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Sample records for dengue virus ns1

  1. Dengue NS1 Antigen - for Early Detection of Dengue Virus Infection

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    Amol Hartalkar

    2015-08-01

    Full Text Available Objectives: To evaluate the efficacy of NS1 antigen assay for early diagnosis of dengue virus infection in a tertiary care hospital. Methods: This cross sectional study was carried out in department of Medicine from August to December 2013. Total 100 patients with dengue fever were included. Complete blood count, alanine aminotransferase (ALT, aspartate aminotransferase (AST, Dengue NS1 antigen and IgM and IgG antibodies of dengue virus were done in all cases. Results: Of the 100 sera tested, 75% were positive for dengue virus infection based on dengue NS1 antigen, IgM antibody and IgG antibody. Dengue NS1 antigen and IgM, IgG antibody were able to detect dengue virus infection between day 1 to day 8 in 92% of samples, 86.7% of samples and 82.6% of samples respectively. Sixty nine percent (69% were found positive for dengue NS1 antigen, 65% were IgM positive and 62% were IgG positive. Based on the dengue NS1 antigen and IgM antibody combination, 74% were positive for dengue virus infections. Sensitivity of Dengue NS1 antigen was 92.3% and specificity of 74.28% in comparison to IgM antibody. Detection rate increased to 75%, based on the antigen and IgG antibody combination. Sensitivity of dengue NS1 antigen was 90.3% and specificity of 65.8% in comparison to IgG antibody. Conclusion: Dengue NS1 antigen is a useful, sensitive and specific test for early diagnosis of dengue virus infection and it improves diagnostic efficiency in combination with antibody test. Key words: Dengue fever, NS1 antigen. Introduction: Dengue fever (DF is the most common arboviral illness in humans. Each year, an estimated 50-100 million cases of dengue fever and 500,000 cases of dengue hemorrhagic fever occur worldwide, with 30000 deaths (mainly in children. Globally 2.5-3 billion people in approximately 112 tropical and subtropical countries are at risk of dengue.of samples respectively. Sixty nine percent (69% were found positive for dengue NS1 antigen, 65% were Ig

  2. Production of recombinant dengue non-structural 1 (NS1) proteins from clinical virus isolates.

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    Yohan, Benediktus; Wardhani, Puspa; Aryati; Trimarsanto, Hidayat; Sasmono, R Tedjo

    2017-01-01

    Dengue is a febrile disease caused by infection of dengue virus (DENV). Early diagnosis of dengue infection is important for better management of the disease. The DENV Non-Structural Protein 1 (NS1) antigen has been routinely used for the early dengue detection. In dengue epidemic countries such as Indonesia, clinicians are increasingly relying on the NS1 detection for confirmation of dengue infection. Various NS1 diagnostic tests are commercially available, however different sensitivities and specificities were observed in various settings. This study was aimed to generate dengue NS1 recombinant protein for the development of dengue diagnostic tests. Four Indonesian DENV isolates were used as the source of the NS1 gene cloning, expression, and purification in bacterial expression system. Recombinant NS1 proteins were successfully purified and their antigenicities were assessed. Immunization of mice with recombinant proteins observed the immunogenicity of the NS1 protein. The generated recombinant proteins can be potentially used in the development of NS1 diagnostic test. With minimal modifications, this method can be used for producing NS1 recombinant proteins from isolates obtained from other geographical regions. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Epitope Sequences in Dengue Virus NS1 Protein Identified by Monoclonal Antibodies

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    Leticia Barboza Rocha

    2017-10-01

    Full Text Available Dengue nonstructural protein 1 (NS1 is a multi-functional glycoprotein with essential functions both in viral replication and modulation of host innate immune responses. NS1 has been established as a good surrogate marker for infection. In the present study, we generated four anti-NS1 monoclonal antibodies against recombinant NS1 protein from dengue virus serotype 2 (DENV2, which were used to map three NS1 epitopes. The sequence 193AVHADMGYWIESALNDT209 was recognized by monoclonal antibodies 2H5 and 4H1BC, which also cross-reacted with Zika virus (ZIKV protein. On the other hand, the sequence 25VHTWTEQYKFQPES38 was recognized by mAb 4F6 that did not cross react with ZIKV. Lastly, a previously unidentified DENV2 NS1-specific epitope, represented by the sequence 127ELHNQTFLIDGPETAEC143, is described in the present study after reaction with mAb 4H2, which also did not cross react with ZIKV. The selection and characterization of the epitope, specificity of anti-NS1 mAbs, may contribute to the development of diagnostic tools able to differentiate DENV and ZIKV infections.

  4. Therapeutic Effects of Monoclonal Antibody against Dengue Virus NS1 in a STAT1 Knockout Mouse Model of Dengue Infection.

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    Wan, Shu-Wen; Chen, Pei-Wei; Chen, Chin-Yu; Lai, Yen-Chung; Chu, Ya-Ting; Hung, Chia-Yi; Lee, Han; Wu, Hsuan Franziska; Chuang, Yung-Chun; Lin, Jessica; Chang, Chih-Peng; Wang, Shuying; Liu, Ching-Chuan; Ho, Tzong-Shiann; Lin, Chiou-Feng; Lee, Chien-Kuo; Wu-Hsieh, Betty A; Anderson, Robert; Yeh, Trai-Ming; Lin, Yee-Shin

    2017-10-15

    Dengue virus (DENV) is the causative agent of dengue fever, dengue hemorrhagic fever, and dengue shock syndrome and is endemic to tropical and subtropical regions of the world. Our previous studies showed the existence of epitopes in the C-terminal region of DENV nonstructural protein 1 (NS1) which are cross-reactive with host Ags and trigger anti-DENV NS1 Ab-mediated endothelial cell damage and platelet dysfunction. To circumvent these potentially harmful events, we replaced the C-terminal region of DENV NS1 with the corresponding region from Japanese encephalitis virus NS1 to create chimeric DJ NS1 protein. Passive immunization of DENV-infected mice with polyclonal anti-DJ NS1 Abs reduced viral Ag expression at skin inoculation sites and shortened DENV-induced prolonged bleeding time. We also investigated the therapeutic effects of anti-NS1 mAb. One mAb designated 2E8 does not recognize the C-terminal region of DENV NS1 in which host-cross-reactive epitopes reside. Moreover, mAb 2E8 recognizes NS1 of all four DENV serotypes. We also found that mAb 2E8 caused complement-mediated lysis in DENV-infected cells. In mouse model studies, treatment with mAb 2E8 shortened DENV-induced prolonged bleeding time and reduced viral Ag expression in the skin. Importantly, mAb 2E8 provided therapeutic effects against all four serotypes of DENV. We further found that mAb administration to mice as late as 1 d prior to severe bleeding still reduced prolonged bleeding time and hemorrhage. Therefore, administration with a single dose of mAb 2E8 can protect mice against DENV infection and pathological effects, suggesting that NS1-specific mAb may be a therapeutic option against dengue disease. Copyright © 2017 by The American Association of Immunologists, Inc.

  5. A thiophene-modified screen printed electrode for detection of dengue virus NS1 protein.

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    Silva, M M S; Dias, A C M S; Cordeiro, M T; Marques, E; Goulart, M O F; Dutra, R F

    2014-10-01

    A thiophene-modified screen printed electrode (SPE) for detection of the Dengue virus non-structural protein 1 (NS1), an important marker for acute phase diagnosis, is described. A sulfur-containing heterocyclic compound, the thiophene was incorporated to a carbon ink to prepare reproducible screen printed electrodes. After cured, the thiophene SPE was coated by gold nanoparticles conjugated to Protein A to form a nanostrutured surface. The Anti-NS1 antibodies immobilized via their Fc portions via Protein A, leaving their antigen specific sites free circumventing the problem of a random antibodies immobilization. Amperometric responses to the NS1 protein of dengue virus were obtained by cyclic voltammetries performed in presence of ferrocyanide/ferricyanide as redox probe. The calibration curve of immunosensor showed a linear response from 0.04 µg mL(-1) to 0.6 µg mL(-1) of NS1 with a good linear correlation (r=0.991, pink enhanced the electroanalytical properties of the SPEs, increasing their reproducibility and sensitivity. This point-of-care testing represents a great potential for use in epidemic situations, facilitating the early diagnosis in acute phase of dengue virus. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Identification of human hnRNP C1/C2 as a dengue virus NS1-interacting protein

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    Noisakran, Sansanee; Sengsai, Suchada; Thongboonkerd, Visith; Kanlaya, Rattiyaporn; Sinchaikul, Supachok; Chen, Shui-Tein; Puttikhunt, Chunya

    2008-01-01

    Dengue virus nonstructural protein 1 (NS1) is a key glycoprotein involved in the production of infectious virus and the pathogenesis of dengue diseases. Very little is known how NS1 interacts with host cellular proteins and functions in dengue virus-infected cells. This study aimed at identifying NS1-interacting host cellular proteins in dengue virus-infected cells by employing co-immunoprecipitation, two-dimensional gel electrophoresis, and mass spectrometry. Using lysates of dengue virus-infected human embryonic kidney cells (HEK 293T), immunoprecipitation with an anti-NS1 monoclonal antibody revealed eight isoforms of dengue virus NS1 and a 40-kDa protein, which was subsequently identified by quadrupole time-of-flight tandem mass spectrometry (Q-TOF MS/MS) as human heterogeneous nuclear ribonucleoprotein (hnRNP) C1/C2. Further investigation by co-immunoprecipitation and co-localization confirmed the association of hnRNP C1/C2 and dengue virus NS1 proteins in dengue virus-infected cells. Their interaction may have implications in virus replication and/or cellular responses favorable to survival of the virus in host cells

  7. Raman spectroscopy based discrimination of NS1 positive and negative dengue virus infected serum

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    Bilal, M.; Saleem, M.; Bilal, Maria; Khurram, M.; Khan, Saranjam; Ullah, Rahat; Ali, Hina; Ahmed, M.

    2016-09-01

    This study is intended to develop a multivariate statistical model for the prediction of nonstructural protein 1 (NS1) in dengue virus (DENV) infected blood serum in humans. The model has been developed on the basis of partial least squares regression using the Raman spectra of NS1 positive and NS1 negative samples. Human blood sera of 218 subjects is included in this study, of which 95 were NS1 positive and 123 were NS1 negative, which was confirmed with the enzyme linked immunosorbent assay method. For model development, 80 NS1 positive and 98 NS1 negative samples were used, while 40 DENV suspected samples were used for double blind testing of the model. This selection of samples was performed by the code in an automatic manner to avoid biasing. A laser at 785 nm was used as the excitation source to acquire Raman spectra of samples with an integration time of 15 s. The multivariate model yields coefficients of regression at corresponding Raman shifts. These coefficients represent changes in the molecular structures associated with NS1 positive and negative samples. The analysis of the regression coefficients which differentiate NS1 positive and NS1 negative groups shows an increasing trend for phosphatidylinositol, ceramide, and amide-III, and a decreasing trend for thiocyanate in the DENV infected serum. The R-squared value of the model was found to be 0.91, which is clinically acceptable. The blind testing of 40 suspected samples yields an accuracy, sensitivity, and specificity of about 100% each.

  8. Inhibition of the Membrane Attack Complex by Dengue Virus NS1 through Interaction with Vitronectin and Terminal Complement Proteins.

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    Conde, Jonas Nascimento; da Silva, Emiliana Mandarano; Allonso, Diego; Coelho, Diego Rodrigues; Andrade, Iamara da Silva; de Medeiros, Luciano Neves; Menezes, Joice Lima; Barbosa, Angela Silva; Mohana-Borges, Ronaldo

    2016-11-01

    Dengue virus (DENV) infects millions of people worldwide and is a major public health problem. DENV nonstructural protein 1 (NS1) is a conserved glycoprotein that associates with membranes and is also secreted into the plasma in DENV-infected patients. The present study describes a novel mechanism by which NS1 inhibits the terminal complement pathway. We first identified the terminal complement regulator vitronectin (VN) as a novel DENV2 NS1 binding partner by using a yeast two-hybrid system. This interaction was further assessed by enzyme-linked immunosorbent assay (ELISA) and surface plasmon resonance (SPR) assay. The NS1-VN complex was also detected in plasmas from DENV-infected patients, suggesting that this interaction occurs during DENV infection. We also demonstrated that the DENV2 NS1 protein, either by itself or by interacting with VN, hinders the formation of the membrane attack complex (MAC) and C9 polymerization. Finally, we showed that DENV2, West Nile virus (WNV), and Zika virus (ZIKV) NS1 proteins produced in mammalian cells inhibited C9 polymerization. Taken together, our results points to a role for NS1 as a terminal pathway inhibitor of the complement system. Dengue is the most important arthropod-borne viral disease nowadays and is caused by dengue virus (DENV). The flavivirus NS1 glycoprotein has been characterized functionally as a complement evasion protein that can attenuate the activation of the classical, lectin, and alternative pathways. The present study describes a novel mechanism by which DENV NS1 inhibits the terminal complement pathway. We identified the terminal complement regulator vitronectin (VN) as a novel DENV NS1 binding partner, and the NS1-VN complex was detected in plasmas from DENV-infected patients, suggesting that this interaction occurs during DENV infection. We also demonstrated that the NS1-VN complex inhibited membrane attack complex (MAC) formation, thus interfering with the complement terminal pathway. Interestingly

  9. Detection of Immune-Complex Dissociated Nonstructural-1 (NS-1) Antigen in Patients with Acute Dengue Virus Infections

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    P. Koraka (Penelope); C.P. Burghoorn-Maas; A. Falconar; T.E. Setiati (Tatty); K. Djamiatun; J. Groen (Jan); A.D.M.E. Osterhaus (Albert)

    2003-01-01

    textabstractAccurate and timely diagnosis of dengue virus (DEN) infections is essential for the differential diagnosis of patients with febrile illness and hemorrhagic fever. In the present study, the diagnostic value of a newly developed immune-complex dissociated nonstructural-1 (NS-1) antigen dot

  10. A sensor tip based on carbon nanotube-ink printed electrode for the dengue virus NS1 protein.

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    Dias, Ana Carolina M S; Gomes-Filho, Sérgio L R; Silva, Mízia M S; Dutra, Rosa F

    2013-06-15

    An immunosensor for the non-structural protein 1 (NS1) of the dengue virus based on carbon nanotube-screen printed electrodes (CNT-SPE) was successfully developed. A homogeneous mixture containing carboxylated carbon nanotubes was dispersed in carbon ink to prepare a screen printed working electrode. Anti-NS1 antibodies were covalently linked to CNT-SPE by an ethylenediamine film strategy. Amperometrical responses were generated at -0.5 V vs. Ag/AgCl by hydrogen peroxide reaction with peroxidase (HRP) conjugated to the anti-NS1. An excellent detection limit (in the order of 12 ng mL(-1)) and a sensitivity of 85.59 μA mM(-1)cm(-2) were achieved permitting dengue diagnostic according to the clinical range required. The matrix effect, as well as the performance of the assays, was successfully evaluated using spiked blood serum sample obtaining excellent recovery values in the results. Carbon nanotubes incorporated to the carbon ink improved the reproducibility and sensitivity of the CNT-SPE immunosensor. This point-of-care approach represents a great potential value for use in epidemic situations and can facilitate the early screening of patients in acute phase of dengue virus. Copyright © 2012 Elsevier B.V. All rights reserved.

  11. NS 1 lasts longer than the dengue virus nucleic acid in the clinically suspected patients with dengue fever and dengue haemorrhagic fever.

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    Sirisena, Nadeera; Noordeen, Faseeha; Fernando, LakKumar

    2017-09-01

    The objectives of the study were to compare the DENV NS1 and nucleic acid positivity in dengue fever (DF) and dengue haemorrhagic fever (DHF) patients and to evaluate the usefulness of these parameters in severe dengue. Blood samples were collected from 91 patients with DF or DHF (fever days 3-9) from Gampaha and Negombo General Hospitals, Sri Lanka and tested for DENV NS1 antigen and nucleic acid. On fever day 3, 67% of the DF and 33% of the DHF patients had DENV nucleic acid whereas 50% of the DF and 67% of the DHF patients had NS1. On fever day 4, 67% of the DF and 100% of the DHF patients had DENV nucleic acid whereas 83% of the DF and DHF patients had NS1. From fever day 5 in the DHF group, DENV nucleic acid declined but NS1 remained detectable even on day 9 ( p   0.05) whereas NS1 positivity significantly correlated with the decrease in the platelet count in DF and DHF patients ( p  < 0.0001). NS1 is a useful marker to detect DENV infection even in the latter stages of DHF.

  12. Activation of TLR2 and TLR6 by Dengue NS1 Protein and Its Implications in the Immunopathogenesis of Dengue Virus Infection.

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    Jincheng Chen

    2015-07-01

    Full Text Available Dengue virus (DV infection is the most prevalent mosquito-borne viral disease and its manifestation has been shown to be contributed in part by the host immune responses. In this study, pathogen recognition receptors, Toll-like receptor (TLR 2 and TLR6 were found to be up-regulated in DV-infected human PBMC using immunofluorescence staining, flow cytometry and Western blot analyses. Using ELISA, IL-6 and TNF-α, cytokines downstream of TLR2 and TLR6 signaling pathways were also found to be up-regulated in DV-infected PBMC. IL-6 and TNF-α production by PBMC were reduced when TLR2 and TLR6 were blocked using TLR2 and TLR6 neutralizing antibodies during DV infection. These results suggested that signaling pathways of TLR2 and TLR6 were activated during DV infection and its activation contributed to IL-6 and TNF-α production. DV NS1 protein was found to significantly increase the production of IL-6 and TNF-α when added to PBMC. The amount of IL-6 and TNF-α stimulated by DV NS1 protein was reduced when TLR2 and TLR6 were blocked, suggesting that DV NS1 protein is the viral protein responsible for the activation of TLR2 and TLR6 during DV infection. Secreted alkaline phosphatase (SEAP reporter assay was used to further confirm activation of TLR2 and TLR6 by DV NS1 protein. In addition, DV-infected and DV NS1 protein-treated TLR6-/- mice have higher survivability compared to DV-infected and DV NS1 protein-treated wild-type mice. Hence, activation of TLR6 via DV NS1 protein could potentially play an important role in the immunopathogenesis of DV infection.

  13. Genome-Wide Mutagenesis of Dengue Virus Reveals Plasticity of the NS1 Protein and Enables Generation of Infectious Tagged Reporter Viruses.

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    Eyre, Nicholas S; Johnson, Stephen M; Eltahla, Auda A; Aloi, Maria; Aloia, Amanda L; McDevitt, Christopher A; Bull, Rowena A; Beard, Michael R

    2017-12-01

    Dengue virus (DENV) is a major global pathogen that causes significant morbidity and mortality in tropical and subtropical areas worldwide. An improved understanding of the regions within the DENV genome and its encoded proteins that are required for the virus replication cycle will expedite the development of urgently required therapeutics and vaccines. We subjected an infectious DENV genome to unbiased insertional mutagenesis and used next-generation sequencing to identify sites that tolerate 15-nucleotide insertions during the virus replication cycle in hepatic cell culture. This revealed that the regions within capsid, NS1, and the 3' untranslated region were the most tolerant of insertions. In contrast, prM- and NS2A-encoding regions were largely intolerant of insertions. Notably, the multifunctional NS1 protein readily tolerated insertions in regions within the Wing , connector , and β- ladder domains with minimal effects on viral RNA replication and infectious virus production. Using this information, we generated infectious reporter viruses, including a variant encoding the APEX2 electron microscopy tag in NS1 that uniquely enabled high-resolution imaging of its localization to the surface and interior of viral replication vesicles. In addition, we generated a tagged virus bearing an mScarlet fluorescent protein insertion in NS1 that, despite an impact on fitness, enabled live cell imaging of NS1 localization and traffic in infected cells. Overall, this genome-wide profile of DENV genome flexibility may be further dissected and exploited in reporter virus generation and antiviral strategies. IMPORTANCE Regions of genetic flexibility in viral genomes can be exploited in the generation of reporter virus tools and should arguably be avoided in antiviral drug and vaccine design. Here, we subjected the DENV genome to high-throughput insertional mutagenesis to identify regions of genetic flexibility and enable tagged reporter virus generation. In particular, the

  14. Interaction of a dengue virus NS1-derived peptide with the inhibitory receptor KIR3DL1 on natural killer cells.

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    Townsley, E; O'Connor, G; Cosgrove, C; Woda, M; Co, M; Thomas, S J; Kalayanarooj, S; Yoon, I-K; Nisalak, A; Srikiatkhachorn, A; Green, S; Stephens, H A F; Gostick, E; Price, D A; Carrington, M; Alter, G; McVicar, D W; Rothman, A L; Mathew, A

    2016-03-01

    Killer immunoglobulin-like receptors (KIRs) interact with human leucocyte antigen (HLA) class I ligands and play a key role in the regulation and activation of NK cells. The functional importance of KIR-HLA interactions has been demonstrated for a number of chronic viral infections, but to date only a few studies have been performed in the context of acute self-limited viral infections. During our investigation of CD8(+) T cell responses to a conserved HLA-B57-restricted epitope derived from dengue virus (DENV) non-structural protein-1 (NS1), we observed substantial binding of the tetrameric complex to non-T/non-B lymphocytes in peripheral blood mononuclear cells (PBMC) from a long-standing clinical cohort in Thailand. We confirmed binding of the NS1 tetramer to CD56(dim) NK cells, which are known to express KIRs. Using depletion studies and KIR-transfected cell lines, we demonstrated further that the NS1 tetramer bound the inhibitory receptor KIR3DL1. Phenotypical analysis of PBMC from HLA-B57(+) subjects with acute DENV infection revealed marked activation of NS1 tetramer-binding natural killer (NK) cells around the time of defervescence in subjects with severe dengue disease. Collectively, our findings indicate that subsets of NK cells are activated relatively late in the course of acute DENV illness and reveal a possible role for specific KIR-HLA interactions in the modulation of disease outcomes. © 2015 The Authors. Clinical & Experimental Immunology published by John Wiley & Sons Ltd on behalf of British Society for Immunology.

  15. Uncaria tomentosa alkaloidal fraction reduces paracellular permeability, IL-8 and NS1 production on human microvascular endothelial cells infected with dengue virus.

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    Lima-Junior, Raimundo Sousa; Mello, Cintia da Silva; Siani, Antonio Carlos; Valente, Ligia M Marino; Kubelka, Claire Fernandes

    2013-11-01

    Dengue is the major Arbovirus in the world, annually causing morbidity and death. Severe dengue is associated with changes in the endothelial barrier function due to the production of inflammatory mediators by immune cells and by the endothelium. Dengue virus (DENV) replicates efficiently in human endothelial cells in vitro and elicits immune responses resulting in endothelial permeability. Uncaria tomentosa (Willd.) DC.(Rubiaceae), known as cat's claw, has been used in folk medicine for the treatment of a wide-array of symptoms, and several scientific studies reported its antiviral, immunomodulatory, anti-inflammatory and antioxidant properties. Here we infected a human lineage of dermal microvascular endothelial cells (HMEC-1) with DENV-2 and treated it with an alkaloidal fraction from U. tomentosa bark (AFUT). We showed antiviral and immunomodulatory activities of U. tomentosa by determining the NS1 antigen and IL-8 in supernatant of DENV-2 infected HMEC-1. Furthermore, by measurement of transendothelial electrical resistance (TEER) we demonstrated, for the first time, that a plant derivative contributed to the reduction of paracellular permeability in DENV-2 infected HMEC-1. We also showed that IL-8 contributed significantly to the induction of permeability. Although further investigations should be conducted before a new drug can be suggested, our in vitro data support evidence that AFUT could be potentially useful in developing a treatment for severe dengue.

  16. Dengue Virus NS1 Protein as a Diagnostic Marker: Commercially Available ELISA and Comparison to qRT-PCR and Serological Diagnostic Assays Currently Used by the State of Florida

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    Jason H. Ambrose

    2017-01-01

    Full Text Available Background. The proper management of patients infected with dengue virus requires early detection. Here, real-time molecular assays have proven useful but have limitations, whereas ELISAs that detect antibodies are still favored but results are obtained too late to be of clinical value. The production of DENV NS1 peaks early during infection and its detection can combine the advantages of both diagnostic approaches. Methods. This study compared assays currently used for detecting DENV infection at the Florida Department of Health including anti-DENV IgM and IgG ELISAs as well as qRT-PCR, against a commercially available DENV NS1 ELISA. These comparisons were made among a group of 21 human sera. Results. Nine of 14 (64.3% DENV qRT-PCR+ samples were also DENV NS1+. Interestingly, the 5 NS1− samples that were qRT-PCR+ were additionally IgM− and IgG+ suggesting a nonprimary infection. Compared to qRT-PCR, the NS1 assay had a sensitivity of 64.3%, specificity 100%, PPV of 100%, and NPV of 58.3%. Conclusions. The NS1 ELISA performed as expected in known DENV qRT-PCR+ samples; however negative NS1 results for qRT-PCR+ and IgG+ sera seemingly reduced the usefulness of the NS1 ELISA for nonprimary cases. We therefore conclude that diagnosis obtained via DENV NS1 ELISA deserves further investigation.

  17. Comprehensive Mapping Antigenic Epitopes of NS1 Protein of Japanese Encephalitis Virus with Monoclonal Antibodies.

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    Rong-Hong Hua

    Full Text Available Japanese encephalitis virus (JEV non-structural protein 1 (NS1 contributes to virus replication and elicits protective immune responses during infection. JEV NS1-specific antibody responses could be a target in the differential diagnosis of different flavivirus infections. However, the epitopes on JEV NS1 are poorly characterized. The present study describes the full mapping of linear B-cell epitopes in JEV NS1. We generated eleven NS1-specific monoclonal antibodies from mice immunized with recombinant NS1. For epitope mapping of monoclonal antibodies, a set of 51 partially-overlapping peptides covering the entire NS1 protein were expressed with a GST-tag and then screened using monoclonal antibodies. Through enzyme-linked immunosorbent assay (ELISA, five linear epitope-containing peptides were identified. By sequentially removing amino acid residues from the carboxy and amino terminal of peptides, the minimal units of the five linear epitopes were identified and confirmed using monoclonal antibodies. Five linear epitopes are located in amino acids residues (5AIDITRK(11, (72RDELNVL(78, (251KSKHNRREGY(260, (269DENGIVLD(276, and (341DETTLVRS(348. Furthermore, it was found that the epitopes are highly conserved among JEV strains through sequence alignment. Notably, none of the homologous regions on NS1 proteins from other flaviviruses reacted with the MAbs when they were tested for cross-reactivity, and all five epitope peptides were not recognized by sera against West Nile virus or Dengue virus. These novel virus-specific linear B-cell epitopes of JEV NS1 would benefit the development of new vaccines and diagnostic assays.

  18. Clinical evaluation of dengue RNA, NS1, and IgM for diagnosis of dengue in Southern China.

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    Chen, Xinliang; Chen, Rui; Gu, Wenshen; He, Jian; Cai, Weipeng; Li, Jiajia; Duan, Chaohui; Yan, Haiyan

    2016-01-01

    In 2014, a large outbreak of dengue occurred in Guangzhou, China. This outbreak prompted us to evaluate NS1 and RNA for the early diagnosis of acute dengue infection, in addition to the combination with IgM antibody. We aimed to find the differences of three assays about dengue diagnosis. This study was an evaluation of diagnosis test. Based on WHO criteria 2009, dengue RNA, NS1, and IgM/IgG were detected from 294 patients (180 dengue patients, 114 non-dengue patients) by three diagnostic kits made in China. The χ(2) test, sensitivity, and specificity were used in statistical analysis. The ratios of dengue patients with low platelet counts (dengue patients (P Dengue NS1 was shown sensitive (93.9%) for diagnostic use. RNA had a better performance with 98.1% of sensitivity from day 1 to day 4 after illness onset. IgM performed better at day 5 or more with 74.0% of sensitivity. The diagnostic rate using a combination of RNA and IgM was 97.8% and 96.7% using NS1 and IgM. A patient with low platelet and white blood cell counts needs additional tests for dengue during an epidemic. RNA and NS1 were most valuable for early diagnosis of dengue, whereas IgM was best suited as a supplementary method for patients at day 5 or more after illness onset. © 2015 Wiley Periodicals, Inc.

  19. Utility of dengue NS1 antigen rapid diagnostic test for use in difficult to reach areas and its comparison with dengue NS1 ELISA and qRT-PCR.

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    Shukla, Mohan K; Singh, Neeru; Sharma, Ravendra K; Barde, Pradip V

    2017-07-01

    The objective of this study was to demonstrate the utility of dengue virus (DENV) non structural protein 1 (NS1) based rapid diagnostic test (RDT) for use in tribal and difficult to reach areas for early dengue (DEN) diagnosis in acute phase patients and evaluate its sensitivity and specificity against DENV NS1 enzyme linked immune sorbent assay (ELISA) and real time reverse transcriptase polymerase chain reaction (qRT-PCR). The DENV NS1 RDT was used for preliminary diagnosis during outbreaks in difficult to reach rural and tribal areas. The diagnosis was confirmed by DENV NS1 ELISA in the laboratory. The samples were also tested and serotyped by qRT-PCR. The results were evaluated using statistical tests. The DENV NS1 RDT showed 99.2% sensitivity and 96.0% specificity when analyzed using DENV NS1 ELISA as standard. The specificity and sensitivity of the RDT when compared with qRT-PCR was 93.6% and 91.1%, respectively. The serotype specific evaluation showed more than 90% sensitivity and specificity for DENV-1, 2, and 3. The RDT proved a good diagnostic tool in difficult to reach rural and tribal areas. Further evaluation studies with different commercially available RDTs in different field conditions are essential, that will help clinicians and patients for treatment and programme managers for timely intervention. © 2017 Wiley Periodicals, Inc.

  20. Increased sensitivity of NS1 ELISA by heat dissociation in acute dengue 4 cases.

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    Buonora, Sibelle Nogueira; Dos Santos, Flavia Barreto; Daumas, Regina Paiva; Passos, Sonia Regina Lambert; da Silva, Manoela Heringer; de Lima, Monique Rocha; Nogueira, Rita Maria Ribeiro

    2017-03-11

    Dengue is an acute febrile illness considered the major arboviral disease in terms of morbidity, mortality, economic impact and dissemination worldwide. Brazil accounts for the highest notification rate, with circulation of all four dengue serotypes. The NS1 antigen is a dengue highly conserved specific soluble glycoprotein essential for viral replication and viability that can be detected 0 to 18 days from the onset of fever (peak first 3 days). It induces a strong humoral response and is known as a complement-fixing antigen. Lower NS1 test sensitivity occurs in secondary dengue infections probably due to immune complex formation impairing antigen detection by ELISA. We compared the sensitivity of NS1 ELISA in heat dissociated and non-dissociated samples from 156 RT-PCR confirmed acute dengue-4 cases from 362 prospectively enrolled patients. Secondary infections accounted for 83.3% of cases. NS1 ELISA was positive in 42.5% and indeterminate in 10.2% of dengue-4 cases. After heat dissociation, 7 negative and 16 indeterminate samples turned positive, increasing the overall test sensitivity to 57.7%. Although it is time consuming and requires the use of specific laboratory equipment, NS1 ELISA combined with heat dissociation could be a slightly better alternative for triage in suspected dengue cases.

  1. Unexpected Functional Divergence of Bat Influenza Virus NS1 Proteins.

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    Turkington, Hannah L; Juozapaitis, Mindaugas; Tsolakos, Nikos; Corrales-Aguilar, Eugenia; Schwemmle, Martin; Hale, Benjamin G

    2018-03-01

    Recently, two influenza A virus (FLUAV) genomes were identified in Central and South American bats. These sequences exhibit notable divergence from classical FLUAV counterparts, and functionally, bat FLUAV glycoproteins lack canonical receptor binding and destroying activity. Nevertheless, other features that distinguish these viruses from classical FLUAVs have yet to be explored. Here, we studied the viral nonstructural protein NS1, a virulence factor that modulates host signaling to promote efficient propagation. Like all FLUAV NS1 proteins, bat FLUAV NS1s bind double-stranded RNA and act as interferon antagonists. Unexpectedly, we found that bat FLUAV NS1s are unique in being unable to bind host p85β, a regulatory subunit of the cellular metabolism-regulating enzyme, phosphoinositide 3-kinase (PI3K). Furthermore, neither bat FLUAV NS1 alone nor infection with a chimeric bat FLUAV efficiently activates Akt, a PI3K effector. Structure-guided mutagenesis revealed that the bat FLUAV NS1-p85β interaction can be reengineered (in a strain-specific manner) by changing two to four NS1 residues (96L, 99M, 100I, and 145T), thereby creating a hydrophobic patch. Notably, ameliorated p85β-binding is insufficient for bat FLUAV NS1 to activate PI3K, and a chimeric bat FLUAV expressing NS1 with engineered hydrophobic patch mutations exhibits cell-type-dependent, but species-independent, propagation phenotypes. We hypothesize that bat FLUAV hijacking of PI3K in the natural bat host has been selected against, perhaps because genes in this metabolic pathway were differentially shaped by evolution to suit the unique energy use strategies of this flying mammal. These data expand our understanding of the enigmatic functional divergence between bat FLUAVs and classical mammalian and avian FLUAVs. IMPORTANCE The potential for novel influenza A viruses to establish infections in humans from animals is a source of continuous concern due to possible severe outbreaks or pandemics. The

  2. Detection of dengue nonstructural 1 (NS1) protein in Vietnamese patients with fever

    NARCIS (Netherlands)

    Phuong, Hoang Lan; Thai, Khoa T. D.; Nga, Tran T. T.; Giao, Phan T.; Hung, Le Q.; Binh, Tran Q.; Nam, Nguyen V.; Groen, Jan; de Vries, Peter J.

    2009-01-01

    Diagnostic dengue in febrile patients is challenging. Of a total of 459 patients with acute undifferentiated fever, randomly selected from 12 primary health facilities and 1 clinic of the provincial malaria station in southern Vietnam, dengue-specific antibody (Ab) and NS1 Ag enzyme-linked

  3. Underreporting of Dengue-4 in Brazil Due to Low Sensitivity of the NS1 Ag Test in Routine Control Programs

    Science.gov (United States)

    Sea, Vanessa Ramos Faria; Cruz, Ana Cecília Ribeiro; Gurgel, Ricardo Q.; Nunes, Bruno Tardelli Diniz; Silva, Eliana Vieira Pinto; Dolabella, Silvio S.; dos Santos, Roseli La Corte

    2013-01-01

    We have identified fifty-eight samples that were positive for Dengue-4 among 119 samples with negative diagnoses for dengue via the Platelia™ dengue NS1 Ag in Aracaju, State of Sergipe, Brazil. We determined that the low sensitivity of the NS1 Ag test could be related to secondary dengue infections in the studied population. Therefore, we concluded that the sensitivity and specificity of the Platelia™ dengue NS1 Ag test as a screening method for monitoring circulating dengue serotypes must be reevaluated. In addition, regional endo-epidemic profiles should also be considered due to the prevalence of secondary responses. PMID:23717529

  4. Quantification of NS1 dengue biomarker in serum via optomagnetic nanocluster detection

    Science.gov (United States)

    Antunes, Paula; Watterson, Daniel; Parmvi, Mattias; Burger, Robert; Boisen, Anja; Young, Paul; Cooper, Matthew A.; Hansen, Mikkel F.; Ranzoni, Andrea; Donolato, Marco

    2015-11-01

    Dengue is a tropical vector-borne disease without cure or vaccine that progressively spreads into regions with temperate climates. Diagnostic tools amenable to resource-limited settings would be highly valuable for epidemiologic control and containment during outbreaks. Here, we present a novel low-cost automated biosensing platform for detection of dengue fever biomarker NS1 and demonstrate it on NS1 spiked in human serum. Magnetic nanoparticles (MNPs) are coated with high-affinity monoclonal antibodies against NS1 via bio-orthogonal Cu-free ‘click’ chemistry on an anti-fouling surface molecular architecture. The presence of the target antigen NS1 triggers MNP agglutination and the formation of nanoclusters with rapid kinetics enhanced by external magnetic actuation. The amount and size of the nanoclusters correlate with the target concentration and can be quantified using an optomagnetic readout method. The resulting automated dengue fever assay takes just 8 minutes, requires 6 μL of serum sample and shows a limit of detection of 25 ng/mL with an upper detection range of 20000 ng/mL. The technology holds a great potential to be applied to NS1 detection in patient samples. As the assay is implemented on a low-cost microfluidic disc the platform is suited for further expansion to multiplexed detection of a wide panel of biomarkers.

  5. Comparison of two dengue NS1 rapid tests for sensitivity, specificity and relationship to viraemia and antibody responses

    Directory of Open Access Journals (Sweden)

    Farrar Jeremy

    2010-05-01

    Full Text Available Abstract Background Dengue is a major public health problem in tropical and subtropical countries. Rapid and easy diagnosis of dengue can assist patient triage and care-management. The detection of DENV NS1 on rapid lateral flow tests offers a fast route to a presumptive dengue diagnosis but careful evaluations are urgently needed as more and more people use them. Methods The sensitivity and specificity of the Bio-Rad NS1 Ag Strip and SD Dengue Duo (NS1/IgM/IgG lateral flow rapid tests were evaluated in a panel of plasma samples from 245 Vietnamese patients with RT-PCR confirmed dengue and 47 with other febrile illnesses. Results The NS1 rapid tests had similar diagnostic sensitivities (respectively 61.6% and 62.4% in confirmed dengue cases but were 100% specific. When IgM/IgG results from the SD Dengue Duo were included in the test interpretation, the sensitivity improved significantly from 62.4% with NS1 alone to 75.5% when NS1 and/or IgM was positive and 83.7% when NS1 and/or IgM and/or IgG was positive. Both NS1 assays were significantly more sensitive for primary than secondary dengue. NS1 positivity was associated with the underlying viraemia as NS1-positive samples had a significantly higher viraemia than NS1-negative samples. Conclusions These data suggest that the NS1 test component of these assays are highly specific and have similar levels of sensitivity. The IgM parameter in the SD Duo test improved overall test sensitivity without compromising specificity. The SD Dengue Duo lateral flow rapid test deserves further prospective evaluation in dengue endemic settings.

  6. Quantification of NS1 dengue biomarker in serum via optomagnetic nanocluster detection

    DEFF Research Database (Denmark)

    Antunes, Paula Soares Martins; Watterson, Daniel; Parmvi, Mattias

    2015-01-01

    Dengue is a tropical vector-borne disease without cure or vaccine that progressively spreads into regions with temperate climates. Diagnostic tools amenable to resource-limited settings would be highly valuable for epidemiologic control and containment during outbreaks. Here, we present a novel low......-cost automated biosensing platform for detection of dengue fever biomarker NS1 and demonstrate it on NS1 spiked in human serum. Magnetic nanoparticles (MNPs) are coated with high-affinity monoclonal antibodies against NS1 via bio-orthogonal Cu-free 'click' chemistry on an anti-fouling surface molecular...... method. The resulting automated dengue fever assay takes just 8 minutes, requires 6 μL of serum sample and shows a limit of detection of 25 ng/mL with an upper detection range of 20000 ng/mL. The technology holds a great potential to be applied to NS1 detection in patient samples. As the assay...

  7. Electrochemical lateral flow immunosensor for detection and quantification of dengue NS1 protein.

    Science.gov (United States)

    Sinawang, Prima Dewi; Rai, Varun; Ionescu, Rodica E; Marks, Robert S

    2016-03-15

    An Electrochemical Lateral Flow Immunosensor (ELFI) is developed combining screen-printed gold electrodes (SPGE) enabling quantification together with the convenience of a lateral flow test strip. A cellulose glassy fiber paper conjugate pad retains the marker immunoelectroactive nanobeads which will bind to the target analyte of interest. The specific immunorecognition event continues to occur along the lateral flow bed until reaching the SPGE-capture antibodies at the end of the cellulosic lateral flow strip. The rationale of the immunoassay consists in the analyte antigen NS1 protein being captured selectively and specifically by the dengue NS1 antibody conjugated onto the immunonanobeads thus forming an immunocomplex. With the aid of a running buffer, the immunocomplexes flow and reach the immuno-conjugated electrode surface and form specific sandwich-type detection due to specific, molecular recognition, while unbound beads move along past the electrodes. The successful sandwich immunocomplex formation is then recorded electrochemically. Specific detection of NS1 is translated into an electrochemical signal contributed by a redox label present on the bead-immobilized detection dengue NS1 antibody while a proportional increase of faradic current is observed with increase in analyte NS1 protein concentration. The first generation ELFI prototype is simply assembled in a cassette and successfully demonstrates wide linear range over a concentration range of 1-25 ng/mL with an ultrasensitive detection limit of 0.5 ng/mL for the qualitative and quantitative detection of analyte dengue NS1 protein. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. The interactomes of influenza virus NS1 and NS2 proteins identify new host factors and provide insights for ADAR1 playing a supportive role in virus replication.

    Science.gov (United States)

    de Chassey, Benoît; Aublin-Gex, Anne; Ruggieri, Alessia; Meyniel-Schicklin, Laurène; Pradezynski, Fabrine; Davoust, Nathalie; Chantier, Thibault; Tafforeau, Lionel; Mangeot, Philippe-Emmanuel; Ciancia, Claire; Perrin-Cocon, Laure; Bartenschlager, Ralf; André, Patrice; Lotteau, Vincent

    2013-01-01

    Influenza A NS1 and NS2 proteins are encoded by the RNA segment 8 of the viral genome. NS1 is a multifunctional protein and a virulence factor while NS2 is involved in nuclear export of viral ribonucleoprotein complexes. A yeast two-hybrid screening strategy was used to identify host factors supporting NS1 and NS2 functions. More than 560 interactions between 79 cellular proteins and NS1 and NS2 proteins from 9 different influenza virus strains have been identified. These interacting proteins are potentially involved in each step of the infectious process and their contribution to viral replication was tested by RNA interference. Validation of the relevance of these host cell proteins for the viral replication cycle revealed that 7 of the 79 NS1 and/or NS2-interacting proteins positively or negatively controlled virus replication. One of the main factors targeted by NS1 of all virus strains was double-stranded RNA binding domain protein family. In particular, adenosine deaminase acting on RNA 1 (ADAR1) appeared as a pro-viral host factor whose expression is necessary for optimal viral protein synthesis and replication. Surprisingly, ADAR1 also appeared as a pro-viral host factor for dengue virus replication and directly interacted with the viral NS3 protein. ADAR1 editing activity was enhanced by both viruses through dengue virus NS3 and influenza virus NS1 proteins, suggesting a similar virus-host co-evolution.

  9. The interactomes of influenza virus NS1 and NS2 proteins identify new host factors and provide insights for ADAR1 playing a supportive role in virus replication.

    Directory of Open Access Journals (Sweden)

    Benoît de Chassey

    Full Text Available Influenza A NS1 and NS2 proteins are encoded by the RNA segment 8 of the viral genome. NS1 is a multifunctional protein and a virulence factor while NS2 is involved in nuclear export of viral ribonucleoprotein complexes. A yeast two-hybrid screening strategy was used to identify host factors supporting NS1 and NS2 functions. More than 560 interactions between 79 cellular proteins and NS1 and NS2 proteins from 9 different influenza virus strains have been identified. These interacting proteins are potentially involved in each step of the infectious process and their contribution to viral replication was tested by RNA interference. Validation of the relevance of these host cell proteins for the viral replication cycle revealed that 7 of the 79 NS1 and/or NS2-interacting proteins positively or negatively controlled virus replication. One of the main factors targeted by NS1 of all virus strains was double-stranded RNA binding domain protein family. In particular, adenosine deaminase acting on RNA 1 (ADAR1 appeared as a pro-viral host factor whose expression is necessary for optimal viral protein synthesis and replication. Surprisingly, ADAR1 also appeared as a pro-viral host factor for dengue virus replication and directly interacted with the viral NS3 protein. ADAR1 editing activity was enhanced by both viruses through dengue virus NS3 and influenza virus NS1 proteins, suggesting a similar virus-host co-evolution.

  10. Development of a quantitative NS1-capture enzyme-linked immunosorbent assay for early detection of yellow fever virus infection.

    Science.gov (United States)

    Ricciardi-Jorge, Taissa; Bordignon, Juliano; Koishi, Andrea; Zanluca, Camila; Mosimann, Ana Luiza; Duarte Dos Santos, Claudia Nunes

    2017-11-24

    Yellow fever is an arboviral disease that causes thousands of deaths every year in Africa and the Americas. However, few commercial diagnostic kits are available. Non-structural protein 1 (NS1) is an early marker of several flavivirus infections and is widely used to diagnose dengue virus (DENV) infection. Nonetheless, little is known about the dynamics of Yellow fever virus (YFV) NS1 expression and secretion, to encourage its use in diagnosis. To tackle this issue, we developed a quantitative NS1-capture ELISA specific for YFV using a monoclonal antibody and recombinant NS1 protein. This test was used to quantify NS1 in mosquito and human cell line cultures infected with vaccine and wild YFV strains. Our results showed that NS1 was detectable in the culture supernatants of both cell lines; however, a higher concentration was maintained as cell-associated rather than secreted into the extracellular milieu. A panel of 73 human samples was used to demonstrate the suitability of YFV NS1 as a diagnostic tool, resulting in 80% sensitivity, 100% specificity, a 100% positive predictive value and a 95.5% negative predictive value compared with RT-PCR. Overall, the developed NS1-capture ELISA showed potential as a promising assay for the detection of early YF infection.

  11. Screen Printed Carbon Electrode Based Electrochemical Immunosensor for the Detection of Dengue NS1 Antigen

    Directory of Open Access Journals (Sweden)

    Om Parkash

    2014-11-01

    Full Text Available An electrochemical immunosensor modified with the streptavidin/biotin system on screen printed carbon electrodes (SPCEs for the detection of the dengue NS1 antigen was developed in this study. Monoclonal anti-NS1 capture antibody was immobilized on streptavidin-modified SPCEs to increase the sensitivity of the assay. Subsequently, a direct sandwich enzyme linked immunosorbent assay (ELISA format was developed and optimized. An anti-NS1 detection antibody conjugated with horseradish peroxidase enzyme (HRP and 3,3,5,5'-tetramethybezidine dihydrochloride (TMB/H2O2 was used as an enzyme mediator. Electrochemical detection was conducted using the chronoamperometric technique, and electrochemical responses were generated at −200 mV reduction potential. The calibration curve of the immunosensor showed a linear response between 0.5 µg/mL and 2 µg/mL and a detection limit of 0.03 µg/mL. Incorporation of a streptavidin/biotin system resulted in a well-oriented antibody immobilization of the capture antibody and consequently enhanced the sensitivity of the assay. In conclusion, this immunosensor is a promising technology for the rapid and convenient detection of acute dengue infection in real serum samples.

  12. NS1-binding protein abrogates the elevation of cell viability by the influenza A virus NS1 protein in association with CRKL

    Energy Technology Data Exchange (ETDEWEB)

    Miyazaki, Masaya [Department of Cancer Pathology, Hokkaido University Graduate School of Medicine, N15W7, Kita-ku, Sapporo 060-8638 (Japan); Nishihara, Hiroshi, E-mail: hnishihara@med.hokudai.ac.jp [Department of Translational Pathology, Hokkaido University Graduate School of Medicine, N15W7, Kita-ku, Sapporo 060-8638 (Japan); Hasegawa, Hideki [Department of Pathology, National Institute of Infectious Diseases, Sinjuku-ku, Tokyo (Japan); Tashiro, Masato [Influenza Virus Research Center, National Institute of Infectious Diseases, Sinjuku-ku, Tokyo (Japan); Wang, Lei [Department of Translational Pathology, Hokkaido University Graduate School of Medicine, N15W7, Kita-ku, Sapporo 060-8638 (Japan); Kimura, Taichi; Tanino, Mishie; Tsuda, Masumi [Department of Cancer Pathology, Hokkaido University Graduate School of Medicine, N15W7, Kita-ku, Sapporo 060-8638 (Japan); Tanaka, Shinya [Department of Cancer Pathology, Hokkaido University Graduate School of Medicine, N15W7, Kita-ku, Sapporo 060-8638 (Japan); Department of Translational Pathology, Hokkaido University Graduate School of Medicine, N15W7, Kita-ku, Sapporo 060-8638 (Japan)

    2013-11-29

    Highlights: •NS1 induced excessive phosphorylation of ERK and elevated cell viability. •NS1-BP expression and CRKL knockdown abolished survival effect of NS1. •NS1-BP and NS1 formed the complex through the interaction with CRKL-SH3(N). -- Abstract: The influenza A virus non-structural protein 1 (NS1) is a multifunctional virulence factor consisting of an RNA binding domain and several Src-homology (SH) 2 and SH3 binding motifs, which promotes virus replication in the host cell and helps to evade antiviral immunity. NS1 modulates general host cell physiology in association with various cellular molecules including NS1-binding protein (NS1-BP) and signaling adapter protein CRK-like (CRKL), while the physiological role of NS1-BP during influenza A virus infection especially in association with NS1 remains unclear. In this study, we analyzed the intracellular association of NS1-BP, NS1 and CRKL to elucidate the physiological roles of these molecules in the host cell. In HEK293T cells, enforced expression of NS1 of A/Beijing (H1N1) and A/Indonesia (H5N1) significantly induced excessive phosphorylation of ERK and elevated cell viability, while the over-expression of NS1-BP and the abrogation of CRKL using siRNA abolished such survival effect of NS1. The pull-down assay using GST-fusion CRKL revealed the formation of intracellular complexes of NS1-BP, NS1 and CRKL. In addition, we identified that the N-terminus SH3 domain of CRKL was essential for binding to NS1-BP using GST-fusion CRKL-truncate mutants. This is the first report to elucidate the novel function of NS1-BP collaborating with viral protein NS1 in modulation of host cell physiology. In addition, an alternative role of adaptor protein CRKL in association with NS1 and NS1-BP during influenza A virus infection is demonstrated.

  13. NS1-binding protein abrogates the elevation of cell viability by the influenza A virus NS1 protein in association with CRKL

    International Nuclear Information System (INIS)

    Miyazaki, Masaya; Nishihara, Hiroshi; Hasegawa, Hideki; Tashiro, Masato; Wang, Lei; Kimura, Taichi; Tanino, Mishie; Tsuda, Masumi; Tanaka, Shinya

    2013-01-01

    Highlights: •NS1 induced excessive phosphorylation of ERK and elevated cell viability. •NS1-BP expression and CRKL knockdown abolished survival effect of NS1. •NS1-BP and NS1 formed the complex through the interaction with CRKL-SH3(N). -- Abstract: The influenza A virus non-structural protein 1 (NS1) is a multifunctional virulence factor consisting of an RNA binding domain and several Src-homology (SH) 2 and SH3 binding motifs, which promotes virus replication in the host cell and helps to evade antiviral immunity. NS1 modulates general host cell physiology in association with various cellular molecules including NS1-binding protein (NS1-BP) and signaling adapter protein CRK-like (CRKL), while the physiological role of NS1-BP during influenza A virus infection especially in association with NS1 remains unclear. In this study, we analyzed the intracellular association of NS1-BP, NS1 and CRKL to elucidate the physiological roles of these molecules in the host cell. In HEK293T cells, enforced expression of NS1 of A/Beijing (H1N1) and A/Indonesia (H5N1) significantly induced excessive phosphorylation of ERK and elevated cell viability, while the over-expression of NS1-BP and the abrogation of CRKL using siRNA abolished such survival effect of NS1. The pull-down assay using GST-fusion CRKL revealed the formation of intracellular complexes of NS1-BP, NS1 and CRKL. In addition, we identified that the N-terminus SH3 domain of CRKL was essential for binding to NS1-BP using GST-fusion CRKL-truncate mutants. This is the first report to elucidate the novel function of NS1-BP collaborating with viral protein NS1 in modulation of host cell physiology. In addition, an alternative role of adaptor protein CRKL in association with NS1 and NS1-BP during influenza A virus infection is demonstrated

  14. Catching Dengue Early: Clinical Features and Laboratory Markers of Dengue Virus Infection.

    Science.gov (United States)

    Babaliche, Prakash; Doshi, Darshan

    2015-05-01

    Dengue fever is one of the most common tropical diseases worldwide. Early diagnosis of dengue helps in patient triage and timely management of dengue virus infection.This study was undertaken to note the early clinical features supported by detection of NS1 antigen for diagnosis of dengue virus infection. In this study a total of 100 adult patients presenting with clinical features of dengue infection from January 2012 to December 2012 were studied.The diagnosis was confirmed with NS1 rapid diagnostic test (RDT) whose efficacy was later tested with IgM ELISA. In this study young males were predominantly affected. NS1 positivity was 68%. The sensitivity of NS1 in predicting dengue infection compared to IgM was 92.86% and specificity was 90% with strength of agreement considered to be 'very good' based on Kappa statistics. Clinical features like retro-orbital pain, myalgia, arthralgia, rashes and bleeding manifestations were significantly associated with NS1 positivity. Similarly icterus, oedema, hypotension, altered sensorium, thrombocytopenia and raised creatinine were significantly more in NS1 positive patients. Anomalously, SGOT was more than SGPT, which can help in differentiating dengue virus infection from other viral infections early in the course. We conclude that dengue infection, which possesses serious public health problem, can be diagnosed early with the help of clinical features like retro-orbital pain, myalgia, bleeding manifestations, thrombocytopenia and anomalously SGOT greater than SGPT that is supported by detection of NS1 antigen.

  15. The Influenza NS1 Protein: What Do We Know in Equine Influenza Virus Pathogenesis?

    Directory of Open Access Journals (Sweden)

    Marta Barba

    2016-08-01

    Full Text Available Equine influenza virus remains a serious health and potential economic problem throughout most parts of the world, despite intensive vaccination programs in some horse populations. The influenza non-structural protein 1 (NS1 has multiple functions involved in the regulation of several cellular and viral processes during influenza infection. We review the strategies that NS1 uses to facilitate virus replication and inhibit antiviral responses in the host, including sequestering of double-stranded RNA, direct modulation of protein kinase R activity and inhibition of transcription and translation of host antiviral response genes such as type I interferon. Details are provided regarding what it is known about NS1 in equine influenza, especially concerning C-terminal truncation. Further research is needed to determine the role of NS1 in equine influenza infection, which will help to understand the pathophysiology of complicated cases related to cytokine imbalance and secondary bacterial infection, and to investigate new therapeutic and vaccination strategies.

  16. Dengue virus receptor

    OpenAIRE

    Hidari, Kazuya I.P.J.; Suzuki, Takashi

    2011-01-01

    Dengue virus is an arthropod-borne virus transmitted by Aedes mosquitoes. Dengue virus causes fever and hemorrhagic disorders in humans and non-human primates. Direct interaction of the virus introduced by a mosquito bite with host receptor molecule(s) is crucial for virus propagation and the pathological progression of dengue diseases. Therefore, elucidation of the molecular mechanisms underlying the interaction between dengue virus and its receptor(s) in both humans and mosquitoes is essent...

  17. Multifunctional adaptive NS1 mutations are selected upon human influenza virus evolution in the mouse.

    Directory of Open Access Journals (Sweden)

    Nicole E Forbes

    Full Text Available The role of the NS1 protein in modulating influenza A virulence and host range was assessed by adapting A/Hong Kong/1/1968 (H3N2 (HK-wt to increased virulence in the mouse. Sequencing the NS genome segment of mouse-adapted variants revealed 11 mutations in the NS1 gene and 4 in the overlapping NEP gene. Using the HK-wt virus and reverse genetics to incorporate mutant NS gene segments, we demonstrated that all NS1 mutations were adaptive and enhanced virus replication (up to 100 fold in mouse cells and/or lungs. All but one NS1 mutant was associated with increased virulence measured by survival and weight loss in the mouse. Ten of twelve NS1 mutants significantly enhanced IFN-β antagonism to reduce the level of IFN β production relative to HK-wt in infected mouse lungs at 1 day post infection, where 9 mutants induced viral yields in the lung that were equivalent to or significantly greater than HK-wt (up to 16 fold increase. Eight of 12 NS1 mutants had reduced or lost the ability to bind the 30 kDa cleavage and polyadenylation specificity factor (CPSF30 thus demonstrating a lack of correlation with reduced IFN β production. Mutant NS1 genes resulted in increased viral mRNA transcription (10 of 12 mutants, and protein production (6 of 12 mutants in mouse cells. Increased transcription activity was demonstrated in the influenza mini-genome assay for 7 of 11 NS1 mutants. Although we have shown gain-of-function properties for all mutant NS genes, the contribution of the NEP mutations to phenotypic changes remains to be assessed. This study demonstrates that NS1 is a multifunctional virulence factor subject to adaptive evolution.

  18. Detection of dengue NS1 and NS3 proteins in placenta and umbilical cord in fetal and maternal death.

    Science.gov (United States)

    Nunes, Priscila Conrado Guerra; Paes, Marciano Viana; de Oliveira, Carlos Alberto Basilio; Soares, Ana Carla Gomes; de Filippis, Ana Maria Bispo; Lima, Monique da Rocha Queiroz; de Barcelos Alves, Ada Maria; da Silva, Juliana Fernandes Amorim; de Oliveira Coelho, Janice Mery Chicarino; de Carvalho Rodrigues, Francisco das Chagas; Nogueira, Rita Maria Ribeiro; Dos Santos, Flávia Barreto

    2016-08-01

    In Brazil, dengue is a public health problem with the occurrence of explosive epidemics. This study reports maternal and fetal deaths due to dengue and which tissues of placenta and umbilical cord were analyzed by molecular methods and immunohistochemistry. The dengue NS3 and NS1 detection revealed the viral presence in different cells from placenta and umbilical cord. In the latter, DENV-2 was detected at a viral titer of 1,02 × 10(4) amounts of viral RNA. It was shown that the DENV markers analyzed here may be an alternative approach for dengue fatal cases investigation, especially involving maternal and fetal death. J. Med. Virol. 88:1448-1452, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  19. Analysis of the PDZ binding specificities of Influenza A Virus NS1 proteins

    Directory of Open Access Journals (Sweden)

    Nagasaka Kazunori

    2011-01-01

    Full Text Available Abstract The Influenza A virus non-structural protein 1 (NS1 is a multifunctional virulence factor with several protein-protein interaction domains, involved in preventing apoptosis of the infected cell and in evading the interferon response. In addition, the majority of influenza A virus NS1 proteins have a class I PDZ-binding motif at the C-terminus, and this itself has been shown to be a virulence determinant. In the majority of human influenza NS1 proteins the consensus motif is RSxV: in avian NS1 it is ESxV. Of the few human strains that have the avian motif, all were from very high mortality outbreaks of the disease. Previous work has shown that minor differences in PDZ-binding motifs can have major effects on the spectrum of cellular proteins targeted. In this study we analyse the effect of these differences upon the binding of Influenza A virus NS1 protein to a range of cellular proteins involved in polarity and signal transduction.

  20. Suppression of Rac1 Signaling by Influenza A Virus NS1 Facilitates Viral Replication

    Science.gov (United States)

    Jiang, Wei; Sheng, Chunjie; Gu, Xiuling; Liu, Dong; Yao, Chen; Gao, Shijuan; Chen, Shuai; Huang, Yinghui; Huang, Wenlin; Fang, Min

    2016-01-01

    Influenza A virus (IAV) is a major human pathogen with the potential to become pandemic. IAV contains only eight RNA segments; thus, the virus must fully exploit the host cellular machinery to facilitate its own replication. In an effort to comprehensively characterize the host machinery taken over by IAV in mammalian cells, we generated stable A549 cell lines with over-expression of the viral non-structural protein (NS1) to investigate the potential host factors that might be modulated by the NS1 protein. We found that the viral NS1 protein directly interacted with cellular Rac1 and facilitated viral replication. Further research revealed that NS1 down-regulated Rac1 activity via post-translational modifications. Therefore, our results demonstrated that IAV blocked Rac1-mediated host cell signal transduction through the NS1 protein to facilitate its own replication. Our findings provide a novel insight into the mechanism of IAV replication and indicate new avenues for the development of potential therapeutic targets. PMID:27869202

  1. Structural Basis for dsRNA Recognition by NS1 Protein of Influenza A Virus

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, A.; Wong, S; Yuan, Y

    2009-01-01

    Influenza A viruses are important human pathogens causing periodic pandemic threats. Nonstructural protein 1 (NS1) protein of influenza A virus (NS1A) shields the virus against host defense. Here, we report the crystal structure of NS1A RNA-binding domain (RBD) bound to a double-stranded RNA (dsRNA) at 1.7A. NS1A RBD forms a homodimer to recognize the major groove of A-form dsRNA in a length-independent mode by its conserved concave surface formed by dimeric anti-parallel alpha-helices. dsRNA is anchored by a pair of invariable arginines (Arg38) from both monomers by extensive hydrogen bonds. In accordance with the structural observation, isothermal titration calorimetry assay shows that the unique Arg38-Arg38 pair and two Arg35-Arg46 pairs are crucial for dsRNA binding, and that Ser42 and Thr49 are also important for dsRNA binding. Agrobacterium co-infiltration assay further supports that the unique Arg38 pair plays important roles in dsRNA binding in vivo.

  2. Outbreak tracking of Aleutian mink disease virus (AMDV) using partial NS1 gene sequencing

    DEFF Research Database (Denmark)

    Ryt-Hansen, Pia; Hjulsager, Charlotte Kristiane; Hagberg, E. E.

    2017-01-01

    . However, in 2015, several outbreaks of AMDV occurred at mink farms throughout Denmark, and the sources of these outbreaks were not known. Partial NS1 gene sequencing, phylogenetic analyses data were utilized along with epidemiological to determine the origin of the outbreaks. The phylogenetic analyses...... of partial NS1 gene sequences revealed that the outbreaks were caused by two different clusters of viruses that were clearly different from the strains found in Northern Jutland. These clusters had restricted geographical distribution, and the variation within the clusters was remarkably low. The outbreaks...... on Zealand were epidemiologically linked and a close sequence match was found to two virus sequences from Sweden. The other cluster of outbreaks restricted to Jutland and Funen were linked to three feed producers (FP) but secondary transmissions between farms in the same geographical area could...

  3. Molecular and biochemical characterization of the NS1 protein of non-cultured influenza B virus strains circulating in Singapore

    KAUST Repository

    Jumat, Muhammad Raihan

    2016-08-04

    In this study we compared the NS1 protein of Influenza B/Lee/40 and several non-cultured Influenza B virus clinical strains detected in Singapore. In B/Lee/40 virus-infected cells and in cells expressing the recombinant B/Lee/40 NS1 protein a full-length 35 kDa NS1 protein and a 23 kDa NS1 protein species (p23) were detected. Mutational analysis of the NS1 gene indicated that p23 was generated by a novel cleavage event within the linker domain between an aspartic acid and proline at amino acid residues at positions 92 and 93 respectively (DP92–93), and that p23 contained the first 92 amino acids of the NS1 protein. Sequence analysis of the Singapore strains indicated the presence of either DP92–93 or NP92–93 in the NS1 protein, but protein expression analysis showed that p23 was only detected in NS1 proteins with DP92–93.. An additional adjacent proline residue at position 94 (P94) was present in some strains and correlated with increased p23 levels, suggesting that P94 has a synergistic effect on the cleavage of the NS1 protein. The first 145 amino acids of the NS1 protein are required for inhibition of ISG15-mediated ubiquitination, and our analysis showed that Influenza B viruses circulating in Singapore with DP92–93 expressed truncated NS1 proteins and may differ in their capacity to inhibit ISG15 activity. Thus, DP92–93 in the NS1 protein may confer a disadvantage to Influenza B viruses circulating in the human population and interestingly the low frequency of DP92–93detection in the NS1 protein since 2004 is consistent with this suggestion.

  4. Dengue Virus Glycosylation: What Do We Know?

    Directory of Open Access Journals (Sweden)

    Sally S. L. Yap

    2017-07-01

    Full Text Available In many infectious diseases caused by either viruses or bacteria, pathogen glycoproteins play important roles during the infection cycle, ranging from entry to successful intracellular replication and host immune evasion. Dengue is no exception. Dengue virus glycoproteins, envelope protein (E and non-structural protein 1 (NS1 are two popular sub-unit vaccine candidates. E protein on the virion surface is the major target of neutralizing antibodies. NS1 which is secreted during DENV infection has been shown to induce a variety of host responses through its binding to several host factors. However, despite their critical role in disease and protection, the glycosylated variants of these two proteins and their biological importance have remained understudied. In this review, we seek to provide a comprehensive summary of the current knowledge on protein glycosylation in DENV, and its role in virus biogenesis, host cell receptor interaction and disease pathogenesis.

  5. Comparative study and grouping of nonstructural (NS1)proteins of influenza A viruses by the method of oligopeptide mapping

    International Nuclear Information System (INIS)

    Sokolov, B.P.; Rudneva, I.A.; Zhdanov, V.M.

    1983-01-01

    Oligopeptide mapping of 35 S-methionine labeled non-stuctural (NS1) proteins of 23 influenza A virus strains showed the presence of both common and variable oligopeptides. Analysis of the oligopeptide maps revealed at least four groups of NS1 proteins. The first group includes NS1 proteins of several human H1N1 influenza viruses (that were designated as H0N1 according to the old classification). The second group is composed of NS1 proteins of H1N1 and H2N2 viruses. The third group includes NS1 proteins of H3N2 human influenza viruses. The fourth group is composed of NS1 proteins of five avian influenza viruses and an equine (H3N8) influenza virus. Two animal influenza viruses A/equi/Prague/56 (H7N7) and A/duck/England/56 (H11N6) contain NS1 proteins that belong to the second group. (Author)

  6. The NS1 glycoprotein can generate dramatic antibody-enhanced dengue viral replication in normal out-bred mice resulting in lethal multi-organ disease.

