was identified as a duck Tembusu virus（DTMUV）and named by Chinese Association of Animal Science and Veterinary Medicine in the first symposium on waterfowl disease control,which was presumed to be a mosquito-borne flavivirus of the Ntaya virus subgroup in the genus Flavivirus,family Flaviviridae.Currently,a large number of studies have been conducted on the epidemiology,clinical symptoms and pathological changes,etiology,and rapid diagnoses of the virus.The disease remains a constant threat to the duck industry.In order to provide reference for subsequent in-depth study,in this paper,research progress on the disease was summarized based on previous studies.Furthermore,the potential infection or asymptomatic infection in humans should be evaluated as soon as possible.展开更多
The aim of this study is to explore the phylogenetic relationship of flaviviruses with the known viruses and to establish a rapid PCR-based method for the characterization of the flaviviruses. To this end, phylogeneti...The aim of this study is to explore the phylogenetic relationship of flaviviruses with the known viruses and to establish a rapid PCR-based method for the characterization of the flaviviruses. To this end, phylogenetic analysis of 25 different strains of flaviviruses was carried out on the basis of the full length genomic sequences as well as the sequences of the individual genes and their untranslated regions (UTRs). From this analysis and the extensive sequence alignment studies, a generic primer pair was identified for amplification of a highly conserved region in the NS5 gene, a molecular marker designed as NS5MM in this study, which was different from NS5 region used previously by other groups. This generic primer pair had been validated by using 22 different strains of flaviviruses in the present study. Furthermore, we have successfully applied this new approach to the rapid identification and characterization of 3 new strains of flaviviruses recently isolated in China.展开更多
There are no approved flaviviral therapies and the development of vaccines against flaviruses has the potential of being undermined by antibody-dependent enhancement(ADE).The flavivirus nonstructural protein 1(NS1)is ...There are no approved flaviviral therapies and the development of vaccines against flaviruses has the potential of being undermined by antibody-dependent enhancement(ADE).The flavivirus nonstructural protein 1(NS1)is a promising vaccine antigen with low ADE risk but has yet to be explored as a broad-spectrum therapeutic antibody target.Here,we provide the structural basis of NS1 antibody cross-reactivity through cocrystallization of the antibody 1G5.3 with NS1 proteins from dengue and Zika viruses.展开更多
Various lipid metabolism-related factors are essential for Zika virus(ZIKV)replication.In this study,we revealed a crucial role of diacylglycerol O-acyltransferase 2(DGAT2)in ZIKV replication using a short hairpin RNA...Various lipid metabolism-related factors are essential for Zika virus(ZIKV)replication.In this study,we revealed a crucial role of diacylglycerol O-acyltransferase 2(DGAT2)in ZIKV replication using a short hairpin RNA-based gene knockdown technique.The replication of ZIKV was significantly inhibited by DGAT2 depletion in multiple cell lines and restored by trans-complementation with DGAT2.Mechanistically,DGAT2 is recruited in the viral replication complex by interacting with non-structural(NS)proteins.Among them,both human and murine DGAT2s can be cleaved by NS2B3 at the 122R-R-S124 site.Interestingly,the cleavage product of DGAT2 becomes more stable and is sufficient to promote the lipid droplet(LD)formation independent of its enzymatic activity.This work identifies DGAT2 as a novel target of the viral protease NS2B3 and elucidates that DGAT2 is recruited by viral proteins into the replication complex,thereby playing a proviral role by promoting LD formation,which advances our understanding of host–flavivirus interaction.展开更多
