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Japanese Encephalitis Virus (japanese + encephalitis_virus)
Selected AbstractsAltered effector functions of virus-specific and virus cross-reactive CD8+ T cells in mice immunized with related flavivirusesEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 5 2010Derek W. Trobaugh Abstract Memory cross-reactive CD8+ T-cell responses may induce protection or immunopathology upon secondary viral challenge. To elucidate the potential role of T cells in sequential flavivirus infection, we characterized cross-reactive CD4+ and CD8+ T-cell responses between attenuated and pathogenic Japanese encephalitis virus (JEV) and pathogenic West Nile virus (WNV). A previously reported WNV NS4b CD8+ T-cell epitope and its JEV variant elicited CD8+ T-cell responses in both JEV- and WNV-infected mice. The peptide variant homologous to the immunizing virus induced greater cytokine secretion and activated higher frequencies of epitope-specific CD8+ T cells. However, there was a virus-dependent, peptide variant-independent pattern of cytokine secretion; the IFN,+ -to-IFN,+TNF,+ CD8+ T-cell ratio was greater in JEV- than in WNV-infected mice. Despite similarities in viral burden for pathogenic WNV and JEV viruses, CD8+ T cells from pathogenic JEV-immunized mice exhibited functional and phenotypic profiles similar to those seen for the attenuated JEV strain. Patterns of killer cell lectin-like receptor G1 (KLRG1) and CD127 expression differed by virus type, with a rapid expansion and contraction of short-lived effector cells in JEV infection and persistence of high levels of short-lived effector cells in WNV infection. Such cross-reactive T-cell responses to primary infection may affect the outcomes of sequential flavivirus infections. [source] Immunomodulatory cytokines determine the outcome of Japanese encephalitis virus infection in miceJOURNAL OF MEDICAL VIROLOGY, Issue 2 2010S.M. Biswas Abstract Japanese encephalitis virus (JEV) induces an acute infection of the central nervous system, the pathogenic mechanism of which is not fully understood. To investigate host response to JEV infection, 14-day-old mice were infected via the extraneural route, which resulted in encephalitis and death. Mice that received JEV immune splenocyte transfer were protected from extraneural JEV infection. Pathology and gene expression profiles were then compared in brains of mice that either succumbed to JEV infection or were protected from infection by JEV immune cell transfer. Mice undergoing progressive JEV infection had increased expression of proinflammatory cytokines, chemokines, and signal transducers associated with the interferon (IFN) pathway. In contrast, mice receiving immune cell transfer had increased production of the Th2 cytokine IL-4, and of IL-10, with subdued expression of IFN-,. We observed IL-10 to be an important factor in determining clinical outcome in JEV infection. Data obtained by microarray analysis were further confirmed by quantitative RT-PCR. Together, these data suggest that JEV infection causes an unregulated inflammatory response that can be countered by the expression of immunomodulatory cytokines in mice that survive lethal infection. J. Med. Virol. 82:304,310, 2010. © 2009 Wiley-Liss, Inc. [source] Development of a consensus microarray method for identification of some highly pathogenic virusesJOURNAL OF MEDICAL VIROLOGY, Issue 11 2009Kang Xiao-Ping Abstract Some highly pathogenic viruses, such as Chikungunya virus, Japanese encephalitis virus, Yellow fever virus, Dengue virus, Hanta virus, SARS-CoV, and H5N1 avian influenza virus can cause severe infectious diseases. However, the consensus method for detecting these viruses has not been well established. A rapid and sensitive microarray approach for detection of these viruses and a panel of specific probes covering nine genera and 16 virus species were designed. 70-mer oligonucleotides were used at the genus level and 50-mer oligonucleotides were at the species level, respectively. To decrease the interference of the host genome in hybridization, the consensus genus primers were designed and used to reverse transcribe only virus genome. The synthesis of the second strand was carried out with a random primer sequence (5,-GTTTCCCAGTAGGTCTCNNNNNNNN-3,). The amplified products were labeled and processed for microarray analyses. This microarray-based method used the highly conserved consensus primers to synthesize specifically the virus cDNA and could identify effectively Chikungunya virus, Japanese encephalitis virus, Yellow fever virus, Dengue virus, Tick borne encephalitis virus, and H5N1 avian influenza virus. Using this method, one unknown virus isolated from pig brain in Shanxi Province, China was identified. This method may have an important potential application for the diagnosis of virus infection. J. Med. Virol. 81:1945,1950, 2009. © 2009 Wiley-Liss, Inc. [source] Emerging viral infections in AustraliaJOURNAL OF PAEDIATRICS AND CHILD HEALTH, Issue 1 2002AJ Daley Abstract: Emerging viruses include known viruses that have increased in incidence or geographic range (such as enteroviruses and Japanese encephalitis virus), new viruses associated with known diseases (Australian bat lyssavirus) and new viruses associated with previously unrecognized diseases (Hendra and Nipah viruses). Some may have a predilection for children (Japanese encephalitis, influenza viruses and enterovirus 71) and vigilance is essential to ensure early recognition of these agents. [source] Identification and characterization of Japanese encephalitis virus envelope protein gene from swineLETTERS IN APPLIED MICROBIOLOGY, Issue 1 2010J.-M. Fan Abstract Aims:, Identification and characterization of Japanese encephalitis virus (JEV) envelope protein gene from swine. Methods and Results:, Genomic RNA was separated from JEV isolated strain Henan-09-03, and used as templates for cDNA synthesis of E gene. The cDNA of E gene was amplified by RT-PCR and cloned into the pMD19-T-Vector and confirmed by sequencing. The cloned gene was then subcloned into the pET-32a and was introduced into Escherichia coli BL21 (DE3) for expression. The E protein was purified by Ni chelating column-based affinity chromatography. The molecular weight of expressed protein was about 50 kDa. Compared with the published sequence of SA14 (AF495589), the homology of the nucleotide sequence was 98% and the seven mutations resulting in amino acid substitutions at Leu 36 Ser, Leu107 Val, Ala167 Thr, Asn 230 Ser, Leu 340 Pro, Asn 430 Ile, Phe 448 Leu. Phylogenetic analysis of the E sequence of isolated strain classified it within genotype III of the JEV. The result of Western blotting indicated that the antigenicity of the protein was specific. Conclusions:, The stable expression of the protein and the analysis of its antigenic specificity provide the foundation for developing the ELISA early stage diagnosis kit. Significance and Impact of the Study:, As coating antigen, the recombinant E protein served a good source in the indirect ELISA method for the detection of JEV antibody. [source] | |||||||||||||