    Directory of Open Access Journals (Sweden)

    Andrew K I Falconar

    Full Text Available Antibody-enhanced replication (AER of dengue type-2 virus (DENV-2 strains and production of antibody-enhanced disease (AED was tested in out-bred mice. Polyclonal antibodies (PAbs generated against the nonstructural-1 (NS1 glycoprotein candidate vaccine of the New Guinea-C (NG-C or NSx strains reacted strongly and weakly with these antigens, respectively. These PAbs contained the IgG2a subclass, which cross-reacted with the virion-associated envelope (E glycoprotein of the DENV-2 NSx strain, suggesting that they could generate its AER via all mouse Fcγ-receptor classes. Indeed, when these mice were challenged with a low dose (<0.5 LD₅₀ of the DENV-2 NSx strain, but not the NG-C strain, they all generated dramatic and lethal DENV-2 AER/AED. These AER/AED mice developed life-threatening acute respiratory distress syndrome (ARDS, displayed by diffuse alveolar damage (DAD resulting from i dramatic interstitial alveolar septa-thickening with mononuclear cells, ii some hyperplasia of alveolar type-II pneumocytes, iii copious intra-alveolar protein secretion, iv some hyaline membrane-covered alveolar walls, and v DENV-2 antigen-positive alveolar macrophages. These mice also developed meningo-encephalitis, with greater than 90,000-fold DENV-2 AER titers in microglial cells located throughout their brain parenchyma, some of which formed nodules around dead neurons. Their spleens contained infiltrated megakaryocytes with DENV-2 antigen-positive red-pulp macrophages, while their livers displayed extensive necrosis, apoptosis and macro- and micro-steatosis, with DENV-2 antigen-positive Kuppfer cells and hepatocytes. Their infections were confirmed by DENV-2 isolations from their lungs, spleens and livers. These findings accord with those reported in fatal human "severe dengue" cases. This DENV-2 AER/AED was blocked by high concentrations of only the NG-C NS1 glycoprotein. These results imply a potential hazard of DENV NS1 glycoprotein-based vaccines

  7. Functional Evolution of Influenza Virus NS1 Protein in Currently Circulating Human 2009 Pandemic H1N1 Viruses.

    Science.gov (United States)

    Clark, Amelia M; Nogales, Aitor; Martinez-Sobrido, Luis; Topham, David J; DeDiego, Marta L

    2017-09-01

    In 2009, a novel H1N1 influenza virus emerged in humans, causing a global pandemic. It was previously shown that the NS1 protein from this human 2009 pandemic H1N1 (pH1N1) virus was an effective interferon (IFN) antagonist but could not inhibit general host gene expression, unlike other NS1 proteins from seasonal human H1N1 and H3N2 viruses. Here we show that the NS1 protein from currently circulating pH1N1 viruses has evolved to encode 6 amino acid changes (E55K, L90I, I123V, E125D, K131E, and N205S) with respect to the original protein. Notably, these 6 residue changes restore the ability of pH1N1 NS1 to inhibit general host gene expression, mainly by their ability to restore binding to the cellular factor CPSF30. This is the first report describing the ability of the pH1N1 NS1 protein to naturally acquire mutations that restore this function. Importantly, a recombinant pH1N1 virus containing these 6 amino acid changes in the NS1 protein (pH1N1/NSs-6mut) inhibited host IFN and proinflammatory responses to a greater extent than that with the parental virus (pH1N1/NS1-wt), yet virus titers were not significantly increased in cell cultures or in mouse lungs, and the disease was partially attenuated. The pH1N1/NSs-6mut virus grew similarly to pH1N1/NSs-wt in mouse lungs, but infection with pH1N1/NSs-6mut induced lower levels of proinflammatory cytokines, likely due to a general inhibition of gene expression mediated by the mutated NS1 protein. This lower level of inflammation induced by the pH1N1/NSs-6mut virus likely accounts for the attenuated disease phenotype and may represent a host-virus adaptation affecting influenza virus pathogenesis. IMPORTANCE Seasonal influenza A viruses (IAVs) are among the most common causes of respiratory infections in humans. In addition, occasional pandemics are caused when IAVs circulating in other species emerge in the human population. In 2009, a swine-origin H1N1 IAV (pH1N1) was transmitted to humans, infecting people then and up

  8. Mutation of the elongin C binding domain of human respiratory syncytial virus non-structural protein 1 (NS1 results in degradation of NS1 and attenuation of the virus

    Directory of Open Access Journals (Sweden)

    Headlam Madeleine J

    2011-05-01

    Full Text Available Abstract Background Human respiratory syncytial virus (RSV is an important cause of lower respiratory tract disease in the paediatic population, immunocompromised individuals and the elderly worldwide. However, despite global efforts over the past several decades there are no commercially available vaccines. RSV encodes 2 non-structural proteins, NS1 and NS2, that are type I interferon antagonists. RSV restricts type I interferon signaling and the expression of antiviral genes by degrading STAT2. It has been proposed that NS1 binds to elongin C to form a ubiquitin ligase (E3 complex that targets STAT2 for ubiquitination and proteosomal degradation. Results Here, we have engineered a live recombinant RSV in which the 3 consensus amino acids of the NS1 elongin C binding domain have been replaced with alanine (NS1F-ELCmut. Mutation of this region of NS1 resulted in attenuation of RSV replication in A549 cells to levels similar to that observed when the NS1 gene is completely deleted (ΔNS1. This mutation also resulted in moderate attenuation in Vero cells. Attenuation was correlated to intracellular degradation of the mutated NS1 protein. Time course analysis showed that mutant NS1 protein accumulated in cytoplasmic bodies that contained the lysosomal marker LAMP1. However lack of cleavage of LC3 suggested that autophagy was not involved. Induction of IFN-β mRNA expression also was observed in association with the degradation of NS1 protein and attenuation of viral growth. Conclusions These results indicate that the elongin C binding region of NS1 is crucial for survival of the protein and that disruption of this region results in the degradation of NS1 and restriction of RSV replication.

  9. Novel Bat Influenza Virus NS1 Proteins Bind Double-Stranded RNA and Antagonize Host Innate Immunity.

    Science.gov (United States)

    Turkington, Hannah L; Juozapaitis, Mindaugas; Kerry, Philip S; Aydillo, Teresa; Ayllon, Juan; García-Sastre, Adolfo; Schwemmle, Martin; Hale, Benjamin G

    2015-10-01

    We demonstrate that novel bat HL17NL10 and HL18NL11 influenza virus NS1 proteins are effective interferon antagonists but do not block general host gene expression. Solving the RNA-binding domain structures revealed the canonical NS1 symmetrical homodimer, and RNA binding required conserved basic residues in this domain. Interferon antagonism was strictly dependent on RNA binding, and chimeric bat influenza viruses expressing NS1s defective in this activity were highly attenuated in interferon-competent cells but not in cells unable to establish antiviral immunity. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  10. The NS1 Glycoprotein Can Generate Dramatic Antibody-Enhanced Dengue Viral Replication in Normal Out-Bred Mice Resulting in Lethal Multi-Organ Disease

    Science.gov (United States)

    Falconar, Andrew K. I.; Martinez, Fernando

    2011-01-01

    Antibody-enhanced replication (AER) of dengue type-2 virus (DENV-2) strains and production of antibody-enhanced disease (AED) was tested in out-bred mice. Polyclonal antibodies (PAbs) generated against the nonstructural-1 (NS1) glycoprotein candidate vaccine of the New Guinea-C (NG-C) or NSx strains reacted strongly and weakly with these antigens, respectively. These PAbs contained the IgG2a subclass, which cross-reacted with the virion-associated envelope (E) glycoprotein of the DENV-2 NSx strain, suggesting that they could generate its AER via all mouse Fcγ-receptor classes. Indeed, when these mice were challenged with a low dose (AER/AED. These AER/AED mice developed life-threatening acute respiratory distress syndrome (ARDS), displayed by diffuse alveolar damage (DAD) resulting from i) dramatic interstitial alveolar septa-thickening with mononuclear cells, ii) some hyperplasia of alveolar type-II pneumocytes, iii) copious intra-alveolar protein secretion, iv) some hyaline membrane-covered alveolar walls, and v) DENV-2 antigen-positive alveolar macrophages. These mice also developed meningo-encephalitis, with greater than 90,000-fold DENV-2 AER titers in microglial cells located throughout their brain parenchyma, some of which formed nodules around dead neurons. Their spleens contained infiltrated megakaryocytes with DENV-2 antigen-positive red-pulp macrophages, while their livers displayed extensive necrosis, apoptosis and macro- and micro-steatosis, with DENV-2 antigen-positive Kuppfer cells and hepatocytes. Their infections were confirmed by DENV-2 isolations from their lungs, spleens and livers. These findings accord with those reported in fatal human “severe dengue” cases. This DENV-2 AER/AED was blocked by high concentrations of only the NG-C NS1 glycoprotein. These results imply a potential hazard of DENV NS1 glycoprotein-based vaccines, particularly against DENV strains that contain multiple mutations or genetic recombination within or between their

  11. Clinical diagnosis of early dengue infection by novel one-step multiplex real-time RT-PCR targeting NS1 gene.

    Science.gov (United States)

    Kim, Je-Hyoung; Chong, Chom-Kyu; Sinniah, Mangalam; Sinnadurai, Jeyaindran; Song, Hyun-Ok; Park, Hyun

    2015-04-01

    Dengue is a mosquito-borne disease that causes a public health problem in tropical and subtropical countries. Current immunological diagnostics based on IgM and/or nonstructural protein 1 (NS1) antigen are limited for acute dengue infection due to low sensitivity and accuracy. This study aimed to develop a one-step multiplex real-time RT-PCR assay showing higher sensitivity and accuracy than previous approaches. Serotype-specific primers and probes were designed through the multiple alignment of NS1 gene. The linearity and limit of detection (LOD) of the assay were determined. The assay was clinically validated with an evaluation panel that was immunologically tested by WHO and Malaysian specimens. The LOD of the assay was 3.0 log10 RNA copies for DENV-1, 2.0 for DENV-3, and 1.0 for DENV-2 and DENV-4. The assay showed 95.2% sensitivity (20/21) in an evaluation panel, whereas NS1 antigen- and anti-dengue IgM-based immunological assays exhibited 0% and 23.8-47.6% sensitivities, respectively. The assay showed 100% sensitivity both in NS1 antigen- and anti-dengue IgM-positive Malaysian specimens (26/26). The assay provided the information of viral loads and serotype with discrimination of heterotypic mixed infection. The assay could be clinically applied to early dengue diagnosis, especially during the first 5 days of illness and approximately 14 days after infection showing an anti-dengue IgM-positive response. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Dengue virus vaccine development.

    Science.gov (United States)

    Yauch, Lauren E; Shresta, Sujan

    2014-01-01

    Dengue virus (DENV) is a significant cause of morbidity and mortality in tropical and subtropical regions, causing hundreds of millions of infections each year. Infections range from asymptomatic to a self-limited febrile illness, dengue fever (DF), to the life-threatening dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS). The expanding of the habitat of DENV-transmitting mosquitoes has resulted in dramatic increases in the number of cases over the past 50 years, and recent outbreaks have occurred in the United States. Developing a dengue vaccine is a global health priority. DENV vaccine development is challenging due to the existence of four serotypes of the virus (DENV1-4), which a vaccine must protect against. Additionally, the adaptive immune response to DENV may be both protective and pathogenic upon subsequent infection, and the precise features of protective versus pathogenic immune responses to DENV are unknown, complicating vaccine development. Numerous vaccine candidates, including live attenuated, inactivated, recombinant subunit, DNA, and viral vectored vaccines, are in various stages of clinical development, from preclinical to phase 3. This review will discuss the adaptive immune response to DENV, dengue vaccine challenges, animal models used to test dengue vaccine candidates, and historical and current dengue vaccine approaches. © 2014 Elsevier Inc. All rights reserved.

  13. The NS1 Protein from Influenza Virus Stimulates Translation Initiation by Enhancing Ribosome Recruitment to mRNAs.

    Science.gov (United States)

    Panthu, Baptiste; Terrier, Olivier; Carron, Coralie; Traversier, Aurélien; Corbin, Antoine; Balvay, Laurent; Lina, Bruno; Rosa-Calatrava, Manuel; Ohlmann, Théophile

    2017-10-27

    The non-structural protein NS1 of influenza A viruses exerts pleiotropic functions during infection. Among these functions, NS1 was shown to be involved in the control of both viral and cellular translation; however, the mechanism by which this occurs remains to be determined. Thus, we have revisited the role of NS1 in translation by using a combination of influenza infection, mRNA reporter transfection, and in vitro functional and biochemical assays. Our data show that the NS1 protein is able to enhance the translation of virtually all tested mRNAs with the exception of constructs bearing the Dicistroviruses Internal ribosome entry segment (IRESes) (DCV and CrPV), suggesting a role at the level of translation initiation. The domain of NS1 required for translation stimulation was mapped to the RNA binding amino-terminal motif of the protein with residues R38 and K41 being critical for activity. Although we show that NS1 can bind directly to mRNAs, it does not correlate with its ability to stimulate translation. This activity rather relies on the property of NS1 to associate with ribosomes and to recruit them to target mRNAs. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. X-ray structure of NS1 from a highly pathogenic H5N1 influenza virus

    Energy Technology Data Exchange (ETDEWEB)

    Bornholdt, Zachary A.; Prasad, B.V. Venkataram (Baylor)

    2009-04-08

    The recent emergence of highly pathogenic avian (H5N1) influenza viruses, their epizootic and panzootic nature, and their association with lethal human infections have raised significant global health concerns. Several studies have underlined the importance of non-structural protein NS1 in the increased pathogenicity and virulence of these strains. NS1, which consists of two domains - a double-stranded RNA (dsRNA) binding domain and the effector domain, separated through a linker - is an antagonist of antiviral type-I interferon response in the host. Here we report the X-ray structure of the full-length NS1 from an H5N1 strain (A/Vietnam/1203/2004) that was associated with 60% of human deaths in an outbreak in Vietnam. Compared to the individually determined structures of the RNA binding domain and the effector domain from non-H5N1 strains, the RNA binding domain within H5N1 NS1 exhibits modest structural changes, while the H5N1 effector domain shows significant alteration, particularly in the dimeric interface. Although both domains in the full-length NS1 individually participate in dimeric interactions, an unexpected finding is that these interactions result in the formation of a chain of NS1 molecules instead of distinct dimeric units. Three such chains in the crystal interact with one another extensively to form a tubular organization of similar dimensions to that observed in the cryo-electron microscopy images of NS1 in the presence of dsRNA. The tubular oligomeric organization of NS1, in which residues implicated in dsRNA binding face a 20-{angstrom}-wide central tunnel, provides a plausible mechanism for how NS1 sequesters varying lengths of dsRNA, to counter cellular antiviral dsRNA response pathways, while simultaneously interacting with other cellular ligands during an infection.

  15. Nine year trends of dengue virus infection in Mumbai, Western India

    Directory of Open Access Journals (Sweden)

    Jayanthi Shastri

    2017-01-01

    Methods and Results: During the nine year period of this study analysis, 6767 strongly suspected cases were tested by RT-PCR. 1685 (24.9% were Dengue PCR positive and confirmed as Dengue cases. Observations on the seasonality were based on the nine year's data as the intensity of sampling was at its maximum during monsoon season. Dengue typing was done on 100 positive samples after storage of Dengue RNA at – 80°C. Dengue serotypes were detected in 69 samples of which Dengue 2 was most predominant. 576 samples were processed for NS1 antigen and PCR simultaneously. 19/576 were positive (3.3 % for NS1 as well as by PCR . 23/576 samples were negative for NS1 antigen, but were positive by RT-PCR. The remaining 534 samples which were negative for NS1 antigen were also negative by Dengue RT-PCR. Conclusion: In this study we sought to standardize rapid, sensitive, and specific fluorogenic probe-based RT-PCR assay to screen and serotype a representative range of Dengue viruses that are found in and around Mumbai. Qualitative Dengue virus TaqMan assays could have tremendous utility for the epidemiological investigation of Dengue illness and especially for the study of the viremic response with candidate live-attenuated dengue virus vaccines.

  16. Virulence Markers of Dengue Viruses

    Science.gov (United States)

    1990-02-20

    pathogenetic mechanism from dengue-2 and dengue-4 viruses . Additional detailed epidemiological, virological and clinical evaluation on dengue-1 and...Soawy Ca saoouj Virulence Markers of Dengue Viruses (U) 12. PCIRSONAL AUTHORS) James L. Hardy, Ph.D. and Srisakul C. Kliks, Ph.D. 13a. TYPE Of REPORT...17. COSATI COOLS I& S UBiJECT TERMS0,G ’-mPJ!’ iwin.. - fl OV nu0a mef) FIELD I GROUP SUS-GROUIP Dengue viruses , dengue hemorrhagic fever, virulence

  17. Influenza A virus NS1 gene mutations F103L and M106I increase replication and virulence

    Directory of Open Access Journals (Sweden)

    Ping Jihui

    2011-01-01

    Full Text Available Abstract Background To understand the evolutionary steps required for a virus to become virulent in a new host, a human influenza A virus (IAV, A/Hong Kong/1/68(H3N2 (HK-wt, was adapted to increased virulence in the mouse. Among eleven mutations selected in the NS1 gene, two mutations F103L and M106I had been previously detected in the highly virulent human H5N1 isolate, A/HK/156/97, suggesting a role for these mutations in virulence in mice and humans. Results To determine the selective advantage of these mutations, reverse genetics was used to rescue viruses containing each of the NS1 mouse adapted mutations into viruses possessing the HK-wt NS1 gene on the A/PR/8/34 genetic backbone. Both F103L and M106I NS1 mutations significantly enhanced growth in vitro (mouse and canine cells and in vivo (BALB/c mouse lungs as well as enhanced virulence in the mouse. Only the M106I NS1 mutation enhanced growth in human cells. Furthermore, these NS1 mutations enhanced early viral protein synthesis in MDCK cells and showed an increased ability to replicate in mouse interferon β (IFN-β pre-treated mouse cells relative to rPR8-HK-NS-wt NS1. The double mutant, rPR8-HK-NS-F103L + M106I, demonstrated growth attenuation late in infection due to increased IFN-β induction in mouse cells. We then generated a rPR8 virus possessing the A/HK/156/97 NS gene that possesses 103L + 106I, and then rescued the L103F + I106M mutant. The 103L + 106I mutations increased virulence by >10 fold in BALB/c mice. We also inserted the avian A/Ck/Beijing/1/95 NS1 gene (the source lineage of the A/HK/156/97 NS1 gene that possesses 103L + 106I, onto the A/WSN/33 backbone and then generated the L103F + I106M mutant. None of the H5N1 and H9N2 NS containing viruses resulted in increased IFN-β induction. The rWSN-A/Ck/Beijing/1/95-NS1 gene possessing 103L and 106I demonstrated 100 fold enhanced growth and >10 fold enhanced virulence that was associated with increased tropism for lung

  18. Influenza A Virus NS1 Protein Promotes Efficient Nuclear Export of Unspliced Viral M1 mRNA.

    Science.gov (United States)

    Pereira, Carina F; Read, Eliot K C; Wise, Helen M; Amorim, Maria J; Digard, Paul

    2017-08-01

    Influenza A virus mRNAs are transcribed by the viral RNA-dependent RNA polymerase in the cell nucleus before being exported to the cytoplasm for translation. Segment 7 produces two major transcripts: an unspliced mRNA that encodes the M1 matrix protein and a spliced transcript that encodes the M2 ion channel. Export of both mRNAs is dependent on the cellular NXF1/TAP pathway, but it is unclear how they are recruited to the export machinery or how the intron-containing but unspliced M1 mRNA bypasses the normal quality-control checkpoints. Using fluorescent in situ hybridization to monitor segment 7 mRNA localization, we found that cytoplasmic accumulation of unspliced M1 mRNA was inefficient in the absence of NS1, both in the context of segment 7 RNPs reconstituted by plasmid transfection and in mutant virus-infected cells. This effect was independent of any major effect on steady-state levels of segment 7 mRNA or splicing but corresponded to a ∼5-fold reduction in the accumulation of M1. A similar defect in intronless hemagglutinin (HA) mRNA nuclear export was seen with an NS1 mutant virus. Efficient export of M1 mRNA required both an intact NS1 RNA-binding domain and effector domain. Furthermore, while wild-type NS1 interacted with cellular NXF1 and also increased the interaction of segment 7 mRNA with NXF1, mutant NS1 polypeptides unable to promote mRNA export did neither. Thus, we propose that NS1 facilitates late viral gene expression by acting as an adaptor between viral mRNAs and the cellular nuclear export machinery to promote their nuclear export. IMPORTANCE Influenza A virus is a major pathogen of a wide variety of mammalian and avian species that threatens public health and food security. A fuller understanding of the virus life cycle is important to aid control strategies. The virus has a small genome that encodes relatively few proteins that are often multifunctional. Here, we characterize a new function for the NS1 protein, showing that, as well as

  19. Synergism of co-mutation of two amino acid residues in NS1 protein increases the pathogenicity of influenza virus in mice.

    Science.gov (United States)

    Pu, Juan; Wang, Jingjing; Zhang, Yi; Fu, Guanghua; Bi, Yuhai; Sun, Yipeng; Liu, Jinhua

    2010-08-01

    The NS1 influenza virus gene is thought to play an important role in replication and pathogenicity during infection. Previous studies have shown that mutations in the highly pathogenic avian NS1 influenza virus gene can influence virulence. However, little is known regarding the pathogenic mechanism of the NS1 gene in low pathogenic avian influenza virus. We found that NS1 genes originating from two H3 avian influenza viruses, A/duck/Beijing/40/04 (Dk/BJ/40/04) and A/duck/Beijing/61/05 (Dk/BJ/61/05), possessing three amino acid residue differences at positions 127, 205 and 209 contributed to an altered virulence in rescued NS1 recombinant viruses on a A/WSN/33 (WSN) virus background (WSN:40NS1 and WSN:61NS1) in mice. To further determine the effect on pathogenicity, we generated a series of recombinant viruses with mutations at positions 127, 205 and 209 in the NS1 gene of WSN:61NS1. Experiments in mice indicated that when compared with WSN:61NS1, viruses with only single mutations enhanced incidence of infection in mice but were not lethal. Viruses bearing substitution of two amino acid residues in the NS1 protein replicated well in lung tissue and caused 20-100% mortality in mice. Our findings demonstrate that co-mutation of amino acid residues at multiple positions in the NS1 protein can increase the pathogenicity of influenza virus in mice. Copyright 2010 Elsevier B.V. All rights reserved.

  20. Dengue Virus Non-Structural Protein 5

    Science.gov (United States)

    El Sahili, Abbas; Lescar, Julien

    2017-01-01

    The World Health Organization estimates that the yearly number of dengue cases averages 390 million. This mosquito-borne virus disease is endemic in over 100 countries and will probably continue spreading, given the observed trend in global warming. So far, there is no antiviral drug available against dengue, but a vaccine has been recently marketed. Dengue virus also serves as a prototype for the study of other pathogenic flaviviruses that are emerging, like West Nile virus and Zika virus. Upon viral entry into the host cell and fusion of the viral lipid membrane with the endosomal membrane, the viral RNA is released and expressed as a polyprotein, that is then matured into three structural and seven non-structural (NS) proteins. The envelope, membrane and capsid proteins form the viral particle while NS1-NS2A-NS2B-NS3-NS4A-NS4B and NS5 assemble inside a cellular replication complex, which is embedded in endoplasmic reticulum (ER)-derived vesicles. In addition to their roles in RNA replication within the infected cell, NS proteins help the virus escape the host innate immunity and reshape the host-cell inner structure. This review focuses on recent progress in characterizing the structure and functions of NS5, a protein responsible for the replication and capping of viral RNA that represents a promising drug target. PMID:28441781

  1. Contribution of the NS1 Gene of H7 Avian Influenza Virus Strains to Pathogenicity in Chickens

    NARCIS (Netherlands)

    Post, J.; Peeters, B.P.H.; Cornelissen, J.B.W.J.; Vervelde, L.; Rebel, J.M.J.

    2013-01-01

    Using reverse genetics (rg), we generated two reassortant viruses carrying the NS1 gene of two closely related HPAIV and LPAIV H7N1 variants (designated rgH7N7 HPHPNS1 and rgH7N7 HPLPNS1, respectively) in the backbone of the HP H7N7 strain A/Chicken/Netherlands/621557/03 (rgH7N7 HP). Comparison of

  2. Nine year trends of dengue virus infection in Mumbai, Western India.

    Science.gov (United States)

    Shastri, Jayanthi; Williamson, Manita; Vaidya, Nilima; Agrawal, Sachee; Shrivastav, Om

    2017-01-01

    Dengue virus (DENV) causes a wide range of diseases in humans, from acute febrile illness Dengue fever (DF) to life-threatening Dengue hemorrhagic fever (DHF) or Dengue shock syndrome (DSS). Factors believed to be responsible for spread of Dengue virus infection include explosive population growth, unplanned urban overpopulation with inadequate public health systems, poor standing water and vector control, climate changes and increased international recreational, business, military travel to endemic areas. All of these factors must be addressed to control the spread of Dengue and other mosquito-borne infections. The detection of Dengue virus RNA by reverse transcriptase PCR (RT-PCR) in human serum or plasma samples is highly indicative of acute Dengue fever. Moreover, the method is able to identify the Dengue virus serotype by demonstrating defined sequence homologies in the viral genomic RNA. During the nine year period of this study analysis, 6767 strongly suspected cases were tested by RT-PCR. 1685 (24.9%) were Dengue PCR positive and confirmed as Dengue cases. Observations on the seasonality were based on the nine year's data as the intensity of sampling was at its maximum during monsoon season. Dengue typing was done on 100 positive samples after storage of Dengue RNA at - 80°C. Dengue serotypes were detected in 69 samples of which Dengue 2 was most predominant. 576 samples were processed for NS1 antigen and PCR simultaneously. 19/576 were positive (3.3 %) for NS1 as well as by PCR. 23/576 samples were negative for NS1 antigen, but were positive by RT-PCR. The remaining 534 samples which were negative for NS1 antigen were also negative by Dengue RT-PCR. In this study we sought to standardize rapid, sensitive, and specific fluorogenic probe-based RT-PCR assay to screen and serotype a representative range of Dengue viruses that are found in and around Mumbai. Qualitative Dengue virus TaqMan assays could have tremendous utility for the epidemiological

  3. PDlim2 selectively interacts with the PDZ binding motif of highly pathogenic avian H5N1 influenza A virus NS1.

    Directory of Open Access Journals (Sweden)

    Jia Yu

    Full Text Available The multi-functional NS1 protein of influenza A virus is a viral virulence determining factor. The last four residues at the C-terminus of NS1 constitute a type I PDZ domain binding motif (PBM. Avian influenza viruses currently in circulation carry an NS1 PBM with consensus sequence ESEV, whereas human influenza viruses bear an NS1 PBM with consensus sequence RSKV or RSEV. The PBM sequence of the influenza A virus NS1 is reported to contribute to high viral pathogenicity in animal studies. Here, we report the identification of PDlim2 as a novel binding target of the highly pathogenic avian influenza virus H5N1 strain with an NS1 PBM of ESEV (A/Chicken/Henan/12/2004/H5N1, HN12-NS1 by yeast two-hybrid screening. The interaction was confirmed by in vitro GST pull-down assays, as well as by in vivo mammalian two-hybrid assays and bimolecular fluorescence complementation assays. The binding was also confirmed to be mediated by the interaction of the PDlim2 PDZ domain with the NS1 PBM motif. Interestingly, our assays showed that PDlim2 bound specifically with HN12-NS1, but exhibited no binding to NS1 from a human influenza H1N1 virus bearing an RSEV PBM (A/Puerto Rico/8/34/H1N1, PR8-NS1. A crystal structure of the PDlim2 PDZ domain fused with the C-terminal hexapeptide from HN12-NS1, together with GST pull-down assays on PDlim2 mutants, reveals that residues Arg16 and Lys31 of PDlim2 are critical for the binding between PDlim2 and HN12-NS1. The identification of a selective binding target of HN12-NS1 (ESEV, but not PR8-NS1 (RSEV, enables us to propose a structural mechanism for the interaction between NS1 PBM and PDlim2 or other PDZ-containing proteins.

  4. Outbreak of dengue virus type-3 in Malakand, Pakistan 2015; A laboratory perspective.

    Science.gov (United States)

    Suleman, Muhammad; Faryal, Rani; Alam, Muhammad Masroor; Khurshid, Adnan; Sharif, Salmaan; Shaukat, Shahzad; Angez, Mehar; Umair, Massab; Sufian, Mian Muhammad; Arshad, Yasir; Inam, Tanveer; Zaidi, Syed Sohail Zahoor

    2017-05-01

    An outbreak of dengue fever was reported in Malakand district, Khyber Pakhtunkhwa (KP) province of Pakistan during 2015. Detection of viral RNA by real-time PCR confirmed dengue virus serotype-3 (DENV-3) to be the causative agent causing the outbreak. Phylogenetic analysis based on partial E-NS1 gene sequences showed that the DENV-3 viruses belonged to genotype III with maximum homology with the dengue-3 strains previously reported from Pakistan and India. Our current report provides updated information on molecular epidemiology and phylogenetic analysis of dengue virus serotypes responsible for 2015 outbreak in KP. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Development of a dual-protective live attenuated vaccine against H5N1 and H9N2 avian influenza viruses by modifying the NS1 gene.

    Science.gov (United States)

    Choi, Eun-hye; Song, Min-Suk; Park, Su-Jin; Pascua, Philippe Noriel Q; Baek, Yun Hee; Kwon, Hyeok-il; Kim, Eun-Ha; Kim, Semi; Jang, Hyung-Kwan; Poo, Haryoung; Kim, Chul-Joong; Choi, Young Ki

    2015-07-01

    An increasing number of outbreaks of avian influenza H5N1 and H9N2 viruses in poultry have caused serious economic losses and raised concerns for human health due to the risk of zoonotic transmission. However, licensed H5N1 and H9N2 vaccines for animals and humans have not been developed. Thus, to develop a dual H5N1 and H9N2 live-attenuated influenza vaccine (LAIV), the HA and NA genes from a virulent mouse-adapted avian H5N2 (A/WB/Korea/ma81/06) virus and a recently isolated chicken H9N2 (A/CK/Korea/116/06) virus, respectively, were introduced into the A/Puerto Rico/8/34 backbone expressing truncated NS1 proteins (NS1-73, NS1-86, NS1-101, NS1-122) but still possessing a full-length NS gene. Two H5N2/NS1-LAIV viruses (H5N2/NS1-86 and H5N2/NS1-101) were highly attenuated compared with the full-length and remaining H5N2/NS-LAIV viruses in a mouse model. Furthermore, viruses containing NS1 modifications were found to induce more IFN-β activation than viruses with full-length NS1 proteins and were correspondingly attenuated in mice. Intranasal vaccination with a single dose (10(4.0) PFU/ml) of these viruses completely protected mice from a lethal challenge with the homologous A/WB/Korea/ma81/06 (H5N2), heterologous highly pathogenic A/EM/Korea/W149/06 (H5N1), and heterosubtypic highly virulent mouse-adapted H9N2 viruses. This study clearly demonstrates that the modified H5N2/NS1-LAIV viruses attenuated through the introduction of mutations in the NS1 coding region display characteristics that are desirable for live attenuated vaccines and hold potential as vaccine candidates for mammalian hosts.

  6. Dengue Virus and Autophagy

    Directory of Open Access Journals (Sweden)

    Nicholas S. Heaton

    2011-08-01

    Full Text Available Several independent groups have published that autophagy is required for optimal RNA replication of dengue virus (DENV. Initially, it was postulated that autophagosomes might play a structural role in replication complex formation. However, cryo-EM tomography of DENV replication complexes showed that DENV replicates on endoplasmic reticulum (ER cisternae invaginations and not on classical autophagosomes. Recently, it was reported that autophagy plays an indirect role in DENV replication by modulating cellular lipid metabolism. DENV-induced autophagosomes deplete cellular triglycerides that are stored in lipid droplets, leading to increased β-oxidation and energy production. This is the first example of a virus triggering autophagy to modulate cellular physiology. In this review, we summarize these data and discuss new questions and implications for autophagy during DENV replication.

  7. Immunopathogenesis of Dengue Virus-Induced Redundant Cell Death: Apoptosis and Pyroptosis.

    Science.gov (United States)

    Suwanmanee, San; Luplertlop, Natthanej

    Dengue virus infection is a self-limited condition, which is of particular importance in tropical and subtropical regions and for which no specific treatment or effective vaccine is available. There are several hypotheses explaining dengue pathogenesis. These usually refer to host immune responses, including antibody-dependent enhancement, cytokine expression, and dengue virus particles including NS1 protein, which lead to cell death by both apoptosis and pyroptosis. A clear understanding of the pathogenesis should facilitate the development of vaccines and therapies. This review focuses on the immunopathogenesis in relation to clinical manifestations and patterns of cell death, focusing on the pathogenesis of severe dengue.

  8. Interplay of PA-X and NS1 Proteins in Replication and Pathogenesis of a Temperature-Sensitive 2009 Pandemic H1N1 Influenza A Virus.

    Science.gov (United States)

    Nogales, Aitor; Rodriguez, Laura; DeDiego, Marta L; Topham, David J; Martínez-Sobrido, Luis

    2017-09-01

    Influenza A viruses (IAVs) cause seasonal epidemics and occasional pandemics, representing a serious public health concern. It has been described that one mechanism used by some IAV strains to escape the host innate immune responses and modulate virus pathogenicity involves the ability of the PA-X and NS1 proteins to inhibit the host protein synthesis in infected cells. It was reported that for the 2009 pandemic H1N1 IAV (pH1N1) only the PA-X protein had this inhibiting capability, while the NS1 protein did not. In this work, we have evaluated, for the first time, the combined effect of PA-X- and NS1-mediated inhibition of general gene expression on virus pathogenesis, using a temperature-sensitive, live-attenuated 2009 pandemic H1N1 IAV (pH1N1 LAIV). We found that viruses containing PA-X and NS1 proteins that simultaneously have (PA WT + /NS1 MUT + ) or do not have (PA MUT - /NS1 WT - ) the ability to block host gene expression showed reduced pathogenicity in vivo However, a virus where the ability to inhibit host protein expression was switched between PA-X and NS1 (PA MUT - /NS1 MUT + ) presented pathogenicity similar to that of a virus containing both wild-type proteins (PA WT + /NS1 WT - ). Our findings suggest that inhibition of host protein expression is subject to a strict balance, which can determine the successful progression of IAV infection. Importantly, knowledge obtained from our studies could be used for the development of new and more effective vaccine approaches against IAV. IMPORTANCE Influenza A viruses (IAVs) are one of the most common causes of respiratory infections in humans, resulting in thousands of deaths annually. Furthermore, IAVs can cause unpredictable pandemics of great consequence when viruses not previously circulating in humans are introduced into humans. The defense machinery provided by the host innate immune system limits IAV replication; however, to counteract host antiviral activities, IAVs have developed different inhibition

  9. [Research progress in the structure and function of dengue virus non-structural 1 protein].

    Science.gov (United States)

    Chen, Yue; Ren, Rui-wen; Liu, Jian-wei

    2014-11-01

    Dengue virus (DENV) is a re-emerging disease transmitted by the Aedes mosquitoes and has become a major public health problem in southern China. Currently, no antiviral drug or effective vaccine exist to control this disease. The chimeric DENV structural protein vaccine cannot elicit balanced levels of protective immunity to each of the four viral serotypes; therefore, non-structural protein components may be required to construct an effective DENV vaccine. The Dengue virus non-structural 1 (DENV NS1) protein plays a critical role in viral pathogenesis and protective immunity. Therefore, immunity to Dengue 1-4 NS1 subtypes may be crucial for the prevention of severe disease. This review attempts to provide an overview about the structure and function of DENV NS1.

  10. Protein clustering and RNA phylogenetic reconstruction of the influenza A [corrected] virus NS1 protein allow an update in classification and identification of motif conservation.

    Science.gov (United States)

    Sevilla-Reyes, Edgar E; Chavaro-Pérez, David A; Piten-Isidro, Elvira; Gutiérrez-González, Luis H; Santos-Mendoza, Teresa

    2013-01-01

    The non-structural protein 1 (NS1) of influenza A virus (IAV), coded by its third most diverse gene, interacts with multiple molecules within infected cells. NS1 is involved in host immune response regulation and is a potential contributor to the virus host range. Early phylogenetic analyses using 50 sequences led to the classification of NS1 gene variants into groups (alleles) A and B. We reanalyzed NS1 diversity using 14,716 complete NS IAV sequences, downloaded from public databases, without host bias. Removal of sequence redundancy and further structured clustering at 96.8% amino acid similarity produced 415 clusters that enhanced our capability to detect distinct subgroups and lineages, which were assigned a numerical nomenclature. Maximum likelihood phylogenetic reconstruction using RNA sequences indicated the previously identified deep branching separating group A from group B, with five distinct subgroups within A as well as two and five lineages within the A4 and A5 subgroups, respectively. Our classification model proposes that sequence patterns in thirteen amino acid positions are sufficient to fit >99.9% of all currently available NS1 sequences into the A subgroups/lineages or the B group. This classification reduces host and virus bias through the prioritization of NS1 RNA phylogenetics over host or virus phenetics. We found significant sequence conservation within the subgroups and lineages with characteristic patterns of functional motifs, such as the differential binding of CPSF30 and crk/crkL or the availability of a C-terminal PDZ-binding motif. To understand selection pressures and evolution acting on NS1, it is necessary to organize the available data. This updated classification may help to clarify and organize the study of NS1 interactions and pathogenic differences and allow the drawing of further functional inferences on sequences in each group, subgroup and lineage rather than on a strain-by-strain basis.

  11. Serum-free microcarrier based production of replication deficient Influenza vaccine candidate virus lacking NS1 using Vero cells

    Directory of Open Access Journals (Sweden)

    Yan Mylene L

    2011-08-01

    Full Text Available Abstract Background Influenza virus is a major health concern that has huge impacts on the human society, and vaccination remains as one of the most effective ways to mitigate this disease. Comparing the two types of commercially available Influenza vaccine, the live attenuated virus vaccine is more cross-reactive and easier to administer than the traditional inactivated vaccines. One promising live attenuated Influenza vaccine that has completed Phase I clinical trial is deltaFLU, a deletion mutant lacking the viral Nonstructural Protein 1 (NS1 gene. As a consequence of this gene deletion, this mutant virus can only propagate effectively in cells with a deficient interferon-mediated antiviral response. To demonstrate the manufacturability of this vaccine candidate, a batch bioreactor production process using adherent Vero cells on microcarriers in commercially available animal-component free, serum-free media is described. Results Five commercially available animal-component free, serum-free media (SFM were evaluated for growth of Vero cells in agitated Cytodex 1 spinner flask microcarrier cultures. EX-CELL Vero SFM achieved the highest cell concentration of 2.6 × 10^6 cells/ml, whereas other SFM achieved about 1.2 × 10^6 cells/ml. Time points for infection between the late exponential and stationary phases of cell growth had no significant effect in the final virus titres. A virus yield of 7.6 Log10 TCID50/ml was achieved using trypsin concentration of 10 μg/ml and MOI of 0.001. The Influenza vaccine production process was scaled up to a 3 liter controlled stirred tank bioreactor to achieve a cell density of 2.7 × 10^6 cells/ml and virus titre of 8.3 Log10 TCID50/ml. Finally, the bioreactor system was tested for the production of the corresponding wild type H1N1 Influenza virus, which is conventionally used in the production of inactivated vaccine. High virus titres of up to 10 Log10 TCID50/ml were achieved. Conclusions We describe for the

  12. Detection of immune-complex-dissociated nonstructural-1 antigen in patients with acute dengue virus infections

    NARCIS (Netherlands)

    P. Koraka (Penelope); C.P. Burghoorn-Maas; A. Falconar; T.E. Setiati (Tatty); K. Djamiatun; J. Groen (Jan); A.D.M.E. Osterhaus (Albert)

    2003-01-01

    textabstractAccurate and timely diagnosis of dengue virus (DEN) infections is essential for the differential diagnosis of patients with febrile illness and hemorrhagic fever. In the present study, the diagnostic value of a newly developed immune-complex dissociated nonstructural-1 (NS-1) antigen dot

  13. Detection of immune-complex-dissociated nonstructural-1 antigen in patients with acute dengue virus infections.

    NARCIS (Netherlands)

    Koraka, P.; Burghoorn-Maas, C.P.; Falconar, A.; Setiati, T.E.; Djamiatun, K.; Groen, J.; Osterhaus, A.D.

    2003-01-01

    Accurate and timely diagnosis of dengue virus (DEN) infections is essential for the differential diagnosis of patients with febrile illness and hemorrhagic fever. In the present study, the diagnostic value of a newly developed immune-complex dissociated nonstructural-1 (NS-1) antigen dot blot

  14. Dengue virus non-structural Protein-1 expression and associated risk factors among febrile Patients attending University of Abuja Teaching Hospital, Nigeria.

    Science.gov (United States)

    Nasir, Idris Abdullahi; Agbede, Olubunmi Olajide; Dangana, Amos; Baba, Marycelin; Haruna, Abubakar Shehu

    2017-02-15

    Dengue is a mosquito-borne and neglected tropical viral disease that has been reported to be hyper-endemic in Nigeria. However, this is the first dengue study in Abuja. This hospital-based cross-sectional study investigated the prevalence of Dengue virus (DENV) non-structural protein-1 (NS1) antigenaemia, anti-Dengue virus IgG and their associated risk factors among febrile patients attending the University of Abuja Teaching Hospital (UATH), Nigeria. From May to August 2016, blood samples were individually collected from 171 consented participants. These samples were analyzed using DENV NS1 and anti-DENV IgG Enzyme Linked Immunosorbent Assay (ELISA) kits. Well-structured questionnaires was used to collect sociodemographic variables of participants. Out of the 171 participants, the prevalence of Dengue virus NS1 antigenaemia and IgG seropositivity were 8.8% and 43.3%, respectively. Three (1.8%) of the patients were NS1 (+) IgG (-), 12 (7.0%) had NS1 (+) IgG (+), 62 (36.3%) were NS1 (-) IgG (+), while 97 (56.7%) of the remaining patients were NS1 (-) IgG (-). There was statistical association between DENV NS1 antigenaemia with age of patients (p=0.034), residence in proximity to waste dumpsites (pDengue virus IgG with occupation (p=0.0034) and education level of patients (pDengue virus IgG with gender (p=0.4060) and residential area of patients (p=0.3896). Findings from this study revealed that DENV infection is one of the etiological agents of acute febrile illnesses in Abuja. It's recommended that Dengue testing be considered during differential diagnosis of febrile patients. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Human respiratory syncytial virus non-structural protein NS1 modifies miR-24 expression via transforming growth factor-β

    Science.gov (United States)

    Bakre, Abhijeet; Wu, Weining; Hiscox, Julian; Spann, Kirsten; Teng, Michael N.

    2015-01-01

    Human respiratory syncytial virus (RSV) is a major health challenge in the young and elderly owing to the lack of a safe and effective vaccine and proven antiviral drugs. Understanding the mechanisms by which viral genes and proteins modulate the host response to infection is critical for identifying novel disease intervention strategies. In this study, the RSV non-structural protein NS1 was shown to suppress miR-24 expression during infection. Lack of NS1 was linked to increased expression of miR-24, whilst NS1 overexpression suppressed miR-24 expression. NS1 was found to induce Kruppel-like factor 6 (KLF6), a transcription factor that positively regulates the transforming growth factor (TGF)-β pathway to induce cell cycle arrest. Silencing of KLF6 led to increased miR-24 expression via downregulation of TGF-β. Treatment with exogenous TGF-β suppressed miR-24 expression and induced KLF6. Confocal microscopy showed co-localization of KLF6 and RSV NS1. These findings indicated that RSV NS1 interacts with KLF6 and modulates miR-24 expression and TGF-β, which facilitates RSV replication. PMID:26253191

  16. Proteomic analysis of endothelial cell autoantigens recognized by anti-dengue virus nonstructural protein 1 antibodies.

    Science.gov (United States)

    Cheng, Hsien-Jen; Lin, Chiou-Feng; Lei, Huan-Yao; Liu, Hsiao-Sheng; Yeh, Trai-Ming; Luo, Yueh-Hsia; Lin, Yee-Shin

    2009-01-01

    We previously showed the occurrence of autoimmune responses in dengue virus (DV) infection, which has potential implications for the pathogenesis of dengue hemorrhagic syndrome. In the present study, we have used a proteomic analysis to identify several candidate proteins on HMEC-1 endothelial cells recognized by anti-DV nonstructural protein 1 (NS1) antibodies. The target proteins, including ATP synthase beta chain, protein disulfide isomerase, vimentin, and heat shock protein 60, co-localize with anti-NS1 binding sites on nonfixed HMEC-1 cells using immunohistochemical double staining and confocal microscopy. The cross-reactivity of anti-target protein antibodies with HMEC-1 cells was inhibited by NS1 protein pre-absorption. Furthermore, a cross-reactive epitope on NS1 amino acid residues 311-330 (P311-330) was predicted using homologous sequence alignment. The reactivity of dengue hemorrhagic patient sera with HMEC-1 cells was blocked by synthetic peptide P311-330 pre-absorption. Taken together, our results identify putative targets on endothelial cells recognized by anti-DV NS1 antibodies, where NS1 P311-330 possesses the shared epitope.

  17. Dengue Virus Nonstructural Protein 1-Induced Antibodies Cross-React with Human Plasminogen and Enhance Its Activation.

    Science.gov (United States)

    Chuang, Yung-Chun; Lin, Jessica; Lin, Yee-Shin; Wang, Shuying; Yeh, Trai-Ming

    2016-02-01

    Dengue virus (DENV) infection is the most common mosquito-borne viral disease, and it can cause life-threatening dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). Abnormal activation of the coagulation and fibrinolysis system is one of the hallmarks of DHF/DSS. However, the mechanism underlying hemorrhage in DHF/DSS remains elusive. In previous studies, plasminogen (Plg) cross-reactive Abs, which can recognize DENV nonstructural protein (NS) 1, have been found in dengue patients. However, it is unclear whether these Abs are indeed induced by DENV NS1. Thus, we immunized mice with recombinant NS1 from both bacteria and drosophila to determine whether NS1 can induce Plg cross-reactive Abs. The results from the NS1-immunized mouse sera indicated that NS1 immunization induced Abs that could cross-react with Plg. To study the effects of these NS1-induced Plg cross-reactive Abs on fibrinolysis, we isolated several Plg cross-reactive anti-NS1 mAbs from these mice and found that some of them could enhance Plg activation. In addition, epitope mapping with a phage-displayed random peptide library revealed that one of these mAbs (2A5) could recognize NS1 C-terminal residues 305-311, which share sequence homology with Plg residues 590-597. A synthetic peptide of NS1 residues 305-311 could inhibit the binding of both 2A5 and its Fab to Plg and its enhanced activation. Thus, our results suggest that DENV NS1 can induce Plg cross-reactive Abs through molecular mimicry, which can enhance Plg activation and may contribute to the pathogenesis of DHF/DSS. Copyright © 2016 by The American Association of Immunologists, Inc.

  18. The dengue viruses.

    OpenAIRE

    Henchal, E A; Putnak, J R

    1990-01-01

    Dengue, a major public health problem throughout subtropical and tropical regions, is an acute infectious disease characterized by biphasic fever, headache, pain in various parts of the body, prostration, rash, lymphadenopathy, and leukopenia. In more severe or complicated dengue, patients present with a severe febrile illness characterized by abnormalities of hemostasis and increased vascular permeability, which in some instances results in a hypovolemic shock. Four distinct serotypes of the...

  19. Differences in the ability to suppress interferon β production between allele A and allele B NS1 proteins from H10 influenza A viruses

    Directory of Open Access Journals (Sweden)

    Zohari Siamak

    2010-12-01

    Full Text Available Abstract Background In our previous study concerning the genetic relationship among H10 avian influenza viruses with different pathogenicity in mink (Mustela vison, we found that these differences were related to amino acid variations in the NS1 protein. In this study, we extend our previous work to further investigate the effect of the NS1 from different gene pools on type I IFN promoter activity, the production of IFN-β, as well as the expression of the IFN-β mRNA in response to poly I:C. Results Using a model system, we first demonstrated that NS1 from A/mink/Sweden/84 (H10N4 (allele A could suppress an interferon-stimulated response element (ISRE reporter system to about 85%. The other NS1 (allele B, from A/chicken/Germany/N/49 (H10N7, was also able to suppress the reporter system, but only to about 20%. The differences in the abilities of the two NS1s from different alleles to suppress the ISRE reporter system were clearly reflected by the protein and mRNA expressions of IFN-β as shown by ELISA and RT-PCR assays. Conclusions These studies reveal that different non-structural protein 1 (NS1 of influenza viruses, one from allele A and another from allele B, show different abilities to suppress the type I interferon β expression. It has been hypothesised that some of the differences in the different abilities of the alleles to suppress ISRE were because of the interactions and inhibitions at later stages from the IFN receptor, such as the JAK/STAT pathway. This might reflect the additional effects of the immune evasion potential of different NS1s.

  20. Identification of one B-cell epitope from NS1 protein of duck Tembusu virus with monoclonal antibodies.

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    Jinfeng Ti

    Full Text Available This study describes the identification of one linear B-cell epitope on TMUV NS1 protein with monoclonal antibody (mAb 3G2 by indirect enzyme-linked immunosorbent assay (ELISA. In this study, NS1 protein was expressed in prokaryotic expression system and purified. One mAb against NS1 protein was generated from Balb/c mice immunized with recombinant protein NS1. A set of 35 partially-overlapping polypeptides covering the entire NS1 protein was expressed with PGEX-6P-1 vector and screened with mAb 3G2. One polypeptide against the mAb was acquired and identified by indirect ELISA and western-blot. To map the epitope accurately, one or two amino acid residues were removed from the carboxy and amino terminal of polypeptide sequentially. A series of truncated oligopeptides were expressed and purified. The minimal determinant of the linear B cell epitope was recognized and identified with mAb 3G2. The accurate linear B-cell epitope was 269DEKEIV274 located in NS1 protein. Furthermore, sequence alignment showed that the epitope was highly conserved and specific among TMUV strains and other flavivirus respectively. The linear B-cell epitope of TMUV NS1 protein could benefit the development of new vaccines and diagnostic assays.

  1. Specific Mutations in the PB2 Protein of Influenza A Virus Compensate for the Lack of Efficient Interferon Antagonism of the NS1 Protein of Bat Influenza A-Like Viruses.

    Science.gov (United States)

    Aydillo, Teresa; Ayllon, Juan; Pavlisin, Amzie; Martinez-Romero, Carles; Tripathi, Shashank; Mena, Ignacio; Moreira-Soto, Andrés; Vicente-Santos, Amanda; Corrales-Aguilar, Eugenia; Schwemmle, Martin; García-Sastre, Adolfo

    2018-04-01

    Recently, two new influenza A-like viruses have been discovered in bats, A/little yellow-shouldered bat/Guatemala/060/2010 (HL17NL10) and A/flat-faced bat/Peru/033/2010 (HL18NL11). The hemagglutinin (HA)-like (HL) and neuraminidase (NA)-like (NL) proteins of these viruses lack hemagglutination and neuraminidase activities, despite their sequence and structural homologies with the HA and NA proteins of conventional influenza A viruses. We have now investigated whether the NS1 proteins of the HL17NL10 and HL18NL11 viruses can functionally replace the NS1 protein of a conventional influenza A virus. For this purpose, we generated recombinant influenza A/Puerto Rico/8/1934 (PR8) H1N1 viruses containing the NS1 protein of the PR8 wild-type, HL17NL10, and HL18NL11 viruses. These viruses (r/NS1PR8, r/NS1HL17, and r/NS1HL18, respectively) were tested for replication in bat and nonbat mammalian cells and in mice. Our results demonstrate that the r/NS1HL17 and r/NS1HL18 viruses are attenuated in vitro and in vivo However, the bat NS1 recombinant viruses showed a phenotype similar to that of the r/NS1PR8 virus in STAT1 -/- human A549 cells and mice, both in vitro and in vivo systems being unable to respond to interferon (IFN). Interestingly, multiple mouse passages of the r/NS1HL17 and r/NS1HL18 viruses resulted in selection of mutant viruses containing single amino acid mutations in the viral PB2 protein. In contrast to the parental viruses, virulence and IFN antagonism were restored in the selected PB2 mutants. Our results indicate that the NS1 protein of bat influenza A-like viruses is less efficient than the NS1 protein of its conventional influenza A virus NS1 counterpart in antagonizing the IFN response and that this deficiency can be overcome by the influenza virus PB2 protein. IMPORTANCE Significant gaps in our understanding of the basic features of the recently discovered bat influenza A-like viruses HL17NL10 and HL18NL11 remain. The basic biology of these unique

  2. Dengue viruses – an overview

    Science.gov (United States)

    Bäck, Anne Tuiskunen; Lundkvist, Åke

    2013-01-01

    Dengue viruses (DENVs) cause the most common arthropod-borne viral disease in man with 50–100 million infections per year. Because of the lack of a vaccine and antiviral drugs, the sole measure of control is limiting the Aedes mosquito vectors. DENV infection can be asymptomatic or a self-limited, acute febrile disease ranging in severity. The classical form of dengue fever (DF) is characterized by high fever, headache, stomach ache, rash, myalgia, and arthralgia. Severe dengue, dengue hemorrhagic fever (DHF), and dengue shock syndrome (DSS) are accompanied by thrombocytopenia, vascular leakage, and hypotension. DSS, which can be fatal, is characterized by systemic shock. Despite intensive research, the underlying mechanisms causing severe dengue is still not well understood partly due to the lack of appropriate animal models of infection and disease. However, even though it is clear that both viral and host factors play important roles in the course of infection, a fundamental knowledge gap still remains to be filled regarding host cell tropism, crucial host immune response mechanisms, and viral markers for virulence. PMID:24003364

  3. Dengue viruses – an overview

    Directory of Open Access Journals (Sweden)

    Anne Tuiskunen Bäck

    2013-08-01

    Full Text Available Dengue viruses (DENVs cause the most common arthropod-borne viral disease in man with 50–100 million infections per year. Because of the lack of a vaccine and antiviral drugs, the sole measure of control is limiting the Aedes mosquito vectors. DENV infection can be asymptomatic or a self-limited, acute febrile disease ranging in severity. The classical form of dengue fever (DF is characterized by high fever, headache, stomach ache, rash, myalgia, and arthralgia. Severe dengue, dengue hemorrhagic fever (DHF, and dengue shock syndrome (DSS are accompanied by thrombocytopenia, vascular leakage, and hypotension. DSS, which can be fatal, is characterized by systemic shock. Despite intensive research, the underlying mechanisms causing severe dengue is still not well understood partly due to the lack of appropriate animal models of infection and disease. However, even though it is clear that both viral and host factors play important roles in the course of infection, a fundamental knowledge gap still remains to be filled regarding host cell tropism, crucial host immune response mechanisms, and viral markers for virulence.

  4. Dengue Virus Tropism in Humanized Mice Recapitulates Human Dengue Fever

    Science.gov (United States)

    Mota, Javier; Rico-Hesse, Rebeca

    2011-01-01

    Animal models of dengue virus disease have been very difficult to develop because of the virus' specificity for infection and replication in certain human cells. We developed a model of dengue fever in immunodeficient mice transplanted with human stem cells from umbilical cord blood. These mice show measurable signs of dengue disease as in humans (fever, viremia, erythema and thrombocytopenia), and after infection with the most virulent strain of dengue serotype 2, humanized mice showed infection in human cells in bone marrow, spleen and blood. Cytokines and chemokines were secreted by these human cells into the mouse bloodstream. We demonstrated that the pathology of dengue virus infection in these mice follows that reported in human patients, making this the first valid and relevant model for studying dengue fever pathogenesis in humans. PMID:21695193

  5. Ns1 is a key protein in the vaccine composition to protect Ifnar(-/- mice against infection with multiple serotypes of African horse sickness virus.

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    Francisco de la Poza

    Full Text Available African horse sickness virus (AHSV belongs to the genus Orbivirus. We have now engineered naked DNAs and recombinant modified vaccinia virus Ankara (rMVA expressing VP2 and NS1 proteins from AHSV-4. IFNAR((-/- mice inoculated with DNA/rMVA-VP2,-NS1 from AHSV-4 in an heterologous prime-boost vaccination strategy generated significant levels of neutralizing antibodies specific of AHSV-4. In addition, vaccination stimulated specific T cell responses against the virus. The vaccine elicited partial protection against an homologous AHSV-4 infection and induced cross-protection against the heterologous AHSV-9. Similarly, IFNAR((-/- mice vaccinated with an homologous prime-boost strategy with rMVA-VP2-NS1 from AHSV-4 developed neutralizing antibodies and protective immunity against AHSV-4. Furthermore, the levels of immunity were very high since none of vaccinated animals presented viraemia when they were challenged against the homologous AHSV-4 and very low levels when they were challenged against the heterologous virus AHSV-9. These data suggest that the immunization with rMVA/rMVA was more efficient in protection against a virulent challenge with AHSV-4 and both strategies, DNA/rMVA and rMVA/rMVA, protected against the infection with AHSV-9. The inclusion of the protein NS1 in the vaccine formulations targeting AHSV generates promising multiserotype vaccines.

  6. Dengue virus exposure among blood donors in Ghana | Narkwa ...

    African Journals Online (AJOL)

    The samples were further tested for dengue virus RNA using RT-PCR. Dengue virus IgG was positive for 43.6% of all the 188 blood donor samples tested but all donors were negative for anti-dengue IgM antibody and dengue virus RNA. The rate of dengue virus total antibody exposure did not differ statistically between ...

  7. Vaccination with NS1-truncated H3N2 swine influenza virus primes T cells and confers cross-protection against an H1N1 heterosubtypic challenge in pigs

    Science.gov (United States)

    The diversity of contemporary swine influenza virus (SIV) strains impedes effective immunization of swine herds. Mucosally delivered, attenuated virus vaccines are one approach with potential to provide broad cross-protection. Reverse genetics-derived H3N2 SIV virus with truncated NS1 (NS1delta126 T...

  8. DENGUE VIRUS VIRULENCE AND DISEASES SEVERITY.

    Science.gov (United States)

    Prommalikit, Olarn; Thisyakorn, Usa

    2015-01-01

    The dengue virus is the causative agent of a wide spectrum of clinical manifestations, ranging from mild acute febrile illness to classical dengue fever, dengue hemorrhagic fever (DHF), and dengue shock syndrome (DSS). DHF and DSS are the potentially fatal forms of dengue virus infection, which has become an intractable public health problem in many countries. The pathogeneses of DHF/ DSS are not clearly understood. One hypothesis concerning virus virulence and the immune enhancement hypothesis has been debated. Although dengue disease severity has been associated with evidence of genetic differences in dengue strains, virus virulence has been difficult to measure because of the lack of in vivo and in vitro models of the disease.

  9. Dengue Virus Non-structural Protein 1 Modulates Infectious Particle Production via Interaction with the Structural Proteins.

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    Pietro Scaturro

    Full Text Available Non-structural protein 1 (NS1 is one of the most enigmatic proteins of the Dengue virus (DENV, playing distinct functions in immune evasion, pathogenesis and viral replication. The recently reported crystal structure of DENV NS1 revealed its peculiar three-dimensional fold; however, detailed information on NS1 function at different steps of the viral replication cycle is still missing. By using the recently reported crystal structure, as well as amino acid sequence conservation, as a guide for a comprehensive site-directed mutagenesis study, we discovered that in addition to being essential for RNA replication, DENV NS1 is also critically required for the production of infectious virus particles. Taking advantage of a trans-complementation approach based on fully functional epitope-tagged NS1 variants, we identified previously unreported interactions between NS1 and the structural proteins Envelope (E and precursor Membrane (prM. Interestingly, coimmunoprecipitation revealed an additional association with capsid, arguing that NS1 interacts via the structural glycoproteins with DENV particles. Results obtained with mutations residing either in the NS1 Wing domain or in the β-ladder domain suggest that NS1 might have two distinct functions in the assembly of DENV particles. By using a trans-complementation approach with a C-terminally KDEL-tagged ER-resident NS1, we demonstrate that the secretion of NS1 is dispensable for both RNA replication and infectious particle production. In conclusion, our results provide an extensive genetic map of NS1 determinants essential for viral RNA replication and identify a novel role of NS1 in virion production that is mediated via interaction with the structural proteins. These studies extend the list of NS1 functions and argue for a central role in coordinating replication and assembly/release of infectious DENV particles.

  10. Molecular surveillance of dengue in Semarang, Indonesia revealed the circulation of an old genotype of dengue virus serotype-1.

    Directory of Open Access Journals (Sweden)

    Sukmal Fahri

    Full Text Available Dengue disease is currently a major health problem in Indonesia and affects all provinces in the country, including Semarang Municipality, Central Java province. While dengue is endemic in this region, only limited data on the disease epidemiology is available. To understand the dynamics of dengue in Semarang, we conducted clinical, virological, and demographical surveillance of dengue in Semarang and its surrounding regions in 2012. Dengue cases were detected in both urban and rural areas located in various geographical features, including the coastal and highland areas. During an eight months' study, a total of 120 febrile patients were recruited, of which 66 were serologically confirmed for dengue infection using IgG/IgM ELISA and/or NS1 tests. The cases occurred both in dry and wet seasons. Majority of patients were under 10 years old. Most patients were diagnosed as dengue hemorrhagic fever, followed by dengue shock syndrome and dengue fever. Serotyping was performed in 31 patients, and we observed the co-circulation of all four dengue virus (DENV serotypes. When the serotypes were correlated with the severity of the disease, no direct correlation was observed. Phylogenetic analysis of DENV based on Envelope gene sequence revealed the circulation of DENV-2 Cosmopolitan genotype and DENV-3 Genotype I. A striking finding was observed for DENV-1, in which we found the co-circulation of Genotype I with an old Genotype II. The Genotype II was represented by a virus strain that has a very slow mutation rate and is very closely related to the DENV strain from Thailand, isolated in 1964 and never reported in other countries in the last three decades. Moreover, this virus was discovered in a cool highland area with an elevation of 1,001 meters above the sea level. The discovery of this old DENV strain may suggest the silent circulation of old virus strains in Indonesia.

  11. Dengue virus markers of virulence and pathogenicity

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    Rico-Hesse, Rebeca

    2009-01-01

    The increased spread of dengue fever and its more severe form, dengue hemorrhagic fever, have made the study of the mosquito-borne dengue viruses that cause these diseases a public health priority. Little is known about how or why the four different (serotypes 1–4) dengue viruses cause pathology in humans only, and there have been no animal models of disease to date. Therefore, there are no vaccines or antivirals to prevent or treat infection and mortality rates of dengue hemorrhagic fever pa...

  12. Identification of two linear B-cell epitopes from West Nile virus NS1 by screening a phage-displayed random peptide library

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    Qin Yong-Li

    2011-07-01

    Full Text Available Abstract Background The West Nile virus (WNV nonstructural protein 1 (NS1 is an important antigenic protein that elicits protective antibody responses in animals and can be used for the serological diagnosis of WNV infection. Although previous work has demonstrated the vital role of WNV NS1-specific antibody responses, the specific epitopes in the NS1 have not been identified. Results The present study describes the identification of two linear B-cell epitopes in WNV NS1 through screening a phage-displayed random 12-mer peptide library with two monoclonal antibodies (mAbs 3C7 and 4D1 that directed against the NS1. The mAbs 3C7 and 4D1 recognized phages displaying peptides with the consensus motifs LTATTEK and VVDGPETKEC, respectively. Exact sequences of both motifs were found in the NS1 (895LTATTEK901 and 925VVDGPETKEC934. Further identification of the displayed B cell epitopes were conducted using a set of truncated peptides expressed as MBP fusion proteins. The data indicated that 896TATTEK901 and925VVDGPETKEC934 are minimal determinants of the linear B cell epitopes recognized by the mAbs 3C7 and 4D1, respectively. Antibodies present in the serum of WNV-positive horses recognized the minimal linear epitopes in Western blot analysis, indicating that the two peptides are antigenic in horses during infection. Furthermore, we found that the epitope recognized by 3C7 is conserved only among WNV strains, whereas the epitope recognized by 4D1 is a common motif shared among WNV and other members of Japanese encephalitis virus (JEV serocomplex. Conclusions We identified TATTEK and VVDGPETKEC as NS1-specific linear B-cell epitopes recognized by the mAbs 3C7 and 4D1, respectively. The knowledge and reagents generated in this study may have potential applications in differential diagnosis and the development of epitope-based marker vaccines against WNV and other viruses of JEV serocomplex.

  13. Characterization of a novel mutation in NS1 protein of influenza A virus induced by a chemical substance for the attenuation of pathogenicity.

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    Kohei Sasaki

    Full Text Available It is generally accepted that live attenuated influenza vaccine (LAIV has the potential for use as a vaccination against flu. In this study, we demonstrated the nature of an influenza A virus (IAV mutant induced by treating the IAV with a stable furan derivative, (1R,2R-1-(5'-methylfur-3'-ylpropane-1,2,3-triol (MFPT, which had been isolated from Streptomyces sp. strain FV60 with the objective of it being an LAIV candidate. The resulting MFPT-resistant (MFPTr IAVs possessed attenuated pathogenicity in vitro and in vivo when compared with that of the parent virus (H1N1 subtype, NWS strain. Sequencing analysis revealed that a novel mutation, C490U in ns gene (P164S in NS1, was detected in all MFPTr virus clones tested. Therefore, NS1 might be a main target of MFPT, and it was suggested that the P164S mutation contributed to the attenuated pathogenicity of the mutants. Although the phosphatidylinositol 3-kinase (PI3K/Akt signaling pathway is one of the targets of NS1, the MFPTr virus suppressed the phosphorylation of Akt when compared with the wild-type (WT virus. It was suggested that this might lead to the subsequent inhibition of the cleavage of PARP-1 and caspase-3, which is important for the progression of apoptosis. At the same time, nucleoprotein (NP was found to be retained in the nuclei in MFPTr virus-infected cells while nuclear export of NP was detected in WT virus-infected cells. In addition, the expression levels of interferon-β transcripts were significantly decreased in MFPTr virus-infected cells. From these results it can be shown that the mutation, NS1P164S, might be one of the key residues to control NS1 function concerning the induction of apoptosis. In conclusion, MFPT induced favorable mutation in the ns gene for the attenuation of IAV, and therefore might provide the novel methodology for preparing LAIVs.

  14. Observation on dengue cases from a virus diagnostic laboratory of a tertiary care hospital in North India.

    Science.gov (United States)

    Prakash, Om; Singh, Desh Deepak; Mishra, Geetika; Prakash, Shantanu; Singh, Arvind; Gupta, Shikha; Singh, Jasmeet; Khan, Danish Nasar; Jain, Parul; Vishal, Anamika; Pandey, Manoj Kumar; Jain, Amita

    2015-12-01

    The epidemiology of dengue fever (DF) is complex in the Indian subcontinent as all the four serotypes are circulating. This study reports observations on dengue cases from a virus diagnostic laboratory of a north Indian tertiary care hospital catering to areas in and around Lucknow, Uttar Pradesh. Serum samples were obtained from suspected cases of dengue referred to the virus diagnostic laboratory during 2011 to 2013, and detailed history was taken on a pre-structured datasheet. All samples were tested for anti-dengue virus (DV) IgM antibodies and DV-non structural protein 1 antigen (NS1Ag) by ELISA. NS1Ag positive samples were tested further by conventional RT-PCR for DV-RNA detection and serotyping. Of the 4019 suspected patients of dengue, 886 (22%) showed laboratory evidence of dengue virus infection. Of these, 19, 17 and 27 per cent were positive in 2011, 2012 and 2013, respectively. Children and adults were similarly affected by dengue in all the three years. Males were more commonly affected than females. The predominant DV serotype detected was DV-2, DV-1 and DV-3 in 2011, 2012 and 2013, respectively. DV-4 serotype was not detected. About half the cases positive for DV infection, showed symptoms of dengue with warning signs/ severe dengue. A distinct seasonality with increase in number of dengue cases in the post monsoon period was seen. Change in circulating serotype of dengue virus; a distinct adult dengue involvement; and a remarkable number of cases presenting with severe dengue manifestations are the main findings of this study.