Flaviviruses are zoonotic pathogens transmitted by infected mosquitoes and ticks,posing a persistent threat to global health.These infections lead to a diverse spectrum of diseases,broadly classified into two phenotyp...Flaviviruses are zoonotic pathogens transmitted by infected mosquitoes and ticks,posing a persistent threat to global health.These infections lead to a diverse spectrum of diseases,broadly classified into two phenotypes:systemic hemorrhagic conditions,such as dengue and yellow fever,and neurological complications,exemplified by West Nile virus(WNV)and Zika virus(ZIKV)infections.The interactions between flaviviruses and human host cells are pivotal to the viral lifecycle and the activation of host immunity.Investigating the molecular mechanisms of flavivirus-host interactions is essential for understanding viral pathogenesis,managing epidemics,optimizing therapeutic strategies,and enhancing public health security.Flaviviruses utilize various strategies to evade the host immune system,and understanding these mechanisms is critical for the development of antiviral therapeutics.This study employs bibliometric methods,leveraging CiteSpace and vOSviewer software,to analyze literature on flavivirus-host interactions and the associated immune responses.By examining developmental trends and pivotal research areas,this analysis provides insights and guidance for future studies in this field.展开更多
Flaviviruses affect the lives of millions of people in endemic regions and also have the potential to impact nonendemic areas.Factors such as climate change,global warming,deforestation,and increased travel and trade ...Flaviviruses affect the lives of millions of people in endemic regions and also have the potential to impact nonendemic areas.Factors such as climate change,global warming,deforestation,and increased travel and trade are linked to the spread of flaviviruses into new habitats and host species.Given the absence of specific treatments and the limited availability of vaccines,it is imperative to understand the biology of flaviviruses and develop rapid and sensitive diagnostic tests.These measures are essential for preventing the transmission of these potentially life-threatening pathogens.Flavivirus infections are mainly diagnosed using conventional methods.However,these techniques present several drawbacks,including high expenses,time-consuming procedures,and the need for skilled professionals.The search for fast,easy-to-use,and affordable alternative techniques as a feasible solution for developing countries is leading to the search for new methods in the diagnosis of flavivi-ruses,such as biosensors.This review provides a comprehensive overview of different biosensor detection strategies for flaviviruses and describes recent advances in diagnostic technologies.Finally,we explore their future prospects and potential applications in pathogen detection.This review serves as a valuable resource to understand advances in ongoing research into new biosensor-based diagnostic methods for flaviviruses.展开更多
Arboviral diseases are viral infections transmitted to humans through the bites of arthropods,such as mosquitoes,often causing a variety of pathologies associated with high levels of morbidity and mortality.Over the p...Arboviral diseases are viral infections transmitted to humans through the bites of arthropods,such as mosquitoes,often causing a variety of pathologies associated with high levels of morbidity and mortality.Over the past decades,these infections have proven to be a significant challenge to health systems worldwide,particularly following the considerable geographic expansion of the dengue virus(DENV)and its most recent outbreak in Latin America as well as the difficult-tocontrol outbreaks of yellow fever virus(YFV),chikungunya virus(CHIKV),and Zika virus(ZIKV),leaving behind a substantial portion of the population with complications related to these infections.Currently,the world is experiencing a period of intense globalization,which,combined with global warming,directly contributes to wider dissemination of arbovirus vectors across the globe.Consequently,all continents remain on high alert for potential new outbreaks.Thus,this review aims to provide a comprehensive understanding of the pathogenesis of the four main arboviruses today(DENV,ZIKV,YFV,and CHIKV)discussing their viral characteristics,immune responses,and mechanisms of viral evasion,as well as important clinical aspects for patient management.This includes associated symptoms,laboratory tests,treatments,existing or developing vaccines and the main associated complications,thus integrating a broad historical,scientific and clinical approach.展开更多
基金Supported by The South Korea Health Technology R and D Project through the South Korea Health Industry Development Institute,Funded by the Ministry of Health and Welfare,South Korea,No.HF20C0020.
