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Search Results: 1 - 10 of 7620 matches for " Japanese encephalitis virus "
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Japanese Encephalitis Virus Replication and Inhibitory Effect of shRNA in Mice  [PDF]
Manabu Murakami, Takafumi Tasaki, Souichi Nukuzuma, Hiroshi Minato, Takayuki Nojima, Yasuhito Ishigaki, Tsutomu Takegami
Advances in Microbiology (AiM) , 2016, DOI: 10.4236/aim.2016.66045
Abstract: Japanese Encephalitis Virus (JEV) is responsible for over 30,000 annual cases of encephalitis worldwide, causing 30% mortality. JEV is thus a continuing threat to public health, so development of new antiviral drugs against JEV is desirable. Here, we examined JEV replication in mouse and used a short hairpin RNA JRi as the antiviral agent. The features of virus replication in neuron and survival rates of mice infected with JEV were different between virus strains. The mice infected with the virulent JEV strain (JaGAr01) were injected with pJRi (100 μg/mouse) which produced shRNAJRi. The survival rates of mice treated at 3 days before, the same day and 3 days after JEV infection were 22%, 78% and 44%, respectively. In addition, we demonstrated that the injection of pJRi induced interferon (IFN) production in cells and mice. These results suggest that the replication of JEV can be efficiently inhibited by RNAi and innate immunity including IFN. These data mean that pJRi has the inhibitory activity against JEV infection in vivo, and could be used as an antiviral drug to treat JEV infection.
Simultaneous detection and differentiation of dengue virus serotypes 1-4, Japanese encephalitis virus, and West Nile virus by a combined reverse-transcription loop-mediated isothermal amplification assay
Shuhua Li, Meiyu Fang, Bin Zhou, Hongxia Ni, Qiuxia Shen, Hongwei Zhang, Yifang Han, Jianhua Yin, Wenjun Chang, Guozhang Xu, Guangwen Cao
Virology Journal , 2011, DOI: 10.1186/1743-422x-8-360
Abstract: We developed a flexible reverse-transcription loop-mediated isothermal amplification (RT-LAMP) unit for the detection and differentiation of dengue virus serotypes 1-4 (DENV1-4), Japanese encephalitis virus (JEV), and West Nile virus (WNV). The unit efficiently amplified the viral genomes specifically at wide ranges of viral template concentrations, and exhibited similar amplification curves as monitored by a real-time PCR engine. The detection limits of the RT-LAMP unit were 100-fold higher than that of RT-PCR in 5 of the six flaviviruses. The results on specificity indicated that the six viruses in the assay had no cross-reactions with each other. By examining 66 viral strains of DENV1-4 and JEV, the unit identified the viruses with 100% accuracy and did not cross-react with influenza viruses and hantaviruses. By screening a panel of specimens containing sera of 168 patients and 279 pools of field-caught blood sucked mosquitoes, results showed that this unit is high feasible in clinical settings and epidemiologic field, and it obtained results 100% correlated with real-time RT-PCR.The RT-LAMP unit developed in this study is able to quickly detect and accurately differentiate the six kinds of flaviviruses, which makes it extremely feasible for screening these viruses in acute-phase sera of the patients and in vector mosquitoes without the need of high-precision instruments.Dengue virus (DENV), Japanese encephalitis virus (JEV), and West Nile virus (WNV) belong to the members of the genus Flavivirus of the family Flaviviridae. DENV has four distinct serotypes, DENV1-4, is maintained in a human-mosquito transmission cycle involving primarily Aedes aegypti and Aedes albopictus, and results in various clinical manifestations ranging from asymptomatic to dengue shock syndrome. Global prevalence of dengue has grown dramatically in the recent decades [1]. JEV is transmitted among birds, pigs, and other domestic animals and human beings by Culex species mosquitoes. Humans
Development and application of an antigen capture ELISA assay for diagnosis of Japanese encephalitis virus in swine, human and mosquito
Li Mei, Peng Wu, Jing Ye, Guangping Gao, Lin Shao, Shaomei Huang, Yaoming Li, Xiaohong Yang, Huanchun Chen, Shengbo Cao
Virology Journal , 2012, DOI: 10.1186/1743-422x-9-4