  15. Cells in Dengue Virus Infection In Vivo

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    Sansanee Noisakran

    2010-01-01

    Full Text Available Dengue has been recognized as one of the most important vector-borne emerging infectious diseases globally. Though dengue normally causes a self-limiting infection, some patients may develop a life-threatening illness, dengue hemorrhagic fever (DHF/dengue shock syndrome (DSS. The reason why DHF/DSS occurs in certain individuals is unclear. Studies in the endemic regions suggest that the preexisting antibodies are a risk factor for DHF/DSS. Viremia and thrombocytopenia are the key clinical features of dengue virus infection in patients. The amounts of virus circulating in patients are highly correlated with severe dengue disease, DHF/DSS. Also, the disturbance, mainly a transient depression, of hematological cells is a critical clinical finding in acute dengue patients. However, the cells responsible for the dengue viremia are unresolved in spite of the intensive efforts been made. Dengue virus appears to replicate and proliferate in many adapted cell lines, but these in vitro properties are extremely difficult to be reproduced in primary cells or in vivo. This paper summarizes reports on the permissive cells in vitro and in vivo and suggests a hematological cell lineage for dengue virus infection in vivo, with the hope that a new focus will shed light on further understanding of the complexities of dengue disease.

  16. Inability of NS1 protein from an H5N1 influenza virus to activate PI3K/Akt signaling pathway correlates to the enhanced virus replication upon PI3K inhibition

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    Li Weizhong

    2012-04-01

    Full Text Available Abstract Background Phosphatidylinositol 3-kinase (PI3K/Akt signaling pathway, activated during influenza A virus infection, can promote viral replication via multiple mechanisms. Direct binding of NS1 protein to p85β subunit of PI3K is required for activation of PI3K/Akt signaling. Binding and subsequent activation of PI3K is believed to be a conserved character of influenza A virus NS1 protein. Sequence variation of NS1 proteins in different influenza A viruses led us to investigate possible deviation from the conservativeness. Results In the present study, NS1 proteins from four different influenza A virus subtypes/strains were tested for their ability to bind p85β subunit of PI3K and to activate PI3K/Akt. All NS1 proteins efficiently bound to p85β and activated PI3K/Akt, with the exception of NS1 protein from an H5N1 virus (A/Chicken/Guangdong/1/05, abbreviated as GD05, which bound to p85β but failed to activate PI3K/Akt, implying that as-yet-unidentified domain(s in NS1 may alternatively mediate the activation of PI3K. Moreover, PI3K inhibitor, LY294002, did not suppress but significantly increased the replication of GD05 virus. Conclusions Our study indicates that activation of PI3K/Akt by NS1 protein is not highly conserved among influenza A viruses and inhibition of the PI3K/Akt pathway as an anti-influenza strategy may not work for all influenza A viruses.

  17. New regulatory mechanisms for the intracellular localization and trafficking of influenza A virus NS1 protein revealed by comparative analysis of A/PR/8/34 and A/Sydney/5/97.

    Science.gov (United States)

    Han, Han; Cui, Zong-Qiang; Wang, Wei; Zhang, Zhi-Ping; Wei, Hong-Ping; Zhou, Ya-Feng; Zhang, Xian-En

    2010-12-01

    During influenza A virus infection, the NS1 protein is engaged in different functions in different intracellular compartments. In this study, we showed that the NS1 of A/PR/8/34 localized in different positions from that of A/Sydney/5/97 when transiently expressed in Madin-Darby canine kidney cells. Residue 221 of NS1 was identified to be a new key residue involved in the C-terminal nuclear localization signal (NLS) and nucleolar localization signal (NoLS) of NS1 from A/Sydney/5/97. Analysis of chimeric NS1 and further mutants showed that residues responsible for the binding between NS1 and the cleavage and polyadenylation specificity factor (CPSF) are correlated with the intracellular localization of transiently expressed NS1 proteins. Fluorescence loss in photobleaching imaging revealed that the NS1 protein with both functional NLSs and nuclear export signal (NES) was able to shuttle between the nucleus and cytoplasm. Drug inhibition experiments and fluorescence resonance energy transfer analysis suggested that NS1 was exported out of the cell nuclei via a Crm1-independent pathway. Moreover, it is likely that another cytoplasmic localization-related sequence exists in the NS1 protein other than the leucine-rich NES. These findings provide new insights into the mechanism of intracellular localization and trafficking of influenza A virus NS1 protein, which is important for understanding its function.

  18. Mass spectrometric analysis of host cell proteins interacting with dengue virus nonstructural protein 1 in dengue virus-infected HepG2 cells.

    Science.gov (United States)

    Dechtawewat, Thanyaporn; Paemanee, Atchara; Roytrakul, Sittiruk; Songprakhon, Pucharee; Limjindaporn, Thawornchai; Yenchitsomanus, Pa-Thai; Saitornuang, Sawanan; Puttikhunt, Chunya; Kasinrerk, Watchara; Malasit, Prida; Noisakran, Sansanee

    2016-09-01

    Dengue virus (DENV) infection is a leading cause of the mosquito-borne infectious diseases that affect humans worldwide. Virus-host interactions appear to play significant roles in DENV replication and the pathogenesis of DENV infection. Nonstructural protein 1 (NS1) of DENV is likely involved in these processes; however, its associations with host cell proteins in DENV infection remain unclear. In this study, we used a combination of techniques (immunoprecipitation, in-solution trypsin digestion, and LC-MS/MS) to identify the host cell proteins that interact with cell-associated NS1 in an in vitro model of DENV infection in the human hepatocyte HepG2 cell line. Thirty-six novel host cell proteins were identified as potential DENV NS1-interacting partners. A large number of these proteins had characteristic binding or catalytic activities, and were involved in cellular metabolism. Coimmunoprecipitation and colocalization assays confirmed the interactions of DENV NS1 and human NIMA-related kinase 2 (NEK2), thousand and one amino acid protein kinase 1 (TAO1), and component of oligomeric Golgi complex 1 (COG1) proteins in virus-infected cells. This study reports a novel set of DENV NS1-interacting host cell proteins in the HepG2 cell line and proposes possible roles for human NEK2, TAO1, and COG1 in DENV infection. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. RNAi: antiviral therapy against dengue virus.

    Science.gov (United States)

    Idrees, Sobia; Ashfaq, Usman A

    2013-03-01

    Dengue virus infection has become a global threat affecting around 100 countries in the world. Currently, there is no licensed antiviral agent available against dengue. Thus, there is a strong need to develop therapeutic strategies that can tackle this life threatening disease. RNA interference is an important and effective gene silencing process which degrades targeted RNA by a sequence specific process. Several studies have been conducted during the last decade to evaluate the efficiency of siRNA in inhibiting dengue virus replication. This review summarizes siRNAs as a therapeutic approach against dengue virus serotypes and concludes that siRNAs against virus and host genes can be next generation treatment of dengue virus infection.

  20. Host-range restriction of vaccinia virus E3L deletion mutant can be overcome in vitro, but not in vivo, by expression of the influenza virus NS1 protein.

    Directory of Open Access Journals (Sweden)

    Susana Guerra

    Full Text Available During the last decades, research focused on vaccinia virus (VACV pathogenesis has been intensified prompted by its potential beneficial application as a vector for vaccine development and anti-cancer therapies, but also due to the fear of its potential use as a bio-terrorism threat. Recombinant viruses lacking a type I interferon (IFN antagonist are attenuated and hence good vaccine candidates. However, vaccine virus growth requires production in IFN-deficient systems, and thus viral IFN antagonists that are active in vitro, yet not in vivo, are of great value. The VACV E3 and influenza virus NS1 proteins are distinct double-stranded RNA-binding proteins that play an important role in pathogenesis by inhibiting the mammalian IFN-regulated innate antiviral response. Based on the functional similarities between E3 and NS1, we investigated the ability of NS1 to replace the biological functions of E3 of VACV in both in vitro and in vivo systems. For this, we generated a VACV recombinant virus lacking the E3L gene, yet expressing NS1 (VVΔE3L/NS1. Our study revealed that NS1 can functionally replace E3 in cultured cells, rescuing the protein synthesis blockade, and preventing apoptosis and RNA breakdown. In contrast, in vivo the VVΔE3L/NS1 virus was highly attenuated after intranasal inoculation, as it was unable to spread to the lungs and other organs. These results indicate that there are commonalities but also functional differences in the roles of NS1 and E3 as inhibitors of the innate antiviral response, which could potentially be utilized for vaccine production purposes in the future.

  1. Dengue virus transovarial transmission by Aedes aegypti

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    Monica Dwi Hartanti

    2010-08-01

    Full Text Available Dengue is a disease that is caused by dengue virus and transmitted to humans through the bite of infected Aedes mosquitoes, especially Aedes aegypti. The disease is hyper-endemic in Southeast Asia, where a more severe form, dengue hemorrhagic fever (DHF and dengue shock syndrome (DSS, is a major public health concern. The purpose of the present study was to find evidence of dengue virus transovarial transmision in local vectors in Jakarta. Fifteen Aedes larvae were collected in 2009 from two areas in Tebet subdistrict in South Jakarta, namely one area with the highest and one with the lowest DHF prevalence. All mosquitoes were reared inside two cages in the laboratory, eight mosquitoes in one cage and seven mosquitoes in another cage and given only sucrose solution as their food. The results showed that 20% of the mosquitoes were positive for dengue virus. Dengue virus detection with an immunohistochemical method demonstrated the occurrence of transovarial transmission in local DHF vectors in Tebet subdistrict. Transovarial dengue infection in Ae.aegypti larvae appeared to maintain or enhance epidemics. Further research is needed to investigate the relation of dengue virus transovarial transmission with DHF endemicity in Jakarta.

  2. The influenza fingerprints: NS1 and M1 proteins contribute to specific host cell ultrastructure signatures upon infection by different influenza A viruses

    Energy Technology Data Exchange (ETDEWEB)

    Terrier, Olivier; Moules, Vincent; Carron, Coralie; Cartet, Gaeelle [Equipe VirCell, Laboratoire de Virologie et Pathologie Humaine, VirPath EMR 4610, Universite de Lyon, Universite Claude Bernard Lyon 1, Hospices Civils de Lyon, Faculte de medecine RTH Laennec, rue Guillaume Paradin, F-69008 Lyon (France); Frobert, Emilie [Laboratoire de Virologie, Centre de Biologie et de Pathologie Est, Hospices Civils de Lyon, 59 boulevard Pinel, F-69677 Bron Cedex, Lyon (France); Yver, Matthieu; Traversier, Aurelien [Equipe VirCell, Laboratoire de Virologie et Pathologie Humaine, VirPath EMR 4610, Universite de Lyon, Universite Claude Bernard Lyon 1, Hospices Civils de Lyon, Faculte de medecine RTH Laennec, rue Guillaume Paradin, F-69008 Lyon (France); Wolff, Thorsten [Division of Influenza/Respiratory Viruses, Robert Koch Institute, Nordufer 20, D-13353 Berlin (Germany); Riteau, Beatrice [Laboratoire de Virologie et Pathologie Humaine, VirPath EMR 4610, Universite de Lyon, Universite Claude Bernard Lyon 1, Hospices Civils de Lyon, Faculte de medecine RTH Laennec, rue Guillaume Paradin, F-69008 Lyon (France); Naffakh, Nadia [Institut Pasteur, Unite de Genetique Moleculaire des Virus Respiratoires, URA CNRS 3015, EA302 Universite Paris Diderot, Paris (France); and others

    2012-10-10

    Influenza A are nuclear replicating viruses which hijack host machineries in order to achieve optimal infection. Numerous functional virus-host interactions have now been characterized, but little information has been gathered concerning their link to the virally induced remodeling of the host cellular architecture. In this study, we infected cells with several human and avian influenza viruses and we have analyzed their ultrastructural modifications by using electron and confocal microscopy. We discovered that infections lead to a major and systematic disruption of nucleoli and the formation of a large number of diverse viral structures showing specificity that depended on the subtype origin and genomic composition of viruses. We identified NS1 and M1 proteins as the main actors in the remodeling of the host ultra-structure and our results suggest that each influenza A virus strain could be associated with a specific cellular fingerprint, possibly correlated to the functional properties of their viral components.

  3. Virus isolation for diagnosing dengue virus infections in returning travelers

    NARCIS (Netherlands)

    Teichmann, D.; Göbels, K.; Niedrig, M.; Sim-Brandenburg, J.-W.; Làge-Stehr, J.; Grobusch, M. P.

    2003-01-01

    Dengue fever is recognized as one of the most frequent imported acute febrile illnesses affecting European tourists returning from the tropics. In order to assess the value of virus isolation for the diagnosis of dengue fever, 70 cases of dengue fever confirmed in German travelers during the period

  4. Elevated Dengue Virus Nonstructural Protein 1 Serum Levels and Altered Toll-Like Receptor 4 Expression, Nitric Oxide, and Tumor Necrosis Factor Alpha Production in Dengue Hemorrhagic Fever Patients

    Directory of Open Access Journals (Sweden)

    Denise Maciel Carvalho

    2014-01-01

    Full Text Available Background. During dengue virus (DV infection, monocytes produce tumor necrosis factor alpha (TNF-α and nitric oxide (NO which might be critical to immunopathogenesis. Since intensity of DV replication may determine clinical outcomes, it is important to know the effects of viral nonstructural protein 1 (NS1 on innate immune parameters of infected patients. The present study investigates the relationships between dengue virus nonstructural protein 1 (NS1 serum levels and innate immune response (TLR4 expression and TNF-α/NO production of DV infected patients presenting different clinical outcomes. Methodology/Principal Findings. We evaluated NO, NS1 serum levels (ELISA, TNF-α production by peripheral blood mononuclear cells (PBMCs, and TLR4 expression on CD14+ cells from 37 dengue patients and 20 healthy controls. Early in infection, increased expression of TLR4 in monocytes of patients with dengue fever (DF was detected compared to patients with dengue hemorrhagic fever (DHF. Moreover, PBMCs of DHF patients showed higher NS1 and lower NO serum levels during the acute febrile phase and a reduced response to TLR4 stimulation by LPS (with a reduced TNF-α production when compared to DF patients. Conclusions/Significance. During DV infection in humans, some innate immune parameters change, depending on the NS1 serum levels, and phase and severity of the disease which may contribute to development of different clinical outcomes.

  5. Antibody Epitopes Identified in Critical Regions of Dengue Virus Nonstructural 1 Protein in Mouse Vaccination and Natural Human Infections.

    Science.gov (United States)

    Hertz, Tomer; Beatty, P Robert; MacMillen, Zachary; Killingbeck, Sarah S; Wang, Chunling; Harris, Eva

    2017-05-15

    Dengue is a global public health problem and is caused by four dengue virus (DENV) serotypes (DENV1-4). A major challenge in dengue vaccine development is that cross-reactive anti-DENV Abs can be protective or potentially increase disease via Ab-dependent enhancement. DENV nonstructural protein 1 (NS1) has long been considered a vaccine candidate as it avoids Ab-dependent enhancement. In this study, we evaluated survival to challenge in a lethal DENV vascular leak model in mice immunized with NS1 combined with aluminum and magnesium hydroxide, monophosphoryl lipid A + AddaVax, or Sigma adjuvant system+CpG DNA, compared with mice infected with a sublethal dose of DENV2 and mice immunized with OVA (negative control). We characterized Ab responses to DENV1, 2, and 3 NS1 using an Ag microarray tiled with 20-mer peptides overlapping by 15 aa and identified five regions of DENV NS1 with significant levels of Ab reactivity in the NS1 + monophosphoryl lipid A + AddaVax group. Additionally, we profiled the Ab responses to NS1 of humans naturally infected with DENV2 or DENV3 in serum samples from Nicaragua collected at acute, convalescent, and 12-mo timepoints. One region in the wing domain of NS1 was immunodominant in both mouse vaccination and human infection studies, and two regions were identified only in NS1-immunized mice; thus, vaccination can generate Abs to regions that are not targeted in natural infection and could provide additional protection against lethal DENV infection. Overall, we identified a small number of immunodominant regions, which were in functionally important locations on the DENV NS1 protein and are potential correlates of protection. Copyright © 2017 by The American Association of Immunologists, Inc.

  6. Construção de uma linhagem recombinante de Kluyveromyces marxianus UFV-3 para expressão da proteína não estrutural (NS1) do vírus da dengue-1

    OpenAIRE

    Bragança, Caio Roberto Soares

    2013-01-01

    A levedura Kluyveromyces marxianus tem sido considerada uma candidata hospedeira para a síntese industrial de biomoléculas. Apesar de seu potencial, são poucos os estudos que relatam a expressão de proteínas heterólogas utilizando esta levedura. Neste trabalho, foi relatado pela primeira vez, a expressão da proteína do vírus da dengue em K. marxianus. O gene que codifica a proteína não estrutural (NS1) do vírus da dengue-1 foi integrado no genoma da levedura K. marxianus UFV-3 no locus LAC4, ...

  7. Human T cell responses to Dengue and Zika virus infection compared to Dengue/Zika coinfection.

    Science.gov (United States)

    Badolato-Corrêa, Jessica; Sánchez-Arcila, Juan Camilo; Alves de Souza, Thiara Manuele; Santos Barbosa, Luciana; Conrado Guerra Nunes, Priscila; da Rocha Queiroz Lima, Monique; Gandini, Mariana; Bispo de Filippis, Ana Maria; Venâncio da Cunha, Rivaldo; Leal de Azeredo, Elzinandes; de-Oliveira-Pinto, Luzia Maria

    2017-12-28

    Zika virus (ZIKV) and dengue virus (DENV) co-circulated during latest outbreaks in Brazil, hence, it is important to evaluate the host cross-reactive immune responses to these viruses. So far, little is known about human T cell responses to ZIKV and no reports detail adaptive immune responses during DENV/ZIKV coinfection. Here, we studied T cells responses in well-characterized groups of DENV, ZIKV, or DENV/ZIKV infected patients and DENV-exposed healthy donors. We evaluated chemokine receptors expression and single/multifunctional frequencies of IFNγ, TNF, and IL2-producing T cells during these infections. Even without antigenic stimulation, it was possible to detect chemokine receptors and IFNγ, TNF, and IL2-producing T cells from all individuals by flow cytometry. Additionally, PBMCs' IFNγ response to DENV NS1 protein and to polyclonal stimuli was evaluated by ELISPOT. DENV and ZIKV infections and DENV/ZIKV coinfections similarly induced expression of CCR5, CX3CR1, and CXCR3 on CD4 and CD8 T cells. DENV/ZIKV coinfection decreased the ability of CD4 + T cells to produce IFNγ + , TNF + , TNF  +  IFNγ + , and TNF  +  IL2 + , compared to DENV and ZIKV infections. A higher magnitude of IFNγ response to DENV NS1 was found in donors with a history of dengue infection, however, a hyporesponsiveness was found in acute DENV, ZIKV, or DENV/ZIKV infected patients, even previously infected with DENV. Therefore, we emphasize the potential impact of coinfection on the immune response from human hosts, mainly in areas where DENV and ZIKV cocirculate. © 2017 The Authors. Immunity, Inflammation and Disease Published by John Wiley & Sons Ltd.

  8. Glycosylation of dengue virus glycoproteins and their interactions with carbohydrate receptors: possible targets for antiviral therapy.

    Science.gov (United States)

    Idris, Fakhriedzwan; Muharram, Siti Hanna; Diah, Suwarni

    2016-07-01

    Dengue virus, an RNA virus belonging to the genus Flavivirus, affects 50 million individuals annually, and approximately 500,000-1,000,000 of these infections lead to dengue hemorrhagic fever or dengue shock syndrome. With no licensed vaccine or specific antiviral treatments available to prevent dengue infection, dengue is considered a major public health problem in subtropical and tropical regions. The virus, like other enveloped viruses, uses the host's cellular enzymes to synthesize its structural (C, E, and prM/M) and nonstructural proteins (NS1-5) and, subsequently, to glycosylate these proteins to produce complete and functional glycoproteins. The structural glycoproteins, specifically the E protein, are known to interact with the host's carbohydrate receptors through the viral proteins' N-glycosylation sites and thus mediate the viral invasion of cells. This review focuses on the involvement of dengue glycoproteins in the course of infection and the virus' exploitation of the host's glycans, especially the interactions between host receptors and carbohydrate moieties. We also discuss the recent developments in antiviral therapies that target these processes and interactions, focusing specifically on the use of carbohydrate-binding agents derived from plants, commonly known as lectins, to inhibit the progression of infection.

  9. Host cell responses to dengue virus infection

    NARCIS (Netherlands)

    Diosa Toro, Mayra

    2017-01-01

    Dengue (ook wel knokkelkoorts) is de meest voorkomende virale infectieziekte dat wordt overgedragen door muggen in de wereld met naar schatting 390 miljoen infecties per jaar. Ondanks de grote klinische impact en economische schade van het dengue virus is er nog steeds geen behandeling beschikbaar.

  10. Sequence evolution of the hypervariable region in the putative envelope region E2/NS1 of hepatitis C virus is correlated with specific humoral immune responses.

    OpenAIRE

    van Doorn, L J; Capriles, I; Maertens, G; DeLeys, R; Murray, K; Kos, T; Schellekens, H; Quint, W

    1995-01-01

    Sequence evolution of the hypervariable region 1 (HVR1) in the N terminus of E2/NS1 of hepatitis C virus (HCV) was studied retrospectively in six chimpanzees inoculated with the same genotype 1b strain, containing a unique predominant HVR1 sequence. Immediately after inoculation, all animals contained the same HVR predominant sequence. Two animals developed an acute self-limiting infection. Anti-HVR1 immunoglobulin G (IgG) was produced 40 to 60 days after inoculation and rapidly disappeared a...

  11. Evasion of the human innate immune system by dengue virus

    OpenAIRE

    Pagni, Sarah; Fernandez-Sesma, Ana

    2012-01-01

    Dengue virus is a worldwide health problem, with billions of people at risk annually. Dengue virus causes a spectrum of diseases, namely dengue fever, dengue hemorrhagic fever and dengue shock syndrome with the latter two being linked to death. Understanding how dengue is able to evade the immune system and cause enhanced severity of disease is the main topics of interest in the Fernandez-Sesma laboratory at Mount Sinai School of Medicine. Using primary human immune cells, our group investiga...

  12. Influenza A Virus Virulence Depends on Two Amino Acids in the N-Terminal Domain of Its NS1 Protein To Facilitate Inhibition of the RNA-Dependent Protein Kinase PKR

    Science.gov (United States)

    Schierhorn, Kristina L.; Jolmes, Fabian; Bespalowa, Julia; Saenger, Sandra; Peteranderl, Christin; Dzieciolowski, Julia; Mielke, Maja; Budt, Matthias; Pleschka, Stephan; Herrmann, Andreas; Herold, Susanne

    2017-01-01

    ABSTRACT The RNA-dependent protein kinase (PKR) has broad antiviral activity inducing translational shutdown of viral and cellular genes and is therefore targeted by various viral proteins to facilitate pathogen propagation. The pleiotropic NS1 protein of influenza A virus acts as silencer of PKR activation and ensures high-level viral replication and virulence. However, the exact manner of this inhibition remains controversial. To elucidate the structural requirements within the NS1 protein for PKR inhibition, we generated a set of mutant viruses, identifying highly conserved arginine residues 35 and 46 within the NS1 N terminus as being most critical not only for binding to and blocking activation of PKR but also for efficient virus propagation. Biochemical and Förster resonance energy transfer (FRET)-based interaction studies showed that mutation of R35 or R46 allowed formation of NS1 dimers but eliminated any detectable binding to PKR as well as to double-stranded RNA (dsRNA). Using in vitro and in vivo approaches to phenotypic restoration, we demonstrated the essential role of the NS1 N terminus for blocking PKR. The strong attenuation conferred by NS1 mutation R35A or R46A was substantially alleviated by stable knockdown of PKR in human cells. Intriguingly, both NS1 mutant viruses did not trigger any signs of disease in PKR+/+ mice, but replicated to high titers in lungs of PKR−/− mice and caused lethal infections. These data not only establish the NS1 N terminus as highly critical for neutralization of PKR's antiviral activity but also identify this blockade as an indispensable contribution of NS1 to the viral life cycle. IMPORTANCE Influenza A virus inhibits activation of the RNA-dependent protein kinase (PKR) by means of its nonstructural NS1 protein, but the underlying mode of inhibition is debated. Using mutational analysis, we identified arginine residues 35 and 46 within the N-terminal NS1 domain as highly critical for binding to and functional

  13. [Molecular characteristics of dengue virus outbreak in China-Myanmar border region, Yunnan province, 2015].

    Science.gov (United States)

    Guo, Xiaofang; Yang, Mingdong; Jiang, Jinyong; Li, Huachang; Zhu, Chongge; Gui, Qin; Bu, Liqun; Zhou, Hongning

    2016-03-01

    To understand the molecular characteristics of a dengue virus outbreak in China-Myanmar border region, Yunnan province, 2015 and provide etiological evidence for the disease control and prevention. Semi-nested RTPCR was conducted to detect the capsid premembrane (CprM) gene of RNA of dengue virus by using dengue virus NS1 positive serum samples collected in Mengdin township, Gengma county, Yunnan province in July, 2015. Some positive samples were then detected by using PCR with specific primers to amplify the full E gene. The positive PCR products were directly sequenced. Then sequences generated in this study were BLAST in NCBI website and aligned in Megalign in DNAstar program. Multiple sequence alignments were carried out by using Mega 5.05 software based on the sequences generated in this study and sequences downloaded from GenBank, including the representative strains from different countries and regions. Phylogenetic trees were constructed by using Neighbor-Joining tree methods with Mega 5.05 software. Twenty one of 25 local cases and 10 of 14 imported cases from Myanmar were positive for DENV-1. Eight serum samples were negative for dengue virus. A total of 13 strains with E gene (1485 bp), including 8 local strains and 5 imported strains, were sequenced, which shared 100% nucleotide sequence identities. Twelve strains with CprM gene (406 bp) from 9 local cases and 3 imported cases shared 100% nucleotide sequence identities. Phylogenetic analyses based on E gene showed that the new 13 strains clustered in genotype I of dengue virus and formed a distinct lineage. This outbreak was caused by genotype I of DENV-1, which had the closest phylogenetic relationships with dengue virus from neighboring Burma area. Comprehensive measures of prevention and control of dengue fever should be strengthened to prevent the spread of dengue virus.

  14. Dengue virus identification by transmission electron microscopy and molecular methods in fatal dengue hemorrhagic fever.

    Science.gov (United States)

    Limonta, D; Falcón, V; Torres, G; Capó, V; Menéndez, I; Rosario, D; Castellanos, Y; Alvarez, M; Rodríguez-Roche, R; de la Rosa, M C; Pavón, A; López, L; González, K; Guillén, G; Diaz, J; Guzmán, M G

    2012-12-01

    Dengue virus is the most significant virus transmitted by arthropods worldwide and may cause a potentially fatal systemic disease named dengue hemorrhagic fever. In this work, dengue virus serotype 4 was detected in the tissues of one fatal dengue hemorrhagic fever case using electron immunomicroscopy and molecular methods. This is the first report of dengue virus polypeptides findings by electron immunomicroscopy in human samples. In addition, not-previously-documented virus-like particles visualized in spleen, hepatic, brain, and pulmonary tissues from a dengue case are discussed.

  15. Suppression of Drug Resistance in Dengue Virus

    Science.gov (United States)

    Mateo, Roberto; Nagamine, Claude M.

    2015-01-01

    ABSTRACT Dengue virus is a major human pathogen responsible for 400 million infections yearly. As with other RNA viruses, daunting challenges to antiviral design exist due to the high error rates of RNA-dependent RNA synthesis. Indeed, treatment of dengue virus infection with a nucleoside analog resulted in the expected genetic selection of resistant viruses in tissue culture and in mice. However, when the function of the oligomeric core protein was inhibited, no detectable selection of drug resistance in tissue culture or in mice was detected, despite the presence of drug-resistant variants in the population. Suppressed selection of drug-resistant virus correlated with cooligomerization of the targeted drug-susceptible and drug-resistant core proteins. The concept of “dominant drug targets,” in which inhibition of oligomeric viral assemblages leads to the formation of drug-susceptible chimeras, can therefore be used to prevent the outgrowth of drug resistance during dengue virus infection. PMID:26670386

  16. Release of Dengue Virus Genome Induced by a Peptide Inhibitor

    OpenAIRE

    Lok, Shee-Mei; Costin, Joshua M.; Hrobowski, Yancey M.; Hoffmann, Andrew R.; Rowe, Dawne K.; Kukkaro, Petra; Holdaway, Heather; Chipman, Paul; Fontaine, Krystal A.; Holbrook, Michael R.; Garry, Robert F.; Kostyuchenko, Victor; Wimley, William C.; Isern, Sharon; Rossmann, Michael G.

    2012-01-01

    Dengue virus infects approximately 100 million people annually, but there is no available therapeutic treatment. The mimetic peptide, DN59, consists of residues corresponding to the membrane interacting, amphipathic stem region of the dengue virus envelope (E) glycoprotein. This peptide is inhibitory to all four serotypes of dengue virus, as well as other flaviviruses. Cryo-electron microscopy image reconstruction of dengue virus particles incubated with DN59 showed that the virus particles w...

  17. Heterotypic Dengue Infection with Live Attenuated Monotypic Dengue Virus Vaccines: Implications for Vaccination of Populations in Areas Where Dengue Is Endemic

    OpenAIRE

    Durbin, Anna P.; Schmidt, Alexander; Elwood, Dan; Wanionek, Kimberli A.; Lovchik, Janece; Thumar, Bhavin; Murphy, Brian R.; Whitehead, Stephen S.

    2011-01-01

    Background. Because infection with any of the 4 Dengue virus serotypes may elicit both protective neutralizing antibodies and nonneutralizing antibodies capable of enhancing subsequent heterotypic Dengue virus infections, the greatest risk for severe dengue occurs during a second, heterotypic Dengue virus infection. It remains unclear whether the replication of live attenuated vaccine viruses will be similarly enhanced when administered to Dengue-immune individuals.

  18. Lectin Switching During Dengue Virus Infection

    Science.gov (United States)

    Dejnirattisai, Wanwisa; Webb, Andrew I.; Chan, Vera; Jumnainsong, Amonrat; Davidson, Andrew; Mongkolsapaya, Juthathip

    2011-01-01

    Dengue virus receptors are relatively poorly characterized, but there has been recent interest in 2 C-type lectin molecules, dendritic cell–specific intercellular adhesion molecule 3 (ICAM-3)–grabbing nonintegrin (DC-SIGN) and its close homologue liver/lymph node–specific ICAM-3–grabbing integrin (L-SIGN), which can both bind dengue and promote infection. In this report we have studied the interaction of dengue viruses produced in insect cells, tumor cell lines, and primary human dendritic cells (DCs) with DC-SIGN and L-SIGN. Virus produced in primary DCs is unable to interact with DC-SIGN but remains infectious for L-SIGN–expressing cells. Skin-resident DCs may thus be a site of initial infection by insect-produced virus, but DCs will likely not participate in large-scale virus replication during dengue infection. These results reveal that differential glycosylation of dengue virus envelope protein is highly dependent on cell state and suggest that studies of virus tropism using virus prepared in insect cells or tumor cell lines should be interpreted with caution. PMID:21606536

  19. Detection of Markers of Increased Virulence Non Structural protein (NS I Avian Influenza Virus H5N1 from Indonesia=DETEKSI PENANDA PENINGKATAN VIRULENSI NON STRUKTURAL PROTEIN (NS1 VIRUS AVIAN INFLUENZA H5N1 ASAL INDONESIA

    Directory of Open Access Journals (Sweden)

    Arief Mulyono

    2015-03-01

    Full Text Available ENGLISHAbstractNS1 protein is a multifunction protein that plays key role of pathogenesis and virulence of avians influenza virus H5N1. The amino acid substitution at the position P42S, D92E, F103I, M106I and 5 amino acid deletion at the position 80 to 84 in NS1 protein reported increasing virulence of avians influenza virus H5N1. Several studies showed avians influenza virus H5N1 in Indonesia has dynamic changed. This study aimed to analyze the markers of virulence of NS1 protein sequences of all H5N1 virus isolates from Indonesia. The source of NS1 protein sequence data gene obtained from GeneBank and Gisaid. Data were analyzed using Bioedit software. The Results showed the isolates from Indonesia had substitutions P42S and 5 amino acids deletions at positions 80-84 resulting in the potential for increased virulence of the virus. However, amino acid substitution at the position D92E, F103L and M106I substitution were not found.INDONESIANAbstrakProtein NS1 adalah protein multifungsi yang memainkan peran kunci dalam patogenesis dan virulensi virus avian influenza H5N1. Substitusi asam amino P42S, D92E, F103I, M106I, dan delesi 5 asam amino di posisi 80 - 84 dilaporkan meningkatkan virulensi virus avian influenza H5N1. Beberapa penelitian menunjukkan bahwa virus avian influenza di Indonesia mengalami perubahan dinamis. Studi ini akan menganalisis motif asam amino yang menjadi penanda peningkatan virulensi pada sekuen protein NS1 virus avian influenza H5N1 asal Indonesia. Data sekuen asam amino protein NS1 diperoleh dari database GeneBank dan Gisaid. Analisis data menggunakan Bioedit software. Hasil analisis menunjukkan subtitusi asam amino dari prolin ke serin di posisi 42 (P42S dan delesi 5 asam amino di posisi 80 – 84 telah ditemukan pada virus avian influenza asal Indonesia, akan tetapi tidak ditemukan substitusi asam amino aspartat ke glutamat diposisi no 92 (D92E dan tidak ada yang mengalami 2 substitusi asam amino sekaligus diposisi 103

  20. Co-circulation and co-infections of all dengue virus serotypes in Hyderabad, India 2014.

    Science.gov (United States)

    Vaddadi, K; Gandikota, C; Jain, P K; Prasad, V S V; Venkataramana, M

    2017-09-01

    The burden of dengue virus infections increased globally during recent years. Though India is considered as dengue hyper-endemic country, limited data are available on disease epidemiology. The present study includes molecular characterization of dengue virus strains occurred in Hyderabad, India, during the year 2014. A total of 120 febrile cases were recruited for this study, which includes only children and 41 were serologically confirmed for dengue positive infections using non-structural (NS1) and/or IgG/IgM ELISA tests. RT-PCR, nucleotide sequencing and evolutionary analyses were carried out to identify the circulating serotypes/genotypes. The data indicated a high percent of severe dengue (63%) in primary infections. Simultaneous circulation of all four serotypes and co-infections were observed for the first time in Hyderabad, India. In total, 15 patients were co-infected with more than one dengue serotype and 12 (80%) of them had severe dengue. One of the striking findings of the present study is the identification of serotype Den-1 as the first report from this region and this strain showed close relatedness to the Thailand 1980 strains but not to any of the strains reported from India until now. Phylogenetically, all four strains of the present study showed close relatedness to the strains, which are reported to be high virulent.

  1. PATHOGENESIS OF HEMORRHAGIC DUE TO DENGUE VIRUS

    Directory of Open Access Journals (Sweden)

    Arief Suseno

    2015-01-01

    Full Text Available Dengue is a viral disease that is mediated by a mosquito, which causes morbidity and mortality. Viruses can increase vascular permeability which can lead to hemorrhagic diathesis or disseminated intravascular coagulation (DIC known as dengue hemorrhagic fever (DHF. In Indonesia, dengue hemorrhagic fever (DHF are caused by dengue virus infection which was found to be endemic accompanied by an explosion of extraordinary events that appear at various specified period. The diagnosis of dengue is determined based on the criteria of the World Health Organization (WHO, 1999, which are sudden high fever accompanied by a marked tendency to hemorrhage positive tourniquet test, petechiae, ecchymosis, purpura, mucosal hemorrhagic, hematemesis or melena and thrombocytopenia. The problem that still exists today is the mechanism of thrombocytopenia in patients with varying degrees of dengue involving levels of vWF (von Willebrand factor and prostaglandin I2 (PGI2 can not be explained. The mechanism of hemorrhagic in dengue virus infections acquired as a result of thrombocytopenia, platelet disfunction decreased coagulation factors, vasculopathy with endothelial injury and disseminated intravascular coagulation (DIC.

  2. Zika Virus-Induced Antibody Response Enhances Dengue Virus Serotype 2 Replication In Vitro.

    Science.gov (United States)

    Kawiecki, Anna B; Christofferson, Rebecca C

    2016-11-01

    Zika virus has emerged in the Americas, where dengue virus is endemic. Among the 4 serotypes of dengue virus, antibody-dependent enhancement is thought to enhance viral replication and disease severity. Reports suggest that anti-dengue virus antibody may enhance Zika virus replication. We investigated whether Zika virus antibodies enhance dengue virus replication, by exposing C57Bl/6 mice to Zika virus. Polyclonal serum was verified for strong Zika virus-neutralizing, dengue virus-subneutralizing capacity. Then we determined the enhancement capabilities of Zika virus-immune serum for dengue virus in vitro. We showed that Zika virus antibodies have the ability to enhance dengue virus infections, which is important, because in many Zika virus-affected areas, dengue virus is expected to remain endemic. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

  3. Seroprevalence of antibodies against dengue virus among pregnant women in the Democratic Republic of Sao Tome and Principe.

    Science.gov (United States)

    Yen, Tsai-Ying; Trovoada dos Santos, Maria de Jesus; Tseng, Lien-Feng; Chang, Shu-Feng; Cheng, Chien-Fu; Carvalho, Arlindo Vicente de Assunção; Shu, Pei-Yun; Lien, Jih-Ching; Tsai, Kun-Hsien

    2016-03-01

    Dengue fever has become a worldwide public health concern, threatening an estimated 40% of the world's population. However, most resources and attention are still focused on malaria, while dengue statuses are poorly recognized in many African countries. In this serological survey, dengue virus (DENV) transmission was demonstrated by using serum samples collected from 78 pregnant women in the Democratic Republic of Sao Tome and Principe (DRSTP) during 2003 to 2004. Immunofluorescence assay was performed and 31 samples (39.74%) were found positive for DENV antibodies. Indirect enzyme-linked immunosorbent assay (ELISA) showed that 53 samples (67.95%) were positive for dengue E IgG, and 38 samples (48.72%) were positive for NS1 IgG. A prevalence of 35.90% was therefore determined for dengue IgG by considering samples that yielded positive results by all three tests. Cross-reactions with other flaviviruses were examined by indirect ELISA against Japanese encephalitis virus, West Nile virus, and yellow fever virus. Only one sample exhibited stronger absorbance against Japanese encephalitis virus and West Nile virus. Moreover, one sample was positive for dengue IgM. These results agreed with the previous researches in neighboring countries and suggested DENV exposure. The study contributes to raising public awareness of dengue and supporting future control strategies. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Development of Lead Compounds as Fusion Inhibitors for Dengue Virus

    Science.gov (United States)

    2009-08-01

    Identification of antiviral agents is critical to the development of therapeutic treatments directed against dengue virus (DENV), for which there is no...infection and exposure of US military personnel to the disease might be offered by antiviral agents as a treatment strategy. The dengue virus...0285 TITLE: DEVELOPMENT OF LEAD COMPOUNDS AS FUSION INHIBITORS FOR DENGUE VIRUS PRINCIPAL INVESTIGATOR: TOMAS PEREZ-ACLE

  5. Dengue Virus Genome Uncoating Requires Ubiquitination.

    Science.gov (United States)

    Byk, Laura A; Iglesias, Néstor G; De Maio, Federico A; Gebhard, Leopoldo G; Rossi, Mario; Gamarnik, Andrea V

    2016-06-28

    The process of genome release or uncoating after viral entry is one of the least-studied steps in the flavivirus life cycle. Flaviviruses are mainly arthropod-borne viruses, including emerging and reemerging pathogens such as dengue, Zika, and West Nile viruses. Currently, dengue virus is one of the most significant human viral pathogens transmitted by mosquitoes and is responsible for about 390 million infections every year around the world. Here, we examined for the first time molecular aspects of dengue virus genome uncoating. We followed the fate of the capsid protein and RNA genome early during infection and found that capsid is degraded after viral internalization by the host ubiquitin-proteasome system. However, proteasome activity and capsid degradation were not necessary to free the genome for initial viral translation. Unexpectedly, genome uncoating was blocked by inhibiting ubiquitination. Using different assays to bypass entry and evaluate the first rounds of viral translation, a narrow window of time during infection that requires ubiquitination but not proteasome activity was identified. In this regard, ubiquitin E1-activating enzyme inhibition was sufficient to stabilize the incoming viral genome in the cytoplasm of infected cells, causing its retention in either endosomes or nucleocapsids. Our data support a model in which dengue virus genome uncoating requires a nondegradative ubiquitination step, providing new insights into this crucial but understudied viral process. Dengue is the most significant arthropod-borne viral infection in humans. Although the number of cases increases every year, there are no approved therapeutics available for the treatment of dengue infection, and many basic aspects of the viral biology remain elusive. After entry, the viral membrane must fuse with the endosomal membrane to deliver the viral genome into the cytoplasm for translation and replication. A great deal of information has been obtained in the last decade

  6. Dengue virus protein recognition by virus-specific murine CD8+ cytotoxic T lymphocytes.

    OpenAIRE

    Rothman, A L; Kurane, I; Lai, C J; Bray, M; Falgout, B; Men, R; Ennis, F A

    1993-01-01

    The identification of the protein targets for dengue virus-specific T lymphocytes may be useful for planning the development of subunit vaccines against dengue. We studied the recognition by murine dengue virus-specific major histocompatibility complex class I-restricted, CD8+ cytotoxic T lymphocytes (CTL) of dengue virus proteins using recombinant vaccinia viruses containing segments of the dengue virus genome. CTL from H-2k mice recognized a single serotype-cross-reactive epitope on the non...

  7. Dengue virus-specific cross-reactive CD8+ human cytotoxic T lymphocytes.

    OpenAIRE

    Bukowski, J F; Kurane, I; Lai, C J; Bray, M; Falgout, B; Ennis, F A

    1989-01-01

    Stimulation with live dengue virus of peripheral blood mononuclear cells from a dengue virus type 4-immune donor generated virus-specific, serotype-cross-reactive, CD8+, class I-restricted cytotoxic T lymphocytes (CTL) capable of lysing dengue virus-infected cells and cells pulsed with dengue virus antigens of all four serotypes. These CTL lysed autologous fibroblasts infected with vaccinia virus-dengue virus recombinant viruses containing the E gene or several nonstructural dengue virus type...

  8. Peptides as Therapeutic Agents for Dengue Virus

    Science.gov (United States)

    Chew, Miaw-Fang; Poh, Keat-Seong; Poh, Chit-Laa

    2017-01-01

    Dengue is an important global threat caused by dengue virus (DENV) that records an estimated 390 million infections annually. Despite the availability of CYD-TDV as a commercial vaccine, its long-term efficacy against all four dengue virus serotypes remains unsatisfactory. There is therefore an urgent need for the development of antiviral drugs for the treatment of dengue. Peptide was once a neglected choice of medical treatment but it has lately regained interest from the pharmaceutical industry following pioneering advancements in technology. In this review, the design of peptide drugs, antiviral activities and mechanisms of peptides and peptidomimetics (modified peptides) action against dengue virus are discussed. The development of peptides as inhibitors for viral entry, replication and translation is also described, with a focus on the three main targets, namely, the host cell receptors, viral structural proteins and viral non-structural proteins. The antiviral peptides designed based on these approaches may lead to the discovery of novel anti-DENV therapeutics that can treat dengue patients. PMID:29200948

  9. Peptides as Therapeutic Agents for Dengue Virus.

    Science.gov (United States)

    Chew, Miaw-Fang; Poh, Keat-Seong; Poh, Chit-Laa

    2017-01-01

    Dengue is an important global threat caused by dengue virus (DENV) that records an estimated 390 million infections annually. Despite the availability of CYD-TDV as a commercial vaccine, its long-term efficacy against all four dengue virus serotypes remains unsatisfactory. There is therefore an urgent need for the development of antiviral drugs for the treatment of dengue. Peptide was once a neglected choice of medical treatment but it has lately regained interest from the pharmaceutical industry following pioneering advancements in technology. In this review, the design of peptide drugs, antiviral activities and mechanisms of peptides and peptidomimetics (modified peptides) action against dengue virus are discussed. The development of peptides as inhibitors for viral entry, replication and translation is also described, with a focus on the three main targets, namely, the host cell receptors, viral structural proteins and viral non-structural proteins. The antiviral peptides designed based on these approaches may lead to the discovery of novel anti-DENV therapeutics that can treat dengue patients.

  10. Visualizing dengue virus through Alexa Fluor labeling.

    Science.gov (United States)

    Zhang, Summer; Tan, Hwee Cheng; Ooi, Eng Eong

    2011-07-09

    The early events in the interaction between virus and cell can have profound influence on the outcome of infection. Determining the factors that influence this interaction could lead to improved understanding of disease pathogenesis and thus influence vaccine or therapeutic design. Hence, the development of methods to probe this interaction would be useful. Recent advancements in fluorophores development and imaging technology can be exploited to improve our current knowledge on dengue pathogenesis and thus pave the way to reduce the millions of dengue infections occurring annually. The enveloped dengue virus has an external scaffold consisting of 90 envelope glycoprotein (E) dimers protecting the nucleocapsid shell, which contains a single positive strand RNA genome. The identical protein subunits on the virus surface can thus be labeled with an amine reactive dye and visualized through immunofluorescent microscopy. Here, we present a simple method of labeling of dengue virus with Alexa Fluor succinimidyl ester dye dissolved directly in a sodium bicarbonate buffer that yielded highly viable virus after labeling. There is no standardized procedure for the labeling of live virus and existing manufacturer's protocol for protein labeling usually requires the reconstitution of dye in dimethyl sulfoxide. The presence of dimethyl sulfoxide, even in minute quantities, can block productive infection of virus and also induce cell cytotoxicity. The exclusion of the use of dimethyl sulfoxide in this protocol thus reduced this possibility. Alexa Fluor dyes have superior photostability and are less pH-sensitive than the common dyes, such as fluorescein and rhodamine, making them ideal for studies on cellular uptake and endosomal transport of the virus. The conjugation of Alexa Fluor dye did not affect the recognition of labeled dengue virus by virus-specific antibody and its putative receptors in host cells. This method could have useful applications in virological studies.

  11. Outbreak of viral hemorrhagic fever caused by dengue virus type 3 in Al-Mukalla, Yemen

    Science.gov (United States)

    2013-01-01

    Background Investigations were conducted by the authors to explore an outbreak of viral hemorrhagic fever (VHF) reported in 2010 from Al-Mukalla city, the capital of Hadramout in Yemen. Methods From 15–17 June 2010, the outbreak investigation period, specimens were obtained within 7 days after onset of illness of 18 acutely ill patients hospitalized with VHF and 15 household asymptomatic contacts of 6 acute cases. Additionally, 189 stored sera taken from acutely ill patients with suspected VHF hospitalized in the preceding 12 months were obtained from the Ministry of Health of Yemen. Thus, a total of 222 human specimens were collected; 207 specimens from acute cases and 15 specimens from contacts. All samples were tested with RT-PCR for dengue (DENV), Alkhumra (ALKV), Rift Valley Fever (RVFV), Yellow Fever (YFV), and Chikungunya (CHIKV) viruses. Samples were also tested for DENV IgM, IgG, and NS1-antigen. Medical records of patients were reviewed and demographic, clinical, and laboratory data was collected. Results Of 207 patients tested, 181 (87.4%) patients were confirmed to have acute dengue with positive dengue NS1-antigen (97 patients, 46.9%) and/or IgM (163 patients, 78.7%). Of the 181 patients with confirmed dengue, 100 (55.2%) patients were IgG-positive. DENV RNA was detected in 2 (1%) patients with acute symptoms; both samples were molecularly typed as DENV type 3. No other VHF viruses were detected. For the 15 contacts tested, RT-PCR tests for the five viruses were negative, one contact was dengue IgM positive, and another one was dengue IgG positive. Of the 181 confirmed dengue patients, 120 (66.3%) patients were males and the median age was 24 years. The most common manifestations included fever (100%), headache (94.5%), backache (93.4%), malaise (88.4%), arthralgia (85.1%), myalgia (82.3%), bone pain (77.9%), and leukopenia (76.2%). Two (1.1%) patients died. Conclusions DENV-3 was confirmed to be the cause of an outbreak of VHF in Al

  12. Outbreak of viral hemorrhagic fever caused by dengue virus type 3 in Al-Mukalla, Yemen.

    Science.gov (United States)

    Madani, Tariq A; Abuelzein, El-Tayeb M E; Al-Bar, Hussein M S; Azhar, Esam I; Kao, Moujahed; Alshoeb, Haj O; Bamoosa, Alabd R

    2013-03-14

    Investigations were conducted by the authors to explore an outbreak of viral hemorrhagic fever (VHF) reported in 2010 from Al-Mukalla city, the capital of Hadramout in Yemen. From 15-17 June 2010, the outbreak investigation period, specimens were obtained within 7 days after onset of illness of 18 acutely ill patients hospitalized with VHF and 15 household asymptomatic contacts of 6 acute cases. Additionally, 189 stored sera taken from acutely ill patients with suspected VHF hospitalized in the preceding 12 months were obtained from the Ministry of Health of Yemen. Thus, a total of 222 human specimens were collected; 207 specimens from acute cases and 15 specimens from contacts. All samples were tested with RT-PCR for dengue (DENV), Alkhumra (ALKV), Rift Valley Fever (RVFV), Yellow Fever (YFV), and Chikungunya (CHIKV) viruses. Samples were also tested for DENV IgM, IgG, and NS1-antigen. Medical records of patients were reviewed and demographic, clinical, and laboratory data was collected. Of 207 patients tested, 181 (87.4%) patients were confirmed to have acute dengue with positive dengue NS1-antigen (97 patients, 46.9%) and/or IgM (163 patients, 78.7%). Of the 181 patients with confirmed dengue, 100 (55.2%) patients were IgG-positive. DENV RNA was detected in 2 (1%) patients with acute symptoms; both samples were molecularly typed as DENV type 3. No other VHF viruses were detected. For the 15 contacts tested, RT-PCR tests for the five viruses were negative, one contact was dengue IgM positive, and another one was dengue IgG positive. Of the 181 confirmed dengue patients, 120 (66.3%) patients were males and the median age was 24 years. The most common manifestations included fever (100%), headache (94.5%), backache (93.4%), malaise (88.4%), arthralgia (85.1%), myalgia (82.3%), bone pain (77.9%), and leukopenia (76.2%). Two (1.1%) patients died. DENV-3 was confirmed to be the cause of an outbreak of VHF in Al-Mukalla. It is important to use both IgM and NS1-antigen

  13. Phenotypic and genotypic characterization of dengue virus isolates differentiates dengue fever and dengue hemorrhagic fever from dengue shock syndrome.

    Science.gov (United States)

    Tuiskunen, Anne; Monteil, Vanessa; Plumet, Sébastien; Boubis, Laetitia; Wahlström, Maria; Duong, Veasna; Buchy, Philippe; Lundkvist, Ake; Tolou, Hugues; Leparc-Goffart, Isabelle

    2011-11-01

    Dengue viruses (DENV) cause 50-100 million cases of acute febrile disease every year, including 500,000 reported cases of dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). Viral factors have been proposed to influence the severity of the disease, but markers of virulence have never been identified on DENV. Three DENV serotype-1 isolates from the 2007 epidemic in Cambodia that are derived from patients experiencing the various clinical forms of dengue were characterized both phenotypically and genetically. Phenotypic characteristics in vitro, based on replication kinetics in different cell lines and apoptosis response, grouped isolates from DF and DHF patients together, whereas the virus isolate from a DSS patient showed unique features: a lower level of replication in mammalian cells and extensive apoptosis in mosquito cells. Genomic comparison of viruses revealed six unique amino acid residues in the membrane, envelope, and in non-structural genes in the virus isolated from the DSS patient.

  14. Evasion of the human innate immune system by dengue virus.

    Science.gov (United States)

    Pagni, Sarah; Fernandez-Sesma, Ana

    2012-12-01

    Dengue virus is a worldwide health problem, with billions of people at risk annually. Dengue virus causes a spectrum of diseases, namely dengue fever, dengue hemorrhagic fever and dengue shock syndrome with the latter two being linked to death. Understanding how dengue is able to evade the immune system and cause enhanced severity of disease is the main topics of interest in the Fernandez-Sesma laboratory at Mount Sinai School of Medicine. Using primary human immune cells, our group investigates the contribution of dengue virus-specific proteins to the evasion of innate immunity by this virus and the host factors that the virus interacts with in order to evade immune recognition and to establish infection in humans. Here, we review recent findings from our group as well as published data from other groups regarding immune modulation by dengue virus.

  15. Characterization of in vitro dengue virus resistance to carrageenan.

    Science.gov (United States)

    Talarico, Laura B; Damonte, Elsa B

    2016-07-01

    The λ-carrageenan (λ-car) is a potent and selective inhibitor of dengue virus (DENV) infection targeted to virus adsorption and internalization, due to the structural similarities with the mammalian cell receptor heparan sulfate. To further characterize the antiviral activity of λ-car, the selection and the phenotypic and genomic features of λ-car resistant DENV-2 variants are studied here in comparison to control virus. Resistant variants were rapidly selected in Vero cells after three passages in presence of the drug. No difference was detected in the growth profiles in Vero and C6/36 cells between resistant and control viruses. By contrast, the kinetics of adsorption and internalization of resistant variants in Vero cells was significantly diminished whereas entry to C6/36 cells was unaffected. By plaque purification and sequence analysis of the population, two types of resistant clones were found: some clones presented two mutations in E protein, K126E, and F422L; but other equally λ-car resistant clones had no mutations in E. Furthermore, no mutations were found in other viral proteins like prM, C, or NS1. The genomic disparity in E protein was also associated to differences in phenotype stability. The stable genomic resistance here described provides information about determinants in E protein involved in receptor binding and membrane fusion for uncoating. © 2016 Wiley Periodicals, Inc.

  16. All Serotypes of Dengue Viruses Circulating in Kuala Lumpur, Malaysia

    OpenAIRE

    M.H. Chew; M.M. Rahman; J. Jelip; M.R. Hassan; I. Isahak

    2012-01-01

    Dengue is a severe disease caused by dengue virus (DENV), transmitted to human being by infected Aedes mosquitoes. It is a major public health concern in Southeast Asia due to its fatality in the form of hemorrhagic fever (DHF) and dengue shock syndrome (DSS). The objective of the study was to isolate and identify dengue virus serotypes prevalent in endemic areas of Kuala Lumpur and Selangor in Malaysia by virus culture, indirect immunoflurecent assay and molecular techniques. A total number ...

  17. Activity of andrographolide against dengue virus.

    Science.gov (United States)

    Panraksa, Patcharee; Ramphan, Suwipa; Khongwichit, Sarawut; Smith, Duncan R

    2017-03-01

    Dengue is the most prevalent arthropod-transmitted viral illness of humans, with an estimated 100 million symptomatic infections occurring each year and more than 2.5 billion people living at risk of infection. There are no approved antiviral agents against dengue virus, and there is only limited introduction of a dengue vaccine in some countries. Andrographolide is derived from Andrographis paniculata, a medicinal plant traditionally used to treat a number of conditions including infections. The antiviral activity of andrographolide against dengue virus (DENV) serotype 2 was evaluated in two cell lines (HepG2 and HeLa) while the activity against DENV 4 was evaluated in one cell line (HepG2). Results showed that andrographolide had significant anti-DENV activity in both cell lines, reducing both the levels of cellular infection and virus output, with 50% effective concentrations (EC 50 ) for DENV 2 of 21.304 μM and 22.739 μM for HepG2 and HeLa respectively. Time of addition studies showed that the activity of andrographolide was confined to a post-infection stage. These results suggest that andrographolide has the potential for further development as an anti-viral agent for dengue virus infection. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Molecular characterization of dengue viruses isolated from patients in Central Java, Indonesia.

    Science.gov (United States)

    Kusmintarsih, Endang S; Hayati, Rahma F; Turnip, Oktaviani N; Yohan, Benediktus; Suryaningsih, Suhestri; Pratiknyo, Hery; Denis, Dionisius; Sasmono, R Tedjo

    2017-10-19

    Dengue is hyper-endemic in Indonesia. Purwokerto city in Central Java province is routinely ravaged by the disease. Despite the endemicity of dengue in this city, there is still no data on the virological aspects of dengue in the city. We conducted a molecular surveillance study of the circulating dengue viruses (DENV) in Purwokerto city to gain information on the virus origin, serotype and genotype distribution, and phylogenetic characteristics of DENV. A cross-sectional dengue molecular surveillance study was conducted in Purwokerto. Sera were collected from dengue-suspected patients attending three hospitals in the city. Diagnosis was performed using dengue NS1 antigen and IgG/IgM antibodies detection. DENV serotyping was performed using Simplexa Dengue real-time RT-PCR. Sequencing was conducted to obtain full-length DENV Envelope (E) gene sequences, which were then used in phylogenetic and genotypic analyses. Patients' clinical and demographic data were collected and analyzed. A total of 105 dengue-suspected patients' sera were collected, in which 80 (76.2%) were positive for IgM and/or IgG, and 57 (54.2%) were confirmed as dengue by NS1 antigen and/or DENV RNA detection using RT-PCR. Serotyping was successful for 47 isolates. All four serotypes circulated in the area with DENV-3 as the predominant serotype. Phylogenetic analyses grouped the isolates into Genotype I for DENV-1, Cosmopolitan genotype for DENV-2, and Genotype I and II for DENV-3 and -4, respectively. The analyses also revealed the close relatedness of Purwokerto isolates to other DENV strains from Indonesia and neighboring countries. We reveal the molecular and virological characteristics of DENV in Purwokerto, Banyumas regency, Central Java. The genotype and phylogenetic analyses indicate the endemicity of the circulating DENV in the city. Our serotype and genotype data provide references for future dengue molecular epidemiology studies and disease management in the region. Copyright © 2017 The

  19. Significance of IgG optical density ratios (index value) in single reactive anti-Dengue virus IgG capture ELISA.

    Science.gov (United States)

    Chatterjee, Shiv Sekhar; Sharma, Ankush; Choudhury, Shilpee; Chumber, Sushil Kumar; Kaur, Mandeep; Bage, Ras; Parkhe, Nittin; Khanduri, Uma

    2016-12-01

    A single reactive IgG anti-Dengue virus ELISA test in the absence of IgM antibodies or NS1 antigen may denote current infection or past exposure to the virus. To determine whether IgG index value can be used to identify true current dengue infection we conducted a prospective observational study. Suspected dengue patients (n =1745) were tested in their first specimen by MAC-ELISA, GAC-ELISA and NS1 antigen ELISA. Patients with MAC-ELISA and NS1Antigen non-reactive but GAC-ELISA reactive results (n =57) in their first test were followed up and repeated sampling was asked for IgG index values were calculated according to the manufacturer's instruction and classified as: low (2.2-2.5), medium (2.5-4.0) and high (>4.0). 16 out of 57 patients (28.1%) had low IgG Index value whereas 26 cases (45.6%) were categorized as medium and 15(26.3%) were classified as patients with high IgG index. Nine patients with paired reactive serology or antigen positive status were categorised as serologically confirmed dengue fever, 11 patients as not dengue with categorical evidence of other infections while the rest 37 casas with clinical, radiological and laboratory parameters suggestive of dengue but no serological confirmation as possible dengue. Among confirmed, possible and non-Dengue cases, 33.3, 32.4 and 0.0% had high Index value in comparison with 22.2, 29.7 and 27.3% showing low Index values, respectively. Our results suggested a high IgG response in favour of true dengue infection than past exposure while no conclusions should drawn from a low or medium reactive GAC-ELISA results in the absence of IgM antibodies and NS1 Ag.

  20. Dengue in Bali: Clinical characteristics and genetic diversity of circulating dengue viruses.

    Science.gov (United States)

    Megawati, Dewi; Masyeni, Sri; Yohan, Benediktus; Lestarini, Asri; Hayati, Rahma F; Meutiawati, Febrina; Suryana, Ketut; Widarsa, Tangking; Budiyasa, Dewa G; Budiyasa, Ngurah; Myint, Khin S A; Sasmono, R Tedjo

    2017-05-01

    A high number of dengue cases are reported annually in Bali. Despite the endemicity, limited data on dengue is available for Bali localities. Molecular surveillance study was conducted to explore the clinical and virological characteristics of dengue patients in urban Denpasar and rural Gianyar areas in Bali during the peak season in 2015. A total of 205 adult dengue-suspected patients were recruited in a prospective cross-sectional study. Demographic and clinical information were obtained, and dengue screening was performed using NS1 and IgM/IgG ELISAs. Viral RNA was subsequently extracted from patients' sera for serotyping using conventional RT-PCR and Simplexa Dengue real-time RT-PCR, followed by genotyping with sequencing method. We confirmed 161 patients as having dengue by NS1 and RT-PCR. Among 154 samples successfully serotyped, the DENV-3 was predominant, followed by DENV-1, DENV-2, and DENV-4. Serotype predominance was different between Denpasar and Gianyar. Genotyping results classify DENV-1 isolates into Genotype I and DENV-2 as Cosmopolitan Genotype. The classification grouped isolates into Genotype I and II for DENV-3 and DENV-4, respectively. Clinical parameters showed no relationship between infecting serotypes and severity. We observed the genetic diversity of circulating DENV isolates and their relatedness with historical data and importation to other countries. Our data highlights the role of this tourist destination as a potential source of dengue transmission in the region.

  1. Contribution of double-stranded RNA and CPSF30 binding domains of influenza virus NS1 to the inhibition of type I interferon production and activation of human dendritic cells.

    Science.gov (United States)

    Ramos, Irene; Carnero, Elena; Bernal-Rubio, Dabeiba; Seibert, Christopher W; Westera, Liset; García-Sastre, Adolfo; Fernandez-Sesma, Ana

    2013-03-01

    The influenza virus nonstructural protein 1 (NS1) inhibits innate immunity by multiple mechanisms. We previously reported that NS1 is able to inhibit the production of type I interferon (IFN) and proinflammatory cytokines in human primary dendritic cells (DCs). Here, we used recombinant viruses expressing mutant NS1 from the A/Texas/36/91 and A/Puerto Rico/08/34 strains in order to analyze the contribution of different NS1 domains to its antagonist functions. We show that the polyadenylation stimulating factor 30 (CPSF30) binding function of the NS1 protein from A/Texas/36/91 influenza virus, which is absent in the A/Puerto Rico/08/34 strain, is essential for counteracting these innate immune events in DCs. However, the double-stranded RNA (dsRNA) binding domain, present in both strains, specifically inhibits the induction of type I IFN genes in infected DCs, while it is essential only for inhibition of type I IFN proteins and proinflammatory cytokine production in cells infected with influenza viruses lacking a functional CPSF30 binding domain, such as A/Puerto Rico/08/34.

  2. Imunocompetent Mice Model for Dengue Virus Infection

    Directory of Open Access Journals (Sweden)

    Denise Gonçalves

    2012-01-01

    Full Text Available Dengue fever is a noncontagious infectious disease caused by dengue virus (DENV. DENV belongs to the family Flaviviridae, genus Flavivirus, and is classified into four antigenically distinct serotypes: DENV-1, DENV-2, DENV-3, and DENV-4. The number of nations and people affected has increased steadily and today is considered the most widely spread arbovirus (arthropod-borne viral disease in the world. The absence of an appropriate animal model for studying the disease has hindered the understanding of dengue pathogenesis. In our study, we have found that immunocompetent C57BL/6 mice infected intraperitoneally with DENV-1 presented some signs of dengue disease such as thrombocytopenia, spleen hemorrhage, liver damage, and increase in production of IFNγ and TNFα cytokines. Moreover, the animals became viremic and the virus was detected in several organs by real-time RT-PCR. Thus, this animal model could be used to study mechanism of dengue virus infection, to test antiviral drugs, as well as to evaluate candidate vaccines.

  3. Dengue Virus Genome Uncoating Requires Ubiquitination

    Directory of Open Access Journals (Sweden)

    Laura A. Byk

    2016-06-01

    Full Text Available The process of genome release or uncoating after viral entry is one of the least-studied steps in the flavivirus life cycle. Flaviviruses are mainly arthropod-borne viruses, including emerging and reemerging pathogens such as dengue, Zika, and West Nile viruses. Currently, dengue virus is one of the most significant human viral pathogens transmitted by mosquitoes and is responsible for about 390 million infections every year around the world. Here, we examined for the first time molecular aspects of dengue virus genome uncoating. We followed the fate of the capsid protein and RNA genome early during infection and found that capsid is degraded after viral internalization by the host ubiquitin-proteasome system. However, proteasome activity and capsid degradation were not necessary to free the genome for initial viral translation. Unexpectedly, genome uncoating was blocked by inhibiting ubiquitination. Using different assays to bypass entry and evaluate the first rounds of viral translation, a narrow window of time during infection that requires ubiquitination but not proteasome activity was identified. In this regard, ubiquitin E1-activating enzyme inhibition was sufficient to stabilize the incoming viral genome in the cytoplasm of infected cells, causing its retention in either endosomes or nucleocapsids. Our data support a model in which dengue virus genome uncoating requires a nondegradative ubiquitination step, providing new insights into this crucial but understudied viral process.