文摘Flaviviruses,which include globally impactful pathogens,such as West Nile virus,yellow fever virus,Zika virus,Japanese encephalitis virus,and dengue virus,contribute significantly to human infections.Despite the ongoing emergence and resurgence of flavivirus-mediated pathogenesis,the absence of specific therapeutic options remains a challenge in the prevention and treatment of flaviviral infections.Through the intricate processes of fusion,transcription,replication,and maturation,the complex interplay of viral and host metabolic interactions affects pathophysiology.Crucial interactions involve metabolic molecules,such as amino acids,glucose,fatty acids,and nucleotides,each playing a pivotal role in the replication and maturation of flaviviruses.These viral-host metabolic molecular interactions hijack and modulate the molecular mechanisms of host metabolism.A comprehensive understanding of these intricate metabolic pathways offers valuable insights,potentially unveiling novel targets for therapeutic interventions against flaviviral pathogenesis.This review emphasizes promising avenues for the development of therapeutic agents that target specific metabolic molecules,such as amino acids,glucose,fatty acids,and nucleotides,which interact with flavivirus replication and are closely linked to the modulation of host metabolism.The clinical limitations of current drugs have prompted the development of new inhibitory strategies for flaviviruses based on an understanding of the molecular interactions between the virus and the host.
基金supported by the National Key Research and Development Program of China(2022YFD1800100)the National Natural Science Foundation of China(32302843,32070702,and 82161128014)+5 种基金GuangDong Basic and Applied Basic Research Foundation(2023A1515010748)Innovation and Technology Fund of Hong Kong(MRP/064/21,GHP/097/20GD,and MHP/072/21)Hong Kong Research Grant Council(RGC)grant(11103620 and 11104422)research grants from Shenzhen Science and Technology Innovation Committee(SGDX20201103093201010 and JCYJ20210324134007020)Kunshan Shuang Chuang Grant(kssc202302073)the Kunshan Municipal Government research funding。
文摘Flaviviruses,such as dengue virus(DENV),Zika virus(ZIKV),and Japanese encephalitis virus(JEV),represent a substantial public health challenge as there are currently no approved treatments available.Here,we investigated the antiviral effects of bis-benzylisoquinoline alkaloids(BBAs)on flavivirus infections.We evaluated five specific BBAs—berbamine,tetrandrine,iso-tetrandrine,fangchinoline,and cepharanthine—and found that they effectively inhibited infections by ZIKV,DENV,or JEV by blocking virus entry and genome replication stages in the flavivirus life cycle.Furthermore,we synthesized a fluorophore-conjugated BBA and showed that BBAs targeted endolysosomes,causing lysosomal pH alkalization.Mechanistic studies on inhibiting ZIKV infection by BBAs revealed that these compounds blocked TRPML channels,leading to lysosomal dysfunction and reducing the expression of NCAM1,a key receptor for the entry of ZIKV into cells,thereby decreasing cells susceptibility to ZIKV infection.Additionally,BBAs inhibited the fusion of autophagosomes and lysosomes,significantly reducing viral RNA replication.Collectively,our results suggest that BBAs inhibit flavivirus entry and replication by compromising endolysosomal trafficking and autophagy,respectively,underscoring the potential of BBAs as therapeutic agents against flavivirus infections.
基金supported by Collaborative Research Grant (KLMVI-OP-201904) of CAS Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciencesthe starting Grant of Institut Pasteur of Shanghai (1185170000), Chinese Academy of Sciences
文摘The family of flaviviruses is one of the most medically important groups of emerging arthropod-borne viruses. Host cell cytoskeletons have been reported to have close contact with flaviviruses during virus entry, intracellular transport, replication, and egress process, although many detailed mechanisms are still unclear. This article provides a brief overview of the function of the most prominent flaviviruses-induced or-hijacked cytoskeletal structures including actin, microtubules and intermediate filaments, mainly focus on infection by dengue virus, Zika virus and West Nile virus. We suggest that virus interaction with host cytoskeleton to be an interesting area of future research.