Abstract: To develop a method for detecting JEV antigen in swine, human, mosquito and other clinical specimens specifically, conveniently and effectively, an antigen capture enzyme-linked immunosorbent assay (ELISA) was established in this study. Sensitivity, specificity, repeatability and stability of the developed method were evaluated, and 60 clinical samples were tested in this study. The results demonstrated that the antigen capture ELISA was capable in detecting JEV antigen with high sensitivity and specificity compared with conventional methods. 14 samples showed the positive result with coincidence rate of 70%, and 46 displayed negative result with coincidence rate of 100% as compared to that of reverse transcription-polymerase chain reaction (RT-PCR).The developed ELISA assay provides a convenient and specific method for the large-scale determination of JEV antigen in infected swine, human and mosquito samples with high sensitivity and specificity.Japanese encephalitis (JE) is a serious mosquito-borne zoonosis caused by the Japanese encephalitis virus (JEV) which threatens public health in southern and eastern Asia. In general, JEV is maintained in a transmission cycle between amplifier swine and vector mosquitoes [1]. As a dead-end, humans are infected by bites of infectious mosquitoes and subsequently develop neurological diseases with an estimated 10,000 JE-related deaths annually [2-5]. As an important pathogen in swine, it also induces terrible consequences in sows reproduction and death in piglets [6,7].JEV, a member of the Flaviviridae family, contains a single positive 11-kb RNA genome with three structural proteins and seven nonstructural proteins [8,9], in which, E protein is the major immunogenic protein of JEV. It has the ability to induce neutralizing antibodies and is recognized as a protein candidate for the development of vaccines and diagnosis methods [10].Several laboratory methods have been developed for the detection of JEV infection, such as viru
Antiviral Activity of Baicalein and Quercetin against the Japanese Encephalitis Virus
Jefree Johari,Aynaz Kianmehr,Mohd Rais Mustafa,Sazaly Abubakar,Keivan Zandi
International Journal of Molecular Sciences , 2012, DOI: 10.3390/ijms131216785
Abstract: Japanese encephalitis (JE), a mosquito-borne viral disease, is endemic to the entire east and southeast Asia, and some other parts of the world. Currently, there is no effective therapeutic available for JE; therefore, finding the effective antiviral agent against JEV replication is crucial. In the present study, the in vitro antiviral activity of baicalein and quercetin, two purportedly antiviral bioflavonoids, was evaluated against Japanese encephalitis virus (JEV) replication in Vero cells. Anti-JEV activities of these compounds were examined on different stages of JEV replication cycle. The effects of the compounds on virus replication were determined by foci forming unit reduction assay (FFURA) and quantitative RT-PCR. Baicalein showed potent antiviral activity with IC 50 = 14.28 μg/mL when it was introduced to the Vero cells after adsorption of JEV. Quercetin exhibited weak anti-JEV effects with IC 50 = 212.1 μg/mL when the JEV infected cells were treated with the compound after virus adsorption. However, baicalein exhibited significant effect against JEV adsorption with IC 50 = 7.27 μg/mL while quercetin did not show any anti-adsorption activity. Baicalein also exhibited direct extracellular virucidal activity on JEV with IC 50 = 3.44 μg/mL. However, results of quantitative RT-PCR experiments confirmed the findings from FFURA. This study demonstrated that baicalein should be considered as an appropriate candidate for further investigations, such as the study of molecular and cellular mechanism(s) of action and in vivo evaluation for the development of an effective antiviral compound against Japanese encephalitis virus.
Seroepidemiological survey on Japanese encephalitis virus in swine raising on the southern border of Thailand
Antarasena, C.,Prommuang, P.,Prommuang, P.,Promkuntod, N.
Songklanakarin Journal of Science and Technology , 2002,
Abstract: From February to March 1999, a seroepidemiological survey on Japanese encephalitis virus (JEV) was carried out. One thousand and thirteen serum samples of swine were collected from 37 farms in 4 provinces at the southern border of Thailand; Songkhla, Yala, Narathiwat and Satun. Japanese encephalitis virus antibody was measured using microtiter hemagglutination inhibition (HI) test. The results indicated that 95.12 - 99.42% of the breeder pigs had JE-HI antibodies at > 1:40 compared with 89.08% of the gilts. The percentages of seropositive animals were 49.75%, 50.65% and 100% in fattening pigs, weaning and suckling piglets, respectively. The study demonstrated a high exposure rate of JEV infection among swine population raised on the southern border of Thailand.