  4. Dengue virus antibodies enhance Zika virus infection.

    Science.gov (United States)

    Paul, Lauren M; Carlin, Eric R; Jenkins, Meagan M; Tan, Amanda L; Barcellona, Carolyn M; Nicholson, Cindo O; Michael, Scott F; Isern, Sharon

    2016-12-01

    For decades, human infections with Zika virus (ZIKV), a mosquito-transmitted flavivirus, were sporadic, associated with mild disease, and went underreported since symptoms were similar to other acute febrile diseases. Recent reports of severe disease associated with ZIKV have greatly heightened awareness. It is anticipated that ZIKV will continue to spread in the Americas and globally where competent Aedes mosquito vectors are found. Dengue virus (DENV), the most common mosquito-transmitted human flavivirus, is both well-established and the source of outbreaks in areas of recent ZIKV introduction. DENV and ZIKV are closely related, resulting in substantial antigenic overlap. Through antibody-dependent enhancement (ADE), anti-DENV antibodies can enhance the infectivity of DENV for certain classes of immune cells, causing increased viral production that correlates with severe disease outcomes. Similarly, ZIKV has been shown to undergo ADE in response to antibodies generated by other flaviviruses. We tested the neutralizing and enhancing potential of well-characterized broadly neutralizing human anti-DENV monoclonal antibodies (HMAbs) and human DENV immune sera against ZIKV using neutralization and ADE assays. We show that anti-DENV HMAbs, cross-react, do not neutralize, and greatly enhance ZIKV infection in vitro . DENV immune sera had varying degrees of neutralization against ZIKV and similarly enhanced ZIKV infection. Our results suggest that pre-existing DENV immunity may enhance ZIKV infection in vivo and may lead to increased disease severity. Understanding the interplay between ZIKV and DENV will be critical in informing public health responses and will be particularly valuable for ZIKV and DENV vaccine design and implementation strategies.

  5. Dengue Virus Serotype 4, Northeastern Peru, 2008

    Science.gov (United States)

    Forshey, Brett M.; Morrison, Amy C.; Cruz, Cristhopher; Rocha, Claudio; Vilcarromero, Stalin; Guevara, Carolina; Camacho, Daria E.; Alava, Araceli; Madrid, César; Beingolea, Luis; Suarez, Víctor; Comach, Guillermo

    2009-01-01

    In 2008, dengue virus serotype 4 (DENV-4) emerged in northeastern Peru, causing a large outbreak and displacing DENV-3, which had predominated for the previous 6 years. Phylogenetic analysis of 2008 and 2009 isolates support their inclusion into DENV-4 genotype II, forming a lineage distinct from strains that had previously circulated in the region. PMID:19891873

  6. Immature Dengue Virus : A Veiled Pathogen?

    NARCIS (Netherlands)

    Rodenhuis-Zybert, Izabela A.; van der Schaar, Hilde M.; Da Silva-Voorham, Júlia; van der Ende-Metselaar, Heidi; Lei, Huan-Yao; Wilschut, Jan; Smit, Jolanda M.

    Cells infected with dengue virus release a high proportion of immature prM-containing virions. In accordance, substantial levels of prM antibodies are found in sera of infected humans. Furthermore, it has been recently described that the rates of prM antibody responses are significantly higher in

  7. Dengue

    Science.gov (United States)

    Dengue is an infection caused by a virus. You can get it if an infected mosquito bites you. Dengue does not spread from person to person. It ... the world. Outbreaks occur in the rainy season. Dengue is rare in the United States. Symptoms include ...

  8. Lineage shift of dengue virus in Eastern India: an increased implication for DHF/DSS.

    Science.gov (United States)

    Shrivastava, A; Soni, M; Shrivastava, S; Sharma, S; Dash, P K; Gopalan, N; Behera, P K; Parida, M M

    2015-06-01

    Dengue fever, a mosquito-borne viral disease, has become a major public health problem with marked expansion in recent decades. Dengue has now become hyperendemic in India with co-circulation of all the four serotypes. Herein, we report an unprecedented outbreak which occurred during August to October 2011 in Odisha, eastern India. This is the first report of a large epidemic in Odisha. Detailed serological and molecular investigation was carried out to identify the aetiology. Almost half of the samples were found to be dengue antigen (NS1) positive. Further molecular assays revealed circulation of mixed dengue serotypes (DENV-2 and DENV-3). Cosmopolitan genotype of DENV-2 and -3 were identified as the aetiology by phylogenetic analysis. Interestingly, a new lineage of DENV-3 within cosmopolitan genotype was incriminated in this outbreak. The emergence of the unprecedented magnitude of the dengue outbreak with the involvement of a novel lineage of DENV in a newer state of India is a major cause for concern. There is an urgent need to monitor phylodynamics of dengue viruses in other endemic areas.

  9. Microparticles Provide a Novel Biomarker To Predict Severe Clinical Outcomes of Dengue Virus Infection

    Science.gov (United States)

    Punyadee, Nuntaya; Mairiang, Dumrong; Thiemmeca, Somchai; Komoltri, Chulaluk; Pan-ngum, Wirichada; Chomanee, Nusara; Charngkaew, Komgrid; Tangthawornchaikul, Nattaya; Limpitikul, Wannee; Vasanawathana, Sirijitt; Malasit, Prida

    2014-01-01

    ABSTRACT Shedding of microparticles (MPs) is a consequence of apoptotic cell death and cellular activation. Low levels of circulating MPs in blood help maintain homeostasis, whereas increased MP generation is linked to many pathological conditions. Herein, we investigated the role of MPs in dengue virus (DENV) infection. Infection of various susceptible cells by DENV led to apoptotic death and MP release. These MPs harbored a viral envelope protein and a nonstructural protein 1 (NS1) on their surfaces. Ex vivo analysis of clinical specimens from patients with infections of different degrees of severity at multiple time points revealed that MPs generated from erythrocytes and platelets are two major MP populations in the circulation of DENV-infected patients. Elevated levels of red blood cell-derived MPs (RMPs) directly correlated with DENV disease severity, whereas a significant decrease in platelet-derived MPs was associated with a bleeding tendency. Removal by mononuclear cells of complement-opsonized NS1–anti-NS1 immune complexes bound to erythrocytes via complement receptor type 1 triggered MP shedding in vitro, a process that could explain the increased levels of RMPs in severe dengue. These findings point to the multiple roles of MPs in dengue pathogenesis. They offer a potential novel biomarker candidate capable of differentiating dengue fever from the more serious dengue hemorrhagic fever. IMPORTANCE Dengue is the most important mosquito-transmitted viral disease in the world. No vaccines or specific treatments are available. Rapid diagnosis and immediate treatment are the keys to achieve a positive outcome. Dengue virus (DENV) infection, like some other medical conditions, changes the level and composition of microparticles (MPs), tiny bag-like structures which are normally present at low levels in the blood of healthy individuals. This study investigated how MPs in culture and patients' blood are changed in response to DENV infection. Infection of cells

  10. Microparticles provide a novel biomarker to predict severe clinical outcomes of dengue virus infection.

    Science.gov (United States)

    Punyadee, Nuntaya; Mairiang, Dumrong; Thiemmeca, Somchai; Komoltri, Chulaluk; Pan-Ngum, Wirichada; Chomanee, Nusara; Charngkaew, Komgrid; Tangthawornchaikul, Nattaya; Limpitikul, Wannee; Vasanawathana, Sirijitt; Malasit, Prida; Avirutnan, Panisadee

    2015-02-01

    Shedding of microparticles (MPs) is a consequence of apoptotic cell death and cellular activation. Low levels of circulating MPs in blood help maintain homeostasis, whereas increased MP generation is linked to many pathological conditions. Herein, we investigated the role of MPs in dengue virus (DENV) infection. Infection of various susceptible cells by DENV led to apoptotic death and MP release. These MPs harbored a viral envelope protein and a nonstructural protein 1 (NS1) on their surfaces. Ex vivo analysis of clinical specimens from patients with infections of different degrees of severity at multiple time points revealed that MPs generated from erythrocytes and platelets are two major MP populations in the circulation of DENV-infected patients. Elevated levels of red blood cell-derived MPs (RMPs) directly correlated with DENV disease severity, whereas a significant decrease in platelet-derived MPs was associated with a bleeding tendency. Removal by mononuclear cells of complement-opsonized NS1-anti-NS1 immune complexes bound to erythrocytes via complement receptor type 1 triggered MP shedding in vitro, a process that could explain the increased levels of RMPs in severe dengue. These findings point to the multiple roles of MPs in dengue pathogenesis. They offer a potential novel biomarker candidate capable of differentiating dengue fever from the more serious dengue hemorrhagic fever. Dengue is the most important mosquito-transmitted viral disease in the world. No vaccines or specific treatments are available. Rapid diagnosis and immediate treatment are the keys to achieve a positive outcome. Dengue virus (DENV) infection, like some other medical conditions, changes the level and composition of microparticles (MPs), tiny bag-like structures which are normally present at low levels in the blood of healthy individuals. This study investigated how MPs in culture and patients' blood are changed in response to DENV infection. Infection of cells led to programmed

  11. Antibody-Dependent Enhancement of Dengue Virus Growth in Human Monocytes as a Risk Factor for Dengue Hemorrhagic Fever

    Science.gov (United States)

    1989-01-01

    Clamfication) Antibody-Dependent Enhancement of Dengue Virus Growth in Human Monocytes as a Risk Factor for Dengue Hemorrhagic Fever 𔃼 PERSONAL AjTHOR(S...FELD GROUP SUBGROUP Antibody-Dependent Enhancement of Dengue Virus Growth in Human Monocytes as a Risk Factor for Dengue Hemorrhagic Fever . 19...clinically diagnosed as dengue hemorrhagic fever . Antibody-dependent enhancement of virus growth was quantitated by measurement of virus yields in

  12. Immature dengue virus: a veiled pathogen?

    Directory of Open Access Journals (Sweden)

    Izabela A Rodenhuis-Zybert

    2010-01-01

    Full Text Available Cells infected with dengue virus release a high proportion of immature prM-containing virions. In accordance, substantial levels of prM antibodies are found in sera of infected humans. Furthermore, it has been recently described that the rates of prM antibody responses are significantly higher in patients with secondary infection compared to those with primary infection. This suggests that immature dengue virus may play a role in disease pathogenesis. Interestingly, however, numerous functional studies have revealed that immature particles lack the ability to infect cells. In this report, we show that fully immature dengue particles become highly infectious upon interaction with prM antibodies. We demonstrate that prM antibodies facilitate efficient binding and cell entry of immature particles into Fc-receptor-expressing cells. In addition, enzymatic activity of furin is critical to render the internalized immature virus infectious. Together, these data suggest that during a secondary infection or primary infection of infants born to dengue-immune mothers, immature particles have the potential to be highly infectious and hence may contribute to the development of severe disease.

  13. Dengue virus serotype in Aceh Province

    Directory of Open Access Journals (Sweden)

    Paisal

    2015-06-01

    Full Text Available WHO estimated 50 million dengue infections happen every year in the world. In Indonesia, there were 90,245 DHF cases on 2012 with 816 deaths. In the Province of Aceh, 2,269 cases happened in the same year. This study aimed to identify dengue virus serotype in Aceh. Sampling was done in Kota Banda Aceh Hospital, Kota Lhokseumawe Hospital, Kabupaten Aceh Tamiang Hospital, Kabupaten Aceh Barat Hospital, and Kabupaten Simeulue Hospital between May to December 2012. This was a clinical laboratory research with observation design using cross sectional approach. Research’s population was sample from patients with dengue clinical symptom. Using purposive sampling technique, we have collected 100 samples from the five hospitals (20 samples from each hospital. From RT-PCR, we found 16 positive samples (9 samples were DENV-4, 3 samples were DENV-1, 2 samples were DENV-2, and 2 samples were DENV-3.

  14. AN APPROPRIATE DIAGNOSIS OF DENGUE VIRUS INFECTION IN SOME CASES WHO HAD AND WERE BEING TREATED IN SOERYA HOSPITAL SEPANJANG – INDONESIA

    Directory of Open Access Journals (Sweden)

    Soegeng Soegijanto

    2015-09-01

    Full Text Available Since January 2014, Soerya Hospital has found many cases with positive result of NS or IgM and IgG Dengue. The clinical manifestations mostly were high fever with headache, vomiting and also malaise convulsion and unconsciousness. Aim of the study is to find out an appropriate diagnosis of Dengue Virus Infection. Observasional study had been done since January–April 2014 with 50 cases of dengue Virus Infection. The diagnostic procedure was made based on the WHO 2011 criteria. Result Many cases had come with fever within couple days, some of them showed convulsions. Therefore, it should be made a differential diagnosis with other disease, such as acute tonsilopharingitis, etc. The patient also had to be tested with NS1 if the patient come in the first, second and third day of fever and followed by IgM/IgG dengue on the fourth, fifth or sixth days of fever. The diagnosis of Dengue Virus Infection was made based on the WHO criteria 2011. This study showed that not all cases showed positive result of NS1 or IgM/IgG dengue on the first or second test. For the negative result, we should not think that the case is not a case of Dengue Virus Infection, especially if it happens at Aedes aegypti breeding season, the patient should be observed and performed the test again to get a proper diagnosis for Dengue Virus Infection. Monitoring clinical manifestation should always be done, to predict the appropriate diagnosis of Dengue Virus Infection.

  15. Dengue viruses in Brazil, 1986-2006 Virus del dengue en Brasil, 1986-2006

    Directory of Open Access Journals (Sweden)

    Rita Maria Ribeiro Nogueira

    2007-11-01

    Full Text Available A total of 4 243 049 dengue cases have been reported in Brazil between 1981 and 2006, including 5 817 cases of dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS and a total of 338 fatal cases. Although all Brazilian regions have been affected, the Northeast and Southeast regions have registered the highest number of notifications. DENV-1 and DENV-4 were isolated for the first time in the Amazon region of Brazil in 1981 and 1982. The disease became a nationwide public health problem following outbreaks of DENV-1 and DENV-2 in the state of Rio de Janeiro in 1986 and 1990, respectively. The introduction of DENV-3 in 2000, also in the state of Rio de Janeiro, led to a severe epidemic with 288 245 reported dengue cases, including 91 deaths. Virus strains that were typed during the 2002 epidemic show that DENV-3 has displaced other dengue virus serotypes and entered new areas, a finding that warrants closer evaluation. Unusual clinical symptoms, including central nervous system involvement, have been observed in dengue patients in at least three regions of the country.En Brasil se han notificado 4 243 049 casos de dengue entre 1981 y 2006, de ellos 5 817 casos de dengue hemorrágico/síndrome de choque por dengue (DH/SCD y un total de 338 casos mortales. A pesar de que la enfermedad ha afectado a todas las regiones brasileñas, el mayor número de casos se ha notificado en las regiones nororiental y suroriental. Los virus del dengue (DENV 1 y 4 se aislaron por primera vez en la región amazónica de Brasil en 1981 y 1982. La enfermedad se convirtió en un problema nacional de salud pública después de los brotes de DENV-1 y DENV-2 en el Estado de Río de Janeiro en 1986 y 1990, respectivamente. La introducción del DENV-3 en 2000, también en el Estado de Río de Janeiro, llevó a una grave epidemia con 288 245 casos notificados de dengue y 91 muertes. Las cepas del virus identificadas durante la epidemia de 2002 demostraron que el DENV-3 ha

  16. Efficient, trans-complementing packaging systems for chimeric, pseudoinfectious dengue 2/yellow fever viruses

    International Nuclear Information System (INIS)

    Shustov, Alexandr V.; Frolov, Ilya

    2010-01-01

    In our previous studies, we have stated to build a new strategy for developing defective, pseudoinfectious flaviviruses (PIVs) and applying them as a new type of vaccine candidates. PIVs combined the efficiency of live vaccines with the safety of inactivated or subunit vaccines. The results of the present work demonstrate further development of chimeric PIVs encoding dengue virus 2 (DEN2V) glycoproteins and yellow fever virus (YFV)-derived replicative machinery as potential vaccine candidates. The newly designed PIVs have synergistically functioning mutations in the prM and NS2A proteins, which abolish processing of the latter proteins and make the defective viruses capable of producing either only noninfectious, immature and/or subviral DEN2V particles. The PIV genomes can be packaged to high titers into infectious virions in vitro using the NS1-deficient YFV helper RNAs, and both PIVs and helpers can then be passaged as two-component genome viruses at an escalating scale.

  17. Reemergence and Autochthonous Transmission of Dengue Virus, Eastern China, 2014.

    Science.gov (United States)

    Wang, Wen; Yu, Bin; Lin, Xian-Dan; Kong, De-Guang; Wang, Jian; Tian, Jun-Hua; Li, Ming-Hui; Holmes, Edward C; Zhang, Yong-Zhen

    2015-09-01

    In 2014, 20 dengue cases were reported in the cities of Wenzhou (5 cases) and Wuhan (15 cases), China, where dengue has rarely been reported. Dengue virus 1 was detected in 4 patients. Although most of these cases were likely imported, epidemiologic analysis provided evidence for autochthonous transmission.

  18. Seroprevalence of Anti-Dengue Virus 2 Serocomplex antibodies in ...

    African Journals Online (AJOL)

    Introduction: There has been a recent increase in the spread of dengue to rural areas. Rural parts of western kenya are naturally prone to mosquito-borne diseases, however, limited research has been documented on infections with dengue. This study therefore investigated the presence of antibodies against dengue virus ...

  19. Phenotypic characterization of patient dengue virus isolates in BALB/c mice differentiates dengue fever and dengue hemorrhagic fever from dengue shock syndrome.

    Science.gov (United States)

    Tuiskunen, Anne; Wahlström, Maria; Bergström, Jakob; Buchy, Philippe; Leparc-Goffart, Isabelle; Lundkvist, Ake

    2011-08-11

    Dengue virus (DENV) infection is the most common arthropod-borne viral disease in man and there are approximately 100 million infections annually. Despite the global burden of DENV infections many important questions regarding DENV pathogenesis remain unaddressed due to the lack of appropriate animal models of infection and disease. A major problem is the fact that no non-human species naturally develop disease similar to human dengue fever (DF) or dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). Apart from other risk factors for severe dengue such as host genetics and secondary infection with a heterologous DENV, virus virulence is a risk factor that is not well characterized. Three clinical DENV-1 isolates from Cambodian patients experiencing the various forms of dengue disease (DF, DHF, and DSS) were inoculated in BALB/c mice at three different concentrations. The DENV-1 isolates had different organ and cell tropism and replication kinetics. The DENV-1 isolate from a DSS patient infected the largest number of mice and was primarily neurotropic. In contrast, the DENV-1 isolates from milder clinical dengue cases infected predominantly lungs and liver, and to a lesser extent brain. In addition, infection with the DENV isolate derived from a DSS patient persisted for more than two weeks in a majority of mice compared to the other DENV-1 isolates that peaked during the first week. These results confirm the in vitro findings of the same DENV-1 isolates, that showed that the isolate derived from a DSS patient can be distinguished based on phenotypic characteristics that differ from the isolates derived from a DF and DHF case 1. We observed in this study that the DSS virus isolate persist longer in vivo with extensive neuroinvasion in contrast to the other DENV-1 isolates originating in milder human cases. Genomic characterization of the three clinical isolates identified six amino acid substitutions unique for the DSS isolates that were located both in

  20. Transmission of dengue virus from deceased donors to solid organ transplant recipients: case report and literature review.

    Science.gov (United States)

    Rosso, Fernando; Pineda, Juan C; Sanz, Ana M; Cedano, Jorge A; Caicedo, Luis A

    Dengue fever is a vector-transmitted viral infection. Non-vectorial forms of transmission can occur through organ transplantation. We reviewed medical records of donors and recipients with suspected dengue in the first post-transplant week. We used serologic and molecular analysis to confirm the infection. Herein, we describe four cases of dengue virus transmission through solid organ transplantation. The recipients had positive serology and RT-PCR. Infection in donors was detected through serology. All cases presented with fever within the first week after transplantation. There were no fatal cases. After these cases, we implemented dengue screening with NS1 antigen detection in donors during dengue outbreaks, and no new cases were detected. In the literature review, additional cases had been published through August 2017. Transmission of Dengue virus can occur through organ donation. In endemic regions, it is important to suspect and screen for dengue in febrile and thrombocytopenic recipients in the postoperative period. Copyright © 2018 Sociedade Brasileira de Infectologia. Published by Elsevier Editora Ltda. All rights reserved.

  1. Cissampelos pareira Linn: Natural Source of Potent Antiviral Activity against All Four Dengue Virus Serotypes.

    Science.gov (United States)

    Sood, Ruchi; Raut, Rajendra; Tyagi, Poornima; Pareek, Pawan Kumar; Barman, Tarani Kanta; Singhal, Smita; Shirumalla, Raj Kumar; Kanoje, Vijay; Subbarayan, Ramesh; Rajerethinam, Ravisankar; Sharma, Navin; Kanaujia, Anil; Shukla, Gyanesh; Gupta, Y K; Katiyar, Chandra K; Bhatnagar, Pradip K; Upadhyay, Dilip J; Swaminathan, Sathyamangalam; Khanna, Navin

    2015-12-01

    Dengue, a mosquito-borne viral disease, poses a significant global public health risk. In tropical countries such as India where periodic dengue outbreaks can be correlated to the high prevalence of the mosquito vector, circulation of all four dengue viruses (DENVs) and the high population density, a drug for dengue is being increasingly recognized as an unmet public health need. Using the knowledge of traditional Indian medicine, Ayurveda, we developed a systematic bioassay-guided screening approach to explore the indigenous herbal bio-resource to identify plants with pan-DENV inhibitory activity. Our results show that the alcoholic extract of Cissampelos pariera Linn (Cipa extract) was a potent inhibitor of all four DENVs in cell-based assays, assessed in terms of viral NS1 antigen secretion using ELISA, as well as viral replication, based on plaque assays. Virus yield reduction assays showed that Cipa extract could decrease viral titers by an order of magnitude. The extract conferred statistically significant protection against DENV infection using the AG129 mouse model. A preliminary evaluation of the clinical relevance of Cipa extract showed that it had no adverse effects on platelet counts and RBC viability. In addition to inherent antipyretic activity in Wistar rats, it possessed the ability to down-regulate the production of TNF-α, a cytokine implicated in severe dengue disease. Importantly, it showed no evidence of toxicity in Wistar rats, when administered at doses as high as 2g/Kg body weight for up to 1 week. Our findings above, taken in the context of the human safety of Cipa, based on its use in Indian traditional medicine, warrant further work to explore Cipa as a source for the development of an inexpensive herbal formulation for dengue therapy. This may be of practical relevance to a dengue-endemic resource-poor country such as India.

  2. Nordihydroguaiaretic acid (NDGA) inhibits replication and viral morphogenesis of dengue virus.

    Science.gov (United States)

    Soto-Acosta, Rubén; Bautista-Carbajal, Patricia; Syed, Gulam H; Siddiqui, Aleem; Del Angel, Rosa M

    2014-09-01

    Dengue is the most common mosquito borne viral disease in humans. The infection with any of the 4 dengue virus serotypes (DENV) can either be asymptomatic or manifest in two clinical forms, the mild dengue fever or the more severe dengue hemorrhagic fever that may progress into dengue shock syndrome. A DENV replicative cycle relies on host lipid metabolism; specifically, DENV infection modulates cholesterol and fatty acid synthesis, generating a lipid-enriched cellular environment necessary for viral replication. Thus, the aim of this work was to evaluate the anti-DENV effect of the Nordihydroguaiaretic acid (NDGA), a hypolipidemic agent with antioxidant and anti-inflammatory properties. A dose-dependent inhibition in viral yield and NS1 secretion was observed in supernatants of infected cells treated for 24 and 48 h with different concentrations of NDGA. To evaluate the effect of NDGA in DENV replication, a DENV4 replicon transfected Vero cells were treated with different concentrations of NDGA. NDGA treatment significantly reduced DENV replication, reiterating the importance of lipids in viral replication. NDGA treatment also led to reduction in number of lipid droplets (LDs), the neutral lipid storage organelles involved in DENV morphogenesis that are known to increase in number during DENV infection. Furthermore, NDGA treatment resulted in dissociation of the C protein from LDs. Overall our results suggest that NDGA inhibits DENV infection by targeting genome replication and viral assembly. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. The Medicinal Chemistry of Dengue Virus.

    Science.gov (United States)

    Behnam, Mira A M; Nitsche, Christoph; Boldescu, Veaceslav; Klein, Christian D

    2016-06-23

    The dengue virus and related flaviviruses are an increasing global health threat. In this perspective, we comment on and review medicinal chemistry efforts aimed at the prevention or treatment of dengue infections. We include target-based approaches aimed at viral or host factors and results from phenotypic screenings in cellular assay systems for viral replication. This perspective is limited to the discussion of results that provide explicit chemistry or structure-activity relationship (SAR), or appear to be of particular interest to the medicinal chemist for other reasons. The discovery and development efforts discussed here may at least partially be extrapolated toward other emerging flaviviral infections, such as West Nile virus. Therefore, this perspective, although not aimed at flaviviruses in general, should also be able to provide an overview of the medicinal chemistry of these closely related infectious agents.

  4. Combined prime-boost vaccination against tick-borne encephalitis (TBE using a recombinant vaccinia virus and a bacterial plasmid both expressing TBE virus non-structural NS1 protein

    Directory of Open Access Journals (Sweden)

    Zakharova LG

    2005-08-01

    Full Text Available Abstract Background Heterologous prime-boost immunization protocols using different gene expression systems have proven to be successful tools in protecting against various diseases in experimental animal models. The main reason for using this approach is to exploit the ability of expression cassettes to prime or boost the immune system in different ways during vaccination procedures. The purpose of the project was to study the ability of recombinant vaccinia virus (VV and bacterial plasmid, both carrying the NS1 gene from tick-borne encephalitis (TBE virus under the control of different promoters, to protect mice against lethal challenge using a heterologous prime-boost vaccination protocol. Results The heterologous prime-boost vaccination protocol, using a VV recombinant and bacterial plasmid, both containing the NS1 TBE virus protein gene under the control of different promoters, achieved a high level of protection in mice against lethal challenge with a highly pathogenic TBE virus strain. No signs of pronounced TBE infection were detected in the surviving animals. Conclusion Heterologous prime-boost vaccination protocols using recombinant VV and bacterial plasmids could be used for the development of flavivirus vaccines.

  5. Isolation of dengue virus from the upper respiratory tract of four patients with dengue fever.

    Science.gov (United States)

    Cheng, Nai-Ming; Sy, Cheng Len; Chen, Bao-Chen; Huang, Tsi-Shu; Lee, Susan Shin-Jung; Chen, Yao-Shen

    2017-04-01

    Dengue fever is an important arboviral disease. The clinical manifestations vary from a mild non-specific febrile syndrome to severe life-threatening illness. The virus can usually be detected in the blood during the early stages of the disease. Dengue virus has also been found in isolated cases in the cerebrospinal fluid, urine, nasopharyngeal sections and saliva. In this report, we describe the isolation of dengue virus from the upper respiratory tract of four confirmed cases of dengue. We reviewed all laboratory reports of the isolation of dengue virus from respiratory specimens at the clinical microbiology laboratory of the Kaohsiung Veterans General Hospital during 2007 to 2015. We then examined the medical records of the cases from whom the virus was isolated to determine their demographic characteristics, family contacts, clinical signs and symptoms, course of illness and laboratory findings. Dengue virus was identified in four patients from a nasopharyngeal or throat culture. Two were classified as group A dengue (dengue without warning signs), one as group B (dengue with warning signs) and one as group C (severe dengue). All had respiratory symptoms. Half had family members with similar respiratory symptoms during the period of their illnesses. All of the patients recovered uneventfully. The isolation of dengue virus from respiratory specimens of patients with cough, rhinorrhea and nasal congestion, although rare, raises the possibility that the virus is capable of transmission by the aerosol route among close contacts. This concept is supported by studies that show that the virus can replicate in cultures of respiratory epithelium and can be transmitted through mucocutaneous exposure to blood from infected patients. However, current evidence is insufficient to prove the hypothesis of transmission through the respiratory route. Further studies will be needed to determine the frequency of respiratory colonization, viable virus titers in respiratory

  6. Mathematical analysis of dengue virus antibody dynamics

    Science.gov (United States)

    Perera, Sulanie; Perera, SSN

    2018-03-01

    Dengue is a mosquito borne viral disease causing over 390 million infections worldwide per annum. Even though information on how infection is controlled and eradicated from the body is lacking, antibodies are thought to play a major role in clearing the virus. In this paper, a non-linear conceptual dynamical model with humoral immune response and absorption effect has been proposed for primary dengue infection. We have included the absorption of pathogens into uninfected cells since this effect causes the virus density in the blood to decrease. The time delay that arises in the production of antibodies was accounted and is introduced through a continuous function. The basic reproduction number R0 is computed and a detailed stability analysis is done. Three equilibrium states, namely the infection free equilibrium, no immune equilibrium and the endemic equilibrium were identified and the existence and the stability conditions of these steady states were obtained. Numerical simulations proved the results that were obtained. By establishing the characteristic equation of the model at infection free equilibrium, it was observed that the infection free equilibrium is locally asymptotically stable if R0 1. Stability regions are identified for infection free equilibrium state with respect to the external variables and it is observed as the virus burst rate increases, the stability regions would decrease. These results implied that for higher virus burst rates, other conditions in the body must be strong enough to eliminate the disease completely from the host. The effect of time delay of antibody production on virus dynamics is discussed. It was seen that as the time delay in production of antibodies increases, the time for viral decline also increased. Also it was observed that the virus count goes to negligible levels within 7 - 14 days after the onset of symptoms as seen in dengue infections.

  7. Antiviral activity of lanatoside C against dengue virus infection.

    Science.gov (United States)

    Cheung, Yan Yi; Chen, Karen Caiyun; Chen, Huixin; Seng, Eng Khuan; Chu, Justin Jang Hann

    2014-11-01

    Dengue infection poses a serious threat globally due to its recent rapid spread and rise in incidence. Currently, there is no approved vaccine or effective antiviral drug for dengue virus infection. In response to the urgent need for the development of an effective antiviral for dengue virus, the US Drug Collection library was screened in this study to identify compounds with anti-dengue activities. Lanatoside C, an FDA approved cardiac glycoside was identified as a candidate anti-dengue compound. Our data revealed that lanatoside C has an IC50 of 0.19μM for dengue virus infection in HuH-7 cells. Dose-dependent reduction in dengue viral RNA and viral proteins synthesis were also observed upon treatment with increasing concentrations of lanatoside C. Time of addition study indicated that lanatoside C inhibits the early processes of the dengue virus replication cycle. Furthermore, lanatoside C can effectively inhibit all four serotypes of dengue virus, flavivirus Kunjin, alphavirus Chikungunya and Sindbis virus as well as the human enterovirus 71. These findings suggest that lanatoside C possesses broad spectrum antiviral activity against several groups of positive-sense RNA viruses. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Evolutionary dynamics of dengue virus populations within the mosquito vector.

    Science.gov (United States)

    Lambrechts, Louis; Lequime, Sebastian

    2016-12-01

    To date, dengue virus evolution has mainly been addressed by studies conducted at the between-host level. Like other pathogens with high mutation rate and rapid replication, dengue viruses also evolve during the course of an infection. Over the last few years, the advent of deep-sequencing technologies has facilitated studies of dengue virus populations at the within-host level. Here, we review recent advances on the evolutionary dynamics of dengue virus populations within their mosquito vector. We discuss how identifying the evolutionary forces acting on dengue virus populations within the mosquito can shed light on the processes underlying vector-virus interactions and the evolution of epidemiologically relevant traits. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. REPLIKASI VIRUS DENGUE PADA KULTUR SEL ENDOTEL PEMBULUH DARAH KELINCI

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    Ni Luh Eka Setiasih

    2012-10-01

    Full Text Available Infeksi virus Dengue (DEN dapat menyebabkan dengue hemorrhagic fever –dengue shock syndrome (DHF-DSS, yang ditandai dengan kebocoran plasma dan gangguan hemostasis. Meskipun sel endotel dipertimbangkan dapat menjadi target sel pada patogenesis DHF, namun sedikit bukti yang menyatakan infeksi virus dengue menyebabkan perubahan fungsi sel endotel. Dalam studi ini sel endotel diisolasi dari aorta desenden thoraxis-abdominalis kelinci, kemudian dilakukan kultur sel primer. Kultur sel kemudian diinokulasi dengan virus Dengue DEN-1, -2, -3, -4, dan DEN-mix. Replikasi virus dengue pada kultur sel endotel diukur dengan uji enzyme-linked immunosorbent assay (ELISA. Titer Ag (DEN-1, -2, -3, -4, dan DEN-mix yang didapat dari supernatan bervariasi. Dengue tipe 2 mempunyai titer paling tinggi dibandingkan dengan DEN-mix dan tipe virus dengue lainnya. Kerusakan sel endotel menyebabkan kebocoran vaskuleryang berperanan pada patogenesis infeksi virus dengue. Hasil tersebut menyiratkan kemungkinan kerusakan sel endotel disebabkan oleh infeksi virus dengue yang mengakibatkan kebocoran vaskuler. ABSTRACT The severe outcome of the Dengue (DEN virus infection known as DEN hemorrhagic fever – DEN shock syndrome (DHF – DSS, is characterized by plasma leakage and hemostasis derangements. Although endothelial cells have been speculated to be a target in the pathogenesis of DHF, there has been little evidence on Dengue virus infection to any alteration in endothelial cell function.In this study, the endothelial cells has been isolatedfrom rabbit thoraxis-abdominalis descendentaortha, then performed primary culture. The culture was then inoculated with virus Dengue DEN-1, -2, -3, -4 and DEN-mix.Replications of dengue virus in endothelial cells culture were demonstrated by enzyme-linked immunosorbent assay (ELISA. Ag titers found among the supernatant of DEN-1, -2, -3, -4, and DEN-mix cultures were vary.Dengue type 2 had the highest virus titers in supernatant

  10. Dengue Epidemiology

    Science.gov (United States)

    ... and dengue shock syndrome (DSS). Transmission of the Dengue Virus Dengue is transmitted between people by the ... the vectors is too infrequent to sustain transmission. Dengue is an Emerging Disease The four dengue viruses ...

  11. Complete genome analysis of dengue virus type 3 isolated from the 2013 dengue outbreak in Yunnan, China.

    Science.gov (United States)

    Wang, Xiaodan; Ma, Dehong; Huang, Xinwei; Li, Lihua; Li, Duo; Zhao, Yujiao; Qiu, Lijuan; Pan, Yue; Chen, Junying; Xi, Juemin; Shan, Xiyun; Sun, Qiangming

    2017-06-15

    In the past few decades, dengue has spread rapidly and is an emerging disease in China. An unexpected dengue outbreak occurred in Xishuangbanna, Yunnan, China, resulting in 1331 patients in 2013. In order to obtain the complete genome information and perform mutation and evolutionary analysis of causative agent related to this largest outbreak of dengue fever. The viruses were isolated by cell culture and evaluated by genome sequence analysis. Phylogenetic trees were then constructed by Neighbor-Joining methods (MEGA6.0), followed by analysis of nucleotide mutation and amino acid substitution. The analysis of the diversity of secondary structure for E and NS1 protein were also performed. Then selection pressures acting on the coding sequences were estimated by PAML software. The complete genome sequences of two isolated strains (YNSW1, YNSW2) were 10,710 and 10,702 nucleotides in length, respectively. Phylogenetic analysis revealed both strain were classified as genotype II of DENV-3. The results indicated that both isolated strains of Xishuangbanna in 2013 and Laos 2013 stains (KF816161.1, KF816158.1, LC147061.1, LC147059.1, KF816162.1) were most similar to Bangladesh (AY496873.2) in 2002. After comparing with the DENV-3SS (H87) 62 amino acid substitutions were identified in translated regions, and 38 amino acid substitutions were identified in translated regions compared with DENV-3 genotype II stains Bangladesh (AY496873.2). 27(YNSW1) or 28(YNSW2) single nucleotide changes were observed in structural protein sequences with 7(YNSW1) or 8(YNSW2) non-synonymous mutations compared with AY496873.2. Of them, 4 non-synonymous mutations were identified in E protein sequences with (2 in the β-sheet, 2 in the coil). Meanwhile, 117(YNSW1) or 115 (YNSW2) single nucleotide changes were observed in non-structural protein sequences with 31(YNSW1) or 30 (YNSW2) non-synonymous mutations. Particularly, 14 single nucleotide changes were observed in NS1 sequences with 4/14 non

  12. Partial maturation : an immune-evasion strategy of dengue virus?

    NARCIS (Netherlands)

    Rodenhuis-Zybert, Izabela A.; Wilschut, Jan; Smit, Jolanda M.

    Cleavage of the precursor membrane (prM) protein is required for the activation of flavivirus infectivity. However, many studies have shown that, for dengue virus in particular, prM cleavage and maturation is inefficient. Heterogeneity of wild-type dengue virus preparations with regard to the

  13. Genetic analysis of imported dengue virus strains by Iranian travelers

    Directory of Open Access Journals (Sweden)

    Nariman Shahhosseini

    2016-11-01

    Full Text Available Dengue virus sequences used in this study were obtained from two Iranian patients who were both with a history of traveling to Malaysia. The maximum likelihood phylogenetic tree demonstrated that two sequences were grouped into dengue virus 1. Specifically, strains IranDF1 and Iran-DF2 clustered in genotype I and III, respectively.

  14. Homotypic Dengue Virus Reinfections in Nicaraguan Children.

    Science.gov (United States)

    Waggoner, Jesse J; Balmaseda, Angel; Gresh, Lionel; Sahoo, Malaya K; Montoya, Magelda; Wang, Chunling; Abeynayake, Janaki; Kuan, Guillermina; Pinsky, Benjamin A; Harris, Eva

    2016-10-01

    Infection with any of the 4 related dengue virus serotypes (DENV-1-4) is thought to result in lifelong immunity to homotypic reinfection (ie, reinfection with the same serotype). Archived serum samples collected as part of an ongoing pediatric dengue cohort study in Nicaragua were tested for DENV by real-time reverse transcription polymerase chain reaction. Samples were collected from 2892 children who presented with an acute febrile illness clinically attributed to a non-DENV cause (hereafter, "C cases"). Test results were added to a database of previously identified symptomatic dengue cases in the cohort to identify repeat infections. Four patients with homotypic DENV reinfections were identified and confirmed among 29 repeat DENV infections (13.8%) with serotype confirmation. Homotypic reinfections with DENV-1, DENV-2, and DENV-3 occurred 325-621 days after the initial infection. Each patient experienced 1 symptomatic dengue case and 1 DENV-positive C case, and 2 patients presented with symptomatic dengue during their second infection. These DENV-positive C cases did not elicit long-lived humoral immune responses, despite viremia levels of up to 6.44 log10 copies per mL of serum. We describe the first set of virologically confirmed homotypic DENV reinfections. Such cases challenge the current understanding of DENV immunity and have important implications for modeling DENV transmission. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

  15. Dengue Hemorrhagic Fever Virus in Saudi Arabia: A Review.

    Science.gov (United States)

    Al-Tawfiq, Jaffar A; Memish, Ziad A

    2018-02-01

    Dengue fever is a global disease with a spectrum of clinical manifestation ranging from mild febrile disease to a severe disease in the form of dengue hemorrhagic fever and dengue shock syndrome. Dengue virus is one viral hemorrhagic fever that exists in the Kingdom of Saudi Arabia in addition to Alkhurma (Alkhurma) Hemorrhagic Fever, Chikungunya virus, Crimean-Congo Hemorrhagic Fever, and Rift Valley Fever. The disease is limited to the Western and South-western regions of Saudi Arabia, where Aedes aegypti exists. The majority of the cases in Saudi Arabia had mild disease and is related to serotypes 1-3 but not 4. The prospect for Dengue virus control relies on vector control, health education, and possibly vaccine use. Despite extensive collaborative efforts between multiple governmental sectors, including Ministry of Health, Ministry of Municipalities and Rural Affairs, and Ministry of Water, dengue remains a major public health concern in the regions affected.

  16. A recombinant, chimeric tetravalent dengue vaccine candidate based on a dengue virus serotype 2 backbone.

    Science.gov (United States)

    Osorio, Jorge E; Wallace, Derek; Stinchcomb, Dan T

    2016-01-01

    Dengue fever is caused by infection with one of four dengue virus (DENV) serotypes (DENV-1-4), necessitating tetravalent dengue vaccines that can induce protection against all four DENV. Takeda's live attenuated tetravalent dengue vaccine candidate (TDV) comprises an attenuated DENV-2 strain plus chimeric viruses containing the prM and E genes of DENV-1, -3 and -4 cloned into the attenuated DENV-2 'backbone'. In Phase 1 and 2 studies, TDV was well tolerated by children and adults aged 1.5-45 years, irrespective of prior dengue exposure; mild injection-site symptoms were the most common adverse events. TDV induced neutralizing antibody responses and seroconversion to all four DENV as well as cross-reactive T cell-mediated responses that may be necessary for broad protection against dengue fever.

  17. Human to mosquito transmission of dengue viruses

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    Lauren B Carrington

    2014-06-01

    Full Text Available The successful transmission of dengue virus from a human host to a mosquito vector requires a complex set of factors to align. It is becoming increasingly important to improve our understanding of the parameters that shape the human to mosquito component of the transmission cycle so that vaccines and therapeutic anti-virals can be fully evaluated and epidemiological models refined. Here we describe these factors, and discuss the biological and environmental impacts and demographic changes that are influencing these dynamics. Specifically, we examine features of the human infection required for the mosquito to acquire the virus via natural blood feeding, as well as the biological and environmental factors that influence a mosquito’s susceptibility to infection, up to the point that they are capable of transmitting the virus to a new host.

  18. Quinic acid derivatives inhibit dengue virus replication in vitro.

    Science.gov (United States)

    Zanello, Paula Rodrigues; Koishi, Andrea Cristine; Rezende Júnior, Celso de Oliveira; Oliveira, Larissa Albuquerque; Pereira, Adriane Antonia; de Almeida, Mauro Vieira; Duarte dos Santos, Claudia Nunes; Bordignon, Juliano

    2015-12-22

    Dengue is the most prevalent arboviral disease in tropical and sub-tropical areas of the world. The incidence of infection is estimated to be 390 million cases and 25,000 deaths per year. Despite these numbers, neither a specific treatment nor a preventive vaccine is available to protect people living in areas of high risk. With the aim of seeking a treatment that can mitigate dengue infection, we demonstrated that the quinic acid derivatives known as compound 2 and compound 10 were effective against all four dengue virus serotypes and safe for use in a human hepatoma cell line (Huh7.5). Both compounds were non-virucidal to dengue virus particles and did not interfere with early steps of the dengue virus life cycle, including binding and internalization. Experiments using a replicon system demonstrated that compounds 2 and 10 impaired dengue virus replication in Huh7.5 cells. Additionally, the anti-dengue virus effects of the quinic acid derivatives were preserved in human peripheral blood mononuclear cells. Taken together, these data suggest that quinic acid derivatives represent a novel chemical class of active compounds that could be used to combat dengue virus infection.

  19. Towards antiviral therapies for treating dengue virus infections.

    Science.gov (United States)

    Kaptein, Suzanne Jf; Neyts, Johan

    2016-10-01

    Dengue virus is an emerging human pathogen that poses a huge public health burden by infecting annually about 390 million individuals of which a quarter report with clinical manifestations. Although progress has been made in understanding dengue pathogenesis, a licensed vaccine or antiviral therapy against this virus is still lacking. Treatment of patients is confined to symptomatic alleviation and supportive care. The development of dengue therapeutics thus remains of utmost importance. This review focuses on the few molecules that were evaluated in dengue virus-infected patients: balapiravir, chloroquine, lovastatin, prednisolone and celgosivir. The lessons learned from these clinical trials can be very helpful for the design of future trials for the next generation of dengue virus inhibitors. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Raman spectroscopy based investigation of molecular changes associated with an early stage of dengue virus infection

    Science.gov (United States)

    Bilal, Maria; Bilal, Muhammad; Saleem, Muhammad; Khurram, Muhammad; Khan, Saranjam; Ullah, Rahat; Ali, Hina; Ahmed, Mushtaq; Shahzada, Shaista; Ullah Khan, Ehsan

    2017-04-01

    Raman spectroscopy based investigations of the molecular changes associated with an early stage of dengue virus infection (DENV) using a partial least squares (PLS) regression model is presented. This study is based on non-structural protein 1 (NS1) which appears after three days of DENV infection. In total, 39 blood sera samples were collected and divided into two groups. The control group contained samples which were the negative for NS1 and antibodies and the positive group contained those samples in which NS1 is positive and antibodies were negative. Out of 39 samples, 29 Raman spectra were used for the model development while the remaining 10 were kept hidden for blind testing of the model. PLS regression yielded a vector of regression coefficients as a function of Raman shift, which were analyzed. Cytokines in the region 775-875 cm-1, lectins at 1003, 1238, 1340, 1449 and 1672 cm-1, DNA in the region 1040-1140 cm-1 and alpha and beta structures of proteins in the region 933-967 cm-1 have been identified in the regression vector for their role in an early stage of DENV infection. Validity of the model was established by its R-square value of 0.891. Sensitivity, specificity and accuracy were 100% each and the area under the receiver operator characteristic curve was found to be 1.

  1. Animal Models of Dengue Virus Infection

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    Eva Harris

    2012-01-01

    Full Text Available The development of animal models of dengue virus (DENV infection and disease has been challenging, as epidemic DENV does not naturally infect non-human species. Non-human primates (NHPs can sustain viral replication in relevant cell types and develop a robust immune response, but they do not develop overt disease. In contrast, certain immunodeficient mouse models infected with mouse-adapted DENV strains show signs of severe disease similar to the ‘vascular-leak’ syndrome seen in severe dengue in humans. Humanized mouse models can sustain DENV replication and show some signs of disease, but further development is needed to validate the immune response. Classically, immunocompetent mice infected with DENV do not manifest disease or else develop paralysis when inoculated intracranially; however, a new model using high doses of DENV has recently been shown to develop hemorrhagic signs after infection. Overall, each model has its advantages and disadvantages and is differentially suited for studies of dengue pathogenesis and immunopathogenesis and/or pre-clinical testing of antiviral drugs and vaccines.

  2. Pharmacological intervention for dengue virus infection.

    Science.gov (United States)

    Lai, Jenn-Haung; Lin, Yi-Ling; Hsieh, Shie-Liang

    2017-04-01

    Dengue virus (DENV) infection has a considerable health impact in tropical and subtropical countries worldwide. Escalation of infection rates greatly increases morbidity and mortality, most commonly from deaths due to dengue hemorrhagic fever and dengue shock syndrome. Although the development of an effective, long-lasting vaccine has been a major aim for control and prevention of DENV infection, the currently licensed vaccine has limitations and is less than satisfactory. Thus, there remains an important need to identify effective and tolerable medications for treatment of DENV-infected patients both in the early phase, to prevent progression to fatal outcomes, and to minimize deaths after patients develop severe complications. This review will address several specific points, including (1) approaches to identify anti-DENV medications, (2) recent advances in the development of potential compounds targeting DENV infection, (3) experience with clinical trials of regimens for DENV infection, (4) some available medications of potential for clinical trials against DENV infection, (5) reasons for unsuccessful outcomes and challenges of anti-DENV treatments, and (6) directions for developing or selecting better anti-DENV strategies. This review provides useful guidance for clinicians selecting drugs for DENV-infected patients with severe manifestations or potential fatal disease progression, and for basic researchers seeking to develop effective anti-DENV regimens. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Concurrent infections by all four dengue virus serotypes during an outbreak of dengue in 2006 in Delhi, India

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    Guleria Randeep

    2008-01-01

    Full Text Available Abstract Background Co-circulation of multiple dengue virus serotypes has been reported from many parts of the world including India, however concurrent infection with more than one serotype of dengue viruses in the same individual is rarely documented. An outbreak of dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS occurred in and around Delhi in 2006. This is the first report from India with high percentage of concurrent infections with different dengue virus serotypes circulating during one outbreak. Results Acute phase sera from patients were tested for the presence of dengue virus RNA by RT-PCR assay. Of the 69 samples tested for dengue virus RNA, 48 (69.5% were found to be positive. All the four dengue virus serotypes were found to be co-circulating in this outbreak with DENV-3 being the predominant serotype. In addition in 9 of 48 (19% dengue virus positive samples, concurrent infection with more than one dengue virus serotype were identified. Conclusion This is the first report in which concurrent infections with different dengue virus serotypes is being reported during an outbreak from India. Delhi is now truly hyperendemic for dengue.

  4. Imported dengue virus serotype 1 from Madeira to Finland 2012.

    Science.gov (United States)

    Huhtamo, E; Korhonen, Em; Vapalahti, O

    2013-02-21

    Imported dengue cases originating from the Madeiran outbreak are increasingly reported. In 2012 five Finnish travellers returning from Madeira were diagnosed with dengue fever. Viral sequence data was obtained from two patients. The partial C-preM sequences (399 and 396 bp respectively) were found similar to that of an autochthonous case from Madeira. The partial E-gene sequence (933 bp) which was identical among the two patients grouped phylogenetically with South American strains of dengue virus serotype 1.

  5. Dengue virus type 3 in Rio de Janeiro, Brazil

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    Nogueira Rita Maria R

    2001-01-01

    Full Text Available Dengue virus type 3 was isolated for the first time in the country as an indigenous case from a 40 year-old woman presenting signs and symptoms of a classical dengue fever in the municipality of Nova Iguaçu, State of Rio de Janeiro. This serotype has been associated with dengue haemorrhagic epidemics and the information could be used to implement appropriate prevention and control measures. Virological surveillance was essential in order to detected this new serotype.

  6. Isolation of dengue virus serotype 4 genotype II from a patient with high viral load and a mixed Th1/Th17 inflammatory cytokine profile in South Brazil.

    Science.gov (United States)

    Kuczera, Diogo; Bavia, Lorena; Mosimann, Ana Luiza Pamplona; Koishi, Andrea Cristine; Mazzarotto, Giovanny Augusto Camacho Antevere; Aoki, Mateus Nóbrega; Mansano, Ana Maria Ferrari; Tomeleri, Ediléia Inês; Costa Junior, Wilson Liuti; Miranda, Milena Menegazzo; Lo Sarzi, Maria; Pavanelli, Wander Rogério; Conchon-Costa, Ivete; Duarte Dos Santos, Claudia Nunes; Bordignon, Juliano

    2016-06-06

    We report the isolation and characterization of dengue virus (DENV) serotype 4 from a resident of Santa Fé, state of Paraná, South Brazil, in March 2013. This patient presented with hemorrhagic manifestations, high viral load and, interestingly, a mixed Th1/Th17 cytokine profile. The patient presented with classical dengue symptoms, such as fever, rash, myalgia, arthralgia, and hemorrhagic manifestations including petechiae, gum bleeding and a positive tourniquet test result. A serum sample obtained 1 day after the initial appearance of clinical symptoms was positive for NS1 viral antigen, but this sample was negative for both IgM and IgG against DENV. Dengue virus infection was confirmed by isolation of the virus from C6/36 cells, and dengue virus serotyping was performed via one-step RT-PCR. The infection was confirmed to be caused by a serotype 4 dengue virus. Additionally, based on multiple alignment and phylogeny analyses of its complete genome sequence, the viral strain was classified as genotype II (termed LRV13/422). Moreover, a mixed Th1/Th17 cytokine profile was detected in the patient's serum, and this result demonstrated significant inflammation. Biological characterization of the virus via in vitro assays comparing LRV13/422 with a laboratory-adapted reference strain of dengue virus serotype 4 (TVP/360) showed that LRV13/422 infects both vertebrate and invertebrate cell lines more efficiently than TVP/360. However, LRV13/422 was unable to inhibit type I interferon responses, as suggested by the results obtained for other dengue virus strains. Furthermore, LRV13/422 is the first completely sequenced serotype 4 dengue virus isolated in South Brazil. The high viral load and mixed Th1/Th17 cytokine profile observed in the patient's serum could have implications for the development of the hemorrhagic signs observed, and these potential relationships can now be further studied using suitable animal models and/or in vitro systems.

  7. Emergence of Dengue virus serotype 3 on Mayotte Island, Indian ...

    African Journals Online (AJOL)

    A serosurvey carried out in 2006 in Mayotte, a French overseas collectivity in the Indian Ocean, confirmed previous circulation of dengue virus (DENV) on the island, but since the set up of a laboratory-based surveillance of dengue-like illness in 2007, no case of DENV has been confirmed. In response to an outbreak of ...

  8. NF90 Binds the Dengue Virus RNA 3′ Terminus and Is a Positive Regulator of Dengue Virus Replication

    Science.gov (United States)

    Gehrke, Lee

    2011-01-01

    Background Viral RNA translation and replication are regulated by sequence and structural elements in the 5′ and 3′ untranslated regions (UTR) and by host cell and/or viral proteins that bind them. Dengue virus has a single-stranded RNA genome with positive polarity, a 5′ m7GpppG cap, and a conserved 3′-terminal stem loop (SL) that is linked to proposed functions in viral RNA transcription and translation. Mechanisms explaining the contributions of host proteins to viral RNA translation and replication are poorly defined, yet understanding host protein-viral RNA interactions may identify new targets for therapeutic intervention. This study was directed at identifying functionally significant host proteins that bind the conserved dengue virus RNA 3′ terminus. Methodology/Principal Findings Proteins eluted from a dengue 3′ SL RNA affinity column at increasing ionic strength included two with double-strand RNA binding motifs (NF90/DRBP76 and DEAH box polypeptide 9/RNA helicase A (RHA)), in addition to NF45, which forms a heterodimer with NF90. Although detectable NF90 and RHA proteins localized to the nucleus of uninfected cells, immunofluorescence revealed cytoplasmic NF90 in dengue virus-infected cells, leading us to hypothesize that NF90 has a functional role(s) in dengue infections. Cells depleted of NF90 were used to quantify viral RNA transcript levels and production of infectious dengue virus. NF90 depletion was accompanied by a 50%-70% decrease in dengue RNA levels and in production of infectious viral progeny. Conclusions/Significance The results indicate that NF90 interacts with the 3′ SL structure of the dengue RNA and is a positive regulator of dengue virus replication. NF90 depletion diminished the production of infectious dengue virus by more than 50%, which may have important significance for identifying therapeutic targets to limit a virus that threatens more than a billion people worldwide. PMID:21386893

  9. Comparison of Surface Plasmon Resonance, Resonant Waveguide Grating Biosensing and Enzyme Linked Immunosorbent Assay (ELISA in the Evaluation of a Dengue Virus Immunoassay

    Directory of Open Access Journals (Sweden)

    Joe Buechler

    2013-07-01

    Full Text Available Two label-free biosensor platforms, Resonance Waveguide Grating (RWG and Surface Plasmon Resonance (SPR, were used to rank a large panel of anti-dengue virus NS1 antibodies. Dengue non-structural 1 (NS1 protein is an established serological marker for the early detection of dengue infection. A variety of commercial dengue NS1 antigen capture immunoassays are available in both ELISA and lateral flow format. However, there is a significant scope to improve both the sensitivity and the specificity of those tests. The interactions of antibody (Ab-antigen (Ag were profiled, with weak interactions (KD = 1–0.1 μM able to be detected under static equilibrium conditions by RWG, but not observed to under more rigorous flow conditions using SPR. There were significant differences in the absolute affinities determined by the two technologies, and there was a poor correlation between antibodies best ranked by RWG and the lower limit of detection (LLOD found by ELISA. Hence, whilst high-throughput RWG can be useful as preliminary screening for higher affinity antibodies, care should be exercised in the assignation of quantitative values for affinity between different assay formats.

  10. Identification of B-Cell Epitope of Dengue Virus Type 1 and Its Application in Diagnosis of Patients

    OpenAIRE

    Wu, Han-Chung; Huang, Yue-Ling; Chao, Ting-Ting; Jan, Jia-Tsrong; Huang, Jau-Ling; Chiang, Hsien-Yuan; King, Chwan-Chuen; Shaio, Men-Fang

    2001-01-01

    Using a serotype-specific monoclonal antibody (MAb) of dengue virus type 1 (DEN-1), 15F3-1, we identified the B-cell epitope of DEN-1 from a random peptide library displayed on phage. Fourteen immunopositive phage clones that bound specifically to MAb 15F3-1 were selected. These phage-borne peptides had a consensus motif of HxYaWb (a = S/T, b = K/H/R) that mimicked the sequence HKYSWK, which corresponded to amino acid residues 111 to 116 of the nonstructural protein 1 (NS1) of DEN-1. Among th...

  11. Cross-Reactive T-Cell Responses to the Nonstructural Regions of Dengue Viruses among Dengue Fever and Dengue Hemorrhagic Fever Patients in Malaysia▿

    OpenAIRE

    Appanna, Ramapraba; Huat, Tan Lian; See, Lucy Lum Chai; Tan, Phoay Lay; Vadivelu, Jamuna; Devi, Shamala

    2007-01-01

    Dengue virus infections are a major cause of morbidity and mortality in tropical and subtropical areas in the world. Attempts to develop effective vaccines have been hampered by the lack of understanding of the pathogenesis of the disease and the absence of suitable experimental models for dengue viral infection. The magnitude of T-cell responses has been reported to correlate with dengue disease severity. Sixty Malaysian adults with dengue viral infections were investigated for their dengue ...

  12. Enhancing the sensitivity of Dengue virus serotype detection by RT-PCR among infected children in India.

    Science.gov (United States)

    Ahamed, Syed Fazil; Vivek, Rosario; Kotabagi, Shalini; Nayak, Kaustuv; Chandele, Anmol; Kaja, Murali-Krishna; Shet, Anita

    2017-06-01

    Dengue surveillance relies on reverse transcription-polymerase chain reaction (RT-PCR), for confirmation of dengue virus (DENV) serotypes. We compared efficacies of published and modified primer sets targeting envelope (Env) and capsid-premembrane (C-prM) genes for detection of circulating DENV serotypes in southern India. Acute samples from children with clinically-diagnosed dengue were used for RT-PCR testing. All samples were also subjected to dengue serology (NS1 antigen and anti-dengue-IgM/IgG rapid immunochromatographic assay). Nested RT-PCR was performed on viral RNA using three methods targeting 654bp C-prM, 511bp C-prM and 641bp Env regions, respectively. RT-PCR-positive samples were validated by population sequencing. Among 171 children with suspected dengue, 121 were dengue serology-positive and 50 were dengue serology-negative. Among 121 serology-positives, RT-PCR detected 91 (75.2%) by CprM654, 72 (59.5%) by CprM511, and 74 (61.1%) by Env641. Among 50 serology-negatives, 10 (20.0%) were detected by CprM654, 12 (24.0%) by CprM511, and 11 (22.0%) by Env641. Overall detection rate using three methods sequentially was 82.6% (100/121) among serology-positive and 40.0% (20/50) among serology-negative samples; 6.6% (8/120) had co-infection with multiple DENV serotypes. We conclude that detection of acute dengue was enhanced by a modified RT-PCR method targeting the 654bp C-prM region, and further improved by using all three methods sequentially. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Heterotypic dengue infection with live attenuated monotypic dengue virus vaccines: implications for vaccination of populations in areas where dengue is endemic.

    Science.gov (United States)

    Durbin, Anna P; Schmidt, Alexander; Elwood, Dan; Wanionek, Kimberli A; Lovchik, Janece; Thumar, Bhavin; Murphy, Brian R; Whitehead, Stephen S

    2011-02-01

    Because infection with any of the 4 Dengue virus serotypes may elicit both protective neutralizing antibodies and nonneutralizing antibodies capable of enhancing subsequent heterotypic Dengue virus infections, the greatest risk for severe dengue occurs during a second, heterotypic Dengue virus infection. It remains unclear whether the replication of live attenuated vaccine viruses will be similarly enhanced when administered to Dengue-immune individuals. We recruited 36 healthy adults who had previously received a monovalent live Dengue virus vaccine 0.6-7.4 years earlier. Participants were assigned to 1 of 4 cohorts and were randomly chosen to receive placebo or a heterotypic vaccine. The level of replication, safety, and immunogenicity of the heterotypic vaccine virus was compared with that of Dengue virus immunologically naive vaccinees. Vaccine virus replication and reactogenicity after monovalent Dengue virus vaccination in naive and heterotypically immune vaccinees was similar. In contrast to naive vaccinees, the antibody response in heterotypically immune vaccinees was broadly neutralizing and mimicked the response observed by natural secondary Dengue virus infection. Enhanced replication of these live attenuated Dengue virus vaccines was minimal in heterotypically immune vaccinees and suggests that the further evaluation of these candidate vaccines in populations with preexisting DENV immunity can proceed safely.

  14. Innate Immunity Evasion by Dengue Virus

    Directory of Open Access Journals (Sweden)

    Ana Fernandez-Sesma

    2012-03-01

    Full Text Available For viruses to productively infect their hosts, they must evade or inhibit important elements of the innate immune system, namely the type I interferon (IFN response, which negatively influences the subsequent development of antigen-specific adaptive immunity against those viruses. Dengue virus (DENV can inhibit both type I IFN production and signaling in susceptible human cells, including dendritic cells (DCs. The NS2B3 protease complex of DENV functions as an antagonist of type I IFN production, and its proteolytic activity is necessary for this function. DENV also encodes proteins that antagonize type I IFN signaling, including NS2A, NS4A, NS4B and NS5 by targeting different components of this signaling pathway, such as STATs. Importantly, the ability of the NS5 protein to bind and degrade STAT2 contributes to the limited host tropism of DENV to humans and non-human primates. In this review, we will evaluate the contribution of innate immunity evasion by DENV to the pathogenesis and host tropism of this virus.

  15. Innate immunity evasion by Dengue virus.

    Science.gov (United States)

    Morrison, Juliet; Aguirre, Sebastian; Fernandez-Sesma, Ana

    2012-03-01

    For viruses to productively infect their hosts, they must evade or inhibit important elements of the innate immune system, namely the type I interferon (IFN) response, which negatively influences the subsequent development of antigen-specific adaptive immunity against those viruses. Dengue virus (DENV) can inhibit both type I IFN production and signaling in susceptible human cells, including dendritic cells (DCs). The NS2B3 protease complex of DENV functions as an antagonist of type I IFN production, and its proteolytic activity is necessary for this function. DENV also encodes proteins that antagonize type I IFN signaling, including NS2A, NS4A, NS4B and NS5 by targeting different components of this signaling pathway, such as STATs. Importantly, the ability of the NS5 protein to bind and degrade STAT2 contributes to the limited host tropism of DENV to humans and non-human primates. In this review, we will evaluate the contribution of innate immunity evasion by DENV to the pathogenesis and host tropism of this virus.

  16. NNDSS - Table II. Cryptosporidiosis to Dengue virus infection

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Cryptosporidiosis to Dengue virus infection - 2018. In this Table, provisional cases of selected notifiable diseases (≥1,000 cases reported...

  17. Dengue viruses cluster antigenically but not as discrete serotypes

    NARCIS (Netherlands)

    L. Katzelnick (Leah); J.M. Fonville (Judith); G.D. Gromowski (Gregory D.); J.B. Arriaga (Jose Bustos); A. Green (Angela); S.L. James (Sarah ); L. Lau (Louis); M. Montoya (Magelda); C. Wang (Chunling); L.A. Van Blargan (Laura A.); C.A. Russell (Colin); H.M. Thu (Hlaing Myat); T.C. Pierson (Theodore C.); P. Buchy (Philippe); J.G. Aaskov (John G.); J.L. Muñoz-Jordán (Jorge L.); N. Vasilakis (Nikos); R.V. Gibbons (Robert V.); R.B. Tesh (Robert B.); A.D.M.E. Osterhaus (Albert); R.A.M. Fouchier (Ron); A. Durbin (Anna); C.P. Simmons (Cameron P.); E.C. Holmes (Edward C.); E. Harris (Eva); S.S. Whitehead (Stephen S.); D.J. Smith (Derek James)

    2015-01-01

    textabstractThe four genetically divergent dengue virus (DENV) types are traditionally classified as serotypes. Antigenic and genetic differences among the DENV types influence disease outcome, vaccine-induced protection, epidemic magnitude, and viral evolution.We scharacterized antigenic diversity

  18. NNDSS - Table II. Cryptosporidiosis to Dengue virus infection

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Cryptosporidiosis to Dengue virus infection - 2018. In this Table, provisional cases of selected notifiable diseases (≥1,000 cases reported during...

  19. Improving dengue viral antigens detection in dengue patient serum specimens using a low pH glycine buffer treatment.

    Science.gov (United States)

    Shen, Wen-Fan; Galula, Jedhan Ucat; Chang, Gwong-Jen J; Wu, Han-Chung; King, Chwan-Chuen; Chao, Day-Yu

    2017-04-01

    Early diagnosis of dengue virus (DENV) infection to monitor the potential progression to hemorrhagic fever can influence the timely management of dengue-associated severe illness. Nonstructural protein 1 (NS1) antigen detection in acute serum specimens has been widely accepted as an early diagnostic assay for dengue infection; however, lower sensitivity of the NS1 antigen-capture enzyme-linked immunosorbent assay (Ag-ELISA) in secondary dengue viral infection has been reported. In this study, we developed two forms of Ag-ELISA capable of detecting E-Ag containing virion and virus-like particles, and secreted NS1 (sNS1) antigens, respectively. The temporal kinetics of viral RNA, sNS1, and E-Ag were evaluated based on the in vitro infection experiment. Meanwhile, a panel of 62 DENV-2 infected patients' sera was tested. The sensitivity was 3.042 ng/mL and 3.840 ng/mL for sNS1 and E, respectively. The temporal kinetics of the appearance of viral RNA, E, NS1, and infectious virus in virus-infected tissue culture media suggested that viral RNAs and NS1 antigens could be detected earlier than E-Ag and infectious virus. Furthermore, a panel of 62 sera from patients infected by DENV Serotype 2 was tested. Treating clinical specimens with the dissociation buffer increased the detectable level of E from 13% to 92% and NS1 antigens from 40% to 85%. Inclusion of a low-pH glycine buffer treatment step in the commercially available Ag-ELISA is crucial for clinical diagnosis and E-containing viral particles could be a valuable target for acute DENV diagnosis, similar to NS1 detection. Copyright © 2015. Published by Elsevier B.V.