基金supported by the National Natural Science Foundation of China (31172345)the Jiangsu Provincial Agricultural Science and Technology InnovationFoundation, China (cx(11)4039)
文摘In order to establish double antibody sandwich enzyme-linked immunosorbent assay （DAS-ELISA） for detection of duck or goose flavivirus, polyclonal antibody against the flavivirus strain JS804 in geese and monoclonal antibody against the E protein of flavivirus strain JS804 in geese were used as the capture antibody and detection antibody, respectively. The optimal dilution of the capture antibody and detecting antibody capable of detecting the flavivirus strain JS804 in geese were 1：3 200 and 1：160 in the check-board titration, respectively. The reaction time of sample was 1 h, and the optimal working dilution of HRP-labeled goat-anti-mouse IgG was 1：10 000. The positive standard value was 0.247 （OD450.m）. The geese flavivirus could be detected at a minimal concentration of 1.875 μg mL^-1. The ELISA had no cross-reaction with Newcastle disease virus （NDV）, Avian influenza virus （AIV）, Infectious bronchitis virus （IBV）, Infectious bursal disease virus （IBDV）, Duck hepatitis virus （DHV）, and Gosling plague virus （GPV）. Twenty clinical samples were detected by the DAS-ELISA and RT-PCR respectively, with the agreement rate of 75%. The results revealed that the DAS-ELISA possessed favorable specificity and higher sensitivity, indicating a suitable method for rapid detection of the duck or goose flavivirus.
基金supported by grants(AI094335) from the National Institute of Health and from the Wadsworth Center Scientific Interaction Group
文摘Many flaviviruses are significant human pathogens causing considerable disease burdens,including encephalitis and hemorrhagic fever,in the regions in which they are endemic.A paucity of treatments for flaviviral infections has driven interest in drug development targeting proteins essential to flavivirus replication,such as the viral protease.During viral replication,the flavivirus genome is translated as a single polyprotein precursor,which must be cleaved into individual proteins by a complex of the viral protease,NS3,and its cofactor,NS2B.Because this cleavage is an obligate step of the viral life-cycle,the flavivirus protease is an attractive target for antiviral drug development.In this review,we will survey recent drug development studies targeting the NS3 active site,as well as studies targeting an NS2B/NS3interaction site determined from flavivirus protease crystal structures.
基金supported by National Institute of Health grants U01 AI061193 and U54-AI057158 (Northeast Biodefense Center).
文摘Many flaviviruses are emerging and reemerging pathogens, such as West Nile virus （WNV）, dengue virus （DENV）, yellow fever virus （YFV）, and Japanese encephalitis virus. Serological assay is the dominant method for diagnosis of flavivirus infections in human. Because antibodies generated during flavivirus infections cross-react with other flavivirus members, plaque reduction neutralization test （PRNT） is the only available assay to determine the infecting flavivirus type. Since PRNT requires culturing raw viruses, it must be performed in biosafety levet-3 or level-4 containment for many flaviviruses, and takes more than ten days to complete. To overcome these problems, we have developed flavivirus viral-like particles （VLPs） that could be used to replace raw viruses in the neutralization assay. The VLPs were prepared by trans packaging a luciferase-reporting replicon with viral structural proteins. This novel assay involves three simple steps： （i） VLPs from a panel of flaviviruses are incubated with flavivirus-infected sera at 37℃ for 1 h; （ii）the neutralized VLPs are used to infect Vero cells; and （iii） the infected cells are measured for luciferase activities at 22 h post-infection. The virus type whose VLP is most efficiently neutralized by the serum specimen （as quantified by the luciferase activities） is the etiologic agent. As a proof-of-concept, we show that a WNV-infected mouse serum neutralized the WNV VLP more efficiently and selectively than the DENV and YFV VLPs. Our results demonstrate that the VLP neutralization assay maintains the ＂gold standard＂ of the classic PRNT; importantly, it shortens the assay time from 〉10 days to 〈1 day, and can be performed in biosafety level-2 facility.
