Japanese encephalitis(JE),a vector-borne disease caused by the Japanese encephalitis virus(JEV),remains a major public health concern in South and Southeast Asia[1].JEV,a Flaviviridae family virus,is primarily transmi...Japanese encephalitis(JE),a vector-borne disease caused by the Japanese encephalitis virus(JEV),remains a major public health concern in South and Southeast Asia[1].JEV,a Flaviviridae family virus,is primarily transmitted by Culex mosquitoes,especially the Culex vishnui subgroup,which breeds extensively in rice fields[1].Birds(Ardeidae family)act as natural reservoirs,while pigs serve as amplifying hosts,and humans are incidental hosts[1].展开更多
The Japanese encephalitis virus(JEV)causes Japanese encephalitis(JE),a severe disease that primarily affects children and induces significant central nervous system complications.With the widespread adoption of vaccin...The Japanese encephalitis virus(JEV)causes Japanese encephalitis(JE),a severe disease that primarily affects children and induces significant central nervous system complications.With the widespread adoption of vaccination in children,the incidence among older individuals has increased substantially.Despite this epidemiological shift,research on JEV infection in the elderly remains limited.We established JEV infection models using both aged and young mice to explore age-related differences in pathology and underlying mechanisms.Brain tissue samples were analyzed for pathological changes and viral tropism in major cell types.To further characterize immune response variations,we conducted transcriptomic sequencing on the brain tissues following JEV infection.Aged mice exhibited lower mortality,delayed disease progression,and milder brain pathology compared to young mice after JEV infection.Viral titers and infection rates of major brain cell types were similar in both groups.Transcriptomic analysis revealed diminished immune activation and weaker inflammatory responses in aged mice.Additionally,microglial activation and CD8^(+) T cell function were significantly reduced.Interestingly,JEV infection induced the selective recruitment of B cells in the brains of aged mice.These B cells may modulate the effects of CD8^(+) T cells in the disease process.Compared to young mice,aged mice showed enhanced resistance to JEV progression and reduced brain pathology.This resistance was associated with a weakened immune response in the aged brain,rather than differences in viral infection.The specific recruitment of B cells in the brains of aged mice may play a crucial role in limiting disease progression.展开更多
Objective The aim of the study was to establish the contemporary epidemiological characteristics of Japanese encephalitis （JE） in Guizhou Province. Methods A retrospective study of National Notifiable Disease Report...Objective The aim of the study was to establish the contemporary epidemiological characteristics of Japanese encephalitis （JE） in Guizhou Province. Methods A retrospective study of National Notifiable Disease Reporting System （NNDRS） data from 2971 through 2009, was conducted to ascertain the geographical, seasonal, and age distributions of JE incidence in Guizhou Province, China. Results A total of 68 425 JE cases were reported in Guizhou from 1971-2009. The JE cases occurred sporadically in all 9 prefectures of Guizhou, mostly among residents of rural areas. Seasonal distribution of JE remained consistent over the period from 1971-2009 with the main transmission season starting from June to September and peaking in August. JE occurred mainly in children under the age of 15 years with peak incidence in the 0-6-year age group. Pearson＇s correlation analysis showed that JE vaccine distribution had a negative correlation with JE incidence rates during 1971-2009 （coefficient of correlation=-0.475, P〈O.01）. Conclusion Over the period of 1971-2009, the JE incidence rate had declined dramatically in terms of geographical and age distributions due to JE vaccination to children at risk.展开更多
BACKGROUND Japanese encephalitis virus(JEV),a mosquito borne flavivirus,is the leading cause of viral encephalitis in Asia,in terms of frequency and severity.JEV infection is thought to confer lifelong immunity.With t...BACKGROUND Japanese encephalitis virus(JEV),a mosquito borne flavivirus,is the leading cause of viral encephalitis in Asia,in terms of frequency and severity.JEV infection is thought to confer lifelong immunity.With the near eradication of poliomyelitis,JEV is now the continent’s leading cause of childhood viral neurologic infection and disability.The most common clinical manifestation of JEV infection is acute encephalitis,and currently there is no specific antiviral therapy.Japanese Encephalitis Vaccine(JE-VC)is an effective prevention measure,including JE-VC,Live(JE-MB),and Inactivated JE-VC.CASE SUMMARY A 9-mo-old girl received injection of Inactivated JE-VC(Vero cell)(Liaoning Chengda,batch number 201611B17)on August 31,2017.On that night,she developed a fever with the body temperature up to 38.5°C,for which Ibuprofen Suspension Drops 1.25 mL was given as antipyretic treatment.On September 1,the patient developed apocleisis,and her parents noticed herpes in her oral cavity.The patient was sent to our hospital on September 3.Physical examination led to a diagnosis of herpetic stomatitis,for which Stomatitis Spray 1 puff,tid,Kangfuxin Liquid 2 mL,tid,and vitamin B20.5 tablet,tid,were prescribed.Routine blood tests for low fever on September 6,2017 revealed an absolute neutrophil count(ANC)of 0.62×109/L,hemoglobin(Hb)of 109 g/L,and platelet count(PLT)of 308×10^(12)/L,and the tests were monitored regularly thereafter.The patient was followed until July 26,2020,when routine blood tests revealed ANC 1.72×109/L,Hb 138 g/L,and PLT 309×1012/L,indicating that the neutropenia count had normalized.CONCLUSION This report attempts to bring to clinical attention that Inactivated JE-VC(Vero cell)might cause prolonged granulocytopenia or even agranulocytosis.展开更多
A multiplex reverse transcriptase-polymerase chain reaction(multiplex RT-PCR) assay was developed and subsequently evaluated for its efficacy in the detection of multiple viral infections simultaneously,in swine.Speci...A multiplex reverse transcriptase-polymerase chain reaction(multiplex RT-PCR) assay was developed and subsequently evaluated for its efficacy in the detection of multiple viral infections simultaneously,in swine.Specific primers for each of the 3 RNA viruses,North American genotype porcine reproductive and respiratory syndrome virus,Japanese encephalitis virus,and swine influenza virus,were used in the testing procedure.The assay was shown to be highly sensitive because it could detect as little as 10-5 ng of each of the respective amplicons in a single sample containing a composite of all 3 viruses.The assay was also effective in detecting one or more of the same viruses in various combinations in specimens,including lymph nodes,lungs,spleens,and tonsils,collected from clinically ill pigs and in spleen specimens collected from aborted pig fetuses.The results from the multiplex RT-PCR were confirmed by virus isolation.The relative efficiency(compared to the efficiency of separate assays for each virus) and apparent sensitivity of the multiplex RT-PCR method show that this method has potential for application in routine molecular diagnostic procedures.展开更多
Objective To detect Japanese encephalitis virus（JEV） rapidly and distinguish its genotypes, a TaqMan-based reverse transcriptase quantitative polymerase chain reaction（RT-PCR） detection system was developed.Method...Objective To detect Japanese encephalitis virus（JEV） rapidly and distinguish its genotypes, a TaqMan-based reverse transcriptase quantitative polymerase chain reaction（RT-PCR） detection system was developed.Methods By aligning the full-length sequences of JEV（G1-G5）, six sets of highly specific TaqMan real-time RT-PCR primers and probes were designed based on the highly conserved NS1, NS2, and M genes of JEV, which included one set for non-specific JEV detection and five sets for the detection of specific JEV genotypes. Twenty batches of mosquito samples were used to evaluate our quantitative PCR assay.Results With the specific assay, no other flavivirus were detected. The lower limits of detection of the system were 1 pfu/mL for JEV titers and 100 RNA copies/μL. The coefficients of variation of this real-time RT-PCR were all 〈 2.8%. The amplification efficiency of this method was between 90% and 103%.Conclusion A TaqMan real-time RT-PCR detection system was successfully established to detect and differentiate all five JEV genotypes.展开更多
Objective To determine the molecular characterization of full-length genome of Japanese encephalitis virus （JEV） genotype V. Methods The full-length nucleotide sequences of JEV strains isolated from different locati...Objective To determine the molecular characterization of full-length genome of Japanese encephalitis virus （JEV） genotype V. Methods The full-length nucleotide sequences of JEV strains isolated from different locations and sources were used in sequence and phylogenetic analysis. Results The full-length genome of genotypes V JEV, XZ0934, and Muar strain were composed of 10 983 and 10 988 nucleotides respectively and shared a lower level of identity with JEV genotypes I-IV, ranging from 78.4% （G I, KV1899） to 79.7% （G III, JaGAr01）, for the nucleotide sequences, and from 90.0%（G I, KV1899） to 91.8%（G III, JaGAr01） for the amino acid sequences. The open reading frame （ORF） of JEV genotype V spanned nucleotides 96 to 10 397 and encoded 3 433 amino acids. Interestingly, a comparison with JEV genotype I-IV revealed that 3 nucleotides （encoded with a serine residue） were inserted in the NS4A gene of JEV genotype V, and the insertion of nucleotides was also found in downstream of the ORF stop codon in 3’-untranslated region. Moreover, numerous amino acid mutations were observed in 3 functional domains of the E gene of JEV genotype V. Conclusion The molecular characterization of JEV genotype V is significantly different from that of the known genotypes I-IV. The mutations located in the coding region and the non-coding region may be molecular markers of JEV genotype V and warrant further studies to determine their effects on biology and immunogenicity of genotype V strains.展开更多
Japanese encephalitis(JE)is a viral encephalitis disease caused by Japanese encephalitis virus(JEV)infection.Uncontrolled inflammatory responses in the central nervous system(CNS)are a hallmark of severe JE.Although t...Japanese encephalitis(JE)is a viral encephalitis disease caused by Japanese encephalitis virus(JEV)infection.Uncontrolled inflammatory responses in the central nervous system(CNS)are a hallmark of severe JE.Although the CCR2-CCL2 axis is important for monocytes trafficking during JEV infection,little is known about its role in CNS trafficking of CD8^+T cells.Here,we characterized a mouse model of JEV infection,induced via intravenous injection(i.v.)and delineated the chemokines and infiltrating peripheral immune cells in the brains of infected mice.The CNS expression of chemokines,Ccl2,Ccl3,and Ccl5,and their receptors,Ccr2 or Ccr5.was significantly up-regulated after JEV infection and was associated with the degree of JE pathogenesis.Moreover,JEV infection resulted in the migration of a large number of CD8^+T cells into the CNS.In the brains of JEV-infected mice,infiltrating CD8^+T cells expressed CCR2 and CCR5 and were found to comprise mainly effector T cells(CD44^+CD62L_).JEV infection dramatically enhanced the expression of programmed death 1(PD-1)on infiltrating CD8^+T cells in the brain,as compared to that on peripheral CD8^+T cells in the spleen.This effect was more pronounced on infiltrating CCR2^+CD8^+T cells than on CCR2-CD8^+T cells.In conclusion,we identified a new subset of CD8^+T cells(PD1^+CCR2^+CD8^+T cells)present in the CNS of mice during acute JEV infection.These CD8^+T cells might play a role in JE pathogenesis.展开更多
Japanese encephalitis virus(JEV)is a mosquito-borne flavivirus,which causes the most commonly diagnosed viral encephalitis named Japanese encephalitis(JE)in the world with an unclear pathogenesis.Axl,a receptor tyrosi...Japanese encephalitis virus(JEV)is a mosquito-borne flavivirus,which causes the most commonly diagnosed viral encephalitis named Japanese encephalitis(JE)in the world with an unclear pathogenesis.Axl,a receptor tyrosine kinase from TAM family,plays crucial role in many inflammatory diseases.We have previously discovered that Axl deficiency resulted in more severe body weight loss in mice during JEV infection,which we speculate is due to the anti-inflammatory effect of Axl during JE.Currently,the role of Axl in regulating the neuroinflammation and brain damage during JE has not been investigated yet.In this study,by using Axl deficient and heterozygous control mice,we discovered that Axl deficient mice displayed accelerated JE progression and exacerbated brain damage characterized by increased neural cell death,extended infiltration of inflammatory cells,and enhanced production of pro-inflammatory cytokines,in comparison to control mice.Additionally,consistent with our previous report,Axl deficiency had no impact on the infection and target cell tropism of JEV in brain.Taken together,our results suggest that Axl plays an anti-inflammatory and neuroprotective role during the pathogenesis of JE.展开更多
Fifteen pediatric cases of suspected Japanese encephalitis （JE） were reported in Beijing Children＇s Hospital during the late summer of 2013. The clinical manifestations in most cases included high fever, seizures, ...Fifteen pediatric cases of suspected Japanese encephalitis （JE） were reported in Beijing Children＇s Hospital during the late summer of 2013. The clinical manifestations in most cases included high fever, seizures, and abnormal magnetic resonance imaging findings. Twelve of 15 cases were laboratory-confirmed as JE cases by pathogen identification. Epidemiological investigations showed that five of the 12 laboratory-confirmed patients had an incomplete JE vaccination history. Follow-up investigations after discharge indicated that seven laboratory-confirmed JE patients without JE vaccinations had relatively poor prognoses, with an average Modified Rankin Scale （MRS） score of 2.6 when compared with the other five laboratory-confirmed, JE-vaccinated patients with an average MRS score of 0.5. The observation of pediatric JE cases among those with a history of JE vaccination warrants further attention.展开更多
Japanese encephalitis virus (JEV) is a mosquito-borne flavivirus closely related to the human pathogens including yellow fever virus, dengue virus and West Nile virus. There are currently no effective antiviral therap...Japanese encephalitis virus (JEV) is a mosquito-borne flavivirus closely related to the human pathogens including yellow fever virus, dengue virus and West Nile virus. There are currently no effective antiviral therapies for all of the flavivirus and only a few highly effective vaccines are licensed for human use. In this paper, the E protein domain III (DIII) of six heterologous flaviviruses (DENV1-4, WNV and JEV) was expressed in Escherichia coli successfully. The proteins were purified after a solubilization and refolding procedure, characterized by SDS-PAGE and Western blotting. Competitive inhibition showed that all recombinant flavivirus DIII proteins blocked the entry of JEV into BHK-21 cells. Further studies indicated that antibodies induced by the soluble recombinant flavivirus DIII partially protected mice against lethal JEV challenge. These results demonstrated that recombinant flavivirus DIII proteins could inhibit JEV infection competitively, and immunization with proper folding flavivirus DIII induced cross-protection against JEV infection in mice, implying a possible role of DIII for the cross-protection among flavivirus as well as its use in antigens for immunization in animal models.展开更多
Objective To construct a model of Seasonal Autoregressive Integrated Moving Average （SARIMA） for forecasting the epidemic of Japanese encephalitis （JE） in Xianyang, Shaanxi, China, and provide valuable reference ...Objective To construct a model of Seasonal Autoregressive Integrated Moving Average （SARIMA） for forecasting the epidemic of Japanese encephalitis （JE） in Xianyang, Shaanxi, China, and provide valuable reference information for JE control and prevention. Methods Theoretically epidemiologic study was employed in the research process. Monthly incidence data on JE for the period from Jan 2005 to Sep 2014 were obtained from a passive surveillance system at the Center for Diseases Prevention and Control in Xianyang, Shaanxi province. An optimal SARIMA model was developed for JE incidence from 2005 to 2013 with the Box and Jenkins approach. This SARIMA model could predict JE incidence for the year 2014 and 2015. Results SARIMA （1, 1, 1） （2, 1, 1）12 was considered to be the best model with the lowest Bayesian information criterion, Akaike information criterion, Mean Absolute Error values, the highest R2, and a lower Mean Absolute Percent Error. SARIMA （1, 1, 1） （2, 1, 1）12 was stationary and accurate for predicting JE incidence in Xianyang. The predicted incidence, around 0.3/100 000 from June to August in 2014 with low errors, was higher compared with the actual incidence. Therefore, SARIMA （1, 1, 1） （2, 1, 1）12 appeared to be reliable and accurate and could be applied to incidence prediction. Conclusions The proposed prediction model could provide clues to early identification of the JE incidence that is increased abnormally （≥0.4/100 000）. According to the predicted results in 2014, the JE incidence in Xianyang will decline slightly and reach its peak from June to August.The authors wish to thank the staff from the CDCs from 13 counties of Xianyang, Shaanxi province, China, for their contribution to Japanese encephalitis cases reporting.展开更多
Japanese encephalitis（JE）is a serious public health issue.This study was undertaken to better understand the relationship between JE distribution and environmental factors in China.JE data from 2005 to 2010 were ret...Japanese encephalitis（JE）is a serious public health issue.This study was undertaken to better understand the relationship between JE distribution and environmental factors in China.JE data from 2005 to 2010 were retrieved from National Notifiable Disease Report System.展开更多
A bacterial cell surface display technique based on an ice nucleation protein has been employed for the development of live vaccine against viral infection. Due to its ubiquitous ability to invade host cells, Salmonel...A bacterial cell surface display technique based on an ice nucleation protein has been employed for the development of live vaccine against viral infection. Due to its ubiquitous ability to invade host cells, Salmonella typhimurium might be a good candidate for displaying viral antigens. We demonstrated the surface display of domain III of Japanese encephalitis virus E protein and the enhanced green fluorescent protein on S. typhimurium BRD509 using the ice nucleation protein. The effects of the motif in the ice nucleation protein on the effective display of integral protein were also investigated. The results showed that display motifs in the protein can target integral foreign protein on the surface of S. typhimurium BRD509. Moreover, recombinant strains with surface displayed viral proteins retained their invasiveness, suggesting that the recombinant S. typhimurium can be used as live vaccine vector for eliciting complete immunogenicity. The data may yield better understanding of the mechanism by which ice nucleation protein displays foreign proteins in the Salmonella strain.展开更多
The Japanese encephalitis serogroup of the neurogenic Flavivirus has a specific feature that expresses a non-structural protein NS1'produced through a programmed-1 ribosomal frameshifting(-1 PRF).Herein,C19orf66,a...The Japanese encephalitis serogroup of the neurogenic Flavivirus has a specific feature that expresses a non-structural protein NS1'produced through a programmed-1 ribosomal frameshifting(-1 PRF).Herein,C19orf66,a novel member of interferon-stimulated gene(ISG)products,exhibited significant activity of antagonizing Japanese encephalitis virus(JEV)infection.Overexpression of C19orf66 in 293T cells significantly inhibited JEV replication,while knock-down of endogenous C19orf66 in HeLa cells and A549 cells significantly increased virus replication.Notably,C19orf66 had an inhibitory effect on frameshift production of JEV NS1'.The inhibition was more significant when C19orf66 and JEV NS1-NS2A were co-expressed in the 293T cells.Both C19orf66-209 and C19orf66-Zinc^(mut) did not significantly change the NS1'to NS1 ratio and had weaker antiviral effects than C19orf66.Similarly,C19orf66-209 and C19orf66-Zinc^(mut) had no significant effect on the expression of the JEV NS3 protein,whose expression was down-regulated by C19orf66 via the lysosome-dependent pathway.These findings suggest that C19orf66 may possess at least two different mechanisms of antagonizing JEV infection.This study identified C19orf66 as a novel interferon-stimulated gene product that can inhibit JEV replication by targeting-1 PRF and the NS3 protein.The study provides baseline information for the future development of broad-spectrum antiviral agents against JEV.展开更多
Japanese encephalitis virus(JEV) is a flavivirus transmitted by mosquitoes that causes severe encephalitis in humans and animals. It has been suggested that AXL, a transmembrane protein, can promote the replication of...Japanese encephalitis virus(JEV) is a flavivirus transmitted by mosquitoes that causes severe encephalitis in humans and animals. It has been suggested that AXL, a transmembrane protein, can promote the replication of various flaviviruses,such as dengue(DENV), Zika(ZIKV), and West Nile(WNV) viruses. However, the effect of AXL on JEV infection has not yet been determined. In the present study, we demonstrate that AXL is down-regulated after JEV infection in the late stage. JEV NS2B-3 protein specifically interacted with AXL, and promoted AXL degradation through the ubiquitin–proteasome pathway. AXL-degradation increased cell apoptosis by disrupting phosphatidylinositol 3-kinase(PI3 K)/Akt signal transduction. In addition, the degradation of AXL promoted JEV release to supernatant, whereas the virus in the cell lysates decreased. The supplementation of AXL ligand Gas6 inhibited the JEV-mediated degradation of AXL. Altogether,we discover a new function of NS2B-3 during the process of JEV replication, and provide a new insight into the interactions between JEV and cell hosts.展开更多
Skin-resident dendritic cells(DCs) likely encounter incoming viruses in the first place, and their migration to lymph nodes following virus capture may promote viral replication. However, the molecular mechanisms unde...Skin-resident dendritic cells(DCs) likely encounter incoming viruses in the first place, and their migration to lymph nodes following virus capture may promote viral replication. However, the molecular mechanisms underlying these processes remain unclear. In the present study, we found that compared to cell-free viruses, DC-bound viruses showed enhanced capture of JEV by T cells.Additionally, JEV infection was increased by co-culturing DCs and T cells. Blocking the C-type lectin receptor DC-specific intercellular adhesion molecule-3-grabbing non-integrin(DC-SIGN) with neutralizing antibodies or antagonists blocked JEV transmission to T cells. Live-cell imaging revealed that DCs captured and transferred JEV viral particles to T cells via virological synapses formed at DC-T cell junctions. These findings indicate that DC-SIGN plays an important role in JEV transmission from DCs to T cells and provide insight into how JEV exploits the migratory and antigen-presenting capabilities of DCs to gain access to lymph nodes for dissemination and persistence in the host.展开更多
Japanese encephalitis virus （jEV） is a mosquito-borne virus of the family Flaviviridae. It is the causative agent of Japanese encephalitis with approximately 50,000 infection cases and 10,000 fatal cases annually in...Japanese encephalitis virus （jEV） is a mosquito-borne virus of the family Flaviviridae. It is the causative agent of Japanese encephalitis with approximately 50,000 infection cases and 10,000 fatal cases annually in Asia （Erlanger et al., 2009）. Although liveattenuated JEV vaccine has been developed and used for human and pig vaccination, JE occurs epidemically or sporadically in some developing countries or even in vaccinated areas （Solomon, 2006）. Host resistance factors play an important role in the outcome of viral infection.展开更多
BACKGROUND Japanese encephalitis(JE) is a serious public health concern with a high mortality rate in many Asian countries. For many years, JE virus(JEV) was considered the major cause of viral encephalitis in Asia. A...BACKGROUND Japanese encephalitis(JE) is a serious public health concern with a high mortality rate in many Asian countries. For many years, JE virus(JEV) was considered the major cause of viral encephalitis in Asia. Although most JE cases are asymptomatic, the case fatality rate approaches 30%, and approximately 30%–50% of survivors have long-term neurological sequelae. To the best of our knowledge, JEV infection has never been reported following liver transplantation.CASE SUMMARY We report a case of a woman who underwent liver transplantation for autoimmune liver disease but presented with fever and neurological symptoms 13 d after transplantation. Magnetic resonance imaging revealed JEV infection,and positive immunoglobulin M antibody to JEV in blood and cerebrospinal fluid confirmed JE. The patient was treated with antiviral agents, immune regulation,and organ function support. No neurological sequelae were present after 1 year of follow-up.CONCLUSION Imaging and lumbar puncture examination should be performed as soon as possible in patients with fever and central nervous system symptoms after liver transplantation, and the possibility of atypical infection should be considered,which is helpful for early diagnosis and improved prognosis.展开更多
[ Objective] To develop an indirect ELISA assay for detecting antibodies against envelope glycoprotein （ E protein） of Japanese encephalitis virus （JEV）. [ Method] Specific primers were designed according to JEV s...[ Objective] To develop an indirect ELISA assay for detecting antibodies against envelope glycoprotein （ E protein） of Japanese encephalitis virus （JEV）. [ Method] Specific primers were designed according to JEV sequences published in the GenBank. The cDNA of JEV E gene （about 1 000 10p） was amplified by the RT-PCR with the specific primers. After sequencing analysis, the E gene was cloned into pET30a expression vector and expressed in E. coli BL21 （DE3） with the induction of IPTG. After denaturation, purification and renaturation, the recombinant protein was analyzed by the SDS-PAGE and the westem blotting. An indirect ELISA was developed to detect antibodies against JEV. [ Result] The E protein was mainly expressed in inclusion body. With the purified E protein, the indirect ELISA was developed and displayed good specificity, sensitivity and repeatability, [ Conclusion]The developed ELISA using the truncated E protein as antigen is a simple, convenient and rapid serological method for diagnosis, monitoring antibody level and epidemiological investigation of JEV.展开更多
文摘Japanese encephalitis(JE),a vector-borne disease caused by the Japanese encephalitis virus(JEV),remains a major public health concern in South and Southeast Asia[1].JEV,a Flaviviridae family virus,is primarily transmitted by Culex mosquitoes,especially the Culex vishnui subgroup,which breeds extensively in rice fields[1].Birds(Ardeidae family)act as natural reservoirs,while pigs serve as amplifying hosts,and humans are incidental hosts[1].
基金the National Natural Science Foundation of China(82172266to P.G.W.)Natural Science Foundation of Beijing(7232002 to N.G.).
文摘The Japanese encephalitis virus(JEV)causes Japanese encephalitis(JE),a severe disease that primarily affects children and induces significant central nervous system complications.With the widespread adoption of vaccination in children,the incidence among older individuals has increased substantially.Despite this epidemiological shift,research on JEV infection in the elderly remains limited.We established JEV infection models using both aged and young mice to explore age-related differences in pathology and underlying mechanisms.Brain tissue samples were analyzed for pathological changes and viral tropism in major cell types.To further characterize immune response variations,we conducted transcriptomic sequencing on the brain tissues following JEV infection.Aged mice exhibited lower mortality,delayed disease progression,and milder brain pathology compared to young mice after JEV infection.Viral titers and infection rates of major brain cell types were similar in both groups.Transcriptomic analysis revealed diminished immune activation and weaker inflammatory responses in aged mice.Additionally,microglial activation and CD8^(+) T cell function were significantly reduced.Interestingly,JEV infection induced the selective recruitment of B cells in the brains of aged mice.These B cells may modulate the effects of CD8^(+) T cells in the disease process.Compared to young mice,aged mice showed enhanced resistance to JEV progression and reduced brain pathology.This resistance was associated with a weakened immune response in the aged brain,rather than differences in viral infection.The specific recruitment of B cells in the brains of aged mice may play a crucial role in limiting disease progression.
基金supported by a grant from NIP of Center for Disease Control and Prevention of China
文摘Objective The aim of the study was to establish the contemporary epidemiological characteristics of Japanese encephalitis （JE） in Guizhou Province. Methods A retrospective study of National Notifiable Disease Reporting System （NNDRS） data from 2971 through 2009, was conducted to ascertain the geographical, seasonal, and age distributions of JE incidence in Guizhou Province, China. Results A total of 68 425 JE cases were reported in Guizhou from 1971-2009. The JE cases occurred sporadically in all 9 prefectures of Guizhou, mostly among residents of rural areas. Seasonal distribution of JE remained consistent over the period from 1971-2009 with the main transmission season starting from June to September and peaking in August. JE occurred mainly in children under the age of 15 years with peak incidence in the 0-6-year age group. Pearson＇s correlation analysis showed that JE vaccine distribution had a negative correlation with JE incidence rates during 1971-2009 （coefficient of correlation=-0.475, P〈O.01）. Conclusion Over the period of 1971-2009, the JE incidence rate had declined dramatically in terms of geographical and age distributions due to JE vaccination to children at risk.
文摘BACKGROUND Japanese encephalitis virus(JEV),a mosquito borne flavivirus,is the leading cause of viral encephalitis in Asia,in terms of frequency and severity.JEV infection is thought to confer lifelong immunity.With the near eradication of poliomyelitis,JEV is now the continent’s leading cause of childhood viral neurologic infection and disability.The most common clinical manifestation of JEV infection is acute encephalitis,and currently there is no specific antiviral therapy.Japanese Encephalitis Vaccine(JE-VC)is an effective prevention measure,including JE-VC,Live(JE-MB),and Inactivated JE-VC.CASE SUMMARY A 9-mo-old girl received injection of Inactivated JE-VC(Vero cell)(Liaoning Chengda,batch number 201611B17)on August 31,2017.On that night,she developed a fever with the body temperature up to 38.5°C,for which Ibuprofen Suspension Drops 1.25 mL was given as antipyretic treatment.On September 1,the patient developed apocleisis,and her parents noticed herpes in her oral cavity.The patient was sent to our hospital on September 3.Physical examination led to a diagnosis of herpetic stomatitis,for which Stomatitis Spray 1 puff,tid,Kangfuxin Liquid 2 mL,tid,and vitamin B20.5 tablet,tid,were prescribed.Routine blood tests for low fever on September 6,2017 revealed an absolute neutrophil count(ANC)of 0.62×109/L,hemoglobin(Hb)of 109 g/L,and platelet count(PLT)of 308×10^(12)/L,and the tests were monitored regularly thereafter.The patient was followed until July 26,2020,when routine blood tests revealed ANC 1.72×109/L,Hb 138 g/L,and PLT 309×1012/L,indicating that the neutropenia count had normalized.CONCLUSION This report attempts to bring to clinical attention that Inactivated JE-VC(Vero cell)might cause prolonged granulocytopenia or even agranulocytosis.
基金supported by a grant from the Out-standing Person Innovation Foundation of Henan,China(0621002100)
文摘A multiplex reverse transcriptase-polymerase chain reaction(multiplex RT-PCR) assay was developed and subsequently evaluated for its efficacy in the detection of multiple viral infections simultaneously,in swine.Specific primers for each of the 3 RNA viruses,North American genotype porcine reproductive and respiratory syndrome virus,Japanese encephalitis virus,and swine influenza virus,were used in the testing procedure.The assay was shown to be highly sensitive because it could detect as little as 10-5 ng of each of the respective amplicons in a single sample containing a composite of all 3 viruses.The assay was also effective in detecting one or more of the same viruses in various combinations in specimens,including lymph nodes,lungs,spleens,and tonsils,collected from clinically ill pigs and in spleen specimens collected from aborted pig fetuses.The results from the multiplex RT-PCR were confirmed by virus isolation.The relative efficiency(compared to the efficiency of separate assays for each virus) and apparent sensitivity of the multiplex RT-PCR method show that this method has potential for application in routine molecular diagnostic procedures.
基金supported by grants from the National Key Research and Development Program[2016YFD0500401]Development Grant of State Key Laboratory of Infectious Disease Prevention and Control[2015SKLID505,2014SKLID03]
文摘Objective To detect Japanese encephalitis virus（JEV） rapidly and distinguish its genotypes, a TaqMan-based reverse transcriptase quantitative polymerase chain reaction（RT-PCR） detection system was developed.Methods By aligning the full-length sequences of JEV（G1-G5）, six sets of highly specific TaqMan real-time RT-PCR primers and probes were designed based on the highly conserved NS1, NS2, and M genes of JEV, which included one set for non-specific JEV detection and five sets for the detection of specific JEV genotypes. Twenty batches of mosquito samples were used to evaluate our quantitative PCR assay.Results With the specific assay, no other flavivirus were detected. The lower limits of detection of the system were 1 pfu/mL for JEV titers and 100 RNA copies/μL. The coefficients of variation of this real-time RT-PCR were all 〈 2.8%. The amplification efficiency of this method was between 90% and 103%.Conclusion A TaqMan real-time RT-PCR detection system was successfully established to detect and differentiate all five JEV genotypes.
基金supported by grants from the Ministry of Science and Technology,China(2011CB504702)National Natural Science Foundation of China(81290342)Development Grant of State Key Laboratory for Infectious Disease Prevention and Control(2008SKLID105)
文摘Objective To determine the molecular characterization of full-length genome of Japanese encephalitis virus （JEV） genotype V. Methods The full-length nucleotide sequences of JEV strains isolated from different locations and sources were used in sequence and phylogenetic analysis. Results The full-length genome of genotypes V JEV, XZ0934, and Muar strain were composed of 10 983 and 10 988 nucleotides respectively and shared a lower level of identity with JEV genotypes I-IV, ranging from 78.4% （G I, KV1899） to 79.7% （G III, JaGAr01）, for the nucleotide sequences, and from 90.0%（G I, KV1899） to 91.8%（G III, JaGAr01） for the amino acid sequences. The open reading frame （ORF） of JEV genotype V spanned nucleotides 96 to 10 397 and encoded 3 433 amino acids. Interestingly, a comparison with JEV genotype I-IV revealed that 3 nucleotides （encoded with a serine residue） were inserted in the NS4A gene of JEV genotype V, and the insertion of nucleotides was also found in downstream of the ORF stop codon in 3’-untranslated region. Moreover, numerous amino acid mutations were observed in 3 functional domains of the E gene of JEV genotype V. Conclusion The molecular characterization of JEV genotype V is significantly different from that of the known genotypes I-IV. The mutations located in the coding region and the non-coding region may be molecular markers of JEV genotype V and warrant further studies to determine their effects on biology and immunogenicity of genotype V strains.
基金supported by grants from the Key Research and Development Program of the Ministry of Science and Technology of China (2016YFD500407)Precision Medicine program of Ministry of Science and Technology of China (2016YFC0905902)the National Natural Science Foundation of China (81630043, 81571552)
文摘Japanese encephalitis(JE)is a viral encephalitis disease caused by Japanese encephalitis virus(JEV)infection.Uncontrolled inflammatory responses in the central nervous system(CNS)are a hallmark of severe JE.Although the CCR2-CCL2 axis is important for monocytes trafficking during JEV infection,little is known about its role in CNS trafficking of CD8^+T cells.Here,we characterized a mouse model of JEV infection,induced via intravenous injection(i.v.)and delineated the chemokines and infiltrating peripheral immune cells in the brains of infected mice.The CNS expression of chemokines,Ccl2,Ccl3,and Ccl5,and their receptors,Ccr2 or Ccr5.was significantly up-regulated after JEV infection and was associated with the degree of JE pathogenesis.Moreover,JEV infection resulted in the migration of a large number of CD8^+T cells into the CNS.In the brains of JEV-infected mice,infiltrating CD8^+T cells expressed CCR2 and CCR5 and were found to comprise mainly effector T cells(CD44^+CD62L_).JEV infection dramatically enhanced the expression of programmed death 1(PD-1)on infiltrating CD8^+T cells in the brain,as compared to that on peripheral CD8^+T cells in the spleen.This effect was more pronounced on infiltrating CCR2^+CD8^+T cells than on CCR2-CD8^+T cells.In conclusion,we identified a new subset of CD8^+T cells(PD1^+CCR2^+CD8^+T cells)present in the CNS of mice during acute JEV infection.These CD8^+T cells might play a role in JE pathogenesis.
基金This work was supported by the National Natural Science Foundation of China(81671971,81871641,81972979,U1902210 and U1602223)the Scientific Research Plan of the Beijing Municipal Education Committee(KM201710025002)+1 种基金the Key Project of Beijing Natural Science Foundation B(KZ201810025035)the Support Project of High-level Teachers in Beijing Municipal Universities in the Period of 13th Five-year Plan(IDHT20190510).
文摘Japanese encephalitis virus(JEV)is a mosquito-borne flavivirus,which causes the most commonly diagnosed viral encephalitis named Japanese encephalitis(JE)in the world with an unclear pathogenesis.Axl,a receptor tyrosine kinase from TAM family,plays crucial role in many inflammatory diseases.We have previously discovered that Axl deficiency resulted in more severe body weight loss in mice during JEV infection,which we speculate is due to the anti-inflammatory effect of Axl during JE.Currently,the role of Axl in regulating the neuroinflammation and brain damage during JE has not been investigated yet.In this study,by using Axl deficient and heterozygous control mice,we discovered that Axl deficient mice displayed accelerated JE progression and exacerbated brain damage characterized by increased neural cell death,extended infiltration of inflammatory cells,and enhanced production of pro-inflammatory cytokines,in comparison to control mice.Additionally,consistent with our previous report,Axl deficiency had no impact on the infection and target cell tropism of JEV in brain.Taken together,our results suggest that Axl plays an anti-inflammatory and neuroprotective role during the pathogenesis of JE.
基金grants from the National Key Research and Development Program(2016YFD0500401)a clinical technological innovation project supervised by the Beijing Hospital Authority(XMLX201401)+3 种基金a Development Grant of the State Key Laboratory of Infectious Disease Prevention and Control(2015SKLID505,2014SKLID03)Ministry of Science and Technology of the People’s Republic of China(No.2013ZX10004202,No.2013ZX10004101,No.2012ZX10004215)the National Natural Science Foundation of China(81290342 and 81501757)the Special National Project on Research and Development of Key Biosafety Technologies(2016YFC1201900)
文摘Fifteen pediatric cases of suspected Japanese encephalitis （JE） were reported in Beijing Children＇s Hospital during the late summer of 2013. The clinical manifestations in most cases included high fever, seizures, and abnormal magnetic resonance imaging findings. Twelve of 15 cases were laboratory-confirmed as JE cases by pathogen identification. Epidemiological investigations showed that five of the 12 laboratory-confirmed patients had an incomplete JE vaccination history. Follow-up investigations after discharge indicated that seven laboratory-confirmed JE patients without JE vaccinations had relatively poor prognoses, with an average Modified Rankin Scale （MRS） score of 2.6 when compared with the other five laboratory-confirmed, JE-vaccinated patients with an average MRS score of 0.5. The observation of pediatric JE cases among those with a history of JE vaccination warrants further attention.
基金supported by Important National Science & Technology Specific Projects (2012ZX10004403, 2012ZX10004219)National Natural Scientific Fund of China (81072675)
文摘Japanese encephalitis virus (JEV) is a mosquito-borne flavivirus closely related to the human pathogens including yellow fever virus, dengue virus and West Nile virus. There are currently no effective antiviral therapies for all of the flavivirus and only a few highly effective vaccines are licensed for human use. In this paper, the E protein domain III (DIII) of six heterologous flaviviruses (DENV1-4, WNV and JEV) was expressed in Escherichia coli successfully. The proteins were purified after a solubilization and refolding procedure, characterized by SDS-PAGE and Western blotting. Competitive inhibition showed that all recombinant flavivirus DIII proteins blocked the entry of JEV into BHK-21 cells. Further studies indicated that antibodies induced by the soluble recombinant flavivirus DIII partially protected mice against lethal JEV challenge. These results demonstrated that recombinant flavivirus DIII proteins could inhibit JEV infection competitively, and immunization with proper folding flavivirus DIII induced cross-protection against JEV infection in mice, implying a possible role of DIII for the cross-protection among flavivirus as well as its use in antigens for immunization in animal models.
基金Supported by the Youth Project of Shaanxi University of Chinese Medicine(2015QN05)
文摘Objective To construct a model of Seasonal Autoregressive Integrated Moving Average （SARIMA） for forecasting the epidemic of Japanese encephalitis （JE） in Xianyang, Shaanxi, China, and provide valuable reference information for JE control and prevention. Methods Theoretically epidemiologic study was employed in the research process. Monthly incidence data on JE for the period from Jan 2005 to Sep 2014 were obtained from a passive surveillance system at the Center for Diseases Prevention and Control in Xianyang, Shaanxi province. An optimal SARIMA model was developed for JE incidence from 2005 to 2013 with the Box and Jenkins approach. This SARIMA model could predict JE incidence for the year 2014 and 2015. Results SARIMA （1, 1, 1） （2, 1, 1）12 was considered to be the best model with the lowest Bayesian information criterion, Akaike information criterion, Mean Absolute Error values, the highest R2, and a lower Mean Absolute Percent Error. SARIMA （1, 1, 1） （2, 1, 1）12 was stationary and accurate for predicting JE incidence in Xianyang. The predicted incidence, around 0.3/100 000 from June to August in 2014 with low errors, was higher compared with the actual incidence. Therefore, SARIMA （1, 1, 1） （2, 1, 1）12 appeared to be reliable and accurate and could be applied to incidence prediction. Conclusions The proposed prediction model could provide clues to early identification of the JE incidence that is increased abnormally （≥0.4/100 000）. According to the predicted results in 2014, the JE incidence in Xianyang will decline slightly and reach its peak from June to August.The authors wish to thank the staff from the CDCs from 13 counties of Xianyang, Shaanxi province, China, for their contribution to Japanese encephalitis cases reporting.
基金supported by the National Key Research and Development Program[2016YFD0500401]National Science and Technology Support Program[2014BAI13B05]the Development Grant of State Key Laboratory for Infectious Disease Prevention and Control[2015SKLID505]
文摘Japanese encephalitis（JE）is a serious public health issue.This study was undertaken to better understand the relationship between JE distribution and environmental factors in China.JE data from 2005 to 2010 were retrieved from National Notifiable Disease Report System.
基金The Knowledge Innovation Program Key Project (KSCX1-YW-R-07)
文摘A bacterial cell surface display technique based on an ice nucleation protein has been employed for the development of live vaccine against viral infection. Due to its ubiquitous ability to invade host cells, Salmonella typhimurium might be a good candidate for displaying viral antigens. We demonstrated the surface display of domain III of Japanese encephalitis virus E protein and the enhanced green fluorescent protein on S. typhimurium BRD509 using the ice nucleation protein. The effects of the motif in the ice nucleation protein on the effective display of integral protein were also investigated. The results showed that display motifs in the protein can target integral foreign protein on the surface of S. typhimurium BRD509. Moreover, recombinant strains with surface displayed viral proteins retained their invasiveness, suggesting that the recombinant S. typhimurium can be used as live vaccine vector for eliciting complete immunogenicity. The data may yield better understanding of the mechanism by which ice nucleation protein displays foreign proteins in the Salmonella strain.
基金This work was supported by grants from the National Natural Science Foundation of China(Grant No.31772756)the National Key Research and Development Program of China(Grant No.2016YFD0500402)the Priority Academic Program Development of Jiangsu Higher Education Institutions。
文摘The Japanese encephalitis serogroup of the neurogenic Flavivirus has a specific feature that expresses a non-structural protein NS1'produced through a programmed-1 ribosomal frameshifting(-1 PRF).Herein,C19orf66,a novel member of interferon-stimulated gene(ISG)products,exhibited significant activity of antagonizing Japanese encephalitis virus(JEV)infection.Overexpression of C19orf66 in 293T cells significantly inhibited JEV replication,while knock-down of endogenous C19orf66 in HeLa cells and A549 cells significantly increased virus replication.Notably,C19orf66 had an inhibitory effect on frameshift production of JEV NS1'.The inhibition was more significant when C19orf66 and JEV NS1-NS2A were co-expressed in the 293T cells.Both C19orf66-209 and C19orf66-Zinc^(mut) did not significantly change the NS1'to NS1 ratio and had weaker antiviral effects than C19orf66.Similarly,C19orf66-209 and C19orf66-Zinc^(mut) had no significant effect on the expression of the JEV NS3 protein,whose expression was down-regulated by C19orf66 via the lysosome-dependent pathway.These findings suggest that C19orf66 may possess at least two different mechanisms of antagonizing JEV infection.This study identified C19orf66 as a novel interferon-stimulated gene product that can inhibit JEV replication by targeting-1 PRF and the NS3 protein.The study provides baseline information for the future development of broad-spectrum antiviral agents against JEV.
基金This work was carried out with support of grants from the National Key Research and Development Plan of China(Grant No.2016YFD0500402)the National Natural Science Foundation of China(Grant No.31772756)the Priority Academic Program Development of Jiangsu Higher Education Institutions。
文摘Japanese encephalitis virus(JEV) is a flavivirus transmitted by mosquitoes that causes severe encephalitis in humans and animals. It has been suggested that AXL, a transmembrane protein, can promote the replication of various flaviviruses,such as dengue(DENV), Zika(ZIKV), and West Nile(WNV) viruses. However, the effect of AXL on JEV infection has not yet been determined. In the present study, we demonstrate that AXL is down-regulated after JEV infection in the late stage. JEV NS2B-3 protein specifically interacted with AXL, and promoted AXL degradation through the ubiquitin–proteasome pathway. AXL-degradation increased cell apoptosis by disrupting phosphatidylinositol 3-kinase(PI3 K)/Akt signal transduction. In addition, the degradation of AXL promoted JEV release to supernatant, whereas the virus in the cell lysates decreased. The supplementation of AXL ligand Gas6 inhibited the JEV-mediated degradation of AXL. Altogether,we discover a new function of NS2B-3 during the process of JEV replication, and provide a new insight into the interactions between JEV and cell hosts.
基金supported by the National Key Research and Development Program of China(2016YFC1200400)the National Natural Science Foundation of China Grants(81572009 and 31570165)the National High Technology Research and Development Program of China(2014AA021406)
文摘Skin-resident dendritic cells(DCs) likely encounter incoming viruses in the first place, and their migration to lymph nodes following virus capture may promote viral replication. However, the molecular mechanisms underlying these processes remain unclear. In the present study, we found that compared to cell-free viruses, DC-bound viruses showed enhanced capture of JEV by T cells.Additionally, JEV infection was increased by co-culturing DCs and T cells. Blocking the C-type lectin receptor DC-specific intercellular adhesion molecule-3-grabbing non-integrin(DC-SIGN) with neutralizing antibodies or antagonists blocked JEV transmission to T cells. Live-cell imaging revealed that DCs captured and transferred JEV viral particles to T cells via virological synapses formed at DC-T cell junctions. These findings indicate that DC-SIGN plays an important role in JEV transmission from DCs to T cells and provide insight into how JEV exploits the migratory and antigen-presenting capabilities of DCs to gain access to lymph nodes for dissemination and persistence in the host.
基金supported by the National Natural Science Foundation of China(Nos.81371814 and 31302116)National Program on Key Research Project of China(No.2016YFD0500400)the Program of International S&T Cooperation(No.2014DFE30140)
文摘Japanese encephalitis virus （jEV） is a mosquito-borne virus of the family Flaviviridae. It is the causative agent of Japanese encephalitis with approximately 50,000 infection cases and 10,000 fatal cases annually in Asia （Erlanger et al., 2009）. Although liveattenuated JEV vaccine has been developed and used for human and pig vaccination, JE occurs epidemically or sporadically in some developing countries or even in vaccinated areas （Solomon, 2006）. Host resistance factors play an important role in the outcome of viral infection.
文摘BACKGROUND Japanese encephalitis(JE) is a serious public health concern with a high mortality rate in many Asian countries. For many years, JE virus(JEV) was considered the major cause of viral encephalitis in Asia. Although most JE cases are asymptomatic, the case fatality rate approaches 30%, and approximately 30%–50% of survivors have long-term neurological sequelae. To the best of our knowledge, JEV infection has never been reported following liver transplantation.CASE SUMMARY We report a case of a woman who underwent liver transplantation for autoimmune liver disease but presented with fever and neurological symptoms 13 d after transplantation. Magnetic resonance imaging revealed JEV infection,and positive immunoglobulin M antibody to JEV in blood and cerebrospinal fluid confirmed JE. The patient was treated with antiviral agents, immune regulation,and organ function support. No neurological sequelae were present after 1 year of follow-up.CONCLUSION Imaging and lumbar puncture examination should be performed as soon as possible in patients with fever and central nervous system symptoms after liver transplantation, and the possibility of atypical infection should be considered,which is helpful for early diagnosis and improved prognosis.
文摘[ Objective] To develop an indirect ELISA assay for detecting antibodies against envelope glycoprotein （ E protein） of Japanese encephalitis virus （JEV）. [ Method] Specific primers were designed according to JEV sequences published in the GenBank. The cDNA of JEV E gene （about 1 000 10p） was amplified by the RT-PCR with the specific primers. After sequencing analysis, the E gene was cloned into pET30a expression vector and expressed in E. coli BL21 （DE3） with the induction of IPTG. After denaturation, purification and renaturation, the recombinant protein was analyzed by the SDS-PAGE and the westem blotting. An indirect ELISA was developed to detect antibodies against JEV. [ Result] The E protein was mainly expressed in inclusion body. With the purified E protein, the indirect ELISA was developed and displayed good specificity, sensitivity and repeatability, [ Conclusion]The developed ELISA using the truncated E protein as antigen is a simple, convenient and rapid serological method for diagnosis, monitoring antibody level and epidemiological investigation of JEV.