  20. Highly pathogenic avian influenza virus H5N1 controls type I IFN induction in chicken macrophage HD-11 cells: a polygenic trait that involves NS1 and the polymerase complex

    Science.gov (United States)

    2012-01-01

    Background Influenza A viruses are well characterized to antagonize type I IFN induction in infected mammalian cells. However, limited information is available for avian cells. It was hypothesised that avian influenza viruses (AIV) with distinct virulence may interact differently with the avian innate immune system. Therefore, the type I IFN responses induced by highly virulent and low virulent H5N1 AIV and reassortants thereof were analysed in chicken cells. Results The highly pathogenic (HP) AIV A/chicken/Yamaguchi/7/04 (H5N1) (Yama) did not induce type I IFN in infected chicken HD-11 macrophage-like cells. This contrasted with an NS1 mutant Yama virus (Yama-NS1A144V) and with the attenuated H5N1 AIV A/duck/Hokkaido/Vac-1/04 (Vac) carrying the haemagglutinin (HA) of the Yama virus (Vac-Yama/HA), that both induced type I IFN in these cells. The substitution of the NS segment from Yama with that from Vac in the Yama backbone resulted in induction of type I IFN secretion in HD-11 cells. However, vice versa, the Yama NS segment did not prevent type I IFN induction by the Vac-Yama/HA virus. This was different with the PB1/PB2/PA segment reassortant Yama and Vac-Yama/HA viruses. Whereas the Yama virus with the Vac PB1/PB2/PA segments induced type I IFN in HD-11 cells, the Vac-Yama/HA virus with the Yama PB1/PB2/PA segments did not. As reported for mammalian cells, the expression of H5N1 PB2 inhibited the activation of the IFN-β promoter in chicken DF-1 fibroblast cells. Importantly, the Yama PB2 was more potent at inhibiting the IFN-β promoter than the Vac PB2. Conclusions The present study demonstrates that the NS1 protein and the polymerase complex of the HPAIV Yama act in concert to antagonize chicken type I IFN secretion in HD-11 cells. PB2 alone can also exert a partial inhibitory effect on type I IFN induction. In conclusion, the control of type I IFN induction by H5N1 HPAIV represents a complex phenotype that involves a particular viral gene constellation

  1. Dengue Virus-Specific Antibodies Enhance Brazilian Zika Virus Infection.

    Science.gov (United States)

    Castanha, Priscila M S; Nascimento, Eduardo J M; Braga, Cynthia; Cordeiro, Marli T; de Carvalho, Otávio V; de Mendonça, Leila R; Azevedo, Elisa A N; França, Rafael F O; Dhalia, Rafael; Marques, Ernesto T A

    2017-03-01

    Anti-Flavivirus antibodies are highly cross-reactive and may facilitate Zika virus (ZIKV) infection through the antibody-dependent enhancement (ADE) mechanism. We demonstrate that dengue-specific antibodies enhance the infection of a primary Brazilian ZIKV isolate in a FcγRII-expressing K562 cell line. In addition, we demonstrate that serum samples from dengue-immune pregnant women enhanced ZIKV infection. These findings highlight the need for epidemiological studies and animal models to further confirm the role of ADE in the development of congenital and neurological complications associated with ZIKV infections. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

  2. Pathogenesis of vascular leak in dengue virus infection.

    Science.gov (United States)

    Malavige, Gathsaurie Neelika; Ogg, Graham S

    2017-07-01

    Endothelial dysfunction leading to vascular leak is the hallmark of severe dengue. Vascular leak typically becomes clinically evident 3-6 days after the onset of illness, which is known as the critical phase. This critical phase follows the period of peak viraemia, and lasts for 24-48 hr and usually shows rapid and complete reversal, suggesting that it is likely to occur as a result of inflammatory mediators, rather than infection of the endothelium. Cytokines such as tumour necrosis factor-α, which are known to be elevated in the critical phase of dengue, are likely to be contributing factors. Dengue NS1, a soluble viral protein, has also been shown to disrupt the endothelial glycocalyx and thus contribute to vascular leak, although there appears to be a discordance between the timing of NS1 antigenaemia and occurrence of vascular leak. In addition, many inflammatory lipid mediators are elevated in acute dengue viral infection such as platelet activating factor (PAF) and leukotrienes. Furthermore, many other inflammatory mediators such as vascular endothelial growth factor and angiopoietin-2 have been shown to be elevated in patients with dengue haemorrhagic fever, exerting their action in part by inducing the activity of phospholipases, which have diverse inflammatory effects including generation of PAF. Platelets have also been shown to significantly contribute to endothelial dysfunction by production of interleukin-1β through activation of the NLRP3 inflammasome and also by inducing production of inflammatory cytokines by monocytes. Drugs that block down-stream immunological mediator pathways such as PAF may also be beneficial in the treatment of severe disease. © 2017 John Wiley & Sons Ltd.

  3. Dengue 2 virus enhancement in asthmatic and non asthmatic individual

    Directory of Open Access Journals (Sweden)

    Maria G. Guzman

    1992-12-01

    Full Text Available During the 1981 dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS Cuban epidemic, bronchial asthma (BA was frequently found as a personal or family antecedent in dengue hemorragic fever patients. Considering that antibody dependent enhancement (ADE plays an important role in the etiopathogenic mechanism of DHF/DSS, we decide to study the Dengue 2 virus (D2V capability of replication in peripheral blood leukocytes (PBL from asthmatic patients and healthy persons. In 90% of asthmatic patients and 53.8% of control group it was obtained PBL with a significant D2V enhancing activity (X² p < 0.01. Power enhancement was higher in asthmatic group. This is the first in vitro study relating BA and the dengue 2 virus immuno enhancement. The results obtained support the role of BA as a risk factor for DHF/DSS as already described on epidemiological data.

  4. Comparison of Seven Commercial Antigen and Antibody Enzyme-Linked Immunosorbent Assays for Detection of Acute Dengue Infection

    Science.gov (United States)

    Jarman, Richard G.; Gibbons, Robert V.; Tanganuchitcharnchai, Ampai; Mammen, Mammen P.; Nisalak, Ananda; Kalayanarooj, Siripen; Bailey, Mark S.; Premaratna, Ranjan; de Silva, H. Janaka; Day, Nicholas P. J.; Lalloo, David G.

    2012-01-01

    Seven commercial assays were evaluated to determine their suitability for the diagnosis of acute dengue infection: (i) the Panbio dengue virus Pan-E NS1 early enzyme-linked immunosorbent assay (ELISA), second generation (Alere, Australia); (ii) the Panbio dengue virus IgM capture ELISA (Alere, Australia); (iii) the Panbio dengue virus IgG capture ELISA (Alere, Australia); (iv) the Standard Diagnostics dengue virus NS1 antigen ELISA (Standard Diagnostics, South Korea); (v) the Standard Diagnostics dengue virus IgM ELISA (Standard Diagnostics, South Korea); (vi) the Standard Diagnostics dengue virus IgG ELISA (Standard Diagnostics, South Korea); and (vii) the Platelia NS1 antigen ELISA (Bio-Rad, France). Samples from 239 Thai patients confirmed to be dengue virus positive and 98 Sri Lankan patients negative for dengue virus infection were tested. The sensitivities and specificities of the NS1 antigen ELISAs ranged from 45 to 57% and 93 to 100% and those of the IgM antibody ELISAs ranged from 85 to 89% and 88 to 100%, respectively. Combining the NS1 antigen and IgM antibody results from the Standard Diagnostics ELISAs gave the best compromise between sensitivity and specificity (87 and 96%, respectively), as well as providing the best sensitivity for patients presenting at different times after fever onset. The Panbio IgG capture ELISA correctly classified 67% of secondary dengue infection cases. This study provides strong evidence of the value of combining dengue virus antigen- and antibody-based test results in the ELISA format for the diagnosis of acute dengue infection. PMID:22441389

  5. Autophagic machinery activated by dengue virus enhances virus replication

    International Nuclear Information System (INIS)

    Lee, Y.-R.; Lei, H.-Y.; Liu, M.-T.; Wang, J.-R.; Chen, S.-H.; Jiang-Shieh, Y.-F.; Lin, Y.-S.; Yeh, T.-M.; Liu, C.-C.; Liu, H.-S.

    2008-01-01

    Autophagy is a cellular response against stresses which include the infection of viruses and bacteria. We unravel that Dengue virus-2 (DV2) can trigger autophagic process in various infected cell lines demonstrated by GFP-LC3 dot formation and increased LC3-II formation. Autophagosome formation was also observed under the transmission electron microscope. DV2-induced autophagy further enhances the titers of extracellular and intracellular viruses indicating that autophagy can promote viral replication in the infected cells. Moreover, our data show that ATG5 protein is required to execute DV2-induced autophagy. All together, we are the first to demonstrate that DV can activate autophagic machinery that is favorable for viral replication

  6. ROLE OF THE SEROLOGIC TEST FOR DENGUE VIRUS INFECTION

    Directory of Open Access Journals (Sweden)

    Ni Luh Sinta Purnama Dewi

    2013-07-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE Dengue virus infection is infection disease cause by dengue virus. Dengue virus infection can cause a broad spectrum disease such as : dengue fever (DF, dengue hemorrhagic fever (DHF, and dengue shock syndrome (DSS. Currently dengue virus ranks eighth as a cause of illness in the State of South-East Asia and Western Pacific. Epidemic dengue hemorrhagic fever (DHF occur each year in Indonesia with a tendency incident and the affected area is increasing. Laboratory tests can be done to detect the dengue virus infection: a complete blood count and serology. Of serology test, positive IgM antibody showed that patients had a primary infection, whereas patients with secondary infections showed positive IgG antibodies, usually accompanied by antibody IgM positive. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

  7. Comparative whole genome analysis of dengue virus serotype-2 strains differing in trans-endothelial cell leakage induction in vitro.

    Science.gov (United States)

    Singh, Sneha; Anupriya, M G; Sreekumar, Easwaran

    2017-08-01

    The role of genetic differences among dengue virus (DENV) in causing increased microvascular permeability is less explored. In the present study, we compared two closely related DENV serotype-2 strains of Cosmopolitan genotype for their in vitro infectivity phenotype and ability to induce trans-endothelial leakage. We found that these laboratory strains differed significantly in infecting human microvascular endothelial cells (HMEC-1) and hepatocytes (Huh7), two major target cells of DENV in in vivo infections. There was a reciprocal correlation in infectivity and vascular leakage induced by these strains, with the less infective strain inducing more trans-endothelial cell leakage in HMEC-1 monolayer upon infection. The cells infected with the strain capable of inducing more permeability were found to secrete more Non-Structural protein (sNS1) into the culture supernatant. A whole genome analysis revealed 37 predicted amino acid changes and changes in the secondary structure of 3' non-translated region between the strains. But none of these changes involved the signal sequence coded by the C-terminal of the Envelope protein and the two glycosylation sites within the NS1 protein critical for its secretion, and the N-terminal NS2A sequence important for surface targeting of NS1. The strain that secreted lower levels of NS1 and caused less leakage had two mutations within the NS1 protein coding region, F103S and T146I that significantly changed amino acid properties. A comparison of the sequences of the two strains with published sequences of various DENV strains known to cause clinically severe dengue identified a number of amino acid changes which could be implicated as possible key genetic differences. Our data supports the earlier observations that the vascular leakage induction potential of DENV strains is linked to the sNS1 levels. The results also indicate that viral genetic determinants, especially the mutations within the NS1 coding region, could affect this

  8. Honeysuckle aqueous extract and induced let-7a suppress dengue virus type 2 replication and pathogenesis.

    Science.gov (United States)

    Lee, Ying-Ray; Yeh, Siao-Fen; Ruan, Xiao-Ming; Zhang, Hao; Hsu, Sheng-Da; Huang, Hsien-Da; Hsieh, Chang-Chi; Lin, Yee-Shin; Yeh, Trai-Ming; Liu, Hsiao-Sheng; Gan, Dai-Di

    2017-02-23

    Honeysuckle (Lonicera japonica Thunb.), a traditional Chinese herb, has widely been used to treat pathogen infection. However, the underlying-mechanism remains elusive. To reveal the host microRNA (miRNA) profile with the anti-viral activity after honeysuckle treatment. Here we reveal the differentially expressed miRNAs by Solexa ® deep sequencing from the blood of human and mice after the aqueous extract treatment. Among these overexpressed innate miRNAs both in human and mice, let-7a is able to target the NS1 region (nt 3313-3330) of dengue virus (DENV) serotypes 1, 2 and 4 predicated by the target predication software. We confirmed that let-7a could target DENV2 at the predicated NS1 sequence and suppress DENV2 replication demonstrated by luciferase-reporter activity, RT-PCR, real-time PCR, Western blotting and plaque assay. ICR-suckling mice consumed honeysuckle aqueous extract either before or after intracranial injection with DENV2 showed decreased levels of NS1 RNA and protein expression accompanied with alleviated disease symptoms, decreased virus load, and prolonged survival time. Similar results were observed when DENV2-infected mice were intracranially injected with let-7a. We reveal that honeysuckle attenuates DENV replication and related pathogenesis in vivo through induction of let-7a expression. This study opens a new direction for prevention and treatment of DENV infection through induction of the innate miRNA let-7a by honeysuckle. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

  9. Prevention and Control Strategies to Counter Dengue Virus Infection

    Directory of Open Access Journals (Sweden)

    Irfan A. Rather

    2017-07-01

    Full Text Available Dengue is currently the highest and rapidly spreading vector-borne viral disease, which can lead to mortality in its severe form. The globally endemic dengue poses as a public health and economic challenge that has been attempted to suppress though application of various prevention and control techniques. Therefore, broad spectrum techniques, that are efficient, cost-effective, and environmentally sustainable, are proposed and practiced in dengue-endemic regions. The development of vaccines and immunotherapies have introduced a new dimension for effective dengue control and prevention. Thus, the present study focuses on the preventive and control strategies that are currently employed to counter dengue. While traditional control strategies bring temporary sustainability alone, implementation of novel biotechnological interventions, such as sterile insect technique, paratransgenesis, and production of genetically modified vectors, has improved the efficacy of the traditional strategies. Although a large-scale vector control strategy can be limited, innovative vaccine candidates have provided evidence for promising dengue prevention measures. The use of tetravalent dengue vaccine (CYD-TDV has been the most effective so far in treating dengue infections. Nonetheless, challenges and limitation hinder the progress of developing integrated intervention methods and vaccines; while the improvement in the latest techniques and vaccine formulation continues, one can hope for a future without the threat of dengue virus.

  10. Prevention and Control Strategies to Counter Dengue Virus Infection.

    Science.gov (United States)

    Rather, Irfan A; Parray, Hilal A; Lone, Jameel B; Paek, Woon K; Lim, Jeongheui; Bajpai, Vivek K; Park, Yong-Ha

    2017-01-01

    Dengue is currently the highest and rapidly spreading vector-borne viral disease, which can lead to mortality in its severe form. The globally endemic dengue poses as a public health and economic challenge that has been attempted to suppress though application of various prevention and control techniques. Therefore, broad spectrum techniques, that are efficient, cost-effective, and environmentally sustainable, are proposed and practiced in dengue-endemic regions. The development of vaccines and immunotherapies have introduced a new dimension for effective dengue control and prevention. Thus, the present study focuses on the preventive and control strategies that are currently employed to counter dengue. While traditional control strategies bring temporary sustainability alone, implementation of novel biotechnological interventions, such as sterile insect technique, paratransgenesis, and production of genetically modified vectors, has improved the efficacy of the traditional strategies. Although a large-scale vector control strategy can be limited, innovative vaccine candidates have provided evidence for promising dengue prevention measures. The use of tetravalent dengue vaccine (CYD-TDV) has been the most effective so far in treating dengue infections. Nonetheless, challenges and limitation hinder the progress of developing integrated intervention methods and vaccines; while the improvement in the latest techniques and vaccine formulation continues, one can hope for a future without the threat of dengue virus.

  11. A Pan-Dengue Virus Reverse Transcription-Insulated Isothermal PCR Assay Intended for Point-of-Need Diagnosis of Dengue Virus Infection by Use of the POCKIT Nucleic Acid Analyzer

    Science.gov (United States)

    Rajapakse, R. P. V. Jayanthe; Kularatne, Senanayake A. M.; Lee, Pei-Yu Alison; Ku, Keun Bon; Nam, Sangwoo; Chou, Pin-Hsing; Tsai, Yun-Long; Liu, Yu-Lun; Chang, Hsiao-Fen Grace; Wang, Hwa-Tang Thomas

    2016-01-01

    Dengue virus (DENV) infection is considered a major public health problem in developing tropical countries where the virus is endemic and continues to cause major disease outbreaks every year. Here, we describe the development of a novel, inexpensive, and user-friendly diagnostic assay based on a reverse transcription-insulated isothermal PCR (RT-iiPCR) method for the detection of all four serotypes of DENV in clinical samples. The diagnostic performance of the newly established pan-DENV RT-iiPCR assay targeting a conserved 3′ untranslated region of the viral genome was evaluated. The limit of detection with a 95% confidence was estimated to be 10 copies of in vitro-transcribed (IVT) RNA. Sensitivity analysis using RNA prepared from 10-fold serial dilutions of tissue culture fluid containing DENVs suggested that the RT-iiPCR assay was comparable to the multiplex real-time quantitative RT-PCR (qRT-PCR) assay for DENV-1, -3, and -4 detection but 10-fold less sensitive for DENV-2 detection. Subsequently, plasma collected from patients suspected of dengue virus infection (n = 220) and individuals not suspected of dengue virus infection (n = 45) were tested by the RT-iiPCR and compared to original test results using a DENV NS1 antigen rapid test and the qRT-PCR. The diagnostic agreement of the pan-DENV RT-iiPCR, NS1 antigen rapid test, and qRT-PCR tests was 93.9%, 84.5%, and 97.4%, respectively, compared to the composite reference results. This new RT-iiPCR assay along with the portable POCKIT nucleic acid analyzer could provide a highly reliable, sensitive, and specific point-of-need diagnostic assay for the diagnosis of DENV in clinics and hospitals in developing countries. PMID:27030492

  12. A Pan-Dengue Virus Reverse Transcription-Insulated Isothermal PCR Assay Intended for Point-of-Need Diagnosis of Dengue Virus Infection by Use of the POCKIT Nucleic Acid Analyzer.

    Science.gov (United States)

    Go, Yun Young; Rajapakse, R P V Jayanthe; Kularatne, Senanayake A M; Lee, Pei-Yu Alison; Ku, Keun Bon; Nam, Sangwoo; Chou, Pin-Hsing; Tsai, Yun-Long; Liu, Yu-Lun; Chang, Hsiao-Fen Grace; Wang, Hwa-Tang Thomas; Balasuriya, Udeni B R

    2016-06-01

    Dengue virus (DENV) infection is considered a major public health problem in developing tropical countries where the virus is endemic and continues to cause major disease outbreaks every year. Here, we describe the development of a novel, inexpensive, and user-friendly diagnostic assay based on a reverse transcription-insulated isothermal PCR (RT-iiPCR) method for the detection of all four serotypes of DENV in clinical samples. The diagnostic performance of the newly established pan-DENV RT-iiPCR assay targeting a conserved 3' untranslated region of the viral genome was evaluated. The limit of detection with a 95% confidence was estimated to be 10 copies of in vitro-transcribed (IVT) RNA. Sensitivity analysis using RNA prepared from 10-fold serial dilutions of tissue culture fluid containing DENVs suggested that the RT-iiPCR assay was comparable to the multiplex real-time quantitative RT-PCR (qRT-PCR) assay for DENV-1, -3, and -4 detection but 10-fold less sensitive for DENV-2 detection. Subsequently, plasma collected from patients suspected of dengue virus infection (n = 220) and individuals not suspected of dengue virus infection (n = 45) were tested by the RT-iiPCR and compared to original test results using a DENV NS1 antigen rapid test and the qRT-PCR. The diagnostic agreement of the pan-DENV RT-iiPCR, NS1 antigen rapid test, and qRT-PCR tests was 93.9%, 84.5%, and 97.4%, respectively, compared to the composite reference results. This new RT-iiPCR assay along with the portable POCKIT nucleic acid analyzer could provide a highly reliable, sensitive, and specific point-of-need diagnostic assay for the diagnosis of DENV in clinics and hospitals in developing countries. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  13. Broad neutralization of wild-type dengue virus isolates following immunization in monkeys with a tetravalent dengue vaccine based on chimeric yellow fever 17D/dengue viruses.

    Science.gov (United States)

    Barban, Veronique; Munoz-Jordan, Jorge L; Santiago, Gilberto A; Mantel, Nathalie; Girerd, Yves; Gulia, Sandrine; Claude, Jean-Baptiste; Lang, Jean

    2012-08-01

    The objective of the study was to evaluate if the antibodies elicited after immunization with a tetravalent dengue vaccine, based on chimeric yellow fever 17D/dengue viruses, can neutralize a large range of dengue viruses (DENV). A panel of 82 DENVs was developed from viruses collected primarily during the last decade in 30 countries and included the four serotypes and the majority of existing genotypes. Viruses were isolated and minimally amplified before evaluation against a tetravalent polyclonal serum generated during vaccine preclinical evaluation in monkey, a model in which protection efficacy of this vaccine has been previously demonstrated (Guirakhoo et al., 2004). Neutralization was observed across all the DENV serotypes, genotypes, geographical origins and isolation years. These data indicate that antibodies elicited after immunization with this dengue vaccine candidate should widely protect against infection with contemporary DENV lineages circulating in endemic countries. Copyright © 2012 Elsevier Inc. All rights reserved.

  14. System Analysis of Dengue Virus Surveillance in BBTKL PP Surabaya Year 2012–2014

    OpenAIRE

    Atina Husnayain; Kurnia Dwi Artanti; Acub Zaenal

    2015-01-01

    Changing the distribution of dengue virus serotypes has occurred in Indonesia. This condition should be monitored continuously through the Dengue Virus Surveillance. Implementation of Dengue Virus Surveillance also conducted by BBTKL PP Surabaya. The purpose of this study was to determine the workflow, identify problems, set priority problem, find the cause of the problem, and provide the alternative solution related to problems of Dengue Virus Surveillance in BBTKL PP Surabaya. This is a ope...

  15. Understanding the Dengue Viruses and Progress towards Their Control

    Science.gov (United States)

    Gould, Ernest A.

    2013-01-01

    Traditionally, the four dengue virus serotypes have been associated with fever, rash, and the more severe forms, haemorrhagic fever and shock syndrome. As our knowledge as well as understanding of these viruses increases, we now recognise not only that they are causing increasing numbers of human infections but also that they may cause neurological and other clinical complications, with sequelae or fatal consequences. In this review we attempt to highlight some of these features in the context of dengue virus pathogenesis. We also examine some of the efforts currently underway to control this “scourge” of the tropical and subtropical world. PMID:23936833

  16. Nine year trends of dengue virus infection in Mumbai, Western India

    OpenAIRE

    Shastri, Jayanthi; Williamson, Manita; Vaidya, Nilima; Agrawal, Sachee; Shrivastav, Om

    2017-01-01

    Introduction: Dengue virus (DENV) causes a wide range of diseases in humans, from acute febrile illness Dengue fever (DF) to life-threatening Dengue hemorrhagic fever (DHF) or Dengue shock syndrome (DSS). Factors believed to be responsible for spread of Dengue virus infection include explosive population growth, unplanned urban overpopulation with inadequate public health systems, poor standing water and vector control, climate changes and increased international recreational, business, milit...

  17. Gamma interferon augments Fc gamma receptor-mediated dengue virus infection of human monocytic cells.

    OpenAIRE

    Kontny, U; Kurane, I; Ennis, F A

    1988-01-01

    It has been reported that anti-dengue antibodies at subneutralizing concentrations augment dengue virus infection of monocytic cells. This is due to the increased uptake of dengue virus in the form of virus-antibody complexes by cells via Fc gamma receptors. We analyzed the effects of recombinant human gamma interferon (rIFN-gamma) on dengue virus infection of human monocytic cells. U937 cells, a human monocytic cell line, were infected with dengue virus in the form of virus-antibody complexe...

  18. Co-infections with Chikungunya and Dengue Viruses, Guatemala, 2015.

    Science.gov (United States)

    Edwards, Thomas; Signor, Leticia Del Carmen Castillo; Williams, Christopher; Donis, Evelin; Cuevas, Luis E; Adams, Emily R

    2016-11-01

    We screened serum samples referred to the national reference laboratory in Guatemala that were positive for chikungunya or dengue viruses in June 2015. Co-infection with both viruses was detected by reverse transcription PCR in 46 (32%) of 144 samples. Specimens should be tested for both arboviruses to detect co-infections.

  19. Interferon-γ-induced protein 10 in Dengue Virus infection.

    Science.gov (United States)

    Fallahi, P; Elia, G

    2016-01-01

    Dengue virus (DENV) infection causes dengue fever, dengue hemorrhagic fever, or dengue shock syndrome. Interferons (IFNs), and IFN-γ dependent chemokines, chemokine (C-X-C motif) ligand (CXCL)10/IFN-γ-induced protein 10 (IP-10), CXCL9/MIG and CXCL11/I-TAC, and their common receptor chemokine (C-X-C motif) receptor (CXCR)3 are induced by DENV infection; however it has been shown that the latter two could not compensate for the absence of IP-10. This paper reviews studies about DENV and IP-10. Evidences show the importance of IP-10 induction during DENV infection, in macrophages, lymphocytes, hepatic cells, denritic cells, in skin and in the brain. Furthermore it has been shown that chemokines IP-10, I-TAC and their receptor CXCR3 are involved in severity of dengue; in fact, pulmonary effusion or ascites, painful hepatomegaly or aspartate aminotransferase increase, are correlated with IP-10 levels. It has been also demonstrated that IP-10 was more elevated in subjects who subsequently developed dengue hemorrhagic fever or dengue shock syndrome. It has been also shown that IP-10 has a direct action in control of dengue viral replication. Furthermore IP-10 circulating levels may be used to discriminate dengue fever from other febbrile diseases. This is of particular importance in certain situations, for example to discriminate occupationally acquired dengue, in patients with febbrile disorders coming from endemic countries. These studies suggested that these chemokines can be used as potential biomarkers for differential diagnosis and the disease progression, while others can be used to control dengue viral replication, thus representing a viable targets for drug therapy.

  20. Proteomic analysis reveals the enhancement of human serum apolipoprotein A-1(APO A-1) in individuals infected with multiple dengue virus serotypes.

    Science.gov (United States)

    Manchala, Nageswar Reddy; Dungdung, Ranjeet; Pilankatta, Rajendra

    2017-10-01

    Human serum protein profiling of the individual infected with multiple dengue virus serotypes for identifying the potential biomarkers and to investigate the cause for the severity of dengue virus infection. Dengue virus NS1-positive serum samples were pooled into two groups (S2 and S3) based on the molecular serotyping and number of heterotypic infections. The pooled serum samples were subjected to two-dimensional gel electrophoresis (2DGE) to identify the differentially expressed proteins. The peptide masses of upregulated protein were detected by matrix-assisted laser desorption-ionisation time-of-flight MALDI-TOF mass spectrometry and analysed by MASCOT search engine. The results were compared with the control group (S1). The commonly upregulated protein was validated by quantitative ELISA and compared with control as well as single serotypic infected samples. Based on 2DGE, total thirteen proteins were differentially upregulated in S2 and S3 groups as compared to control. Some of the upregulated proteins were involved in mediating the complement activation of immune response. The apolipoprotein A-1 (APO A-1) was upregulated in S2 and S3 groups. Upon validation, APO A-1 levels were increased in line with the number of heterotypic infection of dengue viruses. Heterotypic infection of dengue viruses upregulate the serum proteins involved in the complement pathway in the early phase of infection. There was a significant increase in the level of APO A-1 in three different serotypic infections of dengue virus as compared to control. Further, the role of APO-A1 can be explored in elucidating the mechanism of dengue pathogenesis. © 2017 John Wiley & Sons Ltd.

  1. Introducing dengue vaccine: Implications for diagnosis in dengue vaccinated subjects.

    Science.gov (United States)

    Alagarasu, Kalichamy

    2016-05-27

    Diagnosis of dengue virus infections is complicated by preference for different diagnostic tests in different post onset days of illness and the presence of multiple serotypes leading to secondary and tertiary infections. The sensitivity of the most commonly employed diagnostic assays such as anti dengue IgM capture (MAC) ELISA and non structural protein (NS) 1 capture ELISA are lower in secondary and subsequent infections. Introduction of dengue vaccine in endemic regions will affect the way how dengue is diagnosed in vaccinated subjects. This viewpoint article discusses implications of introduction of dengue vaccine on the diagnosis of dengue infections in vaccinated subjects and the strategies that are needed to tackle the issue. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Analysis of the dengue disease model with two virus strains

    Science.gov (United States)

    Adi-Kusumo, F.; Aini, A. N.; Ridwan, M.

    2014-02-01

    Dengue fever (DF) and dengue haemorrhagic fever (DHF) are the disease caused by the dengue virus which is transmitted to the human by infected female mosquitoes. The disease is endemic in more than 100 countries over the world. Dengue virus has four distinct serotypes which are closely related to each other antigenically. A person who infected by the dengue virus will never be infected again by the same serotype, but he looses immunity from the three other serotypes. Infection with one serotype does not provide cross-protective immunity against to others. Here we assume that there are two serotypes exist in the population. Someone who has recovered from one serotype become susceptible to the other serotype and can be reinfected. In this paper we analyze the model of dengue fever with two infections from the different serotype by linear analysis. Then we study the effect of vaccination to the model. In numerical simulation, we use Runge-Kutta order 4 to integrate the solution of the system.

  3. Clinical and Laboratory Diagnosis of Dengue Virus Infection.

    Science.gov (United States)

    Muller, David A; Depelsenaire, Alexandra C I; Young, Paul R

    2017-03-01

    Infection with any of the 4 dengue virus serotypes results in a diverse range of symptoms, from mild undifferentiated fever to life-threatening hemorrhagic fever and shock. Given that dengue virus infection elicits such a broad range of clinical symptoms, early and accurate laboratory diagnosis is essential for appropriate patient management. Virus detection and serological conversion have been the main targets of diagnostic assessment for many years, however cross-reactivity of antibody responses among the flaviviruses has been a confounding issue in providing a differential diagnosis. Furthermore, there is no single, definitive diagnostic biomarker that is present across the entire period of patient presentation, particularly in those experiencing a secondary dengue infection. Nevertheless, the development and commercialization of point-of-care combination tests capable of detecting markers of infection present during different stages of infection (viral nonstructural protein 1 and immunoglobulin M) has greatly simplified laboratory-based dengue diagnosis. Despite these advances, significant challenges remain in the clinical management of dengue-infected patients, especially in the absence of reliable biomarkers that provide an effective prognostic indicator of severe disease progression. This review briefly summarizes some of the complexities and issues surrounding clinical dengue diagnosis and the laboratory diagnostic options currently available. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

  4. The Aedes aegypti toll pathway controls dengue virus infection.

    Directory of Open Access Journals (Sweden)

    Zhiyong Xi

    2008-07-01

    Full Text Available Aedes aegypti, the mosquito vector of dengue viruses, utilizes its innate immune system to ward off a variety of pathogens, some of which can cause disease in humans. To date, the features of insects' innate immune defenses against viruses have mainly been studied in the fruit fly Drosophila melanogaster, which appears to utilize different immune pathways against different types of viruses, in addition to an RNA interference-based defense system. We have used the recently released whole-genome sequence of the Ae. aegypti mosquito, in combination with high-throughput gene expression and RNA interference (RNAi-based reverse genetic analyses, to characterize its response to dengue virus infection in different body compartments. We have further addressed the impact of the mosquito's endogenous microbial flora on virus infection. Our findings indicate a significant role for the Toll pathway in regulating resistance to dengue virus, as indicated by an infection-responsive regulation and functional assessment of several Toll pathway-associated genes. We have also shown that the mosquito's natural microbiota play a role in modulating the dengue virus infection, possibly through basal-level stimulation of the Toll immune pathway.

  5. Genetic susceptibility to West Nile virus and dengue.

    Science.gov (United States)

    Loeb, M

    2013-01-01

    This article focuses on the host genetic predisposition to 2 viruses, West Nile virus and dengue virus, which belong to the genus Flavivirus. Although by definition these viruses have shared characteristics (e.g. similar size, single stranded, RNA viruses, both transmitted by the bite from an infected mosquito), they differ greatly in epidemiology and clinical manifestations. The text below not only summarizes the genetic factors that predispose to complications of these 2 important flaviviruses, but also illustrates the challenges in determining the genomic basis for complications to these viruses. Copyright © 2013 S. Karger AG, Basel.

  6. Dengue Virus in Bats from Southeastern Mexico

    Science.gov (United States)

    Sotomayor-Bonilla, Jesús; Chaves, Andrea; Rico-Chávez, Oscar; Rostal, Melinda K.; Ojeda-Flores, Rafael; Salas-Rojas, Mónica; Aguilar-Setien, Álvaro; Ibáñez-Bernal, Sergio; Barbachano-Guerrero, Arturo; Gutiérrez-Espeleta, Gustavo; Aguilar-Faisal, J. Leopoldo; Aguirre, A. Alonso; Daszak, Peter; Suzán, Gerardo

    2014-01-01

    To identify the relationship between landscape use and dengue virus (DENV) occurrence in bats, we investigated the presence of DENV from anthropogenically changed and unaltered landscapes in two Biosphere Reserves: Calakmul (Campeche) and Montes Azules (Chiapas) in southern Mexico. Spleen samples of 146 bats, belonging to 16 species, were tested for four DENV serotypes with standard reverse transcriptase polymerase chain reaction (RT-PCR) protocols. Six bats (4.1%) tested positive for DENV-2: four bats in Calakmul (two Glossophaga soricina, one Artibeus jamaicensis, and one A. lituratus) and two bats in Montes Azules (both A. lituratus). No effect of anthropogenic disturbance on the occurrence of DENV was detected; however, all three RT-PCR–positive bat species are considered abundant species in the Neotropics and well-adapted to disturbed habitats. To our knowledge, this study is the first study conducted in southeastern Mexico to identify DENV-2 in bats by a widely accepted RT-PCR protocol. The role that bats play on DENV's ecology remains undetermined. PMID:24752688

  7. Construction of dengue virus protease expression plasmid and in vitro protease assay for screening antiviral inhibitors.

    Science.gov (United States)

    Lai, Huiguo; Teramoto, Tadahisa; Padmanabhan, Radhakrishnan

    2014-01-01

    Dengue virus serotypes 1-4 (DENV1-4) are mosquito-borne human pathogens of global significance causing ~390 million cases annually worldwide. The virus infections cause in general a self-limiting disease, known as dengue fever, but occasionally also more severe forms, especially during secondary infections, dengue hemorrhagic fever and dengue shock syndrome causing ~25,000 deaths annually. The DENV genome contains a single-strand positive sense RNA, approximately 11 kb in length. The 5'-end has a type I cap structure. The 3'-end has no poly(A) tail. The viral RNA has a single long open reading frame that is translated by the host translational machinery to yield a polyprotein precursor. Processing of the polyprotein precursor occurs co-translationally by cellular proteases and posttranslationally by the viral serine protease in the endoplasmic reticulum (ER) to yield three structural proteins (capsid (C), precursor membrane (prM), and envelope (E) and seven nonstructural (NS) proteins (NS1, NS2A, NS2B, NS3, NS4A, NS4B, and NS5). The active viral protease consists of both NS2B, an integral membrane protein in the ER, and the N-terminal part of NS3 (180 amino acid residues) that contains the trypsin-like serine protease domain having a catalytic triad of H51, D75, and S135. The C-terminal part of NS3, ~170-618 amino acid residues, encodes an NTPase/RNA helicase and 5'-RNA triphosphatase activities; the latter enzyme is required for the first step in 5'-capping. The cleavage sites of the polyprotein by the viral protease consist of two basic amino acid residues such as KR, RR, or QR, followed by short chain amino acid residues, G, S, or T. Since the cleavage of the polyprotein by the viral protease is absolutely required for assembly of the viral replicase, blockage of NS2B/NS3pro activity provides an effective means for designing dengue virus (DENV) small-molecule therapeutics. Here we describe the screening of small-molecule inhibitors against DENV2 protease.

  8. Improving Dengue Virus Capture Rates in Humans and Vectors in Kamphaeng Phet Province, Thailand, Using an Enhanced Spatiotemporal Surveillance Strategy

    Science.gov (United States)

    2015-05-18

    THOMAS AND OTHERS ENHANCED SURVEILLANCE FOR DENGUE Improving Dengue Virus Capture Rates in Humans and Vectors in Kamphaeng Phet Province...of Medical Sciences, Bangkok, Thailand. Abstract. Dengue is of public health importance in tropical and sub-tropical regions. Dengue virus (DENV...with confirmed dengue (initiates) and associated cluster individuals (associates) with entomologic sampling. A total of 438 associates were enrolled

  9. Dengue Virus Structural Differences That Correlate with Pathogenesis

    Science.gov (United States)

    Leitmeyer, Katrin C.; Vaughn, David W.; Watts, Douglas M.; Salas, Rosalba; Villalobos , Iris; de Chacon; Ramos, Celso; Rico-Hesse, Rebeca

    1999-01-01

    The understanding of dengue virus pathogenesis has been hampered by the lack of in vitro and in vivo models of disease. The study of viral factors involved in the production of severe dengue, dengue hemorrhagic fever (DHF), versus the more common dengue fever (DF), have been limited to indirect clinical and epidemiologic associations. In an effort to identify viral determinants of DHF, we have developed a method for comparing dengue type 2 genomes (reverse transcriptase PCR in six fragments) directly from patient plasma. Samples for comparison were selected from two previously described dengue type 2 genotypes which had been shown to be the cause of DF or DHF. When full genome sequences of 11 dengue viruses were analyzed, several structural differences were seen consistently between those associated with DF only and those with the potential to cause DHF: a total of six encoded amino acid charge differences were seen in the prM, E, NS4b, and NS5 genes, while sequence differences observed within the 5′ nontranslated region (NTR) and 3′ NTR were predicted to change RNA secondary structures. We hypothesize that the primary determinants of DHF reside in (i) amino acid 390 of the E protein, which purportedly alters virion binding to host cells; (ii) in the downstream loop (nucleotides 68 to 80) of the 5′ NTR, which may be involved in translation initiation; and (iii) in the upstream 300 nucleotides of the 3′ NTR, which may regulate viral replication via the formation of replicative intermediates. The significance of four amino acid differences in the nonstructural proteins NS4b and NS5, a presumed transport protein and the viral RNA polymerase, respectively, remains unknown. This new approach to the study of dengue virus genome differences should better reflect the true composition of viral RNA populations in the natural host and permit their association with pathogenesis. PMID:10233934

  10. Virus variation resources at the National Center for Biotechnology Information: dengue virus

    Directory of Open Access Journals (Sweden)

    Rozanov Michael

    2009-04-01

    Full Text Available Abstract Background There is an increasing number of complete and incomplete virus genome sequences available in public databases. This large body of sequence data harbors information about epidemiology, phylogeny, and virulence. Several specialized databases, such as the NCBI Influenza Virus Resource or the Los Alamos HIV database, offer sophisticated query interfaces along with integrated exploratory data analysis tools for individual virus species to facilitate extracting this information. Thus far, there has not been a comprehensive database for dengue virus, a significant public health threat. Results We have created an integrated web resource for dengue virus. The technology developed for the NCBI Influenza Virus Resource has been extended to process non-segmented dengue virus genomes. In order to allow efficient processing of the dengue genome, which is large in comparison with individual influenza segments, we developed an offline pre-alignment procedure which generates a multiple sequence alignment of all dengue sequences. The pre-calculated alignment is then used to rapidly create alignments of sequence subsets in response to user queries. This improvement in technology will also facilitate the incorporation of additional virus species in the future. The set of virus-specific databases at NCBI, which will be referred to as Virus Variation Resources (VVR, allow users to build complex queries against virus-specific databases and then apply exploratory data analysis tools to the results. The metadata is automatically collected where possible, and extended with data extracted from the literature. Conclusion The NCBI Dengue Virus Resource integrates dengue sequence information with relevant metadata (sample collection time and location, disease severity, serotype, sequenced genome region and facilitates retrieval and preliminary analysis of dengue sequences using integrated web analysis and visualization tools.

  11. MAIT cells are activated in acute Dengue virus infection and after in vitro Zika virus infection

    OpenAIRE

    Paquin-Proulx, Dominic; Avelino-Silva, Vivian I.; Santos, Bianca A. N.; Silveira Barsotti, Nathália; Siroma, Fabiana; Fernandes Ramos, Jessica; Coracini Tonacio, Adriana; Song, Alice; Maestri, Alvino; Barros Cerqueira, Natalia; Felix, Alvina Clara; Levi, José Eduardo; Greenspun, Benjamin C.; de Mulder Rougvie, Miguel; Rosenberg, Michael G.

    2018-01-01

    Dengue virus (DENV) and Zika virus (ZIKV) are members of the Flaviviridae and are predominantly transmitted via mosquito bites. Both viruses are responsible for a growing number of infections in tropical and subtropical regions. DENV infection can cause lethargy with severe morbidity and dengue shock syndrome leading to death in some cases. ZIKV is now linked with Guillain-Barré syndrome and fetal malformations including microcephaly and developmental disorders (congenital Zika syndrome). The...

  12. MAIT cells are activated in acute Dengue virus infection and after in vitro Zika virus infection.

    OpenAIRE

    Dominic Paquin-Proulx; Vivian I Avelino-Silva; Bianca A N Santos; Nathália Silveira Barsotti; Fabiana Siroma; Jessica Fernandes Ramos; Adriana Coracini Tonacio; Alice Song; Alvino Maestri; Natalia Barros Cerqueira; Alvina Clara Felix; José Eduardo Levi; Benjamin C Greenspun; Miguel de Mulder Rougvie; Michael G Rosenberg

    2018-01-01

    Dengue virus (DENV) and Zika virus (ZIKV) are members of the Flaviviridae and are predominantly transmitted via mosquito bites. Both viruses are responsible for a growing number of infections in tropical and subtropical regions. DENV infection can cause lethargy with severe morbidity and dengue shock syndrome leading to death in some cases. ZIKV is now linked with Guillain-Barré syndrome and fetal malformations including microcephaly and developmental disorders (congenital Zika syndrome). The...

  13. Properties and Functions of the Dengue Virus Capsid Protein.

    Science.gov (United States)

    Byk, Laura A; Gamarnik, Andrea V

    2016-09-29

    Dengue virus affects hundreds of millions of people each year around the world, causing a tremendous social and economic impact on affected countries. The aim of this review is to summarize our current knowledge of the functions, structure, and interactions of the viral capsid protein. The primary role of capsid is to package the viral genome. There are two processes linked to this function: the recruitment of the viral RNA during assembly and the release of the genome during infection. Although particle assembly takes place on endoplasmic reticulum membranes, capsid localizes in nucleoli and lipid droplets. Why capsid accumulates in these locations during infection remains unknown. In this review, we describe available data and discuss new ideas on dengue virus capsid functions and interactions. We believe that a deeper understanding of how the capsid protein works during infection will create opportunities for novel antiviral strategies, which are urgently needed to control dengue virus infections.

  14. Competitive inhibitor of cellular alpha-glucosidases protects mice from lethal dengue virus infection

    OpenAIRE

    Chang, Jinhong; Schul, Wouter; Yip, Andy; Xu, Xiaodong; Guo, Ju-Tao; Block, Timothy M.

    2011-01-01

    Dengue virus infection causes diseases in people, ranging from the acute febrile illness Dengue fever, to life-threatening Dengue Hemorrhagic Fever/Dengue Shock Syndrome. We previously reported that a host cellular α-glucosidases I and II inhibitor, imino sugar CM-10-18, potently inhibited dengue virus replication in cultured cells, and significantly reduced viremia in dengue virus infected AG129 mice. In this report we show that CM-10-18 also significantly protects mice from death and/or dis...

  15. New genotype of dengue type 3 virus circulating in Brazil and Colombia showed a close relationship to old Asian viruses.

    Science.gov (United States)

    Aquino, Victor Hugo; Amarilla, Alberto Anastacio; Alfonso, Helda Liz; Batista, Weber Cheli; Figueiredo, Luiz Tadeu Moraes

    2009-10-13

    Dengue type 3 genotype V viruses have been recently detected in Brazil and Colombia. In this study, we described another Brazilian isolate belonging to this genotype. Phylogenetic analysis including dengue type 3 viruses isolated worldwide showed that Brazilian and Colombian viruses were closely related to viruses isolated in Asia more than two decades ago. The characteristic evolutionary pattern of dengue type 3 virus cannot explain the close similarity of new circulating viruses with old viruses. Further studies are needed to confirm the origin of the new dengue type III genotype circulating in Brazil and Colombia.

  16. Release of Dengue Virus Genome Induced by a Peptide Inhibitor

    Science.gov (United States)

    Hrobowski, Yancey M.; Hoffmann, Andrew R.; Rowe, Dawne K.; Kukkaro, Petra; Holdaway, Heather; Chipman, Paul; Fontaine, Krystal A.; Holbrook, Michael R.; Garry, Robert F.; Kostyuchenko, Victor; Wimley, William C.; Isern, Sharon; Rossmann, Michael G.; Michael, Scott F.

    2012-01-01

    Dengue virus infects approximately 100 million people annually, but there is no available therapeutic treatment. The mimetic peptide, DN59, consists of residues corresponding to the membrane interacting, amphipathic stem region of the dengue virus envelope (E) glycoprotein. This peptide is inhibitory to all four serotypes of dengue virus, as well as other flaviviruses. Cryo-electron microscopy image reconstruction of dengue virus particles incubated with DN59 showed that the virus particles were largely empty, concurrent with the formation of holes at the five-fold vertices. The release of RNA from the viral particle following incubation with DN59 was confirmed by increased sensitivity of the RNA genome to exogenous RNase and separation of the genome from the E protein in a tartrate density gradient. DN59 interacted strongly with synthetic lipid vesicles and caused membrane disruptions, but was found to be non-toxic to mammalian and insect cells. Thus DN59 inhibits flavivirus infectivity by interacting directly with virus particles resulting in release of the genomic RNA. PMID:23226444

  17. Endothelial Cells Elicit Immune-Enhancing Responses to Dengue Virus Infection

    Science.gov (United States)

    Dalrymple, Nadine A.

    2012-01-01

    Dengue viruses cause two severe diseases that alter vascular fluid barrier functions, dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). Preexisting antibodies to dengue virus disposes patients to immune-enhanced edema (DSS) or hemorrhagic (DHF) disease following infection by a discrete dengue virus serotype. Although the endothelium is the primary vascular fluid barrier, direct effects of dengue virus on endothelial cells (ECs) have not been considered primary factors in pathogenesis. Here, we show that dengue virus infection of human ECs elicits immune-enhancing EC responses. Our results suggest that rapid early dengue virus proliferation within ECs is permitted by dengue virus regulation of early, but not late, beta interferon (IFN-β) responses. The analysis of EC responses following synchronous dengue virus infection revealed the high-level induction and secretion of immune cells (T cells, B cells, and mast cells) as well as activating and recruiting cytokines BAFF (119-fold), IL-6/8 (4- to 7-fold), CXCL9/10/11 (45- to 338-fold), RANTES (724-fold), and interleukin-7 (IL-7; 128-fold). Moreover, we found that properdin factor B, an alternative pathway complement activator that directs chemotactic anaphylatoxin C3a and C5a production, was induced 34-fold. Thus, dengue virus-infected ECs evoke key inflammatory responses observed in dengue virus patients which are linked to DHF and DSS. Our findings suggest that dengue virus-infected ECs directly contribute to immune enhancement, capillary permeability, viremia, and immune targeting of the endothelium. These data implicate EC responses in dengue virus pathogenesis and further rationalize therapeutic targeting of the endothelium as a means of reducing the severity of dengue virus disease. PMID:22496214

  18. Development of Dengue virus type 2 replicons capable of prolonged expression in host cells

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    Dayton Andrew I

    2001-08-01

    Full Text Available Abstract Background As part of a program to develop a Dengue virus vaccine which avoids the deleterious effects of antibody dependent enhancement (ADE of infection mediated by antibodies to Dengue virus structural proteins, we have begun to investigate the possibility of designing Dengue vaccines based on non-structural proteins. Results Dengue constructs which lack major structural proteins replicate intracellularly in tissue culture. These replicons are capable of prolonged expression of Dengue virus non-structural proteins for at least seven days in culture. Conclusions Dengue virus genomes lacking major structural proteins can, like other flaviviruses, replicate intracellularly and express virus non-structural proteins with minimal toxicity to host cells. These findings pave the way for the development of dengue virus replicons as a form of live, attenuated virus vaccine.

  19. Asian genotypes of dengue virus 4 in Brazil.

    Science.gov (United States)

    Pinho, A C O; Sardi, S I; Paula, F L; Peixoto, I B; Brandão, C J; Fernandez, F M C; Campos, G S

    2015-10-01

    Dengue virus, commonly transmitted by mosquitoes, causes a human disease of significant social impact and presents a serious public health problem in Brazil. This report describes the unusual emergence of DENV-4 in northern Brazil after a nearly 30-year-long absence. DENV-4 genotype I is of Asian origin and was identified in the serum of patients receiving treatment at a hospital serving the Salvador area (Brazilian state of Bahia). The identification of dengue virus serotypes through molecular and phylogenetic analysis is essential for predicting disease severity or fatal illness, principally in endemic countries such as Brazil.

  20. Honokiol, a Lignan Biphenol Derived from the Magnolia Tree, Inhibits Dengue Virus Type 2 Infection

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    Chih-Yeu Fang

    2015-09-01

    Full Text Available Dengue is the most widespread arbovirus infection and poses a serious health and economic issue in tropical and subtropical countries. Currently no licensed vaccine or compounds can be used to prevent or manage the severity of dengue virus (DENV infection. Honokiol, a lignan biphenol derived from the Magnolia tree, is commonly used in Eastern medicine. Here we report that honokiol has profound antiviral activity against serotype 2 DENV (DENV-2. In addition to inhibiting the intracellular DENV-2 replicon, honokiol was shown to suppress the replication of DENV-2 in baby hamster kidney (BHK and human hepatocarcinoma Huh7 cells. At the maximum non-toxic dose of honokiol treatment, the production of infectious DENV particles was reduced >90% in BHK and Huh7 cells. The underlying mechanisms revealed that the expression of DENV-2 nonstructural protein NS1/NS3 and its replicating intermediate, double-strand RNA, was dramatically reduced by honokiol treatment. Honokiol has no effect on the expression of DENV putative receptors, but may interfere with the endocytosis of DENV-2 by abrogating the co-localization of DENV envelope glycoprotein and the early endosomes. These results indicate that honokiol inhibits the replication, viral gene expression, and endocytotic process of DENV-2, making it a promising agent for chemotherapy of DENV infection.

  1. Electrical Detection of Dengue Biomarker Using Egg Yolk Immunoglobulin as the Biological Recognition Element

    Science.gov (United States)

    Figueiredo, Alessandra; Vieira, Nirton C. S.; Dos Santos, Juliana F.; Janegitz, Bruno C.; Aoki, Sergio M.; Junior, Paulo P.; Lovato, Rodrigo L.; Nogueira, Maurício L.; Zucolotto, Valtencir; Guimarães, Francisco E. G.

    2015-01-01

    Nonstructural protein 1 (NS1) is secreted by dengue virus in the first days of infection and acts as an excellent dengue biomarker. Here, the direct electrical detection of NS1 from dengue type 2 virus has been achieved by the measurement of variations in open circuit potential (OCP) between a reference electrode and a disposable Au electrode containing immobilized anti-NS1 antibodies acting as immunosensor. Egg yolk immunoglobulin (IgY) was utilized for the first time as the biological recognition element alternatively to conventional mammalian antibodies in the detection of dengue virus NS1 protein. NS1 protein was detected in standard samples in a 0.1 to 10 µg.mL-1 concentration range with (3.2 +/- 0.3) mV/µg.mL-1 of sensitivity and 0.09 µg.mL-1 of detection limit. Therefore, the proposed system can be extended to detect NS1 in real samples and provide an early diagnosis of dengue.

  2. A simple, inexpensive, robust and sensitive dot-blot assay for equal detection of the nonstructural-1 glycoprotein of all dengue virus serotypes.

    Science.gov (United States)

    Falconar, Andrew K I; Romero-Vivas, Claudia M E

    2013-04-22

    Detection of dengue virus (DENV) soluble/excreted (s/e) form of the nonstructural-1 (NS1) glycoprotein in patient acute-phase sera is ideal for diagnosis. The commercially-available detection assays are, however, too expensive for routine use and have low specificity, particularly for the s/e NS1 glycoprotein of DENV-2 and DENV-4, which are important causes of lethal human disease worldwide. Mouse monoclonal antibodies (MAbs) were generated and screened against s/e NS1 glycoprotein purified from each DENV serotype to obtain those that reacted equally with each serotype, but not with yellow fever virus (YFV) s/e NS1 glycoprotein or human serum proteins. One MAb, MAb 2C4.6, was further tested against these DENV glycoproteins in human sera using simple, peroxidase-labelled secondary antibody/substrate-developed dot-blot assays. Optimal quenching of endogenous human serum peroxidases was attained using 3% H(2)O(2) in H(2)0 for 5 min. MAb 2C4.6 showed an acceptable detection sensitivity of simple, inexpensive (US$ 0.05/sample), robust, sensitive and relatively rapid assays, using improved MAbs such as MAb 2C4.6, should be ideal for the diagnosis of all DENV serotypes in DENV endemic regions.

  3. Co-circulation of Dengue and Chikungunya Viruses, Al Hudaydah, Yemen, 2012.

    Science.gov (United States)

    Rezza, Giovanni; El-Sawaf, Gamal; Faggioni, Giovanni; Vescio, Fenicia; Al Ameri, Ranya; De Santis, Riccardo; Helaly, Ghada; Pomponi, Alice; Metwally, Dalia; Fantini, Massimo; Qadi, Hussein; Ciccozzi, Massimo; Lista, Florigio

    2014-08-01

    We investigated 400 cases of dengue-like illness in persons hospitalized during an outbreak in Al Hudaydah, Yemen, in 2012. Overall, 116 dengue and 49 chikungunya cases were diagnosed. Dengue virus type 2 was the predominant serotype. The co-circulation of these viruses indicates that mosquitoborne infections represent a public health threat in Yemen.

  4. T cell immunity to infection with dengue virus in humans

    Directory of Open Access Journals (Sweden)

    Daniela eWeiskopf

    2014-03-01

    Full Text Available Dengue virus (DENV is the etiologic agent of dengue fever, the most significant mosquito-borne viral disease in humans. Up to 400 million DENV infections occur every year, and severity can range from asymptomatic to an acute self-limiting febrile illness. In a small proportion of patients, the disease can exacerbate and progress to dengue hemorrhagic fever (DHF and/or dengue shock syndrome (DSS, characterized by severe vascular leakage, thrombocytopenia, and hemorrhagic manifestations. A unique challenge in vaccine development against DENV is the high degree of sequence variation, characteristically associated with RNA viruses. This is of particular relevance in the case of DENV since infection with one DENV serotype (primary infection presumably affords life-long serotype-specific immunity but only partial and temporary immunity to other serotypes in secondary infections settings. The role of T cells in dengue virus infection and subsequent disease manifestations is not fully understood. According to the original antigenic sin theory, skewing of T cell responses induced by primary infection with one serotype causes less effective response upon secondary infection with a different serotype, predisposing to severe disease. Our recent study has suggested an HLA linked protective role for T cells. Herein we will discuss the role of T cells in protection and pathogenesis from severe disease as well as the implications for vaccine design.

  5. Early diagnosis of dengue virus infection in clinically suspected cases

    International Nuclear Information System (INIS)

    Afridi, N.K.; Ahmed, S.; Ali, N.; Khan, S.A.

    2016-01-01

    Objective: Comparison of real time reverse transcriptase polymerase chain reaction (RTPCR) and immunoglobulin M (IgM) capture enzyme linked immunosorbent assay (ELISA) for diagnosis of dengue virus infection in first week of illness in clinically suspected patients of dengue fever. Study Design: Cross sectional study. Place and Duration of Study: Department of haematology, Armed Forces Institute of Pathology (AFIP) Rawalpindi from Jan 2013 to Nov 2013. Material and Methods: A cross sectional study including 68 clinically suspected patients of dengue fever according to the World Health Organization (WHO) criteria. IgM capture ELISA and RT PCR for dengue virus ribonucleic acid (RNA) was performed on samples collected from patients having fever for 1 to 7 days. These were divided into two groups. Patients in group 1 presented with fever of 4 days or less, patients in group 2 had fever of 5 to 7 days duration. Results: In group 1, 72 percent of the patients were positive by RT PCR while 31 percent were positive by IgM capture ELISA. In group 2, 43 percent of the patients were positive by RT PCR while 97 percent were positive by ELISA. Conclusion: RT PCR can be used for early detection of dengue virus infection in the first few days of fever while IgM ELISA is diagnostic afterwards. (author)

  6. Elevated levels of total and dengue virus-specific immunoglobulin E in patients with varying disease severity

    NARCIS (Netherlands)

    Koraka, Penelopie; Murgue, Bernadette; Deparis, Xavier; Setiati, Tatty E.; Suharti, Catarina; van Gorp, Eric C. M.; Hack, C. E.; Osterhaus, Albert D. M. E.; Groen, Jan

    2003-01-01

    The kinetics of total and dengue virus-specific immunoglobulin E (IgE) were studied in serial serum samples obtained from 168 patients, 41 of whom suffered from primary dengue virus infection and 127 suffered from secondary dengue virus infection. Seventy-one patients were classified as dengue

  7. Elevated levels of total and dengue virus-specific immunoglobulin E in patients with varying disease severity.

    NARCIS (Netherlands)

    Koraka, P.; Murgue, B.; Deparis, X.; Setiati, T.E.; Suharti, C.; Gorp, E. van; Hack, C.E.; Osterhaus, A.D.; Groen, J.

    2003-01-01

    The kinetics of total and dengue virus-specific immunoglobulin E (IgE) were studied in serial serum samples obtained from 168 patients, 41 of whom suffered from primary dengue virus infection and 127 suffered from secondary dengue virus infection. Seventy-one patients were classified as dengue

  8. Dengue

    OpenAIRE

    Rosso Suárez, Fernando; Vélez, Juan Diego

    2013-01-01

    El dengue es un grave problema de salud pública en el mundo, especialmente en la región de las Américas. Esta enfermedad ha puesto en alerta a las autoridades de salud pública y a los habitantes de nuestra región. Diversas situaciones como el cambio climático, sobrepoblación en áreas urbanas, la circulación simultánea de diferentes virus del dengue y el aumento en el número de mosquitos inciden en el incremento en el número de casos de dengue en las áreas tropicales del mundo.

  9. Differential Targeting of Viral Components by CD4+ versus CD8+ T Lymphocytes in Dengue Virus Infection

    Science.gov (United States)

    Kumaran, Emmanuelle A. P.; Jovanovic, Vojislav; Nadua, Karen; Teo, En Wei; Pang, Shyue Wei; Teo, Guo Hui; Gan, Victor Chih Hao; Lye, David C.; Leo, Yee Sin; Hanson, Brendon J.; Smith, Kenneth G. C.; Bertoletti, Antonio; Kemeny, David M.; MacAry, Paul A.

    2013-01-01

    Dengue virus (DENV) is the principal arthropod-borne viral pathogen afflicting human populations. While repertoires of antibodies to DENV have been linked to protection or enhanced infection, the role of T lymphocytes in these processes remains poorly defined. This study provides a comprehensive overview of CD4+ and CD8+ T cell epitope reactivities against the DENV 2 proteome in adult patients experiencing secondary DENV infection. Dengue virus-specific T cell responses directed against an overlapping 15mer peptide library spanning the DENV 2 proteome were analyzed ex vivo by enzyme-linked immunosorbent spot assay, and recognition of individual peptides was further characterized in specific T cell lines. Thirty novel T cell epitopes were identified, 9 of which are CD4+ and 21 are CD8+ T cell epitopes. We observe that whereas CD8+ T cell epitopes preferentially target nonstructural proteins (NS3 and NS5), CD4+ epitopes are skewed toward recognition of viral components that are also targeted by B lymphocytes (envelope, capsid, and NS1). Consistently, a large proportion of dengue virus-specific CD4+ T cells have phenotypic characteristics of circulating follicular helper T cells (CXCR5 expression and production of interleukin-21 or gamma interferon), suggesting that they are interacting with B cells in vivo. This study shows that during a dengue virus infection, the protein targets of human CD4+ and CD8+ T cells are largely distinct, thus highlighting key differences in the immunodominance of DENV proteins for these two cell types. This has important implications for our understanding of how the two arms of the human adaptive immune system are differentially targeted and employed as part of our response to DENV infection. PMID:23255803

  10. Multiple recombinants in two dengue virus, serotype-2 isolates from patients from Oaxaca, Mexico

    Directory of Open Access Journals (Sweden)

    Cisneros Alejandro

    2009-12-01

    Full Text Available Abstract Background Dengue (DEN is a serious cause of mortality and morbidity in the world including Mexico, where the infection is endemic. One of the states with the highest rate of dengue cases is Oaxaca. The cause of DEN is a positive-sense RNA virus, the dengue virus (DENV that evolves rapidly increasing its variability due to the absence of a repair mechanism that leads to approximately one mutational event per genome replication; which results in enhancement of viral adaptation, including the escape from host immune responses. Additionally, recombination may play a role in driving the evolution of DENV, which may potentially affect virulence and cause host tropism changes. Recombination in DENV has not been described in Mexican strains, neither has been described the relevance in virus evolution in an endemic state such as Oaxaca where the four serotypes of DENV are circulating. Results To study whether there are isolates from Oaxaca having recombination, we obtained the sequence of 6 different isolates of DENV-2 Asian/American genotype from the outbreak 2005-6, one clone of the C(91-prM-E-NS1(2400 structural genes, and 10 clones of the E gene from the isolate MEX_OAX_1656_05. Evidence of recombination was found by using different methods along with two softwares: RDP3 and GARD. The Oaxaca MEX_OAX_1656_05 and MEX_OAX_1038_05 isolates sequenced in this study were recombinant viruses that incorporate the genome sequence from the Cosmopolitan genotype. Furthermore, the clone of the E gene namely MEX_OAX_165607_05 from this study was also recombinant, incorporating genome sequence from the American genotype. Conclusions This is the first report of recombination in DENV-2 in Mexico. Given such a recombinant activity new genomic combinations were produced, this could play a significant role in the DENV evolution and must be considered as a potentially important mechanism generating genetic variation in this virus with serious implications for

  11. Multiple recombinants in two dengue virus, serotype-2 isolates from patients from Oaxaca, Mexico.

    Science.gov (United States)

    Perez-Ramirez, Gerardo; Diaz-Badillo, Alvaro; Camacho-Nuez, Minerva; Cisneros, Alejandro; Munoz, Maria de Lourdes

    2009-12-15

    Dengue (DEN) is a serious cause of mortality and morbidity in the world including Mexico, where the infection is endemic. One of the states with the highest rate of dengue cases is Oaxaca. The cause of DEN is a positive-sense RNA virus, the dengue virus (DENV) that evolves rapidly increasing its variability due to the absence of a repair mechanism that leads to approximately one mutational event per genome replication; which results in enhancement of viral adaptation, including the escape from host immune responses. Additionally, recombination may play a role in driving the evolution of DENV, which may potentially affect virulence and cause host tropism changes. Recombination in DENV has not been described in Mexican strains, neither has been described the relevance in virus evolution in an endemic state such as Oaxaca where the four serotypes of DENV are circulating. To study whether there are isolates from Oaxaca having recombination, we obtained the sequence of 6 different isolates of DENV-2 Asian/American genotype from the outbreak 2005-6, one clone of the C(91)-prM-E-NS1(2400) structural genes, and 10 clones of the E gene from the isolate MEX_OAX_1656_05. Evidence of recombination was found by using different methods along with two softwares: RDP3 and GARD. The Oaxaca MEX_OAX_1656_05 and MEX_OAX_1038_05 isolates sequenced in this study were recombinant viruses that incorporate the genome sequence from the Cosmopolitan genotype. Furthermore, the clone of the E gene namely MEX_OAX_165607_05 from this study was also recombinant, incorporating genome sequence from the American genotype. This is the first report of recombination in DENV-2 in Mexico. Given such a recombinant activity new genomic combinations were produced, this could play a significant role in the DENV evolution and must be considered as a potentially important mechanism generating genetic variation in this virus with serious implications for the vaccines and drugs formulation as occurs for other

  12. THE CHANGING CLINICAL PERFORMANCE OF DENGUE VIRUS INFECTION IN THE YEAR 2009

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    Soegeng Soegijanto

    2012-01-01

    Full Text Available Background: Dengue (DEN virus, the most important arthropod-borne human pathogen, represents a serious public health threat. DEN virus is transmitted to humans by the bite of the domestic mosquito, Aedes aegypti, and circulates in nature as four distinct serological types DEN-1 to 4. The aim of Study: To identify Dengue Virus Serotype I which showed mild clinical performance in five years before and afterward showed severe clinical performance. Material and Method: Prospective and analytic observational study had been done in Dr. Soetomo Hospital and the ethical clearance was conduct on January 01, 2009. The population of this research is all cases of dengue virus infection. Diagnosis were done based on WHO 1997. All of these cases were examined for IgM & IgG anti Dengue Virus and then were followed by PCR examination to identify Dengue Virus serotype. Result and Discussion: DEN 2 was predominant virus serotype with produced a spectrum clinical illness from asymptomatic, mild illness to classic dengue fever (DF to the most severe form of illness (DHF. But DEN 1 usually showed mild illness. Helen at al (2009–2010 epidemiologic study of Dengue Virus Infection in Health Centre Surabaya and Mother and Child Health Soerya Sidoarjo found many cases of Dengue Hemorrhagic Fever were caused by DEN 1 Genotype IV. Amor (2009 study in Dr. Soetomo Hospital found DEN 1 showed severe clinical performance of primary Dengue Virus Infection as Dengue Shock Syndrome two cases and one unusual case. Conclusion: The epidemiologic study of Dengue Virus Infection in Surabaya and Sidoarjo; in the year 2009 found changing predominant Dengue Virus Serotype from Dengue Virus II to Dengue Virus 1 Genotype IV which showed a severe clinical performance coincident with primary infection.

  13. Dengue Virus Infection inAedes albopictusduring the 2014 Autochthonous Dengue Outbreak in Tokyo Metropolis, Japan.

    Science.gov (United States)

    Kobayashi, Daisuke; Murota, Katsunori; Fujita, Ryosuke; Itokawa, Kentaro; Kotaki, Akira; Moi, Meng Ling; Ejiri, Hiroko; Maekawa, Yoshihide; Ogawa, Kohei; Tsuda, Yoshio; Sasaki, Toshinori; Kobayashi, Mutsuo; Takasaki, Tomohiko; Isawa, Haruhiko; Sawabe, Kyoko

    2018-03-19

    In 2014 in Japan, 162 autochthonous dengue cases were reported for the first time in nearly 70 years. Here, we report the results of the detection and isolation of dengue virus (DENV) from mosquitoes collected in Tokyo Metropolis in 2014 and 2015. The phylogenetic relationship among DENV isolates from mosquitoes and from patients based on both the entire envelope gene and whole coding sequences was evaluated. Herein, 2,298 female and 956 male Aedes albopictus mosquitoes were collected at six suspected locations of DENV infection in Tokyo Metropolis from August to October in 2014 and grouped into 124 and 35 pools, respectively, for viral genome detection and DENV isolation. Dengue virus RNA was detected using reverse transcription polymerase chain reaction and TaqMan assays from 49 female pools; 16 isolates were obtained using C6/36 and Vero cells. High minimum infection rates (11.2-66.7) persisted until mid-September. All DENV isolates belonged to the genotype I in serotype 1 (DENV-1), and its sequences demonstrated > 99% homology to the sequence of the DENV isolated from a patient in the vicinity of Tokyo Metropolis in 2014. Therefore, Ae. albopictus was a major DENV vector, and a single DENV-1 strain circulated in Tokyo Metropolis in 2014. Dengue virus was not detected from male mosquitoes in 2014 and wild larvae in April 2015. Thus, the possibility of both vertical transmission and overwintering of DENV was extremely low, even in dengue-epidemic areas. This study reports the first entomological information on a dengue outbreak in a temperate region, where no Aedes aegypti mosquitoes are distributed.