基金supported by grants from the Development Grant of State Key Laboratory of Infectious Disease Prevention and Control(2012SKLID204,2015SKLID505)the Ministry of Science and Technology of People’s Republic of China(No.2013ZX10004101)
文摘Based on the Culex flavivirus (CxFV) E gene sequences in GenBank, CxFV-specific primers and probes were designed for real-time reverse transcription-polymerase chain reaction (RT-qPCR). The specificity test revealed that CxFV could be detected using RT-qPCR with the specific CxFV primers and probes; other species of arboviruses were not detected. The stability test demonstrated a coefficient of variation of <1.5%. A quantitative standard curve for CxFV RT-qPCR was established. Quantitative standard curve analysis revealed that the lower detection limit of the RT-qPCR system is 100 copies/mu L. Moreover, RT-qPCR was used to detect CxFV viral RNA in mosquito pool samples. In conclusion, we established a real-time RT-PCR assay for CxFV detection, and this assay is more sensitive and efficient than general RT-PCR. This technology may be used to monitor changes in the environmental virus levels.
文摘Flaviviruses are a genus of mostly arthropod-borne RNA viruses that cause a range of pathologies in humans.Basic knowledge on flaviviruses is rapidly expanding,partly due to their status as frequent emerging or re-emerging pathogens.Flaviviruses include the dengue,Zika,West Nile,tick-borne encephalitis and yellow fever viruses(DENV,ZIKV,WNV,TBEV and YFV,respectively).As is the case with other families of viruses,the success of productive infection of human cells by flaviviruses depends in part on the antiviral activity of a heterogeneous group of cellular antiviral proteins called restriction factors.Restriction factors are the effector proteins of the cell-autonomous innate response against viruses,an immune pathway that also includes virus sensors as well as intracellular and extracellular signal mediators such as type I interferons(IFN-I).In this review,I summarize recent progress toward the identification and characterization of flavivirus restriction factors.In particular,I focus on IFI6,Schlafen 11,FMRP,OAS-RNase L,RyDEN,members of the TRIM family of proteins(TRIM5α,TRIM19,TRIM56,TRIM69 and TRIM79α)and a new mechanism of action proposed for viperin.Recent and future studies on this topic will lead to a more complete picture of the flavivirus restrictome,defined as the ensemble of cellular factors with demonstrated anti-flaviviral activity.
基金Supported by NIAID NIH grant to Zakeri Z,No.1R15AIO94351-01the NIH NIGMS(MARC-USTAR),No.T 34 GM070387
文摘Flaviviruses, ss(+) RNA viruses, include many of mankind's most important pathogens. Their pathogenicity derives from their ability to infect many types of cells including neurons, to replicate, and eventually to kill the cells. Flaviviruses can activate tumor necrosis factor α and both intrinsic(Bax-mediated) and extrinsic pathways to apoptosis. Thus they can use many approaches for activating these pathways. Infection can lead to necrosis if viral load is extremely high or to other types of cell death if routes to apoptosis are blocked. Dengue and Japanese Encephalitis Virus can also activate autophagy. In this case the autophagy temporarily spares the infected cell, allowing a longer period of reproduction for the virus, and the autophagy further protects the cell against other stresses such as those caused by reactive oxygen species. Several of the viral proteins have been shown to induce apoptosis or autophagy on their own, independent of the presence of other viral proteins. Given the versatility of these viruses to adapt to and manipulate the metabolism, and thus to control the survival of, the infected cells, we need to understand much better how the specific viral proteins affect the pathways to apoptosis and autophagy. Only in this manner will we be able to minimize the pathology that they cause.
基金funding from the Ministry of Higher Education,Malaysia for niche area research under the Higher Institution Centre of Excellence(HICoE)program(MO002-2019&TIDREC-2023).
文摘Flaviviruses are a group of positive-stranded RNA viruses that cause a broad spectrum of severe illnesses in humans worldwide.Clinical manifestations of flavivirus infections range from mild febrile illness to hemorrhage,shock,and neurological manifestations.Flavivirus infections cause a substantial global health impact,with an estimated more than 400 million cases of infections annually.Hence,an understanding of flavivirus-host interaction is urgently needed for new antiviral therapeutic strategies.In recent years,many aspects concerning epigenetic therapy for viral infections have been addressed,including methylation of the genome,acetylation/deacetylation of histone complex and microRNA regulation.In this context,we surveyed and reviewed the literature and summarized the epigenetic effects of resveratrol,a natural polyphenol with potential anti-viral properties,on flavivirus infections.
基金funded by the National Public Welfare Agricultural Industry Special(201003012)
文摘[ Objective] Aim to establish a kind of efficient detection method for duck flavivirus（DFV）. E Method] The method of nested PCR based on flavivirus universal primers which were designed according to the GeneBank flavivirus gene sequence. [ Result] The degenerate universal prim ers Flav P1 -Flav P4 were designed by genome comparison to target NS5 gene conserved area. The system could only amplify flavivirus purpose gene and the sensitivity was 90 copies/iJL, higher than the ordinary PCR 1 000 times. Homology and evolutionary analysis showed that duck flavivirus belonged to mosquito-born flavivirus, NTAV group, similar with Tembusu and BYD virus. [ Conclusion] Primers of the nested PCR system had good universality and specificity and method had high sensitivity. This system successfully detected flavivirus and clarified the evolution station of DFV.
基金supported by National Key Research and Development Program of China(2016YFD0501102,2016YFD0500407)National Natural Science Foundation of China(31825025,32022082,32030107,32002268)+1 种基金Fundamental Research Funds for the Central Universities(2662018QD025)Natural Science Foundation of Hubei Province(2019CFA010)
文摘Flaviviruses are important arthropod-borne pathogens that represent an immense global health problem.Their unprecedented epidemic rate and unpredictable clinical features underscore an urgent need for antiviral interventions.Dehydroepiandrosterone(DHEA)is a natural occurring adrenal-derived steroid in the human body that has been associated in protection against various infections.In the present study,the plaque assay based primary screening was conducted on 32 synthetic derivatives of DHEA against Japanese encephalitis virus(JEV)to identify potent anti-flaviviral compounds.Based on primary screening,HAAS-AV3026 and HAAS-AV3027 were selected as hits from DHEA derivatives that exhibited strong antiviral activity against JEV(IC_(50)=2.13 and 1.98μmol/L,respectively)and Zika virus(ZIKV)(IC_(50)=3.73 and 3.42μmol/L,respectively).Mechanism study indicates that HAAS-AV3026 and HAAS-AV3027 do not exhibit inhibitory effect on flavivirus binding and entry process,while significantly inhibit flavivirus infection at the replication stage.Moreover,indirect immunofluorescence assay,Western blot analyses,and quantitative reverse transcription-PCR(qRT-PCR)revealed a potent antiviral activity of DHEA derivatives hits against JEV and ZIKV in terms of inhibition of viral infection,protein production,and viral RNA synthesis in Vero cells.Taken together,our results may provide a basis for the development of new antivirals against flaviviruses.
基金Innovation Team project(STIF-Y02),FuJian Academy of Agriculture SciencesFujian Scientific Research Institutes of Public Welfare Special Fund(2011R1025-2)
文摘[ Objective] This experiment aimed to find out the origin and genetic evolution relationship of chicken flavivirus （CFV） CJD05 strain in Fujian Province. [Method] A pair of primers were designed and synthesized according to the sequences of E gene from Duck flavivirus （DFV） iso- late BYD-1. E gene of CFV isolate CJD05 was specially amplified and its sequences were analyzed. [Result] The target bar which was cloned from CFV isolate C, JD05 was I 503 bp. Homology analysis was conducted to compare E gene nucleotide sequence of CFV isolate CJD05 with DFV iso- late BYD-I and goose flavivirus （GFV） isolate JS804. Results indicated that isolate nuclectide homologies were 99.2% and 99.3%, and amino acid homologies were 99.0% and 98.6% respectively. [Conclusion] CFV isolate C, JD05, DFV isolate BYD-1 and GFV isolate JS804 were highly homologous. The homology of CFV isolate CJD05 with Tembusu virus （TMUV） was higher than with other arthropod-borne flaviviruses.
基金Supported by Natural Science Foundation of Shandong Province(ZR2012CQ012)Special Fund for Applied Technology Research and Development of Binzhou City(200706)Technological Innovation Project of Shandong Province(201220916006)
文摘A severe egg-drop disease caused by the infection of a novel duck flavivirus outbroke successively in many provinces in southeastern China since 2010.It was identified as a duck Tembusu virus（DTMUV）and named by Chinese Association of Animal Science and Veterinary Medicine in the first symposium on waterfowl disease control,which was presumed to be a mosquito-borne flavivirus of the Ntaya virus subgroup in the genus Flavivirus,family Flaviviridae.Currently,a large number of studies have been conducted on the epidemiology,clinical symptoms and pathological changes,etiology,and rapid diagnoses of the virus.The disease remains a constant threat to the duck industry.In order to provide reference for subsequent in-depth study,in this paper,research progress on the disease was summarized based on previous studies.Furthermore,the potential infection or asymptomatic infection in humans should be evaluated as soon as possible.
基金This work was supported by grants (to Guodong Liang) from National Science Foundation of China (No.30170046)
文摘The aim of this study is to explore the phylogenetic relationship of flaviviruses with the known viruses and to establish a rapid PCR-based method for the characterization of the flaviviruses. To this end, phylogenetic analysis of 25 different strains of flaviviruses was carried out on the basis of the full length genomic sequences as well as the sequences of the individual genes and their untranslated regions (UTRs). From this analysis and the extensive sequence alignment studies, a generic primer pair was identified for amplification of a highly conserved region in the NS5 gene, a molecular marker designed as NS5MM in this study, which was different from NS5 region used previously by other groups. This generic primer pair had been validated by using 22 different strains of flaviviruses in the present study. Furthermore, we have successfully applied this new approach to the rapid identification and characterization of 3 new strains of flaviviruses recently isolated in China.
文摘There are no approved flaviviral therapies and the development of vaccines against flaviruses has the potential of being undermined by antibody-dependent enhancement(ADE).The flavivirus nonstructural protein 1(NS1)is a promising vaccine antigen with low ADE risk but has yet to be explored as a broad-spectrum therapeutic antibody target.Here,we provide the structural basis of NS1 antibody cross-reactivity through cocrystallization of the antibody 1G5.3 with NS1 proteins from dengue and Zika viruses.
基金supported by the National Natural Science Foundation of China(82471389,92169110,and 82271385)Natural Science Foundation of Guangdong Province(2022A1515010451,2024A1515010471,and 2023A1515010476)Guangzhou Municipal Science and Technology Program(202206010114 and 2023A04J2235).
文摘Various lipid metabolism-related factors are essential for Zika virus(ZIKV)replication.In this study,we revealed a crucial role of diacylglycerol O-acyltransferase 2(DGAT2)in ZIKV replication using a short hairpin RNA-based gene knockdown technique.The replication of ZIKV was significantly inhibited by DGAT2 depletion in multiple cell lines and restored by trans-complementation with DGAT2.Mechanistically,DGAT2 is recruited in the viral replication complex by interacting with non-structural(NS)proteins.Among them,both human and murine DGAT2s can be cleaved by NS2B3 at the 122R-R-S124 site.Interestingly,the cleavage product of DGAT2 becomes more stable and is sufficient to promote the lipid droplet(LD)formation independent of its enzymatic activity.This work identifies DGAT2 as a novel target of the viral protease NS2B3 and elucidates that DGAT2 is recruited by viral proteins into the replication complex,thereby playing a proviral role by promoting LD formation,which advances our understanding of host–flavivirus interaction.
基金supported by the National Key Research and Development Plan of China(2021YFC2300200)the National Natural Science Foundation of China(32122008).
文摘Flaviviruses are zoonotic pathogens transmitted by infected mosquitoes and ticks,posing a persistent threat to global health.These infections lead to a diverse spectrum of diseases,broadly classified into two phenotypes:systemic hemorrhagic conditions,such as dengue and yellow fever,and neurological complications,exemplified by West Nile virus(WNV)and Zika virus(ZIKV)infections.The interactions between flaviviruses and human host cells are pivotal to the viral lifecycle and the activation of host immunity.Investigating the molecular mechanisms of flavivirus-host interactions is essential for understanding viral pathogenesis,managing epidemics,optimizing therapeutic strategies,and enhancing public health security.Flaviviruses utilize various strategies to evade the host immune system,and understanding these mechanisms is critical for the development of antiviral therapeutics.This study employs bibliometric methods,leveraging CiteSpace and vOSviewer software,to analyze literature on flavivirus-host interactions and the associated immune responses.By examining developmental trends and pivotal research areas,this analysis provides insights and guidance for future studies in this field.
基金supported by the Spanish Ministry of Science and Innovation AEI under grant PID2020-119195RJ-I00(to NJO).
文摘Flaviviruses affect the lives of millions of people in endemic regions and also have the potential to impact nonendemic areas.Factors such as climate change,global warming,deforestation,and increased travel and trade are linked to the spread of flaviviruses into new habitats and host species.Given the absence of specific treatments and the limited availability of vaccines,it is imperative to understand the biology of flaviviruses and develop rapid and sensitive diagnostic tests.These measures are essential for preventing the transmission of these potentially life-threatening pathogens.Flavivirus infections are mainly diagnosed using conventional methods.However,these techniques present several drawbacks,including high expenses,time-consuming procedures,and the need for skilled professionals.The search for fast,easy-to-use,and affordable alternative techniques as a feasible solution for developing countries is leading to the search for new methods in the diagnosis of flavivi-ruses,such as biosensors.This review provides a comprehensive overview of different biosensor detection strategies for flaviviruses and describes recent advances in diagnostic technologies.Finally,we explore their future prospects and potential applications in pathogen detection.This review serves as a valuable resource to understand advances in ongoing research into new biosensor-based diagnostic methods for flaviviruses.
基金Supported by the Permanecer Program(part of the actions of the Office of Affirmative Actions)Education and Diversity of the Dean of Student Assistance at the Federal University of Bahia(UFBA)and CNPq Research Productivity Fellow.
文摘Arboviral diseases are viral infections transmitted to humans through the bites of arthropods,such as mosquitoes,often causing a variety of pathologies associated with high levels of morbidity and mortality.Over the past decades,these infections have proven to be a significant challenge to health systems worldwide,particularly following the considerable geographic expansion of the dengue virus(DENV)and its most recent outbreak in Latin America as well as the difficult-tocontrol outbreaks of yellow fever virus(YFV),chikungunya virus(CHIKV),and Zika virus(ZIKV),leaving behind a substantial portion of the population with complications related to these infections.Currently,the world is experiencing a period of intense globalization,which,combined with global warming,directly contributes to wider dissemination of arbovirus vectors across the globe.Consequently,all continents remain on high alert for potential new outbreaks.Thus,this review aims to provide a comprehensive understanding of the pathogenesis of the four main arboviruses today(DENV,ZIKV,YFV,and CHIKV)discussing their viral characteristics,immune responses,and mechanisms of viral evasion,as well as important clinical aspects for patient management.This includes associated symptoms,laboratory tests,treatments,existing or developing vaccines and the main associated complications,thus integrating a broad historical,scientific and clinical approach.