Changing Trend of T lymphocytes in Mouse Spleen after Japanese Encephalitis Virus Infection
Yan-fang Sun§, Chang-qin Gu§, Rong Jiang , Jing Ye, Yong-mao Li, Hua-zhen Liu , Hui Song and Ke-mei Peng*
Pakistan Veterinary Journal , 2011,
Abstract: Japanese encephalitis is caused by Japanese encephalitis viruses (JEV) with neurotropism. As one of the most important immune organ, spleen is directly involved in immune response against JEV. However, little research about JEV infection process in spleen has been reported. In this study, immunopathological changes in mouse spleen were analyzed every other day after subcutaneous injection of mice with JEV wild-type strain P3 by immunohistochemistry assay. Immunohistochemistry analysis demonstrated that the number of T lymphocytes was reduced from 0 to 3 DPI, increased from 3 to 7 DPI, and reduced again from 7 to 10 DPI. In addition, neurological dysfunction appeared at 6 DPI. These results suggested that spleen of mice suffered incontrovertible damages in influence of JEV infection. It can also be deduced that the cellular immunity took the crucial part in the first phase of transient viremia against JEV. Moreover, immune response was activated after the immune-depressed period in the first phase of viremia and neurological dysfunction appeared when cellular immunity was activated. Taking together, our research showed distinct immunopathological changes in mice after JEV infection, which enriched our understanding of Japanese encephalitis immunopathogenesis.
Screening of Actinomycetes Producing an ATPase Inhibitor of Japanese Encephalitis Virus RNA Helicase from Soil and Leaf Litter Samples
Microbiology Indonesia , 2011, DOI: 10.5454/mi.5.1.3
Abstract: Actinomycetes are commercially important microorganisms for the production of antibiotics, enzymes, inhibitors of enzymes, and other bioactive secondary metabolites. Some 853 isolates of actinomycetes were isolated from soil and leaf litter samples in Kupang NTT and Enrekang, South Sulawesi. Those isolates were then tested for inhibition of ATPase activity of RNA helicase from Japanese encephalitis virus (JEV), in order to identify a drug candidate for the treatment of JEV infection. Results revealed that 14 isolates have relatively high inhibition-activity on JEV ATPase activity of the JEV-RNA-helicase, which range from approximately 40.0-50.0% inhibition. The highest inhibition-activity was identified in Actinoplanes philippinensis 5-849 with 49. 9% of inhibition-activity and Streptomyces chartreusis 5-095 with 49.2% of inhibition-activity
Effect of brefelidin A and monensin on Japanese encephalitis virus maturation and virus release from cells
Vaibhavi Jawahar Lad,Ashok Kumar Gupta
Microbiology Research , 2011, DOI: 10.4081/mr.2011.e9
Abstract: Japanese encephalitis virus (JEV) replicates in a variety of cells, the exact intracellular site of virus assembly is somewhat obscure. The aims of this study were to investigate the role Golgi apparatus in JEV maturation by utilizing two Golgi-disrupting agents- brefeldin A (BFA) and monensin (MN) that inhibit virus assembly at specific cellular sites. JEV-infected porcine kidney stable (PS) cells were treated with BFA (2 ug/ mL) or MN (10 uM/ mL) at different h post-infection (p. i.) and the virus contents were assayed after 48 h p. i. The treated cells were further subjected to immuno-fluorescence (IF) using antibodies directed against JEV envelope glycoprotein (gpE) for localization of intracellular viral antigen as well as the antigen expression on the cell surface. Addition of BFA or MN to cells immediately after virus adsorption or at 4 h and 12 h postinfection (p. i.), resulted in 4- or 8- fold reduction in infectious virus contents along with inhibition of its transport to the cell surface, indicating an essential role of the Golgi-associated membranes in JEV replication. Interestingly, the antigenicity of the virus, in contrast, remained unaffected as no difference in epitope presentation/ expression was observed in BFA/MN-treated and control (untreated) infected cells even though in the former cells a loss of hemagglutinating (HA) activity was observed. Further, BFA addition at 18 h or 24 h p. i. showed only a negligible effect on virus suggesting that once the viral-associated membranes are formed, these membranes appear to be stable. In contrast, the inhibition with MN persisted even after its addition to cells at 18 h and 24 h p. i., indicating its sustained effect on JEV. Although BFA inhibits protein transport from endoplasmic reticulum (ER) to the Golgi complex while MN inhibits transport from medial to trans cisternae of the Golgi complex, none of the two agents however affected the gpE synthesis and folding essentially required for the epitope presentation/expression within the cells. As flaviviruses are known to encode three glycoproteins (gps) within their genomes i. e., prM, E, and NS, it will be worthwhile in future to determine whether vesicular transport occurs within or between the virus-induced membranes and how the individual JEV-encoded proteins are transported to discrete compartments further remain to be seen.