  14. In-vitro effect of human cathelicidin antimicrobial peptide LL-37 on dengue virus type 2.

    Science.gov (United States)

    Alagarasu, K; Patil, P S; Shil, P; Seervi, M; Kakade, M B; Tillu, H; Salunke, A

    2017-06-01

    Human Cathelicidin antimicrobial peptide LL-37 is known to have antiviral activity against many viruses. In the present study, we investigated the in-vitro effect of LL-37 on dengue virus type 2 (DENV-2) infection and replication in Vero E6 cells. To study the effect of pretreatment of virus or cells with LL-37, the virus was pretreated with different concentrations of LL-37 (2.5μM-15μM) or scrambled (Scr) LL-37(5μM-15μM) and used for infection or the cells were first treated with LL-37 and infected. To study the effect of LL-37 post infection (PI), the cells were infected first followed by addition of LL-37 to the culture medium 24h after infection. In all conditions, after the incubation, the culture supernatant was assessed for viral RNA copy number by real time RT-PCR, infectious virus particles by focus forming unit assay (FFU) and non structural protein 1 (NS1) antigen levels by ELISA. Percentage of infection was assessed using immunoflourescence assay (IFA). The results revealed that pretreatment of virus with 10-15μM LL-37 significantly reduced its infectivity as compared to virus control (P0.05). Pretreatment of cells before infection or addition of LL-37 to the culture 24h PI had no effect on viral load. Molecular docking studies revealed possible binding of LL-37 to both the units of DENV envelope (E) protein dimer. Together, the in-vitro experiments and in-silico analyses suggest that LL-37 inhibits DENV-2 at the stage of entry into the cells by binding to the E protein. The results might have implications for prophylaxis against DENV infections and need further in-vivo studies. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. [Modern immunological and clinical determinants of virus dengue infection].

    Science.gov (United States)

    Płusa, Tadeusz

    2014-11-01

    The growing problem of widespread viral infections is a challenge for modern medicine. Emerging reports of dengue virus infections in Europe create a new epidemic problem. The virus responsible for causing the symptoms of the disease is transmitted by mosquitoes. Over 50% of the world's population lives in areas where the risk of dengue feveris high. In total, according to WHO, infected with dengue is 2.4 million people and outbreaks of endemic diseases are present in 100 countries that threaten the 2.5 billion population. There are four serotypes of dengue virus, which belong to the family Flaviviridae and the type of Flavirus. Serotypes are known as DENV-1, DENV-2, DENV-3 and DENV-4. Contact each of the serotypes of the virus causes long-lasting resistance to the other, and each of them is responsible for the induction of disease epidemics, including severe cases. In the first stage of the disease should seek to replace lost fluids and electrolytes. Because of the elevated body temperature is recommended to administer paracetamol formulations and the use of cold compresses. Contraindicated is the use of aspirin and non-steroidal anti-inflammatory drugs. In severe forms of dengue patients absolutely should be hospitalized and treatment in the intensive care centers. In the treatment of shock, it is recommended that the administration of isotonic crystalloid fluids at 5-10 ml/kg/hr. under the control of hematocrit and fill peripheral microcirculation. The administration of blood products for the large current is required to control bleeding. Dengue vaccine containing DEN-DEN chimeras is still at the stage of preclinical studies.

  16. Diagnóstico temprano del Virus Dengue 1 usando RT-PCR y perspectivas para la caracterización molecular de Cepas Autóctonas

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    C Yábar

    1999-01-01

    Full Text Available Un sistema de diagnóstico para la detección temprana del virus Dengue 1 fue llevado a cabo exitosamente usando la reacción en cadena por polimerasa de transcriptasa reversa (RT-PCR, a través de la amplificación de una porción genómica del gen NS1. Los resultados obtenidos, a partir de muestras clínicas, corroboraron los datos de anteriores trabajos de RT-PCR dirigidos hacia la región estructural del virión. Posteriormente el ADNc del virus Dengue, correspondiente a una de las muestras serológicas, fue clonado y secuenciado. La comparación por análisis de secuencia nucleotídica con otras cepas referenciales determinó que la cepa viral correspondía al serotipo 1.

  17. Role of antibodies in controlling dengue virus infection

    NARCIS (Netherlands)

    van der Schaar, Hilde M.; Wilschut, Jan C.; Smit, Jolanda M.

    The incidence and disease burden of arthropod-borne flavivirus infections have dramatically increased during the last decades due to major societal and economic changes, including massive urbanization, lack of vector control, travel, and international trade. Specifically, in the case of dengue virus

  18. Dengue virus life cycle : viral and host factors modulating infectivity

    NARCIS (Netherlands)

    Rodenhuis-Zybert, Izabela A.; Wilschut, Jan; Smit, Jolanda M.

    Dengue virus (DENV 1-4) represents a major emerging arthropod-borne pathogen. All four DENV serotypes are prevalent in the (sub) tropical regions of the world and infect 50-100 million individuals annually. Whereas the majority of DENV infections proceed asymptomatically or result in self-limited

  19. A small molecule fusion inhibitor of dengue virus

    NARCIS (Netherlands)

    Poh, Mee Kian; Yip, Andy; Zhang, Summer; Priestle, John P.; Ma, Ngai Ling; Smit, Jolanda M.; Wischut, Jan; Shi, Pei-Yong; Wenk, Markus R.; Schul, Wouter

    2009-01-01

    The dengue virus envelope protein plays an essential role in viral entry by mediating fusion between the viral and host membranes. The crystal structure of the envelope protein shows a pocket (located at a "hinge" between Domains I and II) that can be occupied by ligand n-octyl-beta-D-glucoside

  20. The successful induction of T-cell and antibody responses by a recombinant measles virus-vectored tetravalent dengue vaccine provides partial protection against dengue-2 infection.

    Science.gov (United States)

    Hu, Hui-Mei; Chen, Hsin-Wei; Hsiao, Yu-Ju; Wu, Szu-Hsien; Chung, Han-Hsuan; Hsieh, Chun-Hsiang; Chong, Pele; Leng, Chih-Hsiang; Pan, Chien-Hsiung

    2016-07-02

    Dengue has a major impact on global public health, and the use of dengue vaccine is very limited. In this study, we evaluated the immunogenicity and protective efficacy of a dengue vaccine made from a recombinant measles virus (MV) that expresses envelope protein domain III (ED3) of dengue-1 to 4. Following immunization with the MV-vectored dengue vaccine, mice developed specific interferon-gamma and antibody responses against dengue virus and MV. Neutralizing antibodies against MV and dengue viruses were also induced, and protective levels of FRNT50 ≥ 10 to 4 serotypes of dengue viruses were detected in the MV-vectored dengue vaccine-immunized mice. In addition, specific interferon-gamma and antibody responses to dengue viruses were still induced by the MV-vectored dengue vaccine in mice that were pre-infected with MV. This finding suggests that the pre-existing immunity to MV did not block the initiation of immune responses. By contrast, mice that were pre-infected with dengue-3 exhibited no effect in terms of their antibody responses to MV and dengue viruses, but a dominant dengue-3-specific T-cell response was observed. After injection with dengue-2, a detectable but significantly lower viremia and a higher titer of anti-dengue-2 neutralizing antibodies were observed in MV-vectored dengue vaccine-immunized mice versus the vector control, suggesting that an anamnestic antibody response that provided partial protection against dengue-2 was elicited. Our results with regard to T-cell responses and the effect of pre-immunity to MV or dengue viruses provide clues for the future applications of an MV-vectored dengue vaccine.

  1. Validation and Application of a Commercial Quantitative Real-Time Reverse Transcriptase-PCR Assay in Investigation of a Large Dengue Virus Outbreak in Southern Taiwan.

    Science.gov (United States)

    Tsai, Huey-Pin; Tsai, You-Yuan; Lin, I-Ting; Kuo, Pin-Hwa; Chang, Kung-Chao; Chen, Jung-Chin; Ko, Wen-Chien; Wang, Jen-Ren

    2016-10-01

    Accurate, rapid, and early diagnosis of dengue virus (DENV) infections is essential for optimal clinical care. Here, we evaluated the efficacy of the quantitative real-time PCR (qRT-PCR)-LightMix dengue virus EC kit for DENV detection using samples from a dengue outbreak in Taiwan in 2015. Sera from patients with suspected DENV infection were analyzed and compared using the LightMix kit, a Dengue NS1 Ag + Ab Combo kit for detection of NS1 antigen and DENV-specific IgM and IgG antibodies, and an "in-house" qualitative DENV-specific RT-PCR assay. A total of 8,989, 8,954, and 1581 samples were subjected to NS1 antigen detection, IgM and IgG detection, and LightMix assays, respectively. The LightMix assay yielded a linear curve for viral loads (VL) between 102 and 106 copies/reaction, and the minimum detection limits for DENV serotype 1 (DENV1) and DENV2, DENV3, and DENV4 were 1, 10, and 100 focus forming units (FFU)/mL, respectively. There was 88.9% concordance between the results obtained using the NS1 antigen combo kit and by LightMix analysis, and the diagnostic sensitivity and specificity of the two methods were 89.4 and 100%, and 84.7 and 100%, respectively. Notably, fatal cases were attributed to DENV2 infection, and 79.5% (27/34) of these cases occurred in patients ≥ 71 years of age. Among these older patients, 82.3% (14/17) were NS1/IgM/IgG (+/-/-), exhibiting VLs between 106-109 copies/mL, which was markedly higher than the rate observed in the other age groups. The LightMix assay was effective for early diagnosis of DENV infection. Our data indicate that high VLs during primary infection in elderly patients may be a positive predictor for severe illness, and may contribute to high mortality rates.

  2. FEVER AS INDICATOR TO SECONDARY INFECTION IN DENGUE VIRAL INFECTION

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    Soegeng Soegijanto

    2018-04-01

    Full Text Available Dengue Virus Infections are distributed in tropical and sub-tropical regions and transmitted by the mosquitoes such as Aedes aegypti and Aedes albopictus. Dengue virus can cause dengue fever, dengue hemorrhagic fever and dengue shock syndrome or dengue and severe dengue classified by World Health Organization. Beside it concurrent infection virus salmonella had been found some cases who showed fever more than 7 days. Concurrent infection with two agents can result in an illness having overlapping symptoms creating a diagnostic dilemma for treating physician, such as dengue fever with typhoid fever. The aim of this research is detection of dengue virus and secondary infection with Salmonella typhi in patients suspected dengue virus infection. Detection of dengue virus and Salmonella typhi using immunochromatography test such as NS1, IgG/IgM for dengue virus infection, and IgM/IgG Salmonella and blood culture. The fifty children with dengue virus infection came to Soerya hospital and 17 cases suspected dengue virus infection, five cases showed a positive NS1 on the second day of fever and one case concurrent with clinical manifestation of convulsi on the third days of fever there were five cases only showed positive. It was showed in this study that on the fourth to six day of fever in dengue virus infection accompanied by antibody IgM & IgG dengue. There were 12 cases showed the clinical manifestation of concurrent dengue viral infection and Salmonella, all of them showed a mild clinical manifestation and did not show plasma leakage and shock. In this study we found the length of stay of concurrent Dengue Virus Infection and Salmonella infection is more than 10 days. These patients were also more likely to have co-existing haemodynamic disturbances and bacterial septicaemia which would have required treatment with inotropes and antibiotics. This idea is very important to make update dengue viral management to decrease mortality in outbreak try to

  3. Observation on dengue cases from a virus diagnostic laboratory of a tertiary care hospital in North India

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    Om Prakash

    2015-01-01

    Interpretation & conclusions: Change in circulating serotype of dengue virus; a distinct adult dengue involvement; and a remarkable number of cases presenting with severe dengue manifestations are the main findings of this study.

  4. Treatment Effectiveness of Amantadine Against Dengue Virus Infection.

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    Lin, Chieh-Cheng; Chen, Wen-Ching

    2016-12-05

    BACKGROUND About 400 million cases of dengue, a mosquito-borne disease, are reported annually, but no drug is yet available for treatment. In 1988, at Feng Lin Clinic, Taiwan, we encountered about 10,000 cases and tested various drugs before confirming an antiviral effect of amantadine against dengue virus in vitro. After we administered amantadine to patients for 1-2 days, most achieved full remission. None experienced potentially life-threatening dengue hemorrhagic fever or dengue shock syndrome. Herein, we present 34 cases from recent clinical experience that show amantadine's unusual effect against dengue virus infection. CASE REPORT We divided 34 patients with symptoms of dengue fever, confirmed by a screening test, into 3 groups: 6 Category 1 patients received amantadine at onset, 21 Category 2 patients received amantadine within 2-6 days, and 7 Contrast group patients received no amantadine because they visited other clinics or were admitted to a large hospital. When Category 1 patients were treated with amantadine 100 mg 3 times per day, all symptoms dramatically subsided within 1-2 days. In Category 2 patients, most symptoms diminished within 1-2 days after starting the same regimen. In the Contrast group, all symptoms persisted 7 days after onset. White blood cell and platelet counts in Category 1 and 2 patients recovered to normal range, but remained below low normal in the Contrast group. CONCLUSIONS Amantadine is effective and should be given as soon as possible to stop the disease course if dengue fever is confirmed through screening or clinical signs and symptoms. A well-designed larger sample study is warranted to test this effectiveness.

  5. The immunogenicity of tetravalent dengue DNA vaccine in mice pre-exposed to Japanese encephalitis or Dengue virus antigens.

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    Prompetchara, Eakachai; Ketloy, Chutitorn; Keelapang, Poonsook; Sittisombut, Nopporn; Ruxrungtham, Kiat

    2015-09-01

    Asian countries are an endemic area for both dengue (DENV) and Japanese encephalitis viruses (JEV). While JEV vaccines have been used extensively in this region, DENV vaccines remains under development. Whether preexisting naturally acquired or vaccination-induced immunity against JEV may affect the immune response to dengue vaccine candidate is unclear. In this study we used mice previously immunized with JEV vaccines to evaluate the impact on dengue-specific neutralizing antibody responses to a tetravalent dengue DNA vaccine candidate (TDNA). A tetravalent cocktail of plasmids encoding pre-membrane and envelope proteins from each dengue serotype was administered into mice which had been previously primed with inactivated or live-attenuated JEV vaccines, or dengue serotype2 virus (DENV-2). Neutralizing antibody response was measured employing a plaque reduction neutralization test at two weeks after the priming and at four weeks after the second dose of the dengue tetravalent plasmids. Inactivated or live-attenuated JEV vaccines, or DENV-2 induced low levels of neutralizing antibodies against the homologous viruses (JE and dengue virus, respectively). DENV-2 injection induced also low levels of cross-reactive antibodies against DENV-1, -3 and -4. JEV vaccines have no effect on the dengue-specific neutralizing antibody responses to the subsequent TDNA immunization. Pre-exposure to DENV-2 infection increased DENV-2 specific response neutralizing antibody to two doses of TDNA plasmids by six folds, but did not affect antibody response to other serotypes. Priming with JEV vaccines did not impact on dengue virus-specific neutralizing antibody response to a dengue TDNA vaccine candidate in mice.

  6. The role of cell proteins in dengue virus infection.

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    Salazar, Ma Isabel; del Angel, Rosa María; Lanz-Mendoza, Humberto; Ludert, Juan E; Pando-Robles, Victoria

    2014-12-05

    Despite 70 years of study, dengue disease continues to be a global health burden. Treatment is only supportive based on presenting symptoms. To date, there is no licensed prophylactic vaccine and no specific antiviral drugs available. The pathogenesis mechanisms during dengue virus infections remain poorly understood, and the complete picture on risk factors for developing severe clinical illness is still unknown. Viruses as obligate intracellular parasites depend on the host cell machinery for replication. As a result of a co-evolution process for million years, viruses have developed sophisticated strategies to hijack and use cellular factors for entry, replication and propagation, alternate host transmission and to combat host cell defenses. This review focuses on recent reports about cellular proteins involved along the dengue virus replication cycle, in prime cellular targets during the infection of both humans and mosquito hosts and also on the proteomics and other approaches that are being used to reveal the entire orchestration and most significant processes altered during infection. Identification of the key host cell factors involve in these processes will provide a better understanding of how viruses replicate and cause disease, and how to develop more effective therapeutic interventions. Dengue disease is as a global health problem. The treatment is only supportive based on presenting symptoms. To date, there is no licensed prophylactic vaccine and no specific antiviral drugs available. The study of the interactions between virus and host cell proteins will provide a better understanding of how viruses replicate and cause disease. Here, we focus on the current knowledge about the cellular proteins involved during DENV infection in different target cells in the two hosts, mosquito and human. Copyright © 2014. Published by Elsevier B.V.

  7. N-Desmethylclozapine, Fluoxetine, and Salmeterol Inhibit Postentry Stages of the Dengue Virus Life Cycle.

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    Medigeshi, Guruprasad R; Kumar, Rinki; Dhamija, Ekta; Agrawal, Tanvi; Kar, Meenakshi

    2016-11-01

    Around 10,000 people die each year due to severe dengue disease, and two-thirds of the world population lives in a region where dengue disease is endemic. There has been remarkable progress in dengue virus vaccine development; however, there are no licensed antivirals for dengue disease, and none appear to be in clinical trials. We took the approach of repositioning approved drugs for anti-dengue virus activity by screening a library of pharmacologically active compounds. We identified N-desmethylclozapine, fluoxetine hydrochloride, and salmeterol xinafoate as dengue virus inhibitors based on reductions in the numbers of infected cells and viral titers. Dengue virus RNA levels were diminished in inhibitor-treated cells, and this effect was specific to dengue virus, as other flaviviruses, such as Japanese encephalitis virus and West Nile virus, or other RNA viruses, such as respiratory syncytial virus and rotavirus, were not affected by these inhibitors. All three inhibitors specifically inhibited dengue virus replication with 50% inhibitory concentrations (IC 50 s) in the high-nanomolar range. Estimation of negative-strand RNA intermediates and time-of-addition experiments indicated that inhibition was occurring at a postentry stage, most probably at the initiation of viral RNA replication. Finally, we show that inhibition is most likely due to the modulation of the endolysosomal pathway and induction of autophagy. Copyright © 2016 Medigeshi et al.

  8. Tyrosine kinase/phosphatase inhibitors decrease dengue virus production in HepG2 cells.

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    Limjindaporn, Thawornchai; Panaampon, Jutatip; Malakar, Shilu; Noisakran, Sansanee; Yenchitsomanus, Pa-Thai

    2017-01-29

    Dengue virus is the causative agent of dengue fever, dengue hemorrhagic fever, and dengue shock syndrome. High rates of dengue virus replication and virion production are related to disease severity. To identify anti-DENV compounds, we performed cell-based ELISA testing to detect the level of DENV E protein expression. Among a total of 83 inhibitors, eight were identified as inhibitors with antiviral activity. Epidermal growth factor receptor inhibitor II (EGFR/ErbB-2/ErbB-4 inhibitor II) and protein tyrosine phosphatase inhibitor IV (PTP inhibitor IV) significantly inhibited dengue virus production and demonstrated low toxicity in hepatocyte cell lines. Our results suggest the efficacy of tyrosine kinase/phosphatase inhibitors in decreasing dengue virus production in HepG2 cells. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Nucleolar localization of influenza A NS1: striking differences between mammalian and avian cells

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    Mazel-Sanchez Beryl

    2010-03-01

    Full Text Available Abstract In mammalian cells, nucleolar localization of influenza A NS1 requires the presence of a C-terminal nucleolar localization signal. This nucleolar localization signal is present only in certain strains of influenza A viruses. Therefore, only certain NS1 accumulate in the nucleolus of mammalian cells. In contrast, we show that all NS1 tested in this study accumulated in the nucleolus of avian cells even in the absence of the above described C-terminal nucleolar localization signal. Thus, nucleolar localization of NS1 in avian cells appears to rely on a different nucleolar localization signal that is more conserved among influenza virus strains.

  10. Serological characterization of dengue virus infections observed among dengue hemorrhagic fever/dengue shock syndrome cases in upper Myanmar.

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    Ngwe Tun, Mya Myat; Thant, Kyaw Zin; Inoue, Shingo; Kurosawa, Yae; Lwin, Yee Yee; Lin, Sanda; Aye, Kay Thi; Thet Khin, Pe; Myint, Tin; Htwe, Khin; Mapua, Cynthia A; Natividad, Filipinas F; Hirayama, Kenji; Morita, Kouichi

    2013-07-01

    In Myanmar, dengue fever (DF)/dengue hemorrhagic fever (DHF) is one of the leading causes of morbidity and mortality among children. From Pyinmana Hospital in 2004 and Mandalay Children Hospital in 2006, 160 patients diagnosed clinically to have DHF/dengue shock syndrome (DSS) were examined for immunoglobulin M (IgM) and IgG levels. A focus reduction neutralization test was also used to determine primary or secondary dengue virus (DENV) infection. By using IgM-capture ELISA, 139 cases were confirmed as DENV infections. Of these IgM-positives, 94 samples were collected 7-24 days from the onset of illness, to which 13 (14%) and 81 (86%) were determined to be primary and secondary DENV infections, respectively. The 13 primary DENV infection cases were spread among the various severity groups (DHF grade I-IV and DSS) and represented age groups ranging from <1 year of age to 9 years of age. The patients in these primary infection cases showed a remarkably high IgM with a low IgG titer response compared with the secondary infection cases. No significant differences were observed in IgG titers with clinical severity. The data obtained in this study suggest that primary DENV infection cases exist certainly among DHF/DSS cases in Myanmar, and that additional mechanism(s) aside from the antibody-dependent enhancement mechanism could have influenced the clinical severity in DHF/DSS cases. Copyright © 2013 Wiley Periodicals, Inc.

  11. Recombinant Production of the Amino Terminal Cytoplasmic Region of Dengue Virus Non-Structural Protein 4A for Structural Studies

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    Hung, Yu-Fu; Valdau, Olga; Schünke, Sven; Stern, Omer; Koenig, Bernd W.; Willbold, Dieter; Hoffmann, Silke

    2014-01-01

    BACKGROUND: Dengue virus (DENV) is a mosquito-transmitted positive single strand RNA virus belonging to the Flaviviridae family. DENV causes dengue fever, currently the world's fastest-spreading tropical disease. Severe forms of the disease like dengue hemorrhagic fever and dengue shock syndrome are life-threatening. There is no specific treatment and no anti-DENV vaccines. Our recent data suggests that the amino terminal cytoplasmic region of the dengue virus non-structural protein 4A (NS4A)...

  12. The Epidemiology, Virology and Clinical Findings of Dengue Virus Infections in a Cohort of Indonesian Adults in Western Java

    NARCIS (Netherlands)

    Kosasih, H.; Alisjahbana, B.; Nurhayati, .; Mast, Q. de; Rudiman, I.F.; Widjaja, S.; Antonjaya, U.; Novriani, H.; Susanto, N.H.; Jusuf, H.; Ven, A. van der; Beckett, C.G.; Blair, P.J.; Burgess, T.H.; Williams, M.; Porter, K.R.

    2016-01-01

    BACKGROUND: Dengue has emerged as one of the most important infectious diseases in the last five decades. Evidence indicates the expansion of dengue virus endemic areas and consequently the exponential increase of dengue virus infections across the subtropics. The clinical manifestations of dengue

  13. Highly Divergent Dengue Virus Type 2 in Traveler Returning from Borneo to Australia.

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    Liu, Wenjun; Pickering, Paul; Duchêne, Sebastián; Holmes, Edward C; Aaskov, John G

    2016-12-01

    Dengue virus type 2 was isolated from a tourist who returned from Borneo to Australia. Phylogenetic analysis identified this virus as highly divergent and occupying a basal phylogenetic position relative to all known human and sylvatic dengue virus type 2 strains and the most divergent lineage not assigned to a new serotype.

  14. Dengue fever and international travel.

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    Ratnam, Irani; Leder, Karin; Black, Jim; Torresi, Joseph

    2013-01-01

    Dengue is a leading public health problem with an expanding global burden. Dengue virus is also a significant cause of illness in international travelers with an increasing number of cases of dengue fever identified in travelers returning from dengue-endemic countries. This review focuses on the clinical illness of dengue infection in international travelers and provides a summary of the risk of infection for travelers, clinical features of infection, and an overview of dengue vaccines and their potential applicability to travelers. Four prospective studies of travelers to dengue-endemic destinations have shown that the dengue infection incidence ranges from 10.2 to 30 per 1,000 person-months. This varies according to travel destination and duration and season of travel. Dengue is also a common cause of fever in returned travelers, accounting for up to 16% of all febrile illnesses in returned travelers. Although the majority of infections are asymptomatic, a small proportion of travelers develop dengue hemorrhagic fever. The diagnosis of dengue in travelers requires a combination of serological testing for IgG and IgM together with either nucleic acid or NS1 antigen testing. Several vaccine candidates have now entered into clinical trials including ChimeriVax Dengue, which is currently in phase 3 trials, live-attenuated chimeric vaccines (DENV-DENV Chimera, Inviragen), live-attenuated viral vaccines, recombinant protein subunit vaccines, and DNA vaccines. Dengue infection in international travelers is not infrequent and may be associated with substantial morbidity. Furthermore, an accurate diagnosis of dengue in travelers requires the use of a combination of diagnostic tests. Although a vaccine is not yet available a number of promising candidates are under clinical evaluation. For now travelers should be provided with accurate advice regarding preventive measures when visiting dengue-endemic areas. © 2013 International Society of Travel Medicine.

  15. Different Innate Signatures Induced in Human Monocyte-derived Dendritic Cells by Wild-Type Dengue 3 Virus, Attenuated but Reactogenic Dengue 3 Vaccine Virus, or Attenuated Nonreactogenic Dengue 1–4 Vaccine Virus Strains

    OpenAIRE

    Balas, Claire; Kennel, Audrey; Deauvieau, Florence; Sodoyer, Regis; Arnaud-Barbe, Nadege; Lang, Jean; Guy, Bruno

    2011-01-01

    DNA microarrays were used to assess the innate gene signature in human myeloid dendritic cells infected with chimeric dengue 1–4 vaccines, a wild-type dengue 3 virus, or a classically attenuated serotype 3 vaccine shown to be reactogenic in humans. We observed a very reproducible signature for each of the 4 chimeric dengue vaccines, involving stimulation of type I interferon and associated genes, together with genes encoding chemokines and other mediators involved in the initiation of adaptiv...

  16. Diagnostic Options and Challenges for Dengue and Chikungunya Viruses.

    Science.gov (United States)

    Mardekian, Stacey K; Roberts, Amity L

    2015-01-01

    Dengue virus (DENV) and Chikungunya virus (CHIKV) are arboviruses that share the same Aedes mosquito vectors and thus overlap in their endemic areas. These two viruses also cause similar clinical presentations, especially in the initial stages of infection, with neither virus possessing any specific distinguishing clinical features. Because the outcomes and management strategies for these two viruses are vastly different, early and accurate diagnosis is imperative. Diagnosis is also important for surveillance, outbreak control, and research related to vaccine and drug development. Available diagnostic tests are aimed at detection of the virus, its antigenic components, or the host immune antibody response. In this review, we describe the recent progress and continued challenges related to the diagnosis of DENV and CHIKV infections.

  17. A small molecule inhibitor of dengue virus type 2 protease inhibits the replication of all four dengue virus serotypes in cell culture.

    Science.gov (United States)

    Raut, Rajendra; Beesetti, Hemalatha; Tyagi, Poornima; Khanna, Ira; Jain, Swatantra K; Jeankumar, Variam U; Yogeeswari, Perumal; Sriram, Dharmarajan; Swaminathan, Sathyamangalam

    2015-02-08

    Dengue has emerged as the most significant of arboviral diseases in the 21st century. It is endemic to >100 tropical and sub-tropical countries around the world placing an estimated 3.6 billion people at risk. It is caused by four genetically similar but antigenically distinct, serotypes of dengue viruses. There is neither a vaccine to prevent nor a drug to treat dengue infections, at the present time. The major objective of this work was to explore the possibility of identifying a small molecule inhibitor of the dengue virus protease and assessing its ability to suppress viral replication in cultured cells. We cloned, expressed and purified recombinant dengue virus type 2 protease. Using an optimized and validated fluorogenic peptide substrate cleavage assay to monitor the activity of this cloned dengue protease we randomly screened ~1000 small molecules from an 'in-house' library to identify potential dengue protease inhibitors. A benzimidazole derivative, named MB21, was found to be the most potent in inhibiting the cloned protease (IC₅₀ = 5.95 μM). In silico docking analysis indicated that MB21 binds to the protease in the vicinity of the active site. Analysis of kinetic parameters of the enzyme reaction suggested that MB21 presumably functions as a mixed type inhibitor. Significantly, this molecule identified as an inhibitor of dengue type 2 protease was also effective in inhibiting each one of the four serotypes of dengue viruses in infected cells in culture, based on analysis of viral antigen synthesis and infectious virus production. Interestingly, MB21 did not manifest any discernible cytotoxicity. This work strengthens the notion that a single drug molecule can be effective against all four dengue virus serotypes. The molecule MB21 could be a potential candidate for 'hit-to-lead' optimization, and may pave the way towards developing a pan-dengue virus antiviral drug.

  18. Anti-Dengue Virus Constituents from Formosan Zoanthid Palythoa mutuki.

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    Lee, Jin-Ching; Chang, Fang-Rong; Chen, Shu-Rong; Wu, Yu-Hsuan; Hu, Hao-Chun; Wu, Yang-Chang; Backlund, Anders; Cheng, Yuan-Bin

    2016-08-09

    A new marine ecdysteroid with an α-hydroxy group attaching at C-4 instead of attaching at C-2 and C-3, named palythone A (1), together with eight known compounds (2-9) were obtained from the ethanolic extract of the Formosan zoanthid Palythoa mutuki. The structures of those compounds were mainly determined by NMR spectroscopic data analyses. The absolute configuration of 1 was further confirmed by comparing experimental and calculated circular dichroism (CD) spectra. Anti-dengue virus 2 activity and cytotoxicity of five isolated compounds were evaluated using virus infectious system and [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt (MTS) assays, respectively. As a result, peridinin (9) exhibited strong antiviral activity (IC50 = 4.50 ± 0.46 μg/mL), which is better than that of the positive control, 2'CMC. It is the first carotene-like substance possessing anti-dengue virus activity. In addition, the structural diversity and bioactivity of the isolates were compared by using a ChemGPS-NP computational analysis. The ChemGPS-NP data suggested natural products with anti-dengue virus activity locate closely in the chemical space.

  19. Anti-Dengue Virus Constituents from Formosan Zoanthid Palythoa mutuki

    Science.gov (United States)

    Lee, Jin-Ching; Chang, Fang-Rong; Chen, Shu-Rong; Wu, Yu-Hsuan; Hu, Hao-Chun; Wu, Yang-Chang; Backlund, Anders; Cheng, Yuan-Bin

    2016-01-01

    A new marine ecdysteroid with an α-hydroxy group attaching at C-4 instead of attaching at C-2 and C-3, named palythone A (1), together with eight known compounds (2–9) were obtained from the ethanolic extract of the Formosan zoanthid Palythoa mutuki. The structures of those compounds were mainly determined by NMR spectroscopic data analyses. The absolute configuration of 1 was further confirmed by comparing experimental and calculated circular dichroism (CD) spectra. Anti-dengue virus 2 activity and cytotoxicity of five isolated compounds were evaluated using virus infectious system and [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt (MTS) assays, respectively. As a result, peridinin (9) exhibited strong antiviral activity (IC50 = 4.50 ± 0.46 μg/mL), which is better than that of the positive control, 2′CMC. It is the first carotene-like substance possessing anti-dengue virus activity. In addition, the structural diversity and bioactivity of the isolates were compared by using a ChemGPS–NP computational analysis. The ChemGPS–NP data suggested natural products with anti-dengue virus activity locate closely in the chemical space. PMID:27517937

  20. Proteasome Inhibition Suppresses Dengue Virus Egress in Antibody Dependent Infection.

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    Milly M Choy

    2015-11-01

    Full Text Available The mosquito-borne dengue virus (DENV is a cause of significant global health burden, with an estimated 390 million infections occurring annually. However, no licensed vaccine or specific antiviral treatment for dengue is available. DENV interacts with host cell factors to complete its life cycle although this virus-host interplay remains to be fully elucidated. Many studies have identified the ubiquitin proteasome pathway (UPP to be important for successful DENV production, but how the UPP contributes to DENV life cycle as host factors remains ill defined. We show here that proteasome inhibition decouples infectious virus production from viral RNA replication in antibody-dependent infection of THP-1 cells. Molecular and imaging analyses in β-lactone treated THP-1 cells suggest that proteasome function does not prevent virus assembly but rather DENV egress. Intriguingly, the licensed proteasome inhibitor, bortezomib, is able to inhibit DENV titers at low nanomolar drug concentrations for different strains of all four serotypes of DENV in primary monocytes. Furthermore, bortezomib treatment of DENV-infected mice inhibited the spread of DENV in the spleen as well as the overall pathological changes. Our findings suggest that preventing DENV egress through proteasome inhibition could be a suitable therapeutic strategy against dengue.

  1. Dengue Virus Type 2 in Travelers Returning to Japan from Sri Lanka, 2017.

    Science.gov (United States)

    Tsuboi, Motoyuki; Kutsuna, Satoshi; Maeki, Takahiro; Taniguchi, Satoshi; Tajima, Shigeru; Kato, Fumihiro; Lim, Chang-Kweng; Saijo, Masayuki; Takaya, Saho; Katanami, Yuichi; Kato, Yasuyuki; Ohmagari, Norio

    2017-11-01

    In June 2017, dengue virus type 2 infection was diagnosed in 2 travelers returned to Japan from Sri Lanka, where the country's largest dengue fever outbreak is ongoing. Travelers, especially those previously affected by dengue fever, should take measures to avoid mosquito bites.

  2. Clinical and laboratory features of dengue virus-infected travellers previously vaccinated against yellow fever

    NARCIS (Netherlands)

    Teichmann, Dieter; Göbels, Klaus; Niedrig, Matthias; Grobusch, Martin P.

    2003-01-01

    Dengue is a mosquito-borne viral infection endemic throughout the tropics and subtropics. The global prevalence of dengue has grown dramatically in recent years and it has become a major international public health concern. The close taxonomic relationships between yellow fever and dengue viruses

  3. Dengue virus detection in Aedes aegypti larvae from southeastern Brazil.

    Science.gov (United States)

    Cecílio, Samyra Giarola; Júnior, Willer Ferreira Silva; Tótola, Antônio Helvécio; de Brito Magalhães, Cíntia Lopes; Ferreira, Jaqueline Maria Siqueira; de Magalhães, José Carlos

    2015-06-01

    The transmission of dengue, the most important arthropod-borne viral disease in Brazil, has been intensified over the past decades, along with the accompanying expansion and adaptation of its Aedes vectors. In the present study, we mapped dengue vectors in Ouro Preto and Ouro Branco, Minas Gerais, by installing ovitraps in 32 public schools. The traps were examined monthly between September, 2011 through July, 2012 and November, 2012 to April, 2013. The larvae were reared until the fourth stadium and identified according to species. The presence of dengue virus was detected by real time PCR and agarose gel electrophoresis. A total of 1,945 eggs was collected during the 17 months of the study. The Ovitrap Positivity Index (OPI) ranged from 0 to 28.13% and the Eggs Density Index (EDI) ranged from 0 to 59.9. The predominant species was Aedes aegypti, with 84.9% of the hatched larvae. Although the collection was low when compared to other ovitraps studies, vertical transmission could be detected. Of the 54 pools, dengue virus was detected in four Ae. aegypti pools. © 2015 The Society for Vector Ecology.

  4. The estimation of imported dengue virus from Thailand.

    Science.gov (United States)

    Polwiang, Sittisede

    2015-01-01

    Dengue fever is one of the important causes of illness among travelers returning from Thailand. The risk of infection depends on the length of stay, activities, and arrival time. Due to globalization, there is a concern that infected travelers may carry dengue virus (DENV) to their country of residence and cause an outbreak. To estimate the infective person-days of travelers returning from Thailand, we developed a model with the following parameters: the probability of travelers being infected, number of arrivals, length of stay of travelers, incubation period, and duration of the infective period. The data used in this study were the dengue incidences in Thailand during 2004-2013 and foreign traveler arrivals in 2013. We estimated the highest infective person-days for each country group. The highest value was from June to August during the rainy season in Thailand for all groups. Infective person-days ranged from 87 to 112 per 100,000 travelers each year. Our results provided a fundamental step toward estimation of the risk of the secondary transmission of DENV in non-epidemic countries via travelers, which can serve as an early warning of a dengue outbreak. The highest infective person-day is associated with the rainy season in Thailand. The increasing number of overseas travelers may increase the risk of global transmission of the DENV. Better understanding of the virus transmission dynamics will enable further quantitative predictions of epidemic risk. © 2015 International Society of Travel Medicine.

  5. Superinfection interference between dengue-2 and dengue-4 viruses in Aedes aegypti mosquitoes.

    Science.gov (United States)

    Muturi, Ephantus J; Buckner, Eva; Bara, Jeffrey

    2017-04-01

    Dengue virus consists of four antigenically distinct serotypes (DENV 1-4) that are transmitted to humans by Aedes aegypti and Aedes albopictus mosquitoes. In many dengue-endemic regions, co-circulation of two or more DENV serotypes is fairly common increasing the likelihood for exposure of the two vectors to multiple serotypes. We used a model system of DENV-2 and DENV-4 to investigate how prior exposure of Aedes aegypti to one DENV serotype affects its susceptibility to another serotype. Aedes aegypti mosquitoes were sequentially infected with DENV-2 and DENV-4 and the infection and dissemination rates for each virus determined. We found that prior infection of Ae. aegypti mosquitoes with DENV-4 rendered them significantly less susceptible to secondary infection with DENV-2. Although the results were not statistically significant, mosquitoes infected with DENV-2 were also less susceptible to secondary infection with DENV-4. The midgut dissemination and population dissemination rates for DENV-2 were significantly higher than those of DENV-4 when either virus was administered 7 days after administration of either a non-infectious blood meal or a blood meal containing a heterologous dengue serotype. These results demonstrate that superinfection interference between DENV serotypes is possible within Ae. aegypti mosquitoes, but its effect on DENV epidemiology may be dependent on the fitness of interacting serotypes. © 2017 John Wiley & Sons Ltd.

  6. Determination of Genotype of Dengue Virus Serotype 1 by Using Primer Design

    Directory of Open Access Journals (Sweden)

    Cita Christine Mayorita

    2014-06-01

    Full Text Available Dengue fever has become a worldwide health problem. This disease occurs more and more frequently and often cause death, especially in some Asian countries including Indonesia. The purpose of this study was to determine the genotype of dengue virus serotype 1 in Indonesia by using primer design as a base to take part in the development of diagnostics and vaccines of the dengue virus. This research consisted of 100 respondents; male and female aged 14-60 years. All samples were selected by consecutive sampling and dengue viruses used in this study were randomly selected in March-December 2010. The next step was sequencing process in January-October 2011 in the Department of Microbiology FKUI by using cross sectional design. The result of this study was dengue virus serotype 1 strains from Indonesia belonged to genotype 4. Keywords: genotype of dengue virus serotype 1, Indonesia, diagnostic, vaccine

  7. Unusual dengue virus 3 epidemic in Nicaragua, 2009.

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    Gamaliel Gutierrez

    2011-11-01

    Full Text Available The four dengue virus serotypes (DENV1-4 cause the most prevalent mosquito-borne viral disease affecting humans worldwide. In 2009, Nicaragua experienced the largest dengue epidemic in over a decade, marked by unusual clinical presentation, as observed in two prospective studies of pediatric dengue in Managua. From August 2009-January 2010, 212 dengue cases were confirmed among 396 study participants at the National Pediatric Reference Hospital. In our parallel community-based cohort study, 170 dengue cases were recorded in 2009-10, compared to 13-65 cases in 2004-9. In both studies, significantly more patients experienced "compensated shock" (poor capillary refill plus cold extremities, tachycardia, tachypnea, and/or weak pulse in 2009-10 than in previous years (42.5% [90/212] vs. 24.7% [82/332] in the hospital study (p<0.001 and 17% [29/170] vs. 2.2% [4/181] in the cohort study (p<0.001. Signs of poor peripheral perfusion presented significantly earlier (1-2 days in 2009-10 than in previous years according to Kaplan-Meier survival analysis. In the hospital study, 19.8% of subjects were transferred to intensive care, compared to 7.1% in previous years - similar to the cohort study. DENV-3 predominated in 2008-9, 2009-10, and 2010-11, and full-length sequencing revealed no major genetic changes from 2008-9 to 2010-11. In 2008-9 and 2010-11, typical dengue was observed; only in 2009-10 was unusual presentation noted. Multivariate analysis revealed only "2009-10" as a significant risk factor for Dengue Fever with Compensated Shock. Interestingly, circulation of pandemic influenza A-H1N1 2009 in Managua was shifted such that it overlapped with the dengue epidemic. We hypothesize that prior influenza A H1N1 2009 infection may have modulated subsequent DENV infection, and initial results of an ongoing study suggest increased risk of shock among children with anti-H1N1-2009 antibodies. This study demonstrates that parameters other than serotype, viral

  8. The Human Antibody Response to Dengue Virus Infection

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    Aravinda M. de Silva

    2011-11-01

    Full Text Available Dengue viruses (DENV are the causative agents of dengue fever (DF and dengue hemorrhagic fever (DHF. Here we review the current state of knowledge about the human antibody response to dengue and identify important knowledge gaps. A large body of work has demonstrated that antibodies can neutralize or enhance DENV infection. Investigators have mainly used mouse monoclonal antibodies (MAbs to study interactions between DENV and antibodies. These studies indicate that antibody neutralization of DENVs is a “multi-hit” phenomenon that requires the binding of multiple antibodies to neutralize a virion. The most potently neutralizing mouse MAbs bind to surface exposed epitopes on domain III of the dengue envelope (E protein. One challenge facing the dengue field now is to extend these studies with mouse MAbs to better understand the human antibody response. The human antibody response is complex as it involves a polyclonal response to primary and secondary infections with 4 different DENV serotypes. Here we review studies conducted with immune sera and MAbs isolated from people exposed to dengue infections. Most dengue-specific antibodies in human immune sera are weakly neutralizing and bind to multiple DENV serotypes. The human antibodies that potently and type specifically neutralize DENV represent a small fraction of the total DENV-specific antibody response. Moreover, these neutralizing antibodies appear to bind to novel epitopes including complex, quaternary epitopes that are only preserved on the intact virion. These studies establish that human and mouse antibodies recognize distinct epitopes on the dengue virion. The leading theory proposed to explain the increased risk of severe disease in secondary cases is antibody dependent enhancement (ADE, which postulates that weakly neutralizing antibodies from the first infection bind to the second serotype and enhance infection of FcγR bearing myeloid cells such as monocytes and macrophages. Here

  9. El citoesqueleto en la infección con virus dengue

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    Francisco Javier Díaz Castrillón

    2004-03-01

    criterios de laboratorio son necesarios para ayudar a los médicos a dar un diagnóstico preciso. El objetivo de este estudio es buscar alteraciones características de las variantes hemorrágicas en el citoesqueleto que permitan diferenciar los cuadros severos y de esta forma permitan alertar sobre posibles brotes hemorrágicos o sobre la severidad de los serotipos circulantes.

    Para ello, líneas celulares de primate (VERO y/o humanas (HeLa, son infectadas con Virus Dengue (DV aislado de muestras clínicas, en células de insecto (C6/36 HT. Después de 5 días post-infección, las células infectadas son fijadas bajo condiciones de preservación de citoesqueleto y después son incubadas con una solución de anticuerpos y fluoróforos conjugados a FITC (para filamentos de actina, anticuerpos anti-vimentina conjugados a Cy3 (para filamentos intermedios, y suero policlonal contra microtúbulos, con una incubación secundaria de suero policlonal anti conejo conjugado a Alexa Fluor-488. La infección con el DV es detectada con anticuerpos monoclonales específicos contra la envoltura (E y proteína no estructural (NS-1 y un anticuerpo secundario conjugado a Alexa Fluor-594.

    Debido a que el citoesqueleto controla las rutas endo y exocítica, en condiciones normales y en la infección viral, éste debe estar implicado en la entrada y ensamblaje del DV. Si nosotros encontramos un marcador celular de severidad, estos datos podrán ser útiles en la vigilancia epidemiológica del dengue.

    Actualmente hemos detectado una reorganización del citoesqueleto de actina y filamentos intermedios de vimentina después de infecciones con el DV. Hay pérdida de fibras de estrés (actina en células epiteliales, generándose una reorganización distinta. Los filamentos

  10. KDEL Receptors Assist Dengue Virus Exit from the Endoplasmic Reticulum

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    Ming Yuan Li

    2015-03-01

    Full Text Available Membrane receptors at the surface of target cells are key host factors for virion entry; however, it is unknown whether trafficking and secretion of progeny virus requires host intracellular receptors. In this study, we demonstrate that dengue virus (DENV interacts with KDEL receptors (KDELR, which cycle between the ER and Golgi apparatus, for vesicular transport from ER to Golgi. Depletion of KDELR by siRNA reduced egress of both DENV progeny and recombinant subviral particles (RSPs. Coimmunoprecipitation of KDELR with dengue structural protein prM required three positively charged residues at the N terminus, whose mutation disrupted protein interaction and inhibited RSP transport from the ER to the Golgi. Finally, siRNA depletion of class II Arfs, which results in KDELR accumulation in the Golgi, phenocopied results obtained with mutagenized prME and KDELR knockdown. Our results have uncovered a function for KDELR as an internal receptor involved in DENV trafficking.

  11. The antimicrobial peptide HS-1 inhibits dengue virus infection.

    Science.gov (United States)

    Monteiro, Juliana M C; Oliveira, Michelle D; Dias, Roberto S; Nacif-Marçal, Lorena; Feio, Renato N; Ferreira, Sukarno O; Oliveira, Leandro L; Silva, Cynthia C; Paula, Sérgio O

    2018-01-15

    Dengue virus (DENV) is an arbovirus that belongs to the Flaviviridae family. Studies reveal that peptides secreted by amphibians have many functions, such as antiviral and antimicrobial activities. As there is no antiviral drug effective against the DENV, the antiviral activity of a synthetic peptide called HS-1, derived from the secretion of the anuran Hypsiboas semilineatus, has been evaluated. The assays of neutralization in the Vero cells show a complete inhibition of infection of the serotypes 2 and 3. Furthermore, the direct action of peptides on the viral particle can be observed through atomic force microscopy. In vivo tests display 80% protection against the dengue-2 virus due to the presence of HS-1, which reveals its potential as an antiviral against the DENV. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Experimental dengue virus challenge of human subjects previously vaccinated with live attenuated tetravalent dengue vaccines.

    Science.gov (United States)

    Sun, Wellington; Eckels, Kenneth H; Putnak, J Robert; Lyons, Arthur G; Thomas, Stephen J; Vaughn, David W; Gibbons, Robert V; Fernandez, Stefan; Gunther, Vicky J; Mammen, Mammen P; Statler, John D; Innis, Bruce L

    2013-03-01

    Protection against dengue requires immunity against all 4 serotypes of dengue virus (DENV). Experimental challenge may be useful in evaluating vaccine-induced immunity. Ten subjects previously vaccinated with a live attenuated tetravalent dengue vaccine (TDV) and 4 DENV-naive control subjects were challenged by subcutaneous inoculation of either 10(3) plaque-forming units (PFU) of DENV-1 or 10(5) PFU of DENV-3. Two additional subjects who did not develop DENV-3 neutralizing antibody (NAb) from TDV were revaccinated with 10(4) PFU of live attenuated DENV-3 vaccine to evaluate memory response. All 5 TDV recipients were protected against DENV-1 challenge. Of the 5 TDV recipients challenged with DENV-3, 2 were protected. All DENV-3-challenge subjects who developed viremia also developed elevated liver enzyme levels, and 2 had values that were >10 times greater than normal. Of the 2 subjects revaccinated with DENV-3 vaccine, 1 showed a secondary response to DENV-2, while neither showed such response to DENV-3. All 4 control subjects developed dengue fever from challenge. Protection was associated with presence of NAb, although 1 subject was protected despite a lack of measurable NAb at the time of DENV-1 challenge. Vaccination with TDV induced variable protection against subcutaneous challenge. DENV-3 experimental challenge was associated with transient but marked elevations of transaminases.

  13. Anthracene-based Inhibitors of Dengue Virus NS2B-NS3 Protease†

    OpenAIRE

    Tomlinson, Suzanne M.; Watowich, Stanley J.

    2010-01-01

    Dengue virus (DENV) is a mosquito-borne flavivirus that has strained global healthcare systems throughout tropical and subtropical regions of the world. In addition to plaguing developing nations, it has re-emerged in several developed countries with recent outbreaks in the USA (CDC, 2010), Australia (Hanna et al., 2009), Taiwan (Kuan et al., 2010) and France (La Ruche et al., 2010). DENV infection can cause significant disease, including dengue fever, dengue hemorrhagic fever, dengue shock s...

  14. Rapid and Massive Virus-Specific Plasmablast Responses during Acute Dengue Virus Infection in Humans

    Science.gov (United States)

    Onlamoon, Nattawat; Akondy, Rama S.; Perng, Guey C.; Polsrila, Korakot; Chandele, Anmol; Kwissa, Marcin; Pulendran, Bali; Wilson, Patrick C.; Wittawatmongkol, Orasri; Yoksan, Sutee; Angkasekwinai, Nasikarn; Pattanapanyasat, Kovit; Chokephaibulkit, Kulkanya; Ahmed, Rafi

    2012-01-01

    Humoral immune responses are thought to play a major role in dengue virus-induced immunopathology; however, little is known about the plasmablasts producing these antibodies during an ongoing infection. Herein we present an analysis of plasmablast responses in patients with acute dengue virus infection. We found very potent plasmablast responses that often increased more than 1,000-fold over the baseline levels in healthy volunteers. In many patients, these responses made up as much 30% of the peripheral lymphocyte population. These responses were largely dengue virus specific and almost entirely made up of IgG-secreting cells, and plasmablasts reached very high numbers at a time after fever onset that generally coincided with the window where the most serious dengue virus-induced pathology is observed. The presence of these large, rapid, and virus-specific plasmablast responses raises the question as to whether these cells might have a role in dengue immunopathology during the ongoing infection. These findings clearly illustrate the need for a detailed understanding of the repertoire and specificity of the antibodies that these plasmablasts produce. PMID:22238318

  15. Phylogeny of Dengue and Chikungunya viruses in Al Hudayda governorate, Yemen.

    Science.gov (United States)

    Ciccozzi, Massimo; Lo Presti, Alessandra; Cella, Eleonora; Giovanetti, Marta; Lai, Alessia; El-Sawaf, Gamal; Faggioni, Giovanni; Vescio, Fenicia; Al Ameri, Ranya; De Santis, Riccardo; Helaly, Ghada; Pomponi, Alice; Metwally, Dalia; Fantini, Massimo; Qadi, Hussein; Zehender, Gianguglielmo; Lista, Florigio; Rezza, Giovanni

    2014-10-01

    Yemen, which is located in the southwestern end of the Arabian Peninsula, is one of countries most affected by recurrent epidemics caused by emerging vector-borne viruses. Dengue virus (DENV) outbreaks have been reported with increasing frequency in several governorates since the year 2000, and the Chikungunya virus (CHIKV) has been also responsible of large outbreaks and it is now a major public health problem in Yemen. We report the results of the phylogenetic analysis of DENV-2 and CHIKV isolates (NS1 and E1 genes, respectively) detected in an outbreak occurred in Al-Hudayda in 2012. Estimates of the introduction date of CHIKV and DENV-2, and the phylogeographic analysis of DENV-2 are also presented. Phylogenetic analysis showed that the Yemen isolates of DENV belonged to the lineage 2 Cosmopolitan subtype, whereas CHIKV isolates from Yemen belonged to the ECSA genotype. All the CHIKV isolates from Yemen were statistically supported and dated back to the year 2010 (95% HPD: 2009-2011); these sequences showed an alanine in the aminoacid position 226 of the E1 protein. Phylogeographic analysis of DENV-2 virus showed that cluster 1, which included Yemen isolates, dated back to 2003 Burkina Faso strains (95% HPD 1999-2007). The Yemen, cluster dated back to 2011 (95% HPD 2009-2012). Our study sheds light on the global spatiotemporal dynamics of DENV-2 and CHIKV in Yemen. This study reinforces both the need to monitor the spread of CHIKV and DENV, and to apply significant measures for vector control. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Dengue hemorrhagic fever

    Science.gov (United States)

    Hemorrhagic dengue; Dengue shock syndrome; Philippine hemorrhagic fever; Thai hemorrhagic fever; Singapore hemorrhagic fever ... Four different dengue viruses are known to cause dengue hemorrhagic fever. Dengue hemorrhagic fever occurs when a person is bitten by ...

  17. [Neonatal Dengue. Presentation of clinical cases].

    Science.gov (United States)

    Romero-Santacruz, Edith; Lira-Canul, Janeth Jaqueline; Pacheco-Tugores, Fredy; Palma-Chan, Adolfo Gonzalo

    2015-05-01

    Dengue is an infectious disease caused by a flavivirus, with four serotypes, transmitted by the mosquito Aedes aegypti. In Mexico it is a public health problem, especially in the region of central and southeast of the country. The disease can be asymptomatic or present serious forms and even death. It is confirmed by detection of the NS1 Antigen; IgM antibodies, polymerase chain reaction and virus isolation. The vertical transmission to de newborn has been little studied. 7 cases in neonates from November to December 2011 are reported. All patients were male, obtained by caesarean section between 34 and 40 weeks of gestation, whose mothers were enrolled with fever and symptoms associated with dengue disease and serology positive for dengue. Six with positive AgNS1 and one positive IgM; one mother died. All the newborns had positive serology for dengue, 4 with positive AgNS1 and 3 positive IgM. The clinical features of the newborn ranged from asymptomatic to one serious dengue fever, shock and hemorrhage. The symptomatic 6 attended with thrombocytopenia, changes in temperature and unspecific disturbance. The severity of mothers conditioned disrepair product at birth, but not with subsequent gravity of the new born. Vertical trasmission of dengue should be suspected in risk areas, to maintain vigilance and to give early treatment. Also is neccesary promote the realization of specific diagnostic and therapeutic guidelines to the neonatal period.

  18. Mouse models to study dengue virus immunology and pathogenesis

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    Raphaël M. Zellweger

    2014-04-01

    Full Text Available The development of a compelling murine model of dengue virus (DENV infection has been challenging, because dengue virus clinical isolates do not readily replicate or cause pathology in immunocompetent mice. However, research using immunocompromised mice and/or mouse-adapted viruses allows to investigate questions that may be impossible to address in human studies. In this review, we discuss the potential strengths and limitations of existing mouse models of dengue disease. Human studies are descriptive by nature; moreover, the strain, time, and sequence of infection are often unknown. In contrast, in mice, the conditions of infection are well defined and a large number of experimental parameters can be varied at will. Therefore, mouse models offer an opportunity to experimentally test hypotheses that are based on epidemiological observations. In particular, gain-of-function or loss-of-function models can be established to assess how different components of the immune system (either alone or in combination contribute to protection or pathogenesis during secondary infections or after vaccination. In addition, mouse models have been used for pre-clinical testing of antiviral drug or for vaccine development studies. Conclusions based on mouse experiments must be extrapolated to DENV infection in humans with caution due to the inherent limitations of animal models. However, research in mouse models is a useful complement to in vitro and epidemiological data, and may delineate new areas that deserve attention during future human studies.

  19. The Battle between Infection and Host Immune Responses of Dengue Virus and Its Implication in Dengue Disease Pathogenesis

    Science.gov (United States)

    Sun, Peifang; Kochel, Tadeusz J.

    2013-01-01

    Dengue virus (DENV) is a mosquito-transmitted single stranded RNA virus belonging to genus Flavivirus. The virus is endemic in the tropical and subtropical countries of the world, causing diseases classified according to symptoms and severity (from mild to severe) as dengue fever, dengue hemorrhagic fever, and dengue shock syndrome. Among a variety of human cell types targeted by DENV, monocytes, macrophages, and dendritic cells are members of innate immunity, capable of mounting rapid inflammatory responses. These cells are also major antigen presenting cells, responsible for activating the adaptive immunity for long-term memory. This paper is an overview of the current understanding of the following mutually affected aspects: DENV structure, viral infectivity, cellular receptors, innate immune response, and adaptive immunity. PMID:23476150

  20. Recent advances in dengue pathogenesis and clinical management.

    Science.gov (United States)

    Simmons, Cameron P; McPherson, Kirsty; Van Vinh Chau, Nguyen; Hoai Tam, D T; Young, Paul; Mackenzie, Jason; Wills, Bridget

    2015-12-10

    This review describes and commentates on recent advances in the understanding of dengue pathogenesis and immunity, plus clinical research on vaccines and therapeutics. We expand specifically on the role of the dermis in dengue virus infection, the contribution of cellular and humoral immune responses to pathogenesis and immunity, NS1 and mechanisms of virus immune evasion. Additionally we review a series of therapeutic intervention trials for dengue, as well as recent clinical research aimed at improving clinical diagnosis, risk prediction and disease classification. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  1. Molecular characterization of dengue viruses circulating during 2009-2012 in Uttar Pradesh, India.

    Science.gov (United States)

    Mishra, Gitika; Jain, Amita; Prakash, Om; Prakash, Shantanu; Kumar, Rashmi; Garg, Ravindra K; Pandey, Nidhi; Singh, Mastan

    2015-01-01

    Dengue is the most rapidly spreading mosquito-borne viral disease in the world; in India it has taken endemic proportion implicating all the four known dengue virus serotypes. Dengue infection is caused by a small, single stranded RNA virus comprising of four antigenically distinct virus serotypes designated as dengue virus type 1-4 (DENV-1-4). On the basis of genomic variations, each serotype is classified further into its genotypes. Epidemiological studies have shown that the emergence of a newer dengue serotype/genotype after an interval always leads to a major outbreak; therefore a continuous epidemiological surveillance is needed to monitor the epidemiology of dengue viruses. The present study was planned to identify the serotype/genotype of dengue viruses circulating in Uttar Pradesh, India. Of 433 dengue suspected patients, tested by reverse transcriptase PCR (RT-PCR), 136 were positive for dengue virus RNA. Of these, DENV-1, 2, and 3 were detected in 26 (19.1%), 77 (56.6%), and 33 (24.3%) patients, respectively. Of 136 RT-PCR positive samples, 24 samples were sequenced to identify their genotypes. For sequencing C-prM gene junction of dengue virus genome was chosen. Phylogenetic analysis of sequenced dengue strains revealed that all the 12 DENV-1 strains were genotype III, all the eight DENV-2 strains were genotype IV (Cosmopolitan genotype) and among four DENV-3 strains, three were genotype III and one was genotype I. In conclusion, the co-circulation of multiple dengue virus serotypes and genotypes is alarming in U.P., India. © 2014 Wiley Periodicals, Inc.

  2. Structural basis of potent Zika-dengue virus antibody cross-neutralization.

    Science.gov (United States)

    Barba-Spaeth, Giovanna; Dejnirattisai, Wanwisa; Rouvinski, Alexander; Vaney, Marie-Christine; Medits, Iris; Sharma, Arvind; Simon-Lorière, Etienne; Sakuntabhai, Anavaj; Cao-Lormeau, Van-Mai; Haouz, Ahmed; England, Patrick; Stiasny, Karin; Mongkolsapaya, Juthathip; Heinz, Franz X; Screaton, Gavin R; Rey, Félix A

    2016-08-04

    Zika virus is a member of the Flavivirus genus that had not been associated with severe disease in humans until the recent outbreaks, when it was linked to microcephaly in newborns in Brazil and to Guillain-Barré syndrome in adults in French Polynesia. Zika virus is related to dengue virus, and here we report that a subset of antibodies targeting a conformational epitope isolated from patients with dengue virus also potently neutralize Zika virus. The crystal structure of two of these antibodies in complex with the envelope protein of Zika virus reveals the details of a conserved epitope, which is also the site of interaction of the envelope protein dimer with the precursor membrane (prM) protein during virus maturation. Comparison of the Zika and dengue virus immunocomplexes provides a lead for rational, epitope-focused design of a universal vaccine capable of eliciting potent cross-neutralizing antibodies to protect simultaneously against both Zika and dengue virus infections.

  3. Evaluation of antibody response against recombinant domain III proteins of dengue virus type 1 and 2

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    Nagesh K Tripathi

    2017-04-01

    Full Text Available Dengue, a mosquito borne viral disease caused by dengue virus has emerged as a major health problem during the last few decades. The envelope domain III (DIII protein of dengue virus is highly immunogenic and capable of inducing neutralizing antibodies against wild-type dengue virus. The envelope domain III protein is a potential subunit vaccine candidate as well as a diagnostic reagent for dengue. This report describes the high yield production and immunogenicity of recombinant DIII proteins of dengue virus type 1 and 2. The subunit DIII proteins were produced in Escherichia coli using batch and fed-batch fermentation process. Immobilized metal affinity chromatography was used to capture DIII proteins of dengue virus type 1 and 2. The purified proteins were refolded by diafiltration to achieve biologically active proteins. After fed-batch fermentation, the recombinant E. coli resulted in purified DIII proteins of about 10.06 mg and 47.70 mg per gram of dry cell weight for recombinant dengue virus type 1 and 2 respectively with more than 95% purity. Biological function of the purified DIII proteins were confirmed by their ability to generate DIII specific antibodies in mice. The DIII antigens in combination with adjuvant resulted antibody endpoint titers of 1:64,000 and 1:1,28,000 for recombinant dengue virus type 1 and 2 respectively. These findings establish that the DIII proteins in combination with adjuvant are immunogenic, which suggests that refolded and purified DIII proteins can be a potential vaccine candidates.

  4. Comparative analysis of full genomic sequences among different genotypes of dengue virus type 3

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    Lin Ting-Hsiang

    2008-05-01

    Full Text Available Abstract Background Although the previous study demonstrated the envelope protein of dengue viruses is under purifying selection pressure, little is known about the genetic differences of full-length viral genomes of DENV-3. In our study, complete genomic sequencing of DENV-3 strains collected from different geographical locations and isolation years were determined and the sequence diversity as well as selection pressure sites in the DENV genome other than within the E gene were also analyzed. Results Using maximum likelihood and Bayesian approaches, our phylogenetic analysis revealed that the Taiwan's indigenous DENV-3 isolated from 1994 and 1998 dengue/DHF epidemics and one 1999 sporadic case were of the three different genotypes – I, II, and III, each associated with DENV-3 circulating in Indonesia, Thailand and Sri Lanka, respectively. Sequence diversity and selection pressure of different genomic regions among DENV-3 different genotypes was further examined to understand the global DENV-3 evolution. The highest nucleotide sequence diversity among the fully sequenced DENV-3 strains was found in the nonstructural protein 2A (mean ± SD: 5.84 ± 0.54 and envelope protein gene regions (mean ± SD: 5.04 ± 0.32. Further analysis found that positive selection pressure of DENV-3 may occur in the non-structural protein 1 gene region and the positive selection site was detected at position 178 of the NS1 gene. Conclusion Our study confirmed that the envelope protein is under purifying selection pressure although it presented higher sequence diversity. The detection of positive selection pressure in the non-structural protein along genotype II indicated that DENV-3 originated from Southeast Asia needs to monitor the emergence of DENV strains with epidemic potential for better epidemic prevention and vaccine development.

  5. Dengue viruses cleave STING in humans but not in nonhuman primates, their presumed natural reservoir

    Science.gov (United States)

    Stabell, Alex C; Meyerson, Nicholas R; Gullberg, Rebekah C; Gilchrist, Alison R; Webb, Kristofor J; Old, William M; Perera, Rushika

    2018-01-01

    Human dengue viruses emerged from primate reservoirs, yet paradoxically dengue does not reach high titers in primate models. This presents a unique opportunity to examine the genetics of spillover versus reservoir hosts. The dengue virus 2 (DENV2) - encoded protease cleaves human STING, reducing type I interferon production and boosting viral titers in humans. We find that both human and sylvatic (reservoir) dengue viruses universally cleave human STING, but not the STING of primates implicated as reservoir species. The special ability of dengue to cleave STING is thus specific to humans and a few closely related ape species. Conversion of residues 78/79 to the human-encoded ‘RG’ renders all primate (and mouse) STINGs sensitive to viral cleavage. Dengue viruses may have evolved to increase viral titers in the dense and vast human population, while maintaining decreased titers and pathogenicity in the more rare animals that serve as their sustaining reservoir in nature. PMID:29557779

  6. Dengue viruses and promising envelope protein domain III-based vaccines.

    Science.gov (United States)

    Fahimi, Hossein; Mohammadipour, Mahshid; Haddad Kashani, Hamed; Parvini, Farshid; Sadeghizadeh, Majid

    2018-04-01

    Dengue viruses are emerging mosquito-borne pathogens belonging to Flaviviridae family which are transmitted to humans via the bites of infected mosquitoes Aedes aegypti and Aedes albopictus. Because of the wide distribution of these mosquito vectors, more than 2.5 billion people are approximately at risk of dengue infection. Dengue viruses cause dengue fever and severe life-threatening illnesses as well as dengue hemorrhagic fever and dengue shock syndrome. All four serotypes of dengue virus can cause dengue diseases, but the manifestations are nearly different depending on type of the virus in consequent infections. Infection by any serotype creates life-long immunity against the corresponding serotype and temporary immunity to the others. This transient immunity declines after a while (6 months to 2 years) and is not protective against other serotypes, even may enhance the severity of a secondary heterotypic infection with a different serotype through a phenomenon known as antibody-depended enhancement (ADE). Although, it can be one of the possible explanations for more severe dengue diseases in individuals infected with a different serotype after primary infection. The envelope protein (E protein) of dengue virus is responsible for a wide range of biological activities, including binding to host cell receptors and fusion to and entry into host cells. The E protein, and especially its domain III (EDIII), stimulates host immunity responses by inducing protective and neutralizing antibodies. Therefore, the dengue E protein is an important antigen for vaccine development and diagnostic purposes. Here, we have provided a comprehensive review of dengue disease, vaccine design challenges, and various approaches in dengue vaccine development with emphasizing on newly developed envelope domain III-based dengue vaccine candidates.

  7. The citrus flavanone naringenin impairs dengue virus replication in human cells

    OpenAIRE

    Sandra Frabasile; Andrea Cristine Koishi; Diogo Kuczera; Guilherme Ferreira Silveira; Waldiceu Aparecido Verri Jr.; Claudia Nunes Duarte dos Santos; Juliano Bordignon

    2017-01-01

    Dengue is one of the most significant health problems in tropical and sub-tropical regions throughout the world. Nearly 390 million cases are reported each year. Although a vaccine was recently approved in certain countries, an anti-dengue virus drug is still needed. Fruits and vegetables may be sources of compounds with medicinal properties, such as flavonoids. This study demonstrates the anti-dengue virus activity of the citrus flavanone naringenin, a class of flavonoid. Naringenin prevente...

  8. Temperature Increase Enhances Aedes albopictus Competence to Transmit Dengue Virus

    Directory of Open Access Journals (Sweden)

    Zhuanzhuan Liu

    2017-12-01

    Full Text Available Dengue is a mosquito-borne disease that has been an epidemic in China for many years. Aedes albopictus is the dominant Aedes mosquito species and the main vector of dengue in China. Epidemiologically, dengue mainly occurs in Guangdong Province; it does not occur or rarely occurs in other areas of mainland China. This distribution may be associated with climate, mosquito density, and other factors in different regions; however, the effect of temperature on the vector competence of Ae. albopictus for dengue viruses (DENV remains unclear. In this study, Ae. albopictus was orally infected with dengue virus 2 (DENV-2 and reared at constant temperatures (18, 23, 28, and 32°C and a fluctuating temperature (28–23–18°C. The infection status of the midguts, ovaries, and salivary glands of each mosquito was detected by polymerase chain reaction (PCR at 0, 5, 10, and 15 days post-infection (dpi. DENV-2 RNA copies from positive tissues were quantified by quantitative real time PCR (qRT-PCR. At 18°C, DENV-2 proliferated slowly in the midgut of Ae. albopictus, and the virus could not spread to the salivary glands. At 23 and 28°C, DENV-2 was detected in the ovaries and salivary glands at 10 dpi. The rates of infection, dissemination, population transmission, and DENV-2 copies at 28°C were higher than those at 23°C at any time point. At 32°C, the extrinsic incubation period (EIP for DENV-2 in Ae. albopictus was only 5 dpi, and the vector competence was the highest among all the temperatures. Compared with 28°C, at 28–23–18°C, the positive rate and the amount of DENV-2 in the salivary glands were significantly lower. Therefore, temperature is an important factor affecting the vector competence of Ae. albopictus for DENV-2. Within the suitable temperature range, the replication of DENV-2 in Ae. albopictus accelerated, and the EIP was shorter with a higher temperature. Our results provide a guide for vector control and an experimental basis for

  9. Depletion of macrophages in mice results in higher dengue virus titers and highlights the role of macrophages for virus control

    NARCIS (Netherlands)

    Fink, K.; Ng, C.; Nkenfou, C.; Vasudevan, S.G.; Rooijen, van N.; Schul, W.

    2009-01-01

    Monocytes and macrophages are target cells for dengue infection. Besides their potential role for virus replication, activated monocytes/macrophages produce cytokines that may be critical for dengue pathology. To study the in vivo role of monocytes and macrophages for virus replication, we depleted

  10. Isolation of serotype-specific antibodies against dengue virus non-structural protein 1 using phage display and application in a multiplexed serotyping assay.

    Directory of Open Access Journals (Sweden)

    Kebaneilwe Lebani

    Full Text Available The multidimensional nature of dengue virus (DENV infections, which can be caused by four distinct serotypes of the virus, complicates the sensitivity of assays designed for the diagnosis of infection. Different viral markers can be optimally detected at different stages of infection. Of particular clinical importance is the early identification of infection, which is pivotal for disease management and the development of blood screening assays. Non-structural protein 1 (NS1 is an early surrogate marker of infection and its detection in serum coincides with detectable viraemia. The aim of this work was to isolate and characterise serotype-specific monoclonal antibodies that bind to NS1 for each of the four DENV serotypes. This was achieved using phage display and a subtractive biopanning strategy to direct the antibody selection towards serotype-specific epitopes. This antibody isolation strategy has advantages over immunisation techniques where it is difficult to avoid antibody responses to cross-reactive, immunodominant epitopes. Serotype specificity to recombinant antigen for each of the antibodies was confirmed by Enzyme Linked Immunosorbent Assay (ELISA and Surface Plasmon Resonance. Confirmation of binding to native DENV NS1 was achieved using ELISA and immunofluorescence assay on DENV infected Vero cells. No cross-reactivity with Zika or Kunjin viruses was observed. A previously isolated pan-reactive antibody that binds to an immunodominant epitope was able to pair with each of the serotype-specific antibodies in a sandwich ELISA, indicating that the serotype specific antibodies bind to epitopes which are all spatially distinct from the immunodominant epitope. These antibodies were suitable for use in a multiplexed assay for simultaneous detection and serotyping of DENV NS1 in human serum. This work demonstrates that phage display coupled with novel biopanning strategies is a valuable in vitro methodology for isolation of binders that can

  11. Isolation of serotype-specific antibodies against dengue virus non-structural protein 1 using phage display and application in a multiplexed serotyping assay.

    Science.gov (United States)

    Lebani, Kebaneilwe; Jones, Martina L; Watterson, Daniel; Ranzoni, Andrea; Traves, Renee J; Young, Paul R; Mahler, Stephen M

    2017-01-01

    The multidimensional nature of dengue virus (DENV) infections, which can be caused by four distinct serotypes of the virus, complicates the sensitivity of assays designed for the diagnosis of infection. Different viral markers can be optimally detected at different stages of infection. Of particular clinical importance is the early identification of infection, which is pivotal for disease management and the development of blood screening assays. Non-structural protein 1 (NS1) is an early surrogate marker of infection and its detection in serum coincides with detectable viraemia. The aim of this work was to isolate and characterise serotype-specific monoclonal antibodies that bind to NS1 for each of the four DENV serotypes. This was achieved using phage display and a subtractive biopanning strategy to direct the antibody selection towards serotype-specific epitopes. This antibody isolation strategy has advantages over immunisation techniques where it is difficult to avoid antibody responses to cross-reactive, immunodominant epitopes. Serotype specificity to recombinant antigen for each of the antibodies was confirmed by Enzyme Linked Immunosorbent Assay (ELISA) and Surface Plasmon Resonance. Confirmation of binding to native DENV NS1 was achieved using ELISA and immunofluorescence assay on DENV infected Vero cells. No cross-reactivity with Zika or Kunjin viruses was observed. A previously isolated pan-reactive antibody that binds to an immunodominant epitope was able to pair with each of the serotype-specific antibodies in a sandwich ELISA, indicating that the serotype specific antibodies bind to epitopes which are all spatially distinct from the immunodominant epitope. These antibodies were suitable for use in a multiplexed assay for simultaneous detection and serotyping of DENV NS1 in human serum. This work demonstrates that phage display coupled with novel biopanning strategies is a valuable in vitro methodology for isolation of binders that can discern amongst

  12. IgG against dengue virus in healthy blood donors, Zanzibar, Tanzania.

    Science.gov (United States)

    Vairo, Francesco; Nicastri, Emanuele; Yussuf, Salma Masauni; Cannas, Angela; Meschi, Silvia; Mahmoud, Mwanakheir A A; Mohamed, Azza H; Maiko, Paul Mohamed; De Nardo, Pasquale; Bevilacqua, Nazario; Castilletti, Concetta; Di Caro, Antonino; Racalbuto, Vincenzo; Ippolito, Giuseppe

    2014-03-01

    We conducted a seroprevalence survey among 500 healthy adult donors at Zanzibar National Blood Transfusion Services. Dengue virus IgG seroprevalence was 50.6% and independently associated with age and urban residence. These data will aid in building a surveillance, preparedness, and response plan for dengue virus infections in the Zanzibar Archipelago.

  13. Use of Insecticide-Treated House Screens to Reduce Infestations of Dengue Virus Vectors, Mexico

    Science.gov (United States)

    Manrique-Saide, Pablo; Che-Mendoza, Azael; Barrera-Perez, Mario; Guillermo-May, Guillermo; Herrera-Bojorquez, Josue; Dzul-Manzanilla, Felipe; Gutierrez-Castro, Cipriano; Lenhart, Audrey; Vazquez-Prokopec, Gonzalo; Sommerfeld, Johannes; McCall, Philip J.; Kroeger, Axel

    2015-01-01

    Dengue prevention efforts rely on control of virus vectors. We investigated use of insecticide-treated screens permanently affixed to windows and doors in Mexico and found that the screens significantly reduced infestations of Aedes aegypti mosquitoes in treated houses. Our findings demonstrate the value of this method for dengue virus vector control. PMID:25625483

  14. Dengue virus cell entry : Unraveling the role of antibodies, maturation status, and antiviral drugs

    NARCIS (Netherlands)

    Ayala Nunez, Vanesa

    2014-01-01

    Antibody-dependent enhancement (ADE) is thought to play a critical role in the exacerbation of dengue virus-induced disease during a heterologous re-infection. Pre-existing cross-reactive anti-dengue antibodies are generally believed to bind to the newly infecting DENV and target the antibody-virus

  15. Increasing usage of rapid diagnostics for Dengue virus detection in Pakistan

    International Nuclear Information System (INIS)

    Hasan, Z.; Razzak, S.; Farhan, M.; Rahim, M.; Islam, N.; Samreen, A.; Khan, E.

    2017-01-01

    To evaluate the trends in usage of dengue virus diagnostics in Pakistan. Methods: This retrospective study was conducted at the Aga Khan University Hospital, Karachi, and comprised data for specimens tested for dengue virus from January 2012 to December 2015. Test for dengue virus ribonucleic acid by reverse transcription polymerase chain reaction, dengue virus antigen by immunochromatic assay and for human immunoglobulin M against dengue virus by enzyme-linked immunosorbent assay were reviewed. SPSS 17 was used for data analysis. Results: Overall, 33,577 specimens tested for dengue virus. Of them, 11,995 (35.7%) were positive. among them, 1,039(8.66%) were reported in 2012; 5,791(48.28%) in 2013; 1,027(8.56%) in 2014; and 4,138(34.49%) in 2015. In 2012, 966(93%) of the positive samples were diagnosed by immunoglobulin M-based method and 73(7%) by non-structural protein-1 antigen. In 2013, 4,401(76%) samples were tested positive by immunoglobulin M, 1,332(23%) by antigen and 58(1%) by polymerase chain reaction. The trend continued in 2014, but in 2015, 2,111(51%) of all dengue positive tests were determined by antigen testing, 1,969(47.6%) by immunoglobulin M and 58(1.4%) by polymerase chain reaction. Conclusion: There was a shift in usage of direct virus identification for rapid diagnosis of dengue virus compared with host immunoglobulin M testing. (author)

  16. Use of insecticide-treated house screens to reduce infestations of dengue virus vectors, Mexico.

    Science.gov (United States)

    Manrique-Saide, Pablo; Che-Mendoza, Azael; Barrera-Perez, Mario; Guillermo-May, Guillermo; Herrera-Bojorquez, Josue; Dzul-Manzanilla, Felipe; Gutierrez-Castro, Cipriano; Lenhart, Audrey; Vazquez-Prokopec, Gonzalo; Sommerfeld, Johannes; McCall, Philip J; Kroeger, Axel; Arredondo-Jimenez, Juan I

    2015-02-01

    Dengue prevention efforts rely on control of virus vectors. We investigated use of insecticide-treated screens permanently affixed to windows and doors in Mexico and found that the screens significantly reduced infestations of Aedes aegypti mosquitoes in treated houses. Our findings demonstrate the value of this method for dengue virus vector control.

  17. Breast milk as a possible route of vertical transmission of dengue virus?

    Science.gov (United States)

    Barthel, Anne; Gourinat, Ann-Claire; Cazorla, Cécile; Joubert, Corinne; Dupont-Rouzeyrol, Myrielle; Descloux, Elodie

    2013-08-01

    We report a case of vertical transmission of dengue infection. The virus was detected and quantified by reverse-transcription polymerase chain reaction in sequential blood samples from mother and child as well as in breast milk, but not in cord blood. This case poses questions about the risk of breastfeeding transmission of dengue virus.

  18. [Dengue fever cases in Czech workers returning from the Maldives].

    Science.gov (United States)

    Trojánek, Milan; Tomíčková, Dora; Roháčová, Hana; Kosina, Pavel; Gebouský, Jan; Dvořák, Jan; Chmelik, Vaclav; Batistová, Květoslava; Husa, Petr; Maixner, Jan; Sojková, Naděžda; Zelená, Hana; Marešová, Vilma; Stejskal, František

    2013-09-01

    The objective of this study is to present epidemiological characteristics and clinical symptoms of dengue fever cases in Czech workers who acquired the infection while working on the island of Fushivelavaru, Maldives. Furthermore, the study compares the sensitivity of novel direct detection assays, i.e. Real-Time Polymerase Chain Reaction (RT-PCR) and detection of Dengue NS1 antigen. The retrospective study evaluated the clinical course of dengue fever cases in Czech workers returning from a job in the Maldives who were diagnosed with dengue virus infection from September 1 to October 31, 2012. The laboratory diagnosis of dengue fever was based on the serological detection of IgM and IgG antibodies, detection of dengue NS1 antigen by enzyme-linked immunosobent assay (ELISA), and detection of dengue virus DNA by RT-PCR. The infection with dengue virus was confirmed in 18 males with a median age of 40 years (IQR 36-47) who returned from a job in the Maldives. Only one patient required admission to the hospital while the others were treated on an outpatient basis. The most frequently observed symptoms were fever (18), headache (9), muscle and joint pain (8 and 7, respectively), and rash (9). Typical laboratory findings were leukocytopenia and thrombocytopenia, a low CRP level, and elevated aminotransferase activity. The clinical course was uncomplicated in all patients. The dengue NS1 antigen detection (positive in all 10 patients with acute dengue fever) showed significantly higher sensitivity than the detection of viral RNA using RT-PCR (positive in 4 patients), p = 0.011. Although the vast majority of dengue fever cases are diagnosed among travellers returning from the tropics, the presented study points out the risks posed by dengue fever to long-term workers in endemic areas. The infection in the serologically naïve hosts is usually uncomplicated; however, infected persons are at significant risk of developing a severe complicated clinical course if challenged

  19. Vectors expressing chimeric Japanese encephalitis dengue 2 viruses.

    Science.gov (United States)

    Wei, Y; Wang, S; Wang, X

    2014-01-01

    Vectors based on self-replicating RNAs (replicons) of flaviviruses are becoming powerful tool for expression of heterologous genes in mammalian cells and development of novel antiviral and anticancer vaccines. We constructed two vectors expressing chimeric viruses consisting of attenuated SA14-14-2 strain of Japanese encephalitis virus (JEV) in which the PrM/M-E genes were replaced fully or partially with those of dengue 2 virus (DENV-2). These vectors, named pJED2 and pJED2-1770 were transfected to BHK-21 cells and produced chimeric viruses JED2V and JED2-1770V, respectively. The chimeric viruses could be passaged in C6/36 but not BHK-21 cells. The chimeric viruses produced in C6/36 cells CPE 4-5 days after infection and RT-PCR, sequencing, immunofluorescence assay (IFA) and Western blot analysis confirmed the chimeric nature of produced viruses. The immunogenicity of chimeric viruses in mice was proved by detecting DENV-2 E protein-specific serum IgG antibodies with neutralization titer of 10. Successful preparation of infectious clones of chimeric JEV-DENV-2 viruses showed that JEV-based expression vectors are fully functional.

  20. Elevated levels of cell-free circulating DNA in patients with acute dengue virus infection.

    Directory of Open Access Journals (Sweden)

    Tran Thi Ngoc Ha

    Full Text Available BACKGROUND: Apoptosis is thought to play a role in the pathogenesis of severe dengue and the release of cell-free DNA into the circulatory system in several medical conditions. Therefore, we investigated circulating DNA as a potential biomarker for severe dengue. METHODS AND FINDINGS: A direct fluorometric degradation assay using PicoGreen was performed to quantify cell-free DNA from patient plasma. Circulating DNA levels were significantly higher in patients with dengue virus infection than with other febrile illnesses and healthy controls. Remarkably, the increase of DNA levels correlated with the severity of dengue. Additionally, multivariate logistic regression analysis showed that circulating DNA levels independently correlated with dengue shock syndrome. CONCLUSIONS: Circulating DNA levels were increased in dengue patients and correlated with dengue severity. Additional studies are required to show the benefits of this biomarker in early dengue diagnosis and for the prognosis of shock complication.

  1. Dengue virus-specific, human CD4+ CD8- cytotoxic T-cell clones: multiple patterns of virus cross-reactivity recognized by NS3-specific T-cell clones.

    OpenAIRE

    Kurane, I; Brinton, M A; Samson, A L; Ennis, F A

    1991-01-01

    Thirteen dengue virus-specific, cytotoxic CD4+ CD8- T-cell clones were established from a donor who was infected with dengue virus type 3. These clones were examined for virus specificity and human leukocyte antigen (HLA) restriction in cytotoxic assays. Six patterns of virus specificities were determined. Two serotype-specific clones recognized only dengue virus type 3. Two dengue virus subcomplex-specific clones recognized dengue virus types 2, 3, and 4, and one subcomplex-specific clone re...

  2. Penentuan Serotipe Virus Dengue dan Gambaran Manifestasi Klinis serta Hematologi Rutin pada Infeksi Virus Dengue

    Directory of Open Access Journals (Sweden)

    Basti Andriyoko

    2012-12-01

    Full Text Available All DENV serotypes can cause a spectrum of disease from dengue fever (DF to dengue hemorrhagic fever (DHF and dengue shock syndrome (DSS. It is difficult to differentiate clinical characteristicand hematologic result for each serotype. Aim of this study were to determine dengue serotype and describe clinical manifestation of DF, DHF, DSS and routine hematologic results, i.e.haemoglobin, hematocrit, leukocyte, and thrombocyte in each serotype. This study was conducted at Dr. Hasan Sadikin Hospital Bandung from March 2010 until July 2011. Subjects were dengue patients aged >14 years with a history of fever <5 days. Blood samples were taken for serotype determination by reverse transcription polymerase chain reaction (RT-PCR followed by semi-nested PCR. Clinical manifestation data and haematologic result were obtained from medical records. This was a descriptive study. Seventy five patients were included in this study. Dengue serotype can be detected in 27 (36% samples with DENV-3 (13 were dominating followed by DENV-2 (8, DENV-4 (4, and DENV-1 (2. DHF was mainly found in DENV-3. DENV-2 gavethe highest decrease in hemoglobin, highest percentage increase in haematocrit, lowest leukocyte, and lowest thrombocyte. In conclusion, all 4 serotypes are found in RSUP Dr. Hasan Sadikin Hospital Bandung with DENV-3 domination. DHF is mainly caused by DENV-3.

  3. Characterization of dengue virus entry into HepG2 cells

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    Suksanpaisan Lukkana

    2009-02-01

    Full Text Available Abstract Background Despite infections by the dengue virus being a significant problem in tropical and sub-tropical countries, the mechanism by which the dengue virus enters into mammalian cells remains poorly described. Methods A combination of biochemical inhibition, dominant negative transfection of Eps15 and siRNA mediated gene silencing was used to explore the entry mechanism of dengue into HepG2 cells. Results Results were consistent with entry via multiple pathways, specifically via clathrin coated pit mediated endocytosis and macropinocytosis, with clathrin mediated endocytosis being the predominant pathway. Conclusion We propose that entry of the dengue virus to mammalian cells can occur by multiple pathways, and this opens the possibility of the virus being directed to multiple cellular compartments. This would have significant implications in understanding the interaction of the dengue virus with the host cell machinery.

  4. Genetic signatures coupled with lineage shift characterise endemic evolution of Dengue virus serotype 2 during 2015 outbreak in Delhi, India.

    Science.gov (United States)

    Choudhary, Manish Chandra; Gupta, Ekta; Sharma, Shvetank; Hasnain, Nadeem; Agarwala, Pragya

    2017-07-01

    In 2015, New Delhi witnessed a massive outbreak of Dengue virus (DENV) resulting in high morbidity and mortality. We report the molecular characterisation of the dominant circulating DENV strain to understand its evolution and dispersal. DENV infections were diagnosed by detection of IgM/NS1 antigen, and serotyping was performed by C-PrM PCR. Envelope gene was amplified, and variation(s) in envelope gene were analysed. Phylogenetic tree construction, time-based phylogeny and origin of DENV were analysed. Site-specific selection pressure of envelope gene variants was analysed. Confirmed DENV infection was observed in 11.34% (32 of 282) cases, while PCR positivity for C-PrM region was observed in 54.16% (13 of 24) of NS1 antigen-positive cases. All samples belonged to serotype 2 and cosmopolitan genotype. Phylogenetic analysis using envelope gene revealed segregation of cosmopolitan genotype strains into specific lineages. The Indian strains clustered separately forming a distinct monophyletic lineage (lineage III) with a signature amino acid substitution viz., I162V and R288K. Selection pressure analysis revealed that 215D, 288R and 304K were positively selected sites. The rate of nucleotide substitution was 6.93 × 10 -4 substitutions site-1 year-1 with time to most common ancestor was around 10 years with JX475906 (Hyderabad strain) and JN030345 (Singapore strain) as its most probable ancestor. We observed evolution of a distinct lineage of DENV-2 strains on the Indian subcontinent with possible changes in endemic circulating dengue strains that might give rise to more pathogenic strains. © 2017 John Wiley & Sons Ltd.

  5. Vector competence of Malaysian Aedes albopictus with and without Wolbachia to four dengue virus serotypes.

    Science.gov (United States)

    Joanne, Sylvia; Vythilingam, Indra; Teoh, Boon-Teong; Leong, Cherng-Shii; Tan, Kim-Kee; Wong, Meng-Li; Yugavathy, Nava; AbuBakar, Sazaly

    2017-09-01

    To determine the susceptibility status of Aedes albopictus with and without Wolbachia to the four dengue virus serotypes. Two newly colonised colonies of Ae. albopictus from the wild were used for the study. One colony was naturally infected with Wolbachia while in the other Wolbachia was removed by tetracycline treatment. Both colonies were orally infected with dengue virus-infected fresh blood meal. Dengue virus load was measured using quantitative RT-PCR at four-time intervals in the salivary glands, midguts and ovaries. Wolbachia did not significantly affect Malaysian Ae. albopictus dengue infection or the dissemination rate for all four dengue virus serotypes. Malaysian Ae. albopictus had the highest replication kinetics for DENV-1 and the highest salivary gland and midgut infection rate for DENV-4. Wolbachia, which naturally exists in Malaysian Ae. albopictus, does not significantly affect dengue virus replication. Malaysian Ae. albopictus is susceptible to dengue virus infections and capable of transmitting dengue virus, especially DENV-1 and DENV-4. Removal of Wolbachia from Malaysian Ae. albopictus would not reduce their susceptibility status. © 2017 John Wiley & Sons Ltd.

  6. Detection of dengue group viruses by fluorescence in situ hybridization

    Directory of Open Access Journals (Sweden)

    Raquin Vincent

    2012-10-01

    Full Text Available Abstract Background Dengue fever (DF and dengue hemorrhagic fever (DHF represent a global challenge in public health. It is estimated that 50 to 100 million infections occur each year causing approximately 20,000 deaths that are usually linked to severe cases like DHF and dengue shock syndrome. The causative agent of DF is dengue virus (genus Flavivirus that comprises four distinct serotypes (DENV-1 to DENV-4. Fluorescence in situ hybridization (FISH has been used successfully to detect pathogenic agents, but has not been implemented in detecting DENV. To improve our understanding of DENV infection and dissemination in host tissues, we designed specific probes to detect DENV in FISH assays. Methods Oligonucleotide probes were designed to hybridize with RNA from the broadest range of DENV isolates belonging to the four serotypes, but not to the closest Flavivirus genomes. Three probes that fit the criteria defined for FISH experiments were selected, targeting both coding and non-coding regions of the DENV genome. These probes were tested in FISH assays against the dengue vector Aedes albopictus (Diptera: Culicidae. The FISH experiments were led in vitro using the C6/36 cell line, and in vivo against dissected salivary glands, with epifluorescence and confocal microscopy. Results The three 60-nt oligonucleotides probes DENV-Probe A, B and C cover a broad range of DENV isolates from the four serotypes. When the three probes were used together, specific fluorescent signals were observed in C6/36 infected with each DENV serotypes. No signal was detected in either cells infected with close Flavivirus members West Nile virus or yellow fever virus. The same protocol was used on salivary glands of Ae. albopictus fed with a DENV-2 infectious blood-meal which showed positive signals in the lateral lobes of infected samples, with no significant signal in uninfected mosquitoes. Conclusion Based on the FISH technique, we propose a way to design and use

  7. Susceptibility of Indigenous and Transplanted Mosquito Spp. to Dengue Virus in Japan.

    Science.gov (United States)

    Sasaki, Toshinori; Higa, Yukiko; Bertuso, Arlene G; Isawa, Haruhiko; Takasaki, Tomohiko; Minakawa, Noboru; Sawabe, Kyoko

    2015-01-01

    Dengue fever, an acute, mosquito-borne, febrile illness caused by Flavivirus spp., is a problem in Africa, South and Southeast Asia, Latin America, and the Caribbean. A dengue outbreak occurred after nearly 70 years of absence or no detection, and then 158 autochthonous cases occurred in Japan from August to October 15, 2014. The most competent mosquito vectors for dengue virus transmission were Aedes aegypti and A. albopictus. Since A. albopictus is widely distributed across Japan and A. aegypti recently invaded Japan by airplane, we examined the susceptibility of these species to infection by dengue virus.

  8. Progress in the Identification of Dengue Virus Entry/Fusion Inhibitors

    Science.gov (United States)

    2014-01-01

    Dengue fever, a reemerging disease, is putting nearly 2.5 billion people at risk worldwide. The number of infections and the geographic extension of dengue fever infection have increased in the past decade. The disease is caused by the dengue virus, a flavivirus that uses mosquitos Aedes sp. as vectors. The disease has several clinical manifestations, from the mild cold-like illness to the more serious hemorrhagic dengue fever and dengue shock syndrome. Currently, there is no approved drug for the treatment of dengue disease or an effective vaccine to fight the virus. Therefore, the search for antivirals against dengue virus is an active field of research. As new possible receptors and biological pathways of the virus biology are discovered, new strategies are being undertaken to identify possible antiviral molecules. Several groups of researchers have targeted the initial step in the infection as a potential approach to interfere with the virus. The viral entry process is mediated by viral proteins and cellular receptor molecules that end up in the endocytosis of the virion, the fusion of both membranes, and the release of viral RNA in the cytoplasm. This review provides an overview of the targets and progress that has been made in the quest for dengue virus entry inhibitors. PMID:25157370

  9. Immunogenicity of novel Dengue virus epitopes identified by bioinformatic analysis.

    Science.gov (United States)

    Sánchez-Burgos, Gilma; Ramos-Castañeda, José; Cedillo-Rivera, Roberto; Dumonteil, Eric

    2010-10-01

    We used T cell epitope prediction tools to identify epitopes from Dengue virus polyprotein sequences, and evaluated in vivo and in vitro the immunogenicity and antigenicity of the corresponding synthetic vaccine candidates. Twenty-two epitopes were predicted to have a high affinity for MHC class I (H-2Kd, H-2Dd, H-2Ld alleles) or class II (IAd alleles). These epitopes were conserved between the four virus serotypes, but with no similarity to human and mouse sequences. Thirteen synthetic peptides induced specific antibodies production with or without T cells activation in mice. Three synthetic peptides induced mostly IgG antibodies, and one of these from the E gene induced a neutralizing response. Ten peptides induced a combination of humoral and cellular responses by CD4+ and CD8+ T cells. Twelve peptides were novel B and T cell epitopes. These results indicate that our bioinformatics strategy is a powerful tool for the identification of novel antigens and its application to human HLA may lead to a potent epitope-based vaccine against Dengue virus and many other pathogens. (c) 2010 Elsevier B.V. All rights reserved.

  10. Drug repurposing of minocycline against dengue virus infection.

    Science.gov (United States)

    Leela, Shilpa Lekshmi; Srisawat, Chatchawan; Sreekanth, Gopinathan Pillai; Noisakran, Sansanee; Yenchitsomanus, Pa-Thai; Limjindaporn, Thawornchai

    2016-09-09

    Dengue virus infection is one of the most common arthropod-borne viral diseases. A complex interplay between host and viral factors contributes to the severity of infection. The antiviral effects of three antibiotics, lomefloxacin, netilmicin, and minocycline, were examined in this study, and minocycline was found to be a promising drug. This antiviral effect was confirmed in all four serotypes of the virus. The effects of minocycline at various stages of the viral life cycle, such as during viral RNA synthesis, intracellular envelope protein expression, and the production of infectious virions, were examined and found to be significantly reduced by minocycline treatment. Minocycline also modulated host factors, including the phosphorylation of extracellular signal-regulated kinase1/2 (ERK1/2). The transcription of antiviral genes, including 2'-5'-oligoadenylate synthetase 1 (OAS1), 2'-5'-oligoadenylate synthetase 3 (OAS3), and interferon α (IFNA), was upregulated by minocycline treatment. Therefore, the antiviral activity of minocycline may have a potential clinical use against Dengue virus infection. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Dengue virus type 3 in Brazil: a phylogenetic perspective

    Directory of Open Access Journals (Sweden)

    Josélio Maria Galvão de Araújo

    2009-05-01

    Full Text Available Circulation of a new dengue virus (DENV-3 genotype was recently described in Brazil and Colombia, but the precise classification of this genotype has been controversial. Here we perform phylogenetic and nucleotide-distance analyses of the envelope gene, which support the subdivision of DENV-3 strains into five distinct genotypes (GI to GV and confirm the classification of the new South American genotype as GV. The extremely low genetic distances between Brazilian GV strains and the prototype Philippines/L11423 GV strain isolated in 1956 raise important questions regarding the origin of GV in South America.

  12. Dengue virus presence and surveillance in Okinawa (Review)

    Science.gov (United States)

    SAKUDO, AKIKAZU; ONODERA, TAKASHI; SHINTANI, HIDEHARU; IKUTA, KAZUYOSHI

    2012-01-01

    Recent reports have shown that the dengue virus (DENV) is a serious concern worldwide, especially in subtropical areas such as South-East Asia. With the development of transportation systems, the risk of DENV infection spreading is increasing. Since mosquitoes transmit DENV to humans, surveillance of DENV-infected mosquito vectors is the most effective approach for preventing DENV. Okinawa is the only prefecture located in a subtropical region in Japan and historically shows continuous importation of DENV-related mosquito vectors. In this review, we describe the current and historical status of DENV in Okinawa. PMID:22969837

  13. Dengue: a trilogy of people, mosquitoes and the virus. Current epidemiology and pathogenesis in (non-)endemic settings

    NARCIS (Netherlands)

    Thai, K.T.D.

    2012-01-01

    Dengue consists of a spectrum of disease manifestations caused by four serotypes of Dengue virus, the most prevalent arthropod-borne virus affecting humans in the tropics and subtropics. The incidence of dengue and its geographical distribution have increased dramatically in the past 6 decades.

  14. Viremia and Clinical Presentation in Nicaraguan Patients Infected With Zika Virus, Chikungunya Virus, and Dengue Virus.

    Science.gov (United States)

    Waggoner, Jesse J; Gresh, Lionel; Vargas, Maria Jose; Ballesteros, Gabriela; Tellez, Yolanda; Soda, K James; Sahoo, Malaya K; Nuñez, Andrea; Balmaseda, Angel; Harris, Eva; Pinsky, Benjamin A

    2016-12-15

     Zika virus (ZIKV), chikungunya virus (CHIKV), and dengue virus (DENV) cocirculate in Nicaragua. In this study, we sought to compare the quantified viremia and clinical presentation of patients infected with 1 or more of these viruses.  Acute-phase serum samples from 346 patients with a suspected arboviral illness were tested using a multiplex real-time reverse-transcription polymerase chain reaction for ZIKV, CHIKV, and DENV. Viremia was quantitated for each detected virus, and clinical information from request forms submitted with each sample was recorded.  A total of 263 patients tested positive for 1 or more viruses: 192 patients tested positive for a single virus (monoinfections) and 71 patients tested positive for 2 or all 3 viruses (coinfections). Quantifiable viremia was lower in ZIKV infections compared with CHIKV or DENV (mean 4.70 vs 6.42 and 5.84 log 10 copies/mL serum, respectively; P virus, mean viremia was significantly lower in coinfections than in monoinfections. Compared with patients with CHIKV or DENV, ZIKV patients were more likely to have a rash (P < .001) and less likely to be febrile (P < .05) or require hospitalization (P < .001). Among all patients, hospitalized cases had higher viremia than those who did not require hospitalization (7.1 vs 4.1 log10 copies/mL serum, respectively; P < .001).  ZIKV, CHIKV, and DENV result in similar clinical presentations, and coinfections may be relatively common. Our findings illustrate the need for accurate, multiplex diagnostics for patient care and epidemiologic surveillance. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America.

  15. Mouse models of dengue virus infection for vaccine testing.

    Science.gov (United States)

    Sarathy, Vanessa V; Milligan, Gregg N; Bourne, Nigel; Barrett, Alan D T

    2015-12-10

    Dengue is a mosquito-borne disease caused by four serologically and genetically related viruses termed DENV-1 to DENV-4. With an annual global burden of approximately 390 million infections occurring in the tropics and subtropics worldwide, an effective vaccine to combat dengue is urgently needed. Historically, a major impediment to dengue research has been development of a suitable small animal infection model that mimics the features of human illness in the absence of neurologic disease that was the hallmark of earlier mouse models. Recent advances in immunocompromised murine infection models have resulted in development of lethal DENV-2, DENV-3 and DENV-4 models in AG129 mice that are deficient in both the interferon-α/β receptor (IFN-α/β R) and the interferon-γ receptor (IFN-γR). These models mimic many hallmark features of dengue disease in humans, such as viremia, thrombocytopenia, vascular leakage, and cytokine storm. Importantly AG129 mice develop lethal, acute, disseminated infection with systemic viral loads, which is characteristic of typical dengue illness. Infected AG129 mice generate an antibody response to DENV, and antibody-dependent enhancement (ADE) models have been established by both passive and maternal transfer of DENV-immune sera. Several steps have been taken to refine DENV mouse models. Viruses generated by peripheral in vivo passages incur substitutions that provide a virulent phenotype using smaller inocula. Because IFN signaling has a major role in immunity to DENV, mice that generate a cellular immune response are desired, but striking the balance between susceptibility to DENV and intact immunity is complicated. Great strides have been made using single-deficient IFN-α/βR mice for DENV-2 infection, and conditional knockdowns may offer additional approaches to provide a panoramic view that includes viral virulence and host immunity. Ultimately, the DENV AG129 mouse models result in reproducible lethality and offer multiple

  16. Multiple dengue serotypes and high frequency of dengue hemorrhagic fever at two tertiary care hospitals in Lahore during the 2008 dengue virus outbreak in Punjab, Pakistan.

    Science.gov (United States)

    Humayoun, Malik Asif; Waseem, Tariq; Jawa, Ali A; Hashmi, Mubashar S; Akram, Javed

    2010-09-01

    The objective of this study was to investigate the clinical characteristics of patients with dengue viral infection during the 2008 outbreak in Lahore in order to better understand the clinical pattern and severity of disease in Lahore. We analyzed the clinical characteristics of 110 patients infected with dengue virus; data were collected on standardized data collection sheets at two tertiary care hospitals from September to December 2008. Dengue infection was confirmed serologically or by real-time polymerase chain reaction (RT-PCR). Out of the total of 110 dengue infected patients, 70 were male and 40 were female. The most common symptoms included fever (100%), myalgia (68.2%), headache (55.5%), nausea (39.1%), skin rash (53.6%), mucocutaneous hemorrhagic manifestations (58.2%), and ocular pain (20%). Classic dengue fever (DF) was seen in 41.8% of the patients, 56.4% had dengue hemorrhagic fever (DHF), and only 1.8% developed dengue shock syndrome (DSS). The mean duration of fever was 6 days. Thrombocytopenia, leukopenia, and abnormal aspartate aminotransferase (AST)/alanine aminotransferase (ALT) were more frequently encountered in DHF and DSS as compared to DF. Viral RNA detection was done by RT-PCR in 17 patients. Ten patients had DEN4, five had DEN2, and two had DEN3 serotypes. The majority of the patients recovered completely without complications. The high frequency of DHF during the 2008 outbreak and the presence of three different dengue serotypes, emphasize the need to prevent and control dengue infection. Health authorities should consider strengthening surveillance for dengue infection, given the potential for future outbreaks with increased severity. It is also suggested that primary care physicians should be educated regarding recognition of DHF and to identify patients at high risk of developing DHF and DSS. Copyright © 2010 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  17. Cross reactivity of commercial anti-dengue immunoassays in patients with acute Zika virus infection.

    Science.gov (United States)

    Felix, Alvina Clara; Souza, Nathalia C Santiago; Figueiredo, Walter M; Costa, Angela A; Inenami, Marta; da Silva, Rosangela M G; Levi, José Eduardo; Pannuti, Claudio Sergio; Romano, Camila Malta

    2017-08-01

    Several countries have local transmission of multiple arboviruses, in particular, dengue and Zika viruses, which have recently spread through many American countries. Cross reactivity among Flaviviruses is high and present a challenge for accurate identification of the infecting agent. Thus, we evaluated the level of cross reactivity of anti-dengue IgM/G Enzyme-Linked Immunosorbent Assays (ELISA) from three manufacturers against 122 serum samples obtained at two time-points from 61 patients with non-dengue confirmed Zika virus infection. All anti-dengue ELISAs cross reacted with serum from patients with acute Zika infection at some level and a worrisome number of seroconversion for dengue IgG and IgM was observed. These findings may impact the interpretation of currently standard criteria for dengue diagnosis in endemic regions. © 2017 Wiley Periodicals, Inc.

  18. Pathogenesis of Dengue Vaccine Viruses in Mosquitoes.

    Science.gov (United States)

    1980-01-01

    per ml. . h Tabl , Yellow fever virus infection rates obtained with heparinized Vertebrate bloods Blood Source Rabbit Guinea g Chicken tk~nkcy Aedes ...were similar. A mosquito inoculation-headsquash-immuno]uflorosecncr te(hni(que was found to L be more sensitive than Aedes albopictus cells(C6/306...12 B. Efficiency of per os infection studies . . . . . .. 13 C. Comparison of Aedes albopictus (C6/3A) cell line and mosquito

  19. Dengue virus surveillance: Detection of DENV-4 in the city of São José do Rio Preto, SP, Brazil.

    Science.gov (United States)

    Colombo, Tatiana Elias; Vedovello, Danila; Pacca-Mazaro, Carolina Colombelli; Mondini, Adriano; Araújo, João Pessoa; Cabrera, Eliana; Lopes, José Carlos; Penha Dos Santos, Izalco Nuremberg; Negri Reis, Andréia Francesli; Costa, Fabiana Rodrigues; Antônio Cruz, Lilian Elisa Arão; Ferreira, Jurandir; de Oliveira Rocha, Eliseu Soares; Kroon, Erna Geessien; de Morais Bronzoni, Roberta Vieira; Vasilakis, Nikos; Nogueira, Maurício Lacerda

    2016-12-01

    Dengue viruses are the most common arbovirus infection worldwide and are caused by four distinct serotypes of the dengue virus (DENV). In the present study, we assessed DENV transmission in São José do Rio Preto (SJRP) from 2010 to 2014. We analyzed blood samples from febrile patients who were attended at health care centers in SJRP. DENV detection was performed using multiplex RT-PCR, using flavivirus generic primers, based on the genes of the non-structural protein (NS5), followed by nested-PCR assay with species-specific primers. We analyzed 1549 samples, of which 1389 were positive for NS1 by rapid test. One thousand and eight-seven samples (78%) were confirmed as positive by multiplex RT-PCR: DENV-4, 48.5% (528/1087); DENV-1, 41.5% (449/1087); DENV-2, 9.5% (104/1087); and co-infection (5 DENV-1/DENV-4, 1 DENV-1/DENV-2), 0.5% (6/1087). Phylogenetic analysis of the DENV-4 grouped the isolates identified in this study with the American genotype and the showed a relationship between isolates from SJRP and isolates from the northern region of South America. Taken together, our data shows the detection and emergence of new dengue genotype in a new region and reiterate the importance of surveillance programs to detect and trace the evolution of DENV. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Infection of Mosquito Cells (C6/36) by Dengue-2 Virus Interferes with Subsequent Infection by Yellow Fever Virus.

    Science.gov (United States)

    Abrao, Emiliana Pereira; da Fonseca, Benedito Antônio Lopes

    2016-02-01

    Dengue is one of the most important diseases caused by arboviruses in the world. Yellow fever is another arthropod-borne disease of great importance to public health that is endemic to tropical regions of Africa and the Americas. Both yellow fever and dengue viruses are flaviviruses transmitted by Aedes aegypti mosquitoes, and then, it is reasonable to consider that in a given moment, mosquito cells could be coinfected by both viruses. Therefore, we decided to evaluate if sequential infections of dengue and yellow fever viruses (and vice-versa) in mosquito cells could affect the virus replication patterns. Using immunofluorescence and real-time PCR-based replication assays in Aedes albopictus C6/36 cells with single or sequential infections with both viruses, we demonstrated the occurrence of viral interference, also called superinfection exclusion, between these two viruses. Our results show that this interference pattern is particularly evident when cells were first infected with dengue virus and subsequently with yellow fever virus (YFV). Reduction in dengue virus replication, although to a lower extent, was also observed when C6/36 cells were initially infected with YFV followed by dengue virus infection. Although the importance that these findings have on nature is unknown, this study provides evidence, at the cellular level, of the occurrence of replication interference between dengue and yellow fever viruses and raises the question if superinfection exclusion could be a possible explanation, at least partially, for the reported lack of urban yellow fever occurrence in regions where a high level of dengue transmission occurs.

  1. Epitope Mapping of Dengue-Virus-Enhancing Monoclonal-Antibody Using Phage Display Peptide Library

    OpenAIRE

    Chung-I Rai; Huan-Yao Lei; Yee-Shin Lin; Hsiao-Sheng Liu; Shun-Hua Chen; Lien-Cheng Chen; Trai-Ming Yeh

    2008-01-01

    The Antibody-Dependent Enhancement (ADE) hypothesis has been proposed to explain why more severe manifestations of Dengue Hemorrhagic Fever and Dengue Shock Syndrome (DHF/DSS) occur predominantly during secondary infections of Dengue Virus (DV) with different serotypes. However, the epitopes recognized by these enhancing antibodies are unclear. Recently, anti-pre-M monoclonal antibody (mAb 70-21), which recognized all DV serotypes without neutralizing activity, were generated and demonstrated...

  2. Identification of New Protein Interactions between Dengue Fever Virus and Its Hosts, Human and Mosquito

    Science.gov (United States)

    Mairiang, Dumrong; Zhang, Huamei; Sodja, Ann; Murali, Thilakam; Suriyaphol, Prapat; Malasit, Prida; Limjindaporn, Thawornchai; Finley, Russell L.

    2013-01-01

    The four divergent serotypes of dengue virus are the causative agents of dengue fever, dengue hemorrhagic fever and dengue shock syndrome. About two-fifths of the world's population live in areas where dengue is prevalent, and thousands of deaths are caused by the viruses every year. Dengue virus is transmitted from one person to another primarily by the yellow fever mosquito, Aedes aegypti. Recent studies have begun to define how the dengue viral proteins interact with host proteins to mediate viral replication and pathogenesis. A combined analysis of these studies, however, suggests that many virus-host protein interactions remain to be identified, especially for the mosquito host. In this study, we used high-throughput yeast two-hybrid screening to identify mosquito and human proteins that physically interact with dengue proteins. We tested each identified host protein against the proteins from all four serotypes of dengue to identify interactions that are conserved across serotypes. We further confirmed many of the interactions using co-affinity purification assays. As in other large-scale screens, we identified some previously detected interactions and many new ones, moving us closer to a complete host – dengue protein interactome. To help summarize and prioritize the data for further study, we combined our interactions with other published data and identified a subset of the host-dengue interactions that are now supported by multiple forms of evidence. These data should be useful for understanding the interplay between dengue and its hosts and may provide candidates for drug targets and vector control strategies. PMID:23326450

  3. Can we find a possible structural explanation for antibody-dependent enhancement of dengue virus infection resulting in hemorrhagic fever?

    Science.gov (United States)

    Mikita, Cecilia P; Padlan, Eduardo A

    2016-03-01

    Dengue virus infection is one of the most prevalent mosquito-borne illnesses worldwide, affecting as many as 400 million persons annually. Most people experience a self-limited viral illness, but some experience life-threatening disease. Subsequent infection with other dengue virus serotypes increases the risk of development of severe dengue disease with plasma leakage with or without hemorrhage and end organ impairment. Antibody-dependent enhancement of dengue virus infection has been implicated in the development of severe dengue disease, previously referred to as dengue hemorrhagic fever and dengue shock syndrome. We propose a structural explanation for the role of non-neutralizing antibodies in the development of antibody-dependent enhancement of dengue virus infection via complement fixation or binding to Fcγ receptors facilitating entry into target cells. Published by Elsevier Ltd.

  4. Enhanced performance of an innovative dengue IgG/IgM rapid diagnostic test using an anti-dengue EDI monoclonal antibody and dengue virus antigen

    Science.gov (United States)

    Lee, Jihoo; Kim, Young-Eun; Kim, Hak-Yong; Sinniah, Mangalam; Chong, Chom-Kyu; Song, Hyun-Ok

    2015-01-01

    High levels of anti-dengue IgM or IgG can be detected using numerous rapid diagnostic tests (RDTs). However, the sensitivity and specificity of these tests are reduced by changes in envelope glycoprotein antigenicity that inevitably occur in limited expression systems. A novel RDT was designed to enhance diagnostic sensitivity. Dengue viruses cultured in animal cells were used as antigens to retain the native viral coat protein. Monoclonal antibodies (mAbs) were then developed, for the first time, against domain I of envelope glycoprotein (EDI). The anti-dengue EDI mAb was employed as a capturer, and EDII and EDIII, which are mainly involved in the induction of neutralizing antibodies in patients, were fully available to bind to anti-dengue IgM or IgG in patients. A one-way automatic blood separation device prevented reverse migration of plasma and maximize the capture of anti-dengue antibodies at the test lines. A clinical evaluation in the field proved that the novel RDT (sensitivities of 96.5% and 96.7% for anti-dengue IgM and IgG) is more effective in detecting anti-dengue antibodies than two major commercial tests (sensitivities of 54.8% and 82% for SD BIOLINE; 50.4% and 75.3% for PanBio). The innovative format of RDT can be applied to other infectious viral diseases. PMID:26655854

  5. The Epidemiology, Virology and Clinical Findings of Dengue Virus Infections in a Cohort of Indonesian Adults in Western Java.

    Science.gov (United States)

    Kosasih, Herman; Alisjahbana, Bachti; Nurhayati; de Mast, Quirijn; Rudiman, Irani F; Widjaja, Susana; Antonjaya, Ungke; Novriani, Harli; Susanto, Nugroho H; Jusuf, Hadi; van der Ven, Andre; Beckett, Charmagne G; Blair, Patrick J; Burgess, Timothy H; Williams, Maya; Porter, Kevin R

    2016-02-01

    Dengue has emerged as one of the most important infectious diseases in the last five decades. Evidence indicates the expansion of dengue virus endemic areas and consequently the exponential increase of dengue virus infections across the subtropics. The clinical manifestations of dengue virus infection include sudden fever, rash, headache, myalgia and in more serious cases, spontaneous bleeding. These manifestations occur in children as well as in adults. Defining the epidemiology of dengue in a given area is critical to understanding the disease and devising effective public health strategies. Here, we report the results from a prospective cohort study of 4380 adults in West Java, Indonesia, from 2000-2004 and 2006-2009. A total of 2167 febrile episodes were documented and dengue virus infections were confirmed by RT-PCR or serology in 268 cases (12.4%). The proportion ranged from 7.6 to 41.8% each year. The overall incidence rate of symptomatic dengue virus infections was 17.3 cases/1,000 person years and between September 2006 and April 2008 asymptomatic infections were 2.6 times more frequent than symptomatic infections. According to the 1997 WHO classification guidelines, there were 210 dengue fever cases, 53 dengue hemorrhagic fever cases (including one dengue shock syndrome case) and five unclassified cases. Evidence for sequential dengue virus infections was seen in six subjects. All four dengue virus serotypes circulated most years. Inapparent dengue virus infections were predominantly associated with DENV-4 infections. Dengue virus was responsible for a significant percentage of febrile illnesses in an adult population in West Java, Indonesia, and this percentage varied from year to year. The observed incidence rate during the study period was 43 times higher than the reported national or provincial rates during the same time period. A wide range of clinical severity was observed with most infections resulting in asymptomatic disease. The circulation of

  6. Aedes aegypti D7 Saliva Protein Inhibits Dengue Virus Infection.

    Directory of Open Access Journals (Sweden)

    Michael J Conway

    2016-09-01

    Full Text Available Aedes aegypti is the primary vector of several medically relevant arboviruses including dengue virus (DENV types 1-4. Ae. aegypti transmits DENV by inoculating virus-infected saliva into host skin during probing and feeding. Ae. aegypti saliva contains over one hundred unique proteins and these proteins have diverse functions, including facilitating blood feeding. Previously, we showed that Ae. aegypti salivary gland extracts (SGEs enhanced dissemination of DENV to draining lymph nodes. In contrast, HPLC-fractionation revealed that some SGE components inhibited infection. Here, we show that D7 proteins are enriched in HPLC fractions that are inhibitory to DENV infection, and that recombinant D7 protein can inhibit DENV infection in vitro and in vivo. Further, binding assays indicate that D7 protein can directly interact with DENV virions and recombinant DENV envelope protein. These data reveal a novel role for D7 proteins, which inhibits arbovirus transmission to vertebrates through a direct interaction with virions.

  7. Oral receptivity of Aedes aegypti from Cape Verde for yellow fever, dengue, and chikungunya viruses.

    Science.gov (United States)

    Vazeille, Marie; Yébakima, André; Lourenço-de-Oliveira, Ricardo; Andriamahefazafy, Barrysson; Correira, Artur; Rodrigues, Julio Monteiro; Veiga, Antonio; Moreira, Antonio; Leparc-Goffart, Isabelle; Grandadam, Marc; Failloux, Anna-Bella

    2013-01-01

    At the end of 2009, 21,313 cases of dengue-3 virus (DENV-3) were reported in the islands of Cape Verde, an archipelago located in the Atlantic Ocean 570 km from the coast of western Africa. It was the first dengue outbreak ever reported in Cape Verde. Mosquitoes collected in July 2010 in the city of Praia, on the island of Santiago, were identified morphologically as Aedes aegypti formosus. Using experimental oral infections, we found that this vector showed a moderate ability to transmit the epidemic dengue-3 virus, but was highly susceptible to chikungunya and yellow fever viruses.

  8. STRUKTUR PROTEOMIK VIRUS DENGUE DAN MANFAATNYA SEBAGAI TARGET ANTIVIRUS

    Directory of Open Access Journals (Sweden)

    Novia Rachmayanti

    2014-09-01

    Full Text Available AbstrakVirus dengue (DENV telah menyebabkan sekitar 50 juta kasus infeksi demam berdarah setiap tahunnya, akan tetapi hingga saat ini belum terdapat vaksin maupun antivirus yang mampu mencegah atau mengobati penyakit tersebut. Selama pengembangan vaksin dan antivirus, diperoleh berbagai informasi tentang struktur protein DENV yang dapat dimanfaatkan sebagai target obat. Makalah membahas tentang struktur proteomik pada DENV, yaitu glikoprotein pada envelope, NS3 protease, NS3 helikase, NS5 metiltransferase, dan NS5 RNA-dependent RNA polimerase.AbstractDengue virus (DENV has caused over 50 millions infection every year. However, to date neither vaccine nor medicine could be used to prevent or cure the illness. During researches in finding the vaccine or antiviral for DENV, information on DENV protein structure has been obtained which is potentially used as drug target. This paper disscuss DENV proteomic structure that consist of envelope glicoprotein, NS3 protease, NS3 helicase, NS5 methyl-transferase, and NS5 RNA-dependent RNA polymerase.

  9. Role of Microparticles in Dengue Virus Infection and Its Impact on Medical Intervention Strategies

    Science.gov (United States)

    Bargeron Clark, Kristina; Hsiao, Hui-Mien; Noisakran, Sansanee; Tsai, Jih-Jin; Perng, Guey Chuen

    2012-01-01

    Dengue virus (DV) is one of the most important vector-borne diseases in the world. It causes a disease that manifests as a spectrum of clinical symptoms, including dengue hemorrhagic fever. DV is proficient at diverting the immune system to facilitate transmission through its vector host, Aedes spp. mosquito. Similar to other vector-borne parasites, dengue may also require a second structural form, a virus of alternative morphology (VAM), to complete its life cycle. DV can replicate to high copy numbers in patient plasma, but no classical viral particles can be detected by ultra-structural microscopy analysis. A VAM appearing as a microparticle has been recapitulated with in vitro cell lines Meg01 and K562, close relatives to the cells harboring dengue virus in vivo. VAMs are likely to contribute to the high viremia levels observed in dengue patients. This review discusses the possible existence of a VAM in the DV life cycle. PMID:22461739

  10. Identification of novel target sites and an inhibitor of the dengue virus E protein

    Science.gov (United States)

    Yennamalli, Ragothaman; Subbarao, Naidu; Kampmann, Thorsten; McGeary, Ross P.; Young, Paul R.; Kobe, Bostjan

    2009-06-01

    Dengue and related flaviviruses represent a significant global health threat. The envelope glycoprotein E mediates virus attachment to a host cell and the subsequent fusion of viral and host cell membranes. The fusion process is driven by conformational changes in the E protein and is an essential step in the virus life cycle. In this study, we analyzed the pre-fusion and post-fusion structures of the dengue virus E protein to identify potential novel sites that could bind small molecules, which could interfere with the conformational transitions that mediate the fusion process. We used an in silico virtual screening approach combining three different docking algorithms (DOCK, GOLD and FlexX) to identify compounds that are likely to bind to these sites. Seven structurally diverse molecules were selected to test experimentally for inhibition of dengue virus propagation. The best compound showed an IC50 in the micromolar range against dengue virus type 2.

  11. Wild dengue virus types 1, 2 and 3 viremia in rhesus monkeys

    Directory of Open Access Journals (Sweden)

    MS Freire

    2007-03-01

    Full Text Available Among the flaviviruses, dengue, with its four serotypes, has spread throughout the tropics. The most advanced vaccines developed so far include live attenuated viruses, which have been tested in humans but none has been licensed. Preclinical testing of dengue vaccine candidates is performed initially in mice and in nonhuman primates. In the latter the main criteria used to assay protection are neutralizing antibodies elicited by the vaccine candidate and the magnitude and duration of peripheral viremia upon challenge of previously immunized animals. Towards the identification of wild-type viruses that could be used in challenge experiments a total of 31 rhesus monkeys were inoculated subcutaneously of wild dengue types 1, 2, and 3 viruses. The viremia caused by the different viruses was variable but it was possible to identify dengue viruses useful as challenge strains.

  12. Incidence of dengue virus infection among Japanese travellers, 2006 to 2010

    Directory of Open Access Journals (Sweden)

    Yuki Tada

    2012-06-01

    Full Text Available Introduction: Dengue continues to be a global public health concern. In Japan, although dengue cases are currently seen only among travellers returning from endemic areas, the number of reported cases is rising according to the national case-based surveillance system. We evaluated the characteristics of dengue cases imported into Japan and the relationship between the incidence of infection and season of travel to popular destinations.Methods: Dengue cases reported to the national surveillance system were retrospectively examined. The number of reported cases per number of Japanese travellers to a dengue-endemic country was calculated to estimate the country-specific incidence of imported dengue virus infection. The incidence of dengue infection among Japanese travellers was compared between dengue high season and low season in each country using relative risk (RR and associated 95% confidence intervals (CI.Results: Among 540 Japanese residents who were reported as dengue cases from 2006 to 2010, the majority had travelled to Indonesia, India, the Philippines and Thailand. The RR of dengue infection among Japanese travellers during dengue high season versus low season was 4.92 (95% CI: 3.01–8.04 for the Philippines, 2.76 (95% CI: 1.67–4.54 for Thailand and 0.37 (95% CI: 0.15–0.92 for Indonesia.Discussion: Overall, higher incidence of imported cases appeared to be related to historic dengue high seasons. Travellers planning to visit dengue-endemic countries should be aware of historic dengue seasonality and the current dengue situation.

  13. Influenza and dengue virus co-infection impairs monocyte recruitment to the lung, increases dengue virus titers, and exacerbates pneumonia.

    Science.gov (United States)

    Schmid, Michael A; González, Karla N; Shah, Sanjana; Peña, José; Mack, Matthias; Talarico, Laura B; Polack, Fernando P; Harris, Eva

    2017-03-01

    Co-infections of influenza virus and bacteria are known to cause severe disease, but little information exists on co-infections with other acute viruses. Seasonal influenza and dengue viruses (DENV) regularly co-circulate in tropical regions. The pandemic spread of influenza virus H1N1 (hereafter H1N1) in 2009 led to additional severe disease cases that were co-infected with DENV. Here, we investigated the impact of co-infection on immune responses and pathogenesis in a new mouse model. Co-infection of otherwise sublethal doses of a Nicaraguan clinical H1N1 isolate and two days later with a virulent DENV2 strain increased systemic DENV titers and caused 90% lethality. Lungs of co-infected mice carried both viruses, developed severe pneumonia, and expressed a unique pattern of host mRNAs, resembling only partial responses against infection with either virus alone. A large number of monocytes were recruited to DENV-infected but not to co-infected lungs, and depletion and adoptive transfer experiments revealed a beneficial role of monocytes. Our study shows that co-infection with influenza and DENV impairs host responses, which fail to control DENV titers and instead, induce severe lung damage. Further, our findings identify key inflammatory pathways and monocyte function as targets for future therapies that may limit immunopathology in co-infected patients. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Microbial Translocation Is Associated with Extensive Immune Activation in Dengue Virus Infected Patients with Severe Disease

    NARCIS (Netherlands)

    C.A.M. van de Weg (Cornelia A.M.); C.S. Pannuti (Cláudio); E.S. Affonso De Araujo (Evaldo); H.J. van den Ham; A.C. Andeweg (Arno); L.S.V. Boas (Lucy); A.C. Felix (Alvina); K.I. Carvalho (Karina); A.M. de Matos (Andreia); J.E. Levi (José); C.M. Romano (Camila); C.C. Centrone (Cristiane); C.L. de Lima Rodrigues (Celia); E. Luna (Expedito); E.C.M. van Gorp (Eric); A.D.M.E. Osterhaus (Albert); B.E.E. Martina (Byron); E.G. Kallas (Esper)

    2013-01-01

    textabstractBackground:Severe dengue virus (DENV) disease is associated with extensive immune activation, characterized by a cytokine storm. Previously, elevated lipopolysaccharide (LPS) levels in dengue were found to correlate with clinical disease severity. In the present cross-sectional study we

  15. Meningitis Associated with Simultaneous Infection by Multiple Dengue Virus Serotypes in Children, Brazil.

    Science.gov (United States)

    Marinho, Paula Eillanny Silva; Bretas de Oliveira, Danilo; Candiani, Talitah Michel Sanchez; Crispim, Ana Paula Correia; Alvarenga, Pedro Paulo Martins; Castro, Fabrizia Cristina Dos Santos; Abrahão, Jonatas Santos; Rios, Maria; Coimbra, Roney Santos; Kroon, Erna Geessien

    2017-01-01

    To determine the causes of viral meningitis, we analyzed 22 cerebrospinal fluid samples collected during the 2014-2015 dengue epidemics in Brazil. We identified 3 serotypes of dengue virus (DENV-1, -2, and -3), as well as co-infection with 2 or 3 serotypes. We also detected the Asian II genotype of DENV-2.

  16. Hyperferritinaemia in dengue virus infected patients is associated with immune activation and coagulation disturbances

    NARCIS (Netherlands)

    van de Weg, Cornelia A. M.; Huits, Ralph M. H. G.; Pannuti, Cláudio S.; Brouns, Rosalba M.; van den Berg, Riemsdijk W. A.; van den Ham, Henk-Jan; Martina, Byron E. E.; Osterhaus, Albert D. M. E.; Netea, Mihai G.; Meijers, Joost C. M.; van Gorp, Eric C. M.; Kallas, Esper G.

    2014-01-01

    During a dengue outbreak on the Caribbean island Aruba, highly elevated levels of ferritin were detected in dengue virus infected patients. Ferritin is an acute-phase reactant and hyperferritinaemia is a hallmark of diseases caused by extensive immune activation, such as haemophagocytic

  17. Dengue Virus Exported from Côte d’Ivoire to Japan, June 2017

    OpenAIRE

    Suzuki, Tetsuya; Kutsuna, Satoshi; Taniguchi, Satoshi; Tajima, Shigeru; Maeki, Takahiro; Kato, Fumihiro; Lim, Chang-Kweng; Saijo, Masayuki; Tsuboi, Motoyuki; Yamamoto, Kei; Morioka, Shinichiro; Ishikane, Masahiro; Hayakawa, Kayoko; Kato, Yasuyuki; Ohmagari, Norio

    2017-01-01

    Since April 2017, a dengue fever outbreak has been ongoing in Côte d’Ivoire. We diagnosed dengue fever (type 2 virus) in a traveler returning to Japan from Côte d’Ivoire. Phylogenetic analysis revealed strain homology with the Burkina Faso 2016 strain. This case may serve as an alert to possible disease spread outside Africa.

  18. Dengue Virus Exported from Côte d'Ivoire to Japan, June 2017.

    Science.gov (United States)

    Suzuki, Tetsuya; Kutsuna, Satoshi; Taniguchi, Satoshi; Tajima, Shigeru; Maeki, Takahiro; Kato, Fumihiro; Lim, Chang-Kweng; Saijo, Masayuki; Tsuboi, Motoyuki; Yamamoto, Kei; Morioka, Shinichiro; Ishikane, Masahiro; Hayakawa, Kayoko; Kato, Yasuyuki; Ohmagari, Norio

    2017-10-01

    Since April 2017, a dengue fever outbreak has been ongoing in Côte d'Ivoire. We diagnosed dengue fever (type 2 virus) in a traveler returning to Japan from Côte d'Ivoire. Phylogenetic analysis revealed strain homology with the Burkina Faso 2016 strain. This case may serve as an alert to possible disease spread outside Africa.

  19. Meta-Analysis of Dengue Severity during Infection by Different Dengue Virus Serotypes in Primary and Secondary Infections.

    Directory of Open Access Journals (Sweden)

    Kuan-Meng Soo

    Full Text Available Dengue virus (DENV infection is currently a major cause of morbidity and mortality in the world; it has become more common and virulent over the past half-century and has gained much attention. Thus, this review compared the percentage of severe cases of both primary and secondary infections with different serotypes of dengue virus.Data related to the number of cases involving dengue fever (DF, dengue hemorrhagic fever (DHF, dengue shock syndrome (DSS or severe dengue infections caused by different serotypes of dengue virus were obtained by using the SCOPUS, the PUBMED and the OVID search engines with the keywords "(dengue* OR dengue virus* AND (severe dengue* OR severity of illness index* OR severity* OR DF* OR DHF* OR DSS* AND (serotypes* OR serogroup*", according to the MESH terms suggested by PUBMED and OVID.Approximately 31 studies encompassing 15,741 cases reporting on the dengue serotypes together with their severity were obtained, and meta-analysis was carried out to analyze the data. This study found that DENV-3 from the Southeast Asia (SEA region displayed the greatest percentage of severe cases in primary infection (95% confidence interval (CI, 31.22-53.67, 9 studies, n = 598, I2 = 71.53%, whereas DENV-2, DENV-3, and DENV-4 from the SEA region, as well as DENV-2 and DENV-3 from non-SEA regions, exhibited the greatest percentage of severe cases in secondary infection (95% CI, 11.64-80.89, 4-14 studies, n = 668-3,149, I2 = 14.77-96.20%. Moreover, DENV-2 and DENV-4 from the SEA region had been found to be more highly associated with dengue shock syndrome (DSS (95% CI, 10.47-40.24, 5-8 studies, n = 642-2,530, I2 = 76.93-97.70%, while DENV-3 and DENV-4 from the SEA region were found to be more highly associated with dengue hemorrhagic fever (DHF (95% CI, 31.86-54.58, 9 studies, n = 674-2,278, I2 = 55.74-88.47%, according to the 1997 WHO dengue classification. Finally, DENV-2 and DENV-4 from the SEA region were discovered to be more highly

  20. Meta-Analysis of Dengue Severity during Infection by Different Dengue Virus Serotypes in Primary and Secondary Infections.

    Science.gov (United States)

    Soo, Kuan-Meng; Khalid, Bahariah; Ching, Siew-Mooi; Chee, Hui-Yee

    2016-01-01

    Dengue virus (DENV) infection is currently a major cause of morbidity and mortality in the world; it has become more common and virulent over the past half-century and has gained much attention. Thus, this review compared the percentage of severe cases of both primary and secondary infections with different serotypes of dengue virus. Data related to the number of cases involving dengue fever (DF), dengue hemorrhagic fever (DHF), dengue shock syndrome (DSS) or severe dengue infections caused by different serotypes of dengue virus were obtained by using the SCOPUS, the PUBMED and the OVID search engines with the keywords "(dengue* OR dengue virus*) AND (severe dengue* OR severity of illness index* OR severity* OR DF* OR DHF* OR DSS*) AND (serotypes* OR serogroup*)", according to the MESH terms suggested by PUBMED and OVID. Approximately 31 studies encompassing 15,741 cases reporting on the dengue serotypes together with their severity were obtained, and meta-analysis was carried out to analyze the data. This study found that DENV-3 from the Southeast Asia (SEA) region displayed the greatest percentage of severe cases in primary infection (95% confidence interval (CI), 31.22-53.67, 9 studies, n = 598, I2 = 71.53%), whereas DENV-2, DENV-3, and DENV-4 from the SEA region, as well as DENV-2 and DENV-3 from non-SEA regions, exhibited the greatest percentage of severe cases in secondary infection (95% CI, 11.64-80.89, 4-14 studies, n = 668-3,149, I2 = 14.77-96.20%). Moreover, DENV-2 and DENV-4 from the SEA region had been found to be more highly associated with dengue shock syndrome (DSS) (95% CI, 10.47-40.24, 5-8 studies, n = 642-2,530, I2 = 76.93-97.70%), while DENV-3 and DENV-4 from the SEA region were found to be more highly associated with dengue hemorrhagic fever (DHF) (95% CI, 31.86-54.58, 9 studies, n = 674-2,278, I2 = 55.74-88.47%), according to the 1997 WHO dengue classification. Finally, DENV-2 and DENV-4 from the SEA region were discovered to be more highly

  1. Development of dengue virus replicons expressing HIV-1 gp120 and other heterologous genes: a potential future tool for dual vaccination against dengue virus and HIV

    Directory of Open Access Journals (Sweden)

    Dayton Andrew I

    2001-11-01

    Full Text Available Abstract Background Toward the goals of providing an additional vector to add to the armamentarium available to HIV vaccinologists and of creating a bivalent vaccine effective against dengue virus and HIV, we have attempted to create vectors which express dengue virus non-structural proteins and HIV immunogens. Previously we reported the successful construction of dengue virus replicons which lack structural genes necessary for virion release and spreading infection in culture but which can replicate intracellularly and abundantly produce dengue non-structural proteins. Here we attempted to express heterologous genetic material from these replicons. Results We cloned into a Δpre-M/E dengue virus replicon genes for either green fluorescent protein (GFP, HIV gp160 or HIV gp120 and tested the ability of these constructs to express dengue virus proteins as well as the heterologous proteins in tissue culture after transfection of replicon RNA. Conclusions Heterologous proteins were readily expressed from these constructs. GFP and gp120 demonstrated minimal or no toxicity. Gp160 expressing replicons were found to express proteins abundantly at 36 hours post transfection, but after 50 hrs of transfection, few replicon positive cells could be found despite the presence of cellular debris positive for replicon proteins. This suggested that gp160 expressed from dengue virus replicons is considerably more toxic than either GFP or gp120. The successful expression of heterologous proteins, including HIV gp120 for long periods in culture suggests this vector system may be useful as a vaccine vector, given appropriate delivery methods.

  2. Productive Dengue Virus Infection of Human Endothelial Cells Is Directed by Heparan Sulfate-Containing Proteoglycan Receptors ▿

    Science.gov (United States)

    Dalrymple, Nadine; Mackow, Erich R.

    2011-01-01

    Dengue virus causes leakage of the vascular endothelium, resulting in dengue hemorrhagic fever and dengue shock syndrome. The endothelial cell lining of the vasculature regulates capillary permeability and is altered by immune and chemokine responses which affect fluid barrier functions of the endothelium. Our findings indicate that human endothelial cells are highly susceptible to infection by dengue virus (type 4). We found that dengue virus productively infects ∼80% of primary human endothelial cells, resulting in the rapid release of ∼105 virions 1 day postinfection. Analysis of potential inhibitors of dengue virus entry demonstrated that antibodies and ligands to integrins and cellular receptors were unable to inhibit dengue virus infection of endothelial cells. In contrast, pretreating cells with heparin or heparan sulfate resulted in a 60 to 80% reduction in dengue virus-infected cells, and pretreatment of endothelial cells with heparinase III or protease reduced dengue infectivity by >80%. Dengue virus bound specifically to resin immobilized heparin, and binding was competitively inhibited by excess heparin but not other ligands. Collectively, these findings suggest that dengue virus specifically attaches to heparan sulfate-containing proteoglycan receptors on endothelial cells. Following attachment to human endothelial cell receptors, dengue virus causes a highly productive infection that has the potential to increase viral dissemination and viremia. This provides the potential for dengue virus-infected endothelial cells to directly alter barrier functions of the endothelium, contribute to enhancement of immune cell activation, and serve as potential targets of immune responses which play a central role in dengue pathogenesis. PMID:21734047

  3. Dengue Virus Hijacks a Noncanonical Oxidoreductase Function of a Cellular Oligosaccharyltransferase Complex

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    David L. Lin

    2017-07-01

    Full Text Available Dengue virus (DENV is the most common arboviral infection globally, infecting an estimated 390 million people each year. We employed a genome-wide clustered regularly interspaced short palindromic repeat (CRISPR screen to identify host dependency factors required for DENV propagation and identified the oligosaccharyltransferase (OST complex as an essential host factor for DENV infection. Mammalian cells express two OSTs containing either STT3A or STT3B. We found that the canonical catalytic function of the OSTs as oligosaccharyltransferases is not necessary for DENV infection, as cells expressing catalytically inactive STT3A or STT3B are able to support DENV propagation. However, the OST subunit MAGT1, which associates with STT3B, is also required for DENV propagation. MAGT1 expression requires STT3B, and a catalytically inactive STT3B also rescues MAGT1 expression, supporting the hypothesis that STT3B serves to stabilize MAGT1 in the context of DENV infection. We found that the oxidoreductase CXXC active site motif of MAGT1 was necessary for DENV propagation, as cells expressing an AXXA MAGT1 mutant were unable to support DENV infection. Interestingly, cells expressing single-cysteine CXXA or AXXC mutants of MAGT1 were able to support DENV propagation. Utilizing the engineered peroxidase APEX2, we demonstrate the close proximity between MAGT1 and NS1 or NS4B during DENV infection. These results reveal that the oxidoreductase activity of the STT3B-containing OST is necessary for DENV infection, which may guide the development of antiviral agents targeting DENV.

  4. Electrochemical impedance spectroscopy characterization of nanoporous alumina dengue virus biosensor.

    Science.gov (United States)

    Nguyen, Binh Thi Thanh; Peh, Alister En Kai; Chee, Celine Yue Ling; Fink, Katja; Chow, Vincent T K; Ng, Mary M L; Toh, Chee-Seng

    2012-12-01

    The Faradaic electrochemical impedance technique is employed to characterize the impedance change of a nanoporous alumina biosensor in response towards the specific binding of dengue serotype 2 (Denv2) viral particles to its serotype 2-specific immunoglobulin G antibody within the thin alumina layer. The optimal equivalent circuit model that matches the impedimetric responses of the sensor describes three distinct regions: the electrolyte solution (R(s)), the porous alumina channels (including biomaterials) (Q(1), R(1)) and the conductive electrode substrate layer (Q(2), R(2)). Both channel resistance R(1) and capacitance Q(1) change in response to the increase of the Denv2 virus concentration. A linear relationship between R(1) and Denv2 concentration from 1 to 900 plaque forming unit per mL (pfu mL(-1)) can be derived using Langmuir-Freundlich isotherm model. At 1pfu mL(-1) Denv2 concentration, R(1) can be distinguished from that of the cell culture control sample. Moreover, Q(1) doubles when Denv2 is added but remains unchanged in the presence of two other non-specific viruses - West Nile virus and Chikungunya virus indicates biosensor specificity can be quantitatively measured using channel capacitance. Copyright © 2012 Elsevier B.V. All rights reserved.

  5. New insights into the immunopathology and control of dengue virus infection.

    Science.gov (United States)

    Screaton, Gavin; Mongkolsapaya, Juthathip; Yacoub, Sophie; Roberts, Catherine

    2015-12-01

    Dengue virus poses a major threat to global public health: two-thirds of the world's population is now at risk from infection by this mosquito-borne virus. Dengue virus causes a range of diseases with a small proportion of infected patients developing severe plasma leakage that leads to dengue shock syndrome, organ impairment and bleeding. Infection with one of the four viral serotypes results in the development of homotypic immunity to that serotype. However, subsequent infection with a different serotype is associated with an increased risk of developing severe disease, which has led to the suggestion that severe disease is triggered by immunopathology. This Review outlines recent advances in the understanding of immunopathology, vaccine development and human monoclonal antibodies produced against dengue virus.

  6. Complement-mediated neutralization of dengue virus requires mannose-binding lectin

    DEFF Research Database (Denmark)

    Avirutnan, Panisadee; Hauhart, Richard E; Marovich, Mary A

    2011-01-01

    -dependent activation of the complement cascade neutralized insect cell-derived West Nile virus (WNV) in cell culture and restricted pathogenesis in mice. Here, we investigated the antiviral activity of MBL in infection by dengue virus (DENV), a related flavivirus. Using a panel of naïve sera from mouse strains...... with lower levels. Our studies suggest that allelic variation of MBL in humans may impact complement-dependent control of DENV pathogenesis. IMPORTANCE Dengue virus (DENV) is a mosquito-transmitted virus that causes a spectrum of clinical disease in humans ranging from subclinical infection to dengue...... hemorrhagic fever and dengue shock syndrome. Four serotypes of DENV exist, and severe illness is usually associated with secondary infection by a different serotype. Here, we show that mannose-binding lectin (MBL), a pattern recognition molecule that initiates the lectin pathway of complement activation...

  7. Complement-mediated neutralization of dengue virus requires mannose-binding lectin

    DEFF Research Database (Denmark)

    Avirutnan, Panisadee; Hauhart, Richard E; Marovich, Mary A

    2011-01-01

    hemorrhagic fever and dengue shock syndrome. Four serotypes of DENV exist, and severe illness is usually associated with secondary infection by a different serotype. Here, we show that mannose-binding lectin (MBL), a pattern recognition molecule that initiates the lectin pathway of complement activation......-dependent activation of the complement cascade neutralized insect cell-derived West Nile virus (WNV) in cell culture and restricted pathogenesis in mice. Here, we investigated the antiviral activity of MBL in infection by dengue virus (DENV), a related flavivirus. Using a panel of naïve sera from mouse strains...... with lower levels. Our studies suggest that allelic variation of MBL in humans may impact complement-dependent control of DENV pathogenesis. IMPORTANCE Dengue virus (DENV) is a mosquito-transmitted virus that causes a spectrum of clinical disease in humans ranging from subclinical infection to dengue...

  8. Dengue Fever/Dengue Haemorrhagic Fever : Case Management

    OpenAIRE

    Nimmannitya, Suchitra

    1995-01-01

    Dengue infections caused by the four antigenically distinct dengue virus serotypes (dengue virus 1, dengue virus 2, dengue virus 3, dengue virus 4) of the family Flavivindae, are the most important arbovirus disease in man, both in terms of morbidity and mortality. The infection is transmitted from man to man by Aedes mosquitoes. Since 1956, dengue virus infection has resulted in more than 3 million hospital admissions and more than 50,000 deaths in Southeast Asia, Western Pacific countries, ...

  9. ELEVATED LEVELS OF SOLUBLE ST2 PROTEIN IN DENGUE VIRUS INFECTED PATIENTS

    Science.gov (United States)

    Becerra, Aniuska; Warke, Rajas V.; de Bosch, Norma; Rothman, Alan L.; Bosch, Irene

    2008-01-01

    Levels of the soluble form of the interleukin-1 receptor like 1 protein (IL-1RL-1 / ST2) are elevated in the serum of patients with diseases characterized by an inflammatory response. The objective of this study was to determine the concentration of soluble ST2 (sST2) in dengue infected patients during the course of the disease. Twenty four patients with confirmed dengue infection, classified as dengue fever, and eleven patients with other febrile illness (OFI) were evaluated. Levels of sST2 in serum and laboratory variables usually altered during dengue infections were measured. Dengue infected patients had higher serum sST2 levels than OFI at the end of the febrile stage and at defervescence (p=0.0088 and p=0.0004 respectively). Patients with secondary dengue infections had higher serum sST2 levels compared with patients with primary dengue infections (p=0.047 at last day of fever and p=0.030 at defervescence). Furthermore, in dengue infected patients, we found a significant negative correlation of sST2 with platelet and WBC counts, and positive correlation with thrombin time and transaminases activity. We suggest that sST2 could be a potential marker of dengue infection, could be associated with severity or could play a role in the immune response in secondary dengue virus infection. PMID:18226917

  10. Rapid Identification of Dengue Virus Serotypes Using Monoclonal Antibodies in an Indirect Immunofluorescence Test.

    Science.gov (United States)

    1982-06-18

    encephalitis(TBH-28), West Nile(E-101), Yellow fever (French neurotropic and 17D strains), and Zika. Two Sandfly Fever viruses (213452 and Candiru) were...derived ascitic fluid, DEN-2 HMAF which reacts with all four dengue serotypes, flavivirus HMAF (equal portions of DEN-2, Yellow fever , St. Louis...Igarashi, A., 1978. Isolation of a Singh’s Aedes albopictus cell clone sensitive to dengue and chikungunya viruses. J. Gen. Virol., 40: 531-544. 23

  11. Dissecting the Cell Entry Pathway of Dengue Virus by Single-Particle Tracking in Living Cells

    NARCIS (Netherlands)

    van der Schaar, Hilde M.; Rust, Michael J.; Chen, Chen; van der Ende-Metselaar, Heidi; Wilschut, Jan; Zhuang, Xiaowei; Smit, Jolanda M.

    2008-01-01

    Dengue virus (DENV) is an enveloped RNA virus that causes the most common arthropod-borne infection worldwide. The mechanism by which DENV infects the host cell remains unclear. In this work, we used live-cell imaging and single-virus tracking to investigate the cell entry, endocytic trafficking,

  12. Bioekologi vektor demam berdarah dengue (DBD serta deteksi virus dengue pada Aedes aegypti (Linnaeus dan Ae. albopictus (Skuse (Diptera: Culicidae di kelurahan endemik DBD Bantarjati, Kota Bogor

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    Zahara Fadilla

    2015-09-01

    Full Text Available Dengue hemorrhagic fever (DHF is a viral disease that threatened community health in Indonesia. As part of an eradication program, it is important to learn the behavioral aspect of the disease vector. The aims of this study were to detect the presence of dengue virus in Aedes spp., at Bantarjati Village, Bogor City and to learn to bioecology of. Aedes aegypti (Linnaeus. Detection of dengue virus in Aedes spp. were done by reverse transcription-polymerase chain reaction (RT-PCR technique that consist of two phase were synthesis phase and cDNA amplification and dengue virus serotipe characterization. The Ae. aegypti and Ae. albopictus (Skuse mosquitoes were collected using the landing and resting moquito collection technique booth indoors and outdoors. The highest density of Ae. aegypti and Ae. albopictus were found in April and the peak activity was occurred at 10:00-11:00 am. Dengue virus was not detected in female mosquitoes Aedes spp.

  13. Adherence to vector preventive measures decrease cases of acute Dengue among Abuja residents, Nigeria

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    Idris Abdullahi Nasir

    2017-07-01

    Full Text Available Background: Nigeria is one of the dengue hyper-endemic nations. This study investigated the level of knowledge about dengue and vector preventive practices and their impacts on acute dengue among febrile patients at Abuja, Nigeria. Materials and methods: This cross-sectional survey was conducted on febrile patients attending University of Abuja Teaching Hospital, Abuja, Nigeria. Blood samples were individually collected from 171 febrile patients residing at Gwagwalada suburb. Interviewer administered questionnaires were used to assess subjects’ knowledge about preventive measures against vector breeding and bites. Blood samples were tested for dengue virus Nonstructural glycoprotein-1antigen using enzyme linked Immunosorbent assay (ELISA. Results: Fifteen out of 171 febrile persons (8.8% were Dengue NS1 positive. Sixty percent of the subjects do not know about dengue, while 33% knew about dengue virus infection through television/ radio programs, 5% through healthcare professionals and 2% from friends/families. Those who persistently use indoor residual spraying and long sleeves/trousers during daytime had less cases of DENV NS1 than those who do not. There was statistical association between DENV NS1 and residence in proximity to waste dumpsites (P<0.0001 and frequent use of long sleeve clothing and trousers (P=0.005. However, there was no statistical association between DENV NS1 antigenemia and persistent use of indoor residual spraying and presence of in-door water containers (P>0.05. Conclusions: Findings from this study imply that proper education and adherence to preventive measures minimize people from being susceptible to Dengue virus infections.

  14. Achieving safe, effective, and durable Zika virus vaccines: lessons from dengue.

    Science.gov (United States)

    Halstead, Scott B

    2017-11-01

    Newly proposed candidate Zika virus vaccines might or might not succeed in raising safe, effective, and durable protection against human Zika virus infections or syndromes. Analyses of a clinically tested and licensed dengue vaccine that failed to protect seronegative individuals from breakthrough or enhanced dengue infections suggest that poor T-cell immunity might have contributed to protection failure. Because of the similarity of Zika and dengue viruses, an analogous unwanted outcome might occur with some Zika virus vaccine designs. A successful Zika virus vaccine requires challenge experiments that are done at long intervals after immunisation and that identify protection as the absence of viraemia and the absence of an anamnestic antibody response. T-cell immunity might be an essential component of safe, efficacious, and durable Zika virus vaccines. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Susceptibility and Response of Human Blood Monocyte Subsets to Primary Dengue Virus Infection

    Science.gov (United States)

    Wong, Kok Loon; Chen, Weiqiang; Balakrishnan, Thavamalar; Toh, Ying Xiu

    2012-01-01

    Human blood monocytes play a central role in dengue infections and form the majority of virus infected cells in the blood. Human blood monocytes are heterogeneous and divided into CD16− and CD16+ subsets. Monocyte subsets play distinct roles during disease, but it is not currently known if monocyte subsets differentially contribute to dengue protection and pathogenesis. Here, we compared the susceptibility and response of the human CD16− and CD16+ blood monocyte subsets to primary dengue virus in vitro. We found that both monocyte subsets were equally susceptible to dengue virus (DENV2 NGC), and capable of supporting the initial production of new infective virus particles. Both monocyte subsets produced anti-viral factors, including IFN-α, CXCL10 and TRAIL. However, CD16+ monocytes were the major producers of inflammatory cytokines and chemokines in response to dengue virus, including IL-1β, TNF-α, IL-6, CCL2, 3 and 4. The susceptibility of both monocyte subsets to infection was increased after IL-4 treatment, but this increase was more profound for the CD16+ monocyte subset, particularly at early time points after virus exposure. These findings reveal the differential role that monocyte subsets might play during dengue disease. PMID:22574162

  16. Susceptibility and response of human blood monocyte subsets to primary dengue virus infection.

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    Kok Loon Wong

    Full Text Available Human blood monocytes play a central role in dengue infections and form the majority of virus infected cells in the blood. Human blood monocytes are heterogeneous and divided into CD16(- and CD16(+ subsets. Monocyte subsets play distinct roles during disease, but it is not currently known if monocyte subsets differentially contribute to dengue protection and pathogenesis. Here, we compared the susceptibility and response of the human CD16(- and CD16(+ blood monocyte subsets to primary dengue virus in vitro. We found that both monocyte subsets were equally susceptible to dengue virus (DENV2 NGC, and capable of supporting the initial production of new infective virus particles. Both monocyte subsets produced anti-viral factors, including IFN-α, CXCL10 and TRAIL. However, CD16(+ monocytes were the major producers of inflammatory cytokines and chemokines in response to dengue virus, including IL-1β, TNF-α, IL-6, CCL2, 3 and 4. The susceptibility of both monocyte subsets to infection was increased after IL-4 treatment, but this increase was more profound for the CD16(+ monocyte subset, particularly at early time points after virus exposure. These findings reveal the differential role that monocyte subsets might play during dengue disease.

  17. Attenuation of Dengue Virus Infection by Adeno-Associated Virus-Mediated siRNA Delivery

    Science.gov (United States)

    2004-08-09

    and effective prophylaxis or treatment for dengue virus (DEN) infection, a category A mosquito - borne human pathogen, is a critical global priority...through Aedes aegypti mosquito bites, and resident skin DCs are regarded as the targets of DEN infection [12]. DCs are thought to be 10-fold more per...do not induce production of neutralizing antibodies that could reduce transgene function. They possess a broad-range of tissue tropism and the

  18. Decrease in Dengue virus-2 infection and reduction of cytokine/chemokine production by Uncaria guianensis in human hepatocyte cell line Huh-7

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    Cíntia da Silva Mello

    Full Text Available ABSTRACT BACKGROUND Dengue fever may present hemorrhages and cavitary effusions as result of exacerbated immune responses. We investigated hydro-alcoholic extracts from leaves (UGL and bark (UGB of the medicinal species Uncaria guinanensis with respect to antiviral effects in Dengue virus (DENV infection and in immunological parameters associated with in vivo physiopathological features. METHODS Chemical profiles from UGB or UGL were compared in thin layer chromatography and 1H nuclear magnetic resonance using flavonoid compounds and a pentacyclic oxindole alkaloid-enriched fraction as references. DENV-2-infected hepatocytes (Huh-7 were treated with extracts. Cell viability, DENV antigens and immunological factors were detected by enzyme-linked immunosorbent assay (ELISA or flow cytometry. FINDINGS The UGL mainly differed from UGB by selectively containing the flavonoid kaempferitrin. UGB and UGL improved hepatocyte viability. Both extracts reduced intracellular viral antigen and inhibited the secretion of viral non-structural protein (NS1, which is indicative of viral replication. Reduction in secretion of macrophage migration inhibitory factor was achieved by UGB, of interleukin-6 by UGL, and of interleukin-8 by both UGB and UGL. MAIN CONCLUSIONS The U. guianensis extracts presented, antiviral and immunomodulatory effects for DENV and possibly a hepatocyte-protective activity. Further studies may be performed to consider these products as potential candidates for the development of an herbal product for the future treatment of dengue.

  19. Decrease in Dengue virus-2 infection and reduction of cytokine/chemokine production by Uncaria guianensis in human hepatocyte cell line Huh-7.

    Science.gov (United States)

    Mello, Cíntia da Silva; Valente, Ligia Maria Marino; Wolff, Thiago; Lima-Junior, Raimundo Sousa; Fialho, Luciana Gomes; Marinho, Cintia Ferreira; Azeredo, Elzinandes Leal; Oliveira-Pinto, Luzia Maria; Pereira, Rita de Cássia Alves; Siani, Antonio Carlos; Kubelka, Claire Fernandes

    2017-06-01

    Dengue fever may present hemorrhages and cavitary effusions as result of exacerbated immune responses. We investigated hydro-alcoholic extracts from leaves (UGL) and bark (UGB) of the medicinal species Uncaria guinanensis with respect to antiviral effects in Dengue virus (DENV) infection and in immunological parameters associated with in vivo physiopathological features. Chemical profiles from UGB or UGL were compared in thin layer chromatography and 1H nuclear magnetic resonance using flavonoid compounds and a pentacyclic oxindole alkaloid-enriched fraction as references. DENV-2-infected hepatocytes (Huh-7) were treated with extracts. Cell viability, DENV antigens and immunological factors were detected by enzyme-linked immunosorbent assay (ELISA) or flow cytometry. The UGL mainly differed from UGB by selectively containing the flavonoid kaempferitrin. UGB and UGL improved hepatocyte viability. Both extracts reduced intracellular viral antigen and inhibited the secretion of viral non-structural protein (NS1), which is indicative of viral replication. Reduction in secretion of macrophage migration inhibitory factor was achieved by UGB, of interleukin-6 by UGL, and of interleukin-8 by both UGB and UGL. MAIN. The U. guianensis extracts presented, antiviral and immunomodulatory effects for DENV and possibly a hepatocyte-protective activity. Further studies may be performed to consider these products as potential candidates for the development of an herbal product for the future treatment of dengue.

  20. Dynamics of midgut microflora and dengue virus impact on life history traits in Aedes aegypti.

    Science.gov (United States)

    Hill, Casey L; Sharma, Avinash; Shouche, Yogesh; Severson, David W

    2014-12-01

    Significant morbidity and potential mortality following dengue virus infection is a re-emerging global health problem. Due to the limited effectiveness of current disease control methods, mosquito biologists have been searching for new methods of controlling dengue transmission. While much effort has concentrated on determining genetic aspects to vector competence, paratransgenetic approaches could also uncover novel vector control strategies. The interactions of mosquito midgut microflora and pathogens may play significant roles in vector biology. However, little work has been done to see how the microbiome influences the host's fitness and ultimately vector competence. Here we investigated the effects of the midgut microbial environment and dengue infection on several fitness characteristics among three strains of the primary dengue virus vector mosquito Aedes aegypti. This included comparisons of dengue infection rates of females with and without their normal midgut flora. According to our findings, few effects on fitness characteristics were evident following microbial clearance or with dengue virus infection. Adult survivorship significantly varied due to strain and in one strain varied due to antibiotic treatment. Fecundity varied in one strain due to microbial clearance by antibiotics but no variation was observed in fertility due to either treatment. We show here that fitness characteristics of Ae. aegypti vary largely between strains, including varying response to microflora presence or absence, but did not vary in response to dengue virus infection. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. [Phylogenetic analysis of envelope gene of dengue virus serotype 2 in Guangzhou, 2001-2015].

    Science.gov (United States)

    Liu, Y; Jiang, L Y; Luo, L; Cao, Y M; Jing, Q L; Yang, Z C

    2017-01-10

    Objective: To investigate the molecular characteristics of dengue virus serotype 2 (DENV2) in Guangzhou during 2001-2015, and analyze the E gene of the strains isolated, the phylogenetic tree and molecular clock were constructed to know about the evolution of the strains. Methods: The serum samples of the patients were detected by real time PCR, and positive samples were used to isolate dengue virus by using C6/36 cells. The E gene of the isolated strains were sequenced. The phylogenetic tree was constructed by using software Mega 4.0, and the molecular clock was drawn by using software BEASTv1.8.2. Results: Twenty-six dengue virus strains were isolated between 2001 and 2015. They were all clustered into 2 genotypes, i.e. cosmopolitan genotype and Asian genotype Ⅰ. The strains isolated in Guangzhou shared high homology with Southeast Asian strains. The cosmopolitan genotype was divided into 2 sub-genotype at about 46 and 35 years ago. The substitution rate of dengue virus serotype 2 in Guangzhou was 7.1 × 10(-4) per year per site. Conclusions: There were close relationship between the Guangzhou strains and Southeast Asian strains. Guangzhou was at high risk of imported dengue fever, outbreak of dengue hemorrhagic fever and dengue shock syndrome. There might be two ways of introduction of cosmopolitan genotype. The substitution rate of the strains in Guangzhou was similar to that in the neighbor countries.

  2. Vaccination with dengue virus-like particles induces humoral and cellular immune responses in mice

    Directory of Open Access Journals (Sweden)

    Zhang Quanfu

    2011-06-01

    Full Text Available Abstract Background The incidence of dengue, an infectious disease caused by dengue virus (DENV, has dramatically increased around the world in recent decades and is becoming a severe public health threat. However, there is currently no specific treatment for dengue fever, and licensed vaccine against dengue is not available. Vaccination with virus-like particles (VLPs has shown considerable promise for many viral diseases, but the effect of DENV VLPs to induce specific immune responses has not been adequately investigated. Results By optimizing the expression plasmids, recombinant VLPs of four antigenically different DENV serotypes DENV1-4 were successfully produced in 293T cells. The vaccination effect of dengue VLPs in mice showed that monovalent VLPs of each serotype stimulated specific IgG responses and potent neutralizing antibodies against homotypic virus. Tetravalent VLPs efficiently enhanced specific IgG and neutralizing antibodies against all four serotypes of DENV. Moreover, vaccination with monovalent or tetravalent VLPs resulted in the induction of specific cytotoxic T cell responses. Conclusions Mammalian cell expressed dengue VLPs are capable to induce VLP-specific humoral and cellular immune responses in mice, and being a promising subunit vaccine candidate for prevention of dengue virus infection.

  3. Lack of Durable Cross-Neutralizing Antibodies Against Zika Virus from Dengue Virus Infection.

    Science.gov (United States)

    Collins, Matthew H; McGowan, Eileen; Jadi, Ramesh; Young, Ellen; Lopez, Cesar A; Baric, Ralph S; Lazear, Helen M; de Silva, Aravinda M

    2017-05-01

    Cross-reactive antibodies elicited by dengue virus (DENV) infection might affect Zika virus infection and confound serologic tests. Recent data demonstrate neutralization of Zika virus by monoclonal antibodies or human serum collected early after DENV infection. Whether this finding is true in late DENV convalescence (>6 months after infection) is unknown. We studied late convalescent serum samples from persons with prior DENV or Zika virus exposure. Despite extensive cross-reactivity in IgG binding, Zika virus neutralization was not observed among primary DENV infections. We observed low-frequency (23%) Zika virus cross-neutralization in repeat DENV infections. DENV-immune persons who had Zika virus as a secondary infection had distinct populations of antibodies that neutralized DENVs and Zika virus, as shown by DENV-reactive antibody depletion experiments. These data suggest that most DENV infections do not induce durable, high-level Zika virus cross-neutralizing antibodies. Zika virus-specific antibody populations develop after Zika virus infection irrespective of prior DENV immunity.

  4. Dengue Virus and Its Inhibitors: A Brief Review.

    Science.gov (United States)

    Tian, Yu-Shi; Zhou, Yi; Takagi, Tatsuya; Kameoka, Masanori; Kawashita, Norihito

    2018-01-01

    The global occurrence of viral infectious diseases poses a significant threat to human health. Dengue virus (DENV) infection is one of the most noteworthy of these infections. According to a WHO survey, approximately 400 million people are infected annually; symptoms deteriorate in approximately one percent of cases. Numerous foundational and clinical investigations on viral epidemiology, structure and function analysis, infection source and route, therapeutic targets, vaccines, and therapeutic drugs have been conducted by both academic and industrial researchers. At present, CYD-TDV or Dengvaxia ® is the only approved vaccine, but potent inhibitors are currently under development. In this review, an overview of the viral life circle and the history of DENVs is presented, and the most recently reported antiviral candidates and newly discovered promising targets are focused and summarized. We believe that these successes and failures have enabled progress in anti-DENV drug discovery and hope that our review will stimulate further innovation in this area.

  5. Human antibody responses after dengue virus infection are highly cross-reactive to Zika virus

    Science.gov (United States)

    Priyamvada, Lalita; Quicke, Kendra M.; Hudson, William H.; Onlamoon, Nattawat; Sewatanon, Jaturong; Edupuganti, Srilatha; Pattanapanyasat, Kovit; Chokephaibulkit, Kulkanya; Mulligan, Mark J.; Wilson, Patrick C.; Ahmed, Rafi; Suthar, Mehul S.; Wrammert, Jens

    2016-01-01

    Zika virus (ZIKV) is an emerging mosquito-borne flavivirus of significant public health concern. ZIKV shares a high degree of sequence and structural homology compared with other flaviviruses, including dengue virus (DENV), resulting in immunological cross-reactivity. Improving our current understanding of the extent and characteristics of this immunological cross-reactivity is important, as ZIKV is presently circulating in areas that are highly endemic for dengue. To assess the magnitude and functional quality of cross-reactive immune responses between these closely related viruses, we tested acute and convalescent sera from nine Thai patients with PCR-confirmed DENV infection against ZIKV. All of the sera tested were cross-reactive with ZIKV, both in binding and in neutralization. To deconstruct the observed serum cross-reactivity in depth, we also characterized a panel of DENV-specific plasmablast-derived monoclonal antibodies (mAbs) for activity against ZIKV. Nearly half of the 47 DENV-reactive mAbs studied bound to both whole ZIKV virion and ZIKV lysate, of which a subset also neutralized ZIKV. In addition, both sera and mAbs from the dengue-infected patients enhanced ZIKV infection of Fc gamma receptor (FcγR)-bearing cells in vitro. Taken together, these findings suggest that preexisting immunity to DENV may impact protective immune responses against ZIKV. In addition, the extensive cross-reactivity may have implications for ZIKV virulence and disease severity in DENV-experienced populations. PMID:27354515

  6. Tetravalent Dengue Vaccine Reduces Symptomatic and Asymptomatic Dengue Virus Infections in Healthy Children and Adolescents Aged 2-16 Years in Asia and Latin America.

    Science.gov (United States)

    Olivera-Botello, Gustavo; Coudeville, Laurent; Fanouillere, Karen; Guy, Bruno; Chambonneau, Laurent; Noriega, Fernando; Jackson, Nicholas

    2016-10-01

    Asymptomatic dengue virus-infected individuals are thought to play a major role in dengue virus transmission. The efficacy of the recently approved quadrivalent CYD-TDV dengue vaccine against asymptomatic dengue virus infection has not been previously assessed. We pooled data for 3 736 individuals who received either CYD-TDV or placebo at 0, 6, and 12 months in the immunogenicity subsets of 2 phase 3 trials (clinical trials registration NCT01373281 and NCT01374516). We defined a seroconversion algorithm (ie, a ≥4-fold increase in the neutralizing antibody titer and a titer of ≥40 from month 13 to month 25) as a surrogate marker of asymptomatic infection in the vaccine and placebo groups. The algorithm detected seroconversion in 94% of individuals with a diagnosis of virologically confirmed dengue between months 13 and 25, validating its discriminatory power. Among those without virologically confirmed dengue (n = 3 669), 219 of 2 485 in the vaccine group and 157 of 1 184 in the placebo group seroconverted between months 13 and 25, giving a vaccine efficacy of 33.5% (95% confidence interval [CI], 17.9%-46.1%) against asymptomatic infection. Vaccine efficacy was marginally higher in subjects aged 9-16 years (38.6%; 95% CI, 22.1%-51.5%). The annual incidence of asymptomatic dengue virus infection in this age group was 14.8%, which was 4.4 times higher than the incidence for symptomatic dengue (3.4%). The observed vaccine efficacy against asymptomatic dengue virus infections is expected to translate into reduced dengue virus transmission if sufficient individuals are vaccinated in dengue-endemic areas. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America.

  7. [Dengue, Zika and Chikungunya].

    Science.gov (United States)

    Kantor, Isabel N

    2016-01-01

    Arboviruses are transmitted by arthropods, including those responsible for the current pandemic: alphavirus (Chikungunya) and flaviviruses (dengue and Zika). Its importance increased in the Americas over the past 20 years. The main vectors are Aedes aegypti and A. albopictus. Dengue infection provides long lasting immunity against the specific serotype and temporary to the other three. Subsequent infection by another serotype determines more serious disease. There is a registered vaccine for dengue, Dengvaxia (Sanofi Pasteur). Other two (Butantan and Takeda) are in Phase III in 2016. Zika infection is usually asymptomatic or occurs with rash, conjunctivitis and not very high fever. There is no vaccine or specific treatment. It can be transmitted by parental, sexual and via blood transfusion. It has been associated with microcephaly. Chikungunya causes prolonged joint pain and persistent immune response. Two candidate vaccines are in Phase II. Dengue direct diagnosis is performed by virus isolation, RT-PCR and ELISA for NS1 antigen detection; indirect methods are ELISA-IgM (cross-reacting with other flavivirus), MAC-ELISA, and plaque neutralization. Zika is diagnosed by RT-PCR and virus isolation. Serological diagnosis cross-reacts with other flavivirus. For CHIKV culture, RT-PCR, MAC-ELISA and plaque neutralization are used. Against Aedes organophosphate larvicides (temephos), organophosphorus insecticides (malathion and fenitrothion) and pyrethroids (permethrin and deltamethrin) are usually employed. Resistance has been described to all these products. Vegetable derivatives are less expensive and biodegradable, including citronella oil, which microencapsulated can be preserved from evaporation.

  8. Modelling Virus and Antibody Dynamics during Dengue Virus Infection Suggests a Role for Antibody in Virus Clearance.

    Directory of Open Access Journals (Sweden)

    Hannah E Clapham

    2016-05-01

    Full Text Available Dengue is an infection of increasing global importance, yet uncertainty remains regarding critical aspects of its virology, immunology and epidemiology. One unanswered question is how infection is controlled and cleared during a dengue infection. Antibody is thought to play a role, but little past work has examined the kinetics of both virus and antibody during natural infections. We present data on multiple virus and antibody titres measurements recorded sequentially during infection from 53 Vietnamese dengue patients. We fit mechanistic mathematical models of the dynamics of viral replication and the host immune response to these data. These models fit the data well. The model with antibody removing virus fits the data best, but with a role suggested for ADCC or other infected cell clearance mechanisms. Our analysis therefore shows that the observed viral and antibody kinetics are consistent with antibody playing a key role in controlling viral replication. This work gives quantitative insight into the relationship between antibody levels and the efficiency of viral clearance. It will inform the future development of mechanistic models of how vaccines and antivirals might modify the course of natural dengue infection.

  9. Attenuation and immunogenicity of recombinant yellow fever 17D-dengue type 2 virus for rhesus monkeys

    Directory of Open Access Journals (Sweden)

    Galler R.

    2005-01-01

    Full Text Available A chimeric yellow fever (YF-dengue serotype 2 (dengue 2 virus was constructed by replacing the premembrane and envelope genes of the YF 17D virus with those from dengue 2 virus strains of Southeast Asian genotype. The virus grew to high titers in Vero cells and, after passage 2, was used for immunogenicity and attenuation studies in rhesus monkeys. Subcutaneous immunization of naive rhesus monkeys with the 17D-D2 chimeric virus induced a neutralizing antibody response associated with the protection of 6 of 7 monkeys against viremia by wild-type dengue 2 virus. Neutralizing antibody titers to dengue 2 were significantly lower in YF-immune animals than in YF-naive monkeys and protection against challenge with wild-type dengue 2 virus was observed in only 2 of 11 YF-immune monkeys. An anamnestic response to dengue 2, indicated by a sharp increase of neutralizing antibody titers, was observed in the majority of the monkeys after challenge with wild-type virus. Virus attenuation was demonstrated using the standard monkey neurovirulence test. The 17D-D2 chimera caused significantly fewer histological lesions than the YF 17DD virus. The attenuated phenotype could also be inferred from the limited viremias compared to the YF 17DD vaccine. Overall, these results provide further support for the use of chimeric viruses for the development of a new live tetravalent dengue vaccine.

  10. The first case of laboratory-confirmed dengue virus infection in Mimika, Papua province, Indonesia

    Directory of Open Access Journals (Sweden)

    Agustiningsih Agustiningsih

    2016-07-01

    Full Text Available Abstrak Latar belakang: Dengue merupakan penyakit bersumber vektor yang berkontribusi cukup besar dalam menyebabkan masalah kesehatan baik di negara tropis maupun subtropis. Hingga saat ini virus dengue telah menyebar ke seluruh provinsi di Indonesia sejak pertama kali ditemukan di Surabaya pada tahun 1968. Kabupaten Mimika di propinsi Papua, Indonesia, merupakan daerah non-endemis dengue dan tidak pernah melaporkan munculnya kasus dengue. Walau begitu, pada tahun 2012 ditemukan 13 kasus tersangka dengue yang dirawat di Rumah Sakit Umum di Mimika. Studi ini bertujuan memberi gambaran karakteristik genetik virus dengue dari kasus terkonfirmasi (laboratory-confirmed pertama di kabupaten Mimika, propinsi Papua, Indonesia. Metode: Isolasi virus pada sel nyamuk C6/36, RT-PCR dan penentuan serotipe dilakukan untuk mengkonfirmasi adanya virus dengue (DENV di dalam serum pasien tersangka dengue dari kabupaten Mimika, propinsi Papua, Indonesia. Sekuensing dan analisis pohon filogenetik terhadap complete-coding sequence (CDS gen E dilakukan terhadap sampel yang telah positif DENV untuk penentuan genotipe virus. Hasil: Sebanyak 4 kasus tersangka dengue terkonfirmasi positif DENV berdasarkan pemeriksaan RT-PCR, sedangkan 2 sampel berhasil dilakukan kultur pada sel C6/36. Hasil penentuan serotipe menunjukkan bahwa virus DENV dari kabupaten Mimika, propinsi Papua, Indonesia, termasuk ke dalam serotipe DENV 3.  Analisis CDS gen E menunjukkan DENV 3 termasuk ke dalam genotipe I. Kesimpulan: Studi ini melaporkan kasus pertama dengue yang terkonfirmasi secara laboratorium dari kabupaten Mimika, propinsi Papua, Indonesia, yang merupakan daerah non-endemis dengue. Kata Kunci: dengue, penentuan serotipe, penentuan genotipe, kabupaten Mimika Abstract Background: Dengue is the most important vector-borne disease that poses serious health problem both in tropical and subtropical countries. Since the first outbreak in Surabaya in 1968, dengue infection has spread in

  11. Dengue Hemorrhagic Fever in a Japanese Traveler with Pre-existing Japanese Encephalitis Virus Antibody.

    Science.gov (United States)

    Sato, Rumi; Hamada, Nobuyuki; Kashiwagi, Takahito; Imamura, Yoshihiro; Hara, Koyu; Nishimura, Munetsugu; Kamimura, Tomoko; Takasaki, Tomohiko; Watanabe, Hiroshi; Koga, Takeharu

    2015-06-01

    An adult Japanese man who had just returned from Thailand developed dengue hemorrhagic fever (DHF). A primary infection of dengue virus (DENV) was confirmed, specifically DENV serotype 2 (DENV-2), on the basis of the detection of the virus genome, a significant increase in the neutralizing antibody and the isolation of DENV-2. DHF is often observed following a secondary infection from another serotype of dengue virus, particularly in children, but this case was a primary infection of DENV. Japan is a non-endemic country for dengue disease. In fact, only Japanese encephalitis (JE) is known to be a member of the endemic flavivirus family. In this study, IgG antibody against Japanese encephalitis virus (JEV) was detected. JEV belongs to the family of dengue virus and prevails in Japan, particularly Kyushu. Among many risk factors for the occurrence of DHF, a plausible candidate could be a cross-reactive antibody-dependent enhancement (ADE) mechanism caused by JEV antibody. This indicates that most Japanese travelers who living in dengue non-endemic areas, particularly Kyushu, should be aware of the occurrence of DHF.

  12. High-throughput quantitative proteomic analysis of dengue virus type 2 infected A549 cells.

    Directory of Open Access Journals (Sweden)

    Han-Chen Chiu

    Full Text Available Disease caused by dengue virus is a global health concern with up to 390 million individuals infected annually worldwide. There are no vaccines or antiviral compounds available to either prevent or treat dengue disease which may be fatal. To increase our understanding of the interaction of dengue virus with the host cell, we analyzed changes in the proteome of human A549 cells in response to dengue virus type 2 infection using stable isotope labelling in cell culture (SILAC in combination with high-throughput mass spectrometry (MS. Mock and infected A549 cells were fractionated into nuclear and cytoplasmic extracts before analysis to identify proteins that redistribute between cellular compartments during infection and reduce the complexity of the analysis. We identified and quantified 3098 and 2115 proteins in the cytoplasmic and nuclear fractions respectively. Proteins that showed a significant alteration in amount during infection were examined using gene enrichment, pathway and network analysis tools. The analyses revealed that dengue virus infection modulated the amounts of proteins involved in the interferon and unfolded protein responses, lipid metabolism and the cell cycle. The SILAC-MS results were validated for a select number of proteins over a time course of infection by Western blotting and immunofluorescence microscopy. Our study demonstrates for the first time the power of SILAC-MS for identifying and quantifying novel changes in cellular protein amounts in response to dengue virus infection.

  13. Characteristics of Mild Dengue Virus Infection in Thai Children

    Science.gov (United States)

    2013-12-01

    dengue fever (DF) or dengue hemorrhagic fever (DHF) according to the 1997 WHO case definitions.2 Symptomatic DENV infec- tions that did not require...A, Pant S, Venkatesh V, 2008. Prevalence and clinical differentiation of dengue fever in children in northern India. Infection 36: 444–449. 18...ChadwickD,ArchB,Wilder-SmithA, PatonN, 2006.Distinguishing dengue fever from other infections on the basis of simple clinical and laboratory features

  14. Impact of the emergence and re-emergence of different dengue viruses' serotypes in Rio de Janeiro, Brazil, 2010 to 2012.

    Science.gov (United States)

    Heringer, Manoela; Nogueira, Rita Maria R; de Filippis, Ana Maria B; Lima, Monique R Q; Faria, Nieli R C; Nunes, Priscila C G; Nogueira, Fernanda B; dos Santos, Flávia B

    2015-04-01

    Rio de Janeiro (RJ) has been of major importance for the epidemiology of dengue viruses (DENVs) in Brazil. After the DENV 1-4 introductions in 1986, 1990, 2000 and 2011, respectively, the state has suffered explosive epidemics. We aimed to describe laboratorial, epidemiological and clinical aspects due to the emergence and re-emergence of distinct DENV in a 2-year period. Suspected dengue cases (n=2833), including 190 fatal cases, were submitted to virus isolation, RT-PCR and non-structural 1 (NS1) antigen capture ELISA, IgM antibody-capture (MAC)-ELISA and IgG-ELISA. Case confirmation was 47.5%. MAC-ELISA confirmed 32.6% of the cases, RT-PCR confirmed 56.3%; DENV was recovered in 33.1% of samples inoculated and NS1 ELISA confirmed 27.5% of the cases. DENV-2 was prevalent in 2010, DENV-1 in 2011 and DENV-4 in 2012. Individuals infected by DENV-3 and over 65 years-old, and children 15 years-old and under infected by DENV-2 had a significantly higher risk of developing a severe disease. Fatal cases confirmed (n=67) were due to DENV-1 (26.8%), DENV-2 (14.9%), DENV-3 (2.9%) and DENV-4 (7.4%). It has been shown here that viral emergences or re-emergences may play different roles in the disease epidemiology, especially when many serotypes co-circulate. © The Author 2015. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  15. Identification of bioflavonoid as fusion inhibitor of dengue virus using molecular docking approach

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    Asif Mir

    Full Text Available Dengue virus with four distinct serotypes belongs to Flavivirus, poses a significant threat to human health and becomes an emerging global problem. Membrane fusion is a central molecular event during viral entry into host cell. To prevent viral infection it is necessary to interrupt the virus replication at an early stage of attachment. Dengue Virus (DENV envelope protein experiences conformational changes and it causes the virus to fuse with host cell. Hinge region movement of domain I and II in envelope protein facilitates the fusion process. Small molecules that bind in this pocket may have the ability to interrupt the conformational changes that trigger fusion process. We chose different flavonoids (baicalein, fisetin, hesperetin, naringenin/ naringin, quercetin and rutin that possess anti dengue activity. Molecular docking analysis was done to examine the inhibitory effect of flavonoids against envelope protein of DENV-2. Results manifest quercetin (flavonoid found in Carica papaya, apple and even in lemon as the only flavone that can interrupt the fusion process of virus by inhibiting the hinge region movement and by blocking the conformational rearrangement in envelope protein. These novel findings using computational approach are worthwhile and will be a bridge to check the efficacy of compounds using appropriate animal model under In vivo studies. This information can be used by new techniques and provides a way to control dengue virus infection. Keywords: Dengue virus, Inhibitor identification, Molecular docking, Interaction analysis

  16. A Rapid and Improved Method to Generate Recombinant Dengue Virus Vaccine Candidates.

    Science.gov (United States)

    Govindarajan, Dhanasekaran; Guan, Liming; Meschino, Steven; Fridman, Arthur; Bagchi, Ansu; Pak, Irene; ter Meulen, Jan; Casimiro, Danilo R; Bett, Andrew J

    2016-01-01

    Dengue is one of the most important mosquito-borne infections accounting for severe morbidity and mortality worldwide. Recently, the tetravalent chimeric live attenuated Dengue vaccine Dengvaxia® was approved for use in several dengue endemic countries. In general, live attenuated vaccines (LAV) are very efficacious and offer long-lasting immunity against virus-induced disease. Rationally designed LAVs can be generated through reverse genetics technology, a method of generating infectious recombinant viruses from full length cDNA contained in bacterial plasmids. In vitro transcribed (IVT) viral RNA from these infectious clones is transfected into susceptible cells to generate recombinant virus. However, the generation of full-length dengue virus cDNA clones can be difficult due to the genetic instability of viral sequences in bacterial plasmids. To circumvent the need for a single plasmid containing a full length cDNA, in vitro ligation of two or three cDNA fragments contained in separate plasmids can be used to generate a full-length dengue viral cDNA template. However, in vitro ligation of multiple fragments often yields low quality template for IVT reactions, resulting in inconsistent low yield RNA. These technical difficulties make recombinant virus recovery less efficient. In this study, we describe a simple, rapid and efficient method of using LONG-PCR to recover recombinant chimeric Yellow fever dengue (CYD) viruses as potential dengue vaccine candidates. Using this method, we were able to efficiently generate several viable recombinant viruses without introducing any artificial mutations into the viral genomes. We believe that the techniques reported here will enable rapid and efficient recovery of recombinant flaviviruses for evaluation as vaccine candidates and, be applicable to the recovery of other RNA viruses.

  17. A Rapid and Improved Method to Generate Recombinant Dengue Virus Vaccine Candidates.

    Directory of Open Access Journals (Sweden)

    Dhanasekaran Govindarajan

    Full Text Available Dengue is one of the most important mosquito-borne infections accounting for severe morbidity and mortality worldwide. Recently, the tetravalent chimeric live attenuated Dengue vaccine Dengvaxia® was approved for use in several dengue endemic countries. In general, live attenuated vaccines (LAV are very efficacious and offer long-lasting immunity against virus-induced disease. Rationally designed LAVs can be generated through reverse genetics technology, a method of generating infectious recombinant viruses from full length cDNA contained in bacterial plasmids. In vitro transcribed (IVT viral RNA from these infectious clones is transfected into susceptible cells to generate recombinant virus. However, the generation of full-length dengue virus cDNA clones can be difficult due to the genetic instability of viral sequences in bacterial plasmids. To circumvent the need for a single plasmid containing a full length cDNA, in vitro ligation of two or three cDNA fragments contained in separate plasmids can be used to generate a full-length dengue viral cDNA template. However, in vitro ligation of multiple fragments often yields low quality template for IVT reactions, resulting in inconsistent low yield RNA. These technical difficulties make recombinant virus recovery less efficient. In this study, we describe a simple, rapid and efficient method of using LONG-PCR to recover recombinant chimeric Yellow fever dengue (CYD viruses as potential dengue vaccine candidates. Using this method, we were able to efficiently generate several viable recombinant viruses without introducing any artificial mutations into the viral genomes. We believe that the techniques reported here will enable rapid and efficient recovery of recombinant flaviviruses for evaluation as vaccine candidates and, be applicable to the recovery of other RNA viruses.

  18. Immature dengue virus : functional properties and potential contribution to disease

    NARCIS (Netherlands)

    Da Silva-Voorham, Júlia Maria

    2013-01-01

    Beter inzicht in mechanismen achter infectieziekte dengue Dengue (‘knokkelkoorts’) is een veelvoorkomende, tropische infectieziekte die wordt overgebracht door muggen. Naar schatting raken jaarlijks zo’n vijftig tot honderd miljoen mensen besmet. Meestal gaat dengue vanzelf over, maar in zo’n

  19. Molecular surveillance of dengue in Minas Gerais provides insights on dengue virus 1 and 4 circulation in Brazil.

    Science.gov (United States)

    Dutra, Karina Rocha; Drumond, Betânia Paiva; de Rezende, Izabela Maurício; Nogueira, Maurício Lacerda; de Oliveira Lopes, Débora; Calzavara Silva, Carlos Eduardo; Siqueira Ferreira, Jaqueline Maria; Dos Santos, Luciana Lara

    2017-06-01

    Dengue, caused by any of the four types of Dengue virus (DENV) is the most important arbovirus in the world. In this study we performed a molecular surveillance of dengue during the greatest dengue outbreak that took place in Divinópolis, Minas Gerais state, Southeast Brazil, in 2013. Samples from 100 patients with clinical symptoms of dengue were studied and 26 were positive. The capsid/premembrane (CprM) and envelope gene sequences of some samples were amplified and sequenced. Molecular analyses demonstrated that two DENV-1 lineages, belonging to genotype V were introduced and co-circulated in Divinópolis. When compared to each other, those lineages presented high genetic diversity and showed unique amino acids substitutions in the envelope protein, including in domains I, II, and III. DENV-4 strains from Divinópolis clustered within genotype IIb and the most recent common ancestor was probably introduced into the city three years before the 2013 epidemic. Here we demonstrated for the first time the circulation of DENV-4 and the co-circulation of two DENV-1 lineages in Midwest region of Minas Gerais, Brazil. Moreover our analysis indicated the introduction of five DENV-1 lineages, genotype V into Brazil, in different times. J. Med. Virol. 89:966-973, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  20. Morphological studies in a model for dengue-2 virus infection in mice

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    Ortrud Monika Barth

    2006-12-01

    Full Text Available One of the main difficulties in studying dengue virus infection in humans and in developing a vaccine is the absence of a suitable animal model which develops the full spectrum of dengue fever, dengue haemorrhagic fever, and dengue shock syndrome. It is our proposal to present morphological aspects of an animal model which shows many similarities with the dengue infection in humans. BALB/c mice were intraperitoneally infected with non-neuroadapted dengue virus serotype 2 (DENV-2. Histopathological and morphometrical analyses of liver tissue revealed focal alterations along the infection, reaching wide-ranging portal and centrolobular veins congestion and sinusoidal cell death. Additional ultrastructural observations demonstrated multifocal endothelial injury, platelet recruitment, and alterated hepatocytes. Dengue virus antigen was detected in hepatocytes and in the capillar endothelium of the central lobular vein area. Liver function tests showed high levels of aspartate transaminase and alanine transaminase enzyme activity. Lung tissue showed interstitial pneumonia and mononuclear cells, interseptal oedema, hyperplasia, and hypertrophy of the bronchiolar epithelial cells. DENV-2 led to a transient inflammatory process, but caused focal alterations of the blood-exchange barrier. Viremia was observed from 2nd to 11th day p.i. by isolation of DENV-2 in C6/36 mosquito cell line inoculated with the supernatant of macerated liver, lung, kidney, and cerebellum tissues of the infected mice.

  1. Structure and Function of the Non-Structural Protein of Dengue Virus and its Applications in Antiviral Therapy.

    Science.gov (United States)

    Xie, Qian; Zhang, Bao; Yu, JianHai; Wu, Qinghua; Yang, Fangji; Cao, Hong; Zhao, Wei

    2017-01-01

    Dengue fever, a type of global and tropical infectious disease, and its prevention has become a challenging issue worldwide. Antibody-dependent enhancement effects and the virus pathogenic mechanism have not yet been fully elucidated, hindering the development of dengue fever prevention and suitable drug treatment. There is currently no specific prevention and therapy in clinical trials, however, in recent years, studies have focused on the pathogenesis and treatment of dengue. Research focusing on dengue virus nonstructural protein in special drugs for the prevention and control of dengue fever is a new progress leading to improved understanding regarding the prevention and control of dengue fever and suitable drugs for the treatment. The main challenges regarding the structure of dengue virus nonstructural protein and the drugs for antiviral therapy are summarized in this paper.

  2. Dengue fever

    African Journals Online (AJOL)

    Introduction. Dengue fever is caused by dengue viruses. (DENV). Transmission of DENV has increased dramatically in the past two decades making DENV the most important human pathogens among arthropod-borne viruses (1). About 50-. 100 million dengue fever infections occur every year in tropical and subtropical.

  3. Interactions between the Dengue Virus Polymerase NS5 and Stem-Loop A.

    Science.gov (United States)

    Bujalowski, Paul J; Bujalowski, Wlodzimierz; Choi, Kyung H

    2017-06-01

    The process of RNA replication by dengue virus is still not completely understood despite the significant progress made in the last few years. Stem-loop A (SLA), a part of the viral 5' untranslated region (UTR), is critical for the initiation of dengue virus replication, but quantitative analysis of the interactions between the dengue virus polymerase NS5 and SLA in solution has not been performed. Here, we examine how solution conditions affect the size and shape of SLA and the formation of the NS5-SLA complex. We show that dengue virus NS5 binds SLA with a 1:1 stoichiometry and that the association reaction is primarily entropy driven. We also observe that the NS5-SLA interaction is influenced by the magnesium concentration in a complex manner. Binding is optimal with 1 mM MgCl 2 but decreases with both lower and higher magnesium concentrations. Additionally, data from a competition assay between SLA and single-stranded RNA (ssRNA) indicate that SLA competes with ssRNA for the same binding site on the NS5 polymerase. SLA 70 and SLA 80 , which contain the first 70 and 80 nucleotides (nt), respectively, bind NS5 with similar binding affinities. Dengue virus NS5 also binds SLAs from different serotypes, indicating that NS5 recognizes the overall shape of SLA as well as specific nucleotides. IMPORTANCE Dengue virus is an important human pathogen responsible for dengue hemorrhagic fever, whose global incidence has increased dramatically over the last several decades. Despite the clear medical importance of dengue virus infection, the mechanism of viral replication, a process commonly targeted by antiviral therapeutics, is not well understood. In particular, stem-loop A (SLA) and stem-loop B (SLB) located in the 5' untranslated region (UTR) are critical for binding the viral polymerase NS5 to initiate minus-strand RNA synthesis. However, little is known regarding the kinetic and thermodynamic parameters driving these interactions. Here, we quantitatively examine the

  4. Synchrony of sylvatic dengue isolations: a multi-host, multi-vector SIR model of dengue virus transmission in Senegal.

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    Benjamin M Althouse

    Full Text Available Isolations of sylvatic dengue-2 virus from mosquitoes, humans and non-human primates in Senegal show synchronized multi-annual dynamics over the past 50 years. Host demography has been shown to directly affect the period between epidemics in other pathogen systems, therefore, one might expect unsynchronized multi-annual cycles occurring in hosts with dramatically different birth rates and life spans. However, in Senegal, we observe a single synchronized eight-year cycle across all vector species, suggesting synchronized dynamics in all vertebrate hosts. In the current study, we aim to explore two specific hypotheses: 1 primates with different demographics will experience outbreaks of dengue at different periodicities when observed as isolated systems, and that coupling of these subsystems through mosquito biting will act to synchronize incidence; and 2 the eight-year periodicity of isolations observed across multiple primate species is the result of long-term cycling in population immunity in the host populations. To test these hypotheses, we develop a multi-host, multi-vector Susceptible, Infected, Removed (SIR model to explore the effects of coupling multiple host-vector systems of dengue virus transmission through cross-species biting rates. We find that under small amounts of coupling, incidence in the host species synchronize. Long-period multi-annual dynamics are observed only when prevalence in troughs reaches vanishingly small levels (< 10(-10, suggesting that these dynamics are inconsistent with sustained transmission in this setting, but are consistent with local dengue virus extinctions followed by reintroductions. Inclusion of a constant introduction of infectious individuals into the system causes the multi-annual periods to shrink, while the effects of coupling remain the same. Inclusion of a stochastic rate of introduction allows for multi-annual periods at a cost of reduced synchrony. Thus, we conclude that the eight-year period

  5. Serum Metabolomics Investigation of Humanized Mouse Model of Dengue Virus Infection.

    Science.gov (United States)

    Cui, Liang; Hou, Jue; Fang, Jinling; Lee, Yie Hou; Costa, Vivian Vasconcelos; Wong, Lan Hiong; Chen, Qingfeng; Ooi, Eng Eong; Tannenbaum, Steven R; Chen, Jianzhu; Ong, Choon Nam

    2017-07-15

    Dengue is an acute febrile illness caused by dengue virus (DENV) and a major cause of morbidity and mortality in tropical and subtropical regions of the world. The lack of an appropriate small-animal model of dengue infection has greatly hindered the study of dengue pathogenesis and the development of therapeutics. In this study, we conducted mass spectrometry-based serum metabolic profiling from a model using humanized mice (humice) with DENV serotype 2 infection at 0, 3, 7, 14, and 28 days postinfection (dpi). Forty-eight differential metabolites were identified, including fatty acids, purines and pyrimidines, acylcarnitines, acylglycines, phospholipids, sphingolipids, amino acids and derivatives, free fatty acids, and bile acid. These metabolites showed a reversible-change trend-most were significantly perturbed at 3 or 7 dpi and returned to control levels at 14 or 28 dpi, indicating that the metabolites might serve as prognostic markers of the disease in humice. The major perturbed metabolic pathways included purine and pyrimidine metabolism, fatty acid β-oxidation, phospholipid catabolism, arachidonic acid and linoleic acid metabolism, sphingolipid metabolism, tryptophan metabolism, phenylalanine metabolism, lysine biosynthesis and degradation, and bile acid biosynthesis. Most of these disturbed pathways are similar to our previous metabolomics findings in a longitudinal cohort of adult human dengue patients across different infection stages. Our analyses revealed the commonalities of host responses to DENV infection between humice and humans and suggested that humice could be a useful small-animal model for the study of dengue pathogenesis and the development of dengue therapeutics. IMPORTANCE Dengue virus is the most widespread arbovirus, causing an estimated 390 million dengue infections worldwide every year. There is currently no effective treatment for the disease, and the lack of an appropriate small-animal model of dengue infection has greatly

  6. Identification of covalent active site inhibitors of dengue virus protease

    Directory of Open Access Journals (Sweden)

    Koh-Stenta X

    2015-12-01

    Full Text Available Xiaoying Koh-Stenta,1 Joma Joy,1 Si Fang Wang,1 Perlyn Zekui Kwek,1 John Liang Kuan Wee,1 Kah Fei Wan,2 Shovanlal Gayen,1 Angela Shuyi Chen,1 CongBao Kang,1 May Ann Lee,1 Anders Poulsen,1 Subhash G Vasudevan,3 Jeffrey Hill,1 Kassoum Nacro11Experimental Therapeutics Centre, Agency for Science, Technology and Research (A*STAR, Singapore; 2Novartis Institute for Tropical Diseases, Singapore; 3Program in Emerging Infectious Diseases, Duke-NUS Graduate Medical School, SingaporeAbstract: Dengue virus (DENV protease is an attractive target for drug development; however, no compounds have reached clinical development to date. In this study, we utilized a potent West Nile virus protease inhibitor of the pyrazole ester derivative class as a chemical starting point for DENV protease drug development. Compound potency and selectivity for DENV protease were improved through structure-guided small molecule optimization, and protease-inhibitor binding interactions were validated biophysically using nuclear magnetic resonance. Our work strongly suggests that this class of compounds inhibits flavivirus protease through targeted covalent modification of active site serine, contrary to an allosteric binding mechanism as previously described.Keywords: flavivirus protease, small molecule optimization, covalent inhibitor, active site binding, pyrazole ester derivatives

  7. Vaccines and immunization strategies for dengue prevention

    Science.gov (United States)

    Liu, Yang; Liu, Jianying; Cheng, Gong

    2016-01-01

    Dengue is currently the most significant arboviral disease afflicting tropical and sub-tropical countries worldwide. Dengue vaccines, such as the multivalent attenuated, chimeric, DNA and inactivated vaccines, have been developed to prevent dengue infection in humans, and they function predominantly by stimulating immune responses against the dengue virus (DENV) envelope (E) and nonstructural-1 proteins (NS1). Of these vaccines, a live attenuated chimeric tetravalent DENV vaccine developed by Sanofi Pasteur has been licensed in several countries. However, this vaccine renders only partial protection against the DENV2 infection and is associated with an unexplained increased incidence of hospitalization for severe dengue disease among children younger than nine years old. In addition to the virus-based vaccines, several mosquito-based dengue immunization strategies have been developed to interrupt the vector competence and effectively reduce the number of infected mosquito vectors, thus controlling the transmission of DENV in nature. Here we summarize the recent progress in the development of dengue vaccines and novel immunization strategies and propose some prospective vaccine strategies for disease prevention in the future. PMID:27436365

  8. Vaccines and immunization strategies for dengue prevention.

    Science.gov (United States)

    Liu, Yang; Liu, Jianying; Cheng, Gong

    2016-07-20

    Dengue is currently the most significant arboviral disease afflicting tropical and sub-tropical countries worldwide. Dengue vaccines, such as the multivalent attenuated, chimeric, DNA and inactivated vaccines, have been developed to prevent dengue infection in humans, and they function predominantly by stimulating immune responses against the dengue virus (DENV) envelope (E) and nonstructural-1 proteins (NS1). Of these vaccines, a live attenuated chimeric tetravalent DENV vaccine developed by Sanofi Pasteur has been licensed in several countries. However, this vaccine renders only partial protection against the DENV2 infection and is associated with an unexplained increased incidence of hospitalization for severe dengue disease among children younger than nine years old. In addition to the virus-based vaccines, several mosquito-based dengue immunization strategies have been developed to interrupt the vector competence and effectively reduce the number of infected mosquito vectors, thus controlling the transmission of DENV in nature. Here we summarize the recent progress in the development of dengue vaccines and novel immunization strategies and propose some prospective vaccine strategies for disease prevention in the future.

  9. Evolutionary Analysis of Dengue Serotype 2 Viruses Using Phylogenetic and Bayesian Methods from New Delhi, India.

    Directory of Open Access Journals (Sweden)

    Nazia Afreen

    2016-03-01

    Full Text Available Dengue fever is the most important arboviral disease in the tropical and sub-tropical countries of the world. Delhi, the metropolitan capital state of India, has reported many dengue outbreaks, with the last outbreak occurring in 2013. We have recently reported predominance of dengue virus serotype 2 during 2011-2014 in Delhi. In the present study, we report molecular characterization and evolutionary analysis of dengue serotype 2 viruses which were detected in 2011-2014 in Delhi. Envelope genes of 42 DENV-2 strains were sequenced in the study. All DENV-2 strains grouped within the Cosmopolitan genotype and further clustered into three lineages; Lineage I, II and III. Lineage III replaced lineage I during dengue fever outbreak of 2013. Further, a novel mutation Thr404Ile was detected in the stem region of the envelope protein of a single DENV-2 strain in 2014. Nucleotide substitution rate and time to the most recent common ancestor were determined by molecular clock analysis using Bayesian methods. A change in effective population size of Indian DENV-2 viruses was investigated through Bayesian skyline plot. The study will be a vital road map for investigation of epidemiology and evolutionary pattern of dengue viruses in India.

  10. Evolutionary Analysis of Dengue Serotype 2 Viruses Using Phylogenetic and Bayesian Methods from New Delhi, India.

    Science.gov (United States)

    Afreen, Nazia; Naqvi, Irshad H; Broor, Shobha; Ahmed, Anwar; Kazim, Syed Naqui; Dohare, Ravins; Kumar, Manoj; Parveen, Shama

    2016-03-01

    Dengue fever is the most important arboviral disease in the tropical and sub-tropical countries of the world. Delhi, the metropolitan capital state of India, has reported many dengue outbreaks, with the last outbreak occurring in 2013. We have recently reported predominance of dengue virus serotype 2 during 2011-2014 in Delhi. In the present study, we report molecular characterization and evolutionary analysis of dengue serotype 2 viruses which were detected in 2011-2014 in Delhi