Multiple linear epitopes (B-cell, CTL and Th) of JEV expressed in recombinant MVA as multiple epitope vaccine induces a protective immune response
Wang Fengjuan,Feng Xiuli,Zheng Qisheng,Hou Hongyan
Virology Journal , 2012, DOI: 10.1186/1743-422x-9-204
Abstract: Epitope-based vaccination might play an important role in the protective immunity against Japanese encephalitis virus (JEV) infection. The purpose of the study is to evaluate the immune characteristics of recombinant MVA carrying multi-epitope gene of JEV (rMVA-mep). The synthetic gene containing critical epitopes (B-cell, CTL and Th) of JEV was cloned into the eukaryotic expression vector pGEM-K1L, and the rMVA-mep was prepared. BALB/c mice were immunized with different dosages of purified rMVA-mep and the immune responses were determined in the form of protective response against JEV, antibodies titers (IgG1 and IgG2a), spleen cell lymphocyte proliferation, and the levels of interferon-γ and interleukin-4 cytokines. The results showed that live rMVA-mep elicited strongly immune responses in dose-dependent manner, and the highest level of immune responses was observed from the groups immunized with 107 TCID50 rMVA-mep among the experimental three concentrations. There were almost no difference of cytokines and neutralizing antibody titers among 107 TCID50 rMVA-mep, recombinant ED3 and inactivated JEV vaccine. It was noteworthy that rMVA-mep vaccination potentiates the Th1 and Th2-type immune responses in dose-dependent manner, and was sufficient to protect the mice survival against lethal JEV challenge. These findings demonstrated that rMVA-mep can produce adequate humoral and cellular immune responses, and protection in mice, which suggested that rMVA-mep might be an attractive candidate vaccine for preventing JEV infection.
Protection of mice against Japanese encephalitis virus group II strain infections by combinations of monoclonal antibodies to different antigenic domains on glycoprotein E
Ashok Kumar Gupta,Attiyaril Abraham Koshy,Vaibhavi Jawahar Lad
Microbiology Research , 2012, DOI: 10.4081/mr.2012.e18
Abstract: A combination of at least three hemagglutination- inhibition-positive (HAI) and virus-specific (Hs) monoclonal antibodies (MAbs) to glycoprotein E (gpE) of Japanese encephalitis virus (JEV) fully protected (100%) mice against JEV strain 733913 infections (group 1). However, these representative epitopes are reported to have been lost on JEV group II strains. In the present study, therefore, the protective effect of various combinations of anti-gpE MAbs representing antigenic epitopes other than Hs was studied on mice infections with JEV group II strains: JEV strains 641686 and 691004. MAbs used in the protective experiments were characterized as HAI-negative virus-specific (NHs) and HAI-positive flavivirus cross-reactive (Hx). Additionally, one of the Hs MAbs (MAb Hs-3) was included in the experiments. Mice were first administered single MAbs or their combinations intraperitoneally and 24 h later, infected with the virus intracerebrally. Protection rates of 70-75% were obtained with a combination of four MAbs: MAbs NHs-1, Hx-1, Hx-3 and Hs-3. However, protection rates of only 20-40% were obtained with three MAbs but none was observed with single or two MAbs. There was, however, a substantial increase in mice survival. The protective effect of several combinations of anti-gpE MAbs representing different antigenic epitopes might be due to the enhancement of binding within the same group and also between different MAb groups. The present results indicate that NHs and Hx epitopes should be incorporated with three Hs epitopes in a JEV vaccine that would have an added advantage, particularly in the flaviviral endemic areas with JEV strain variations.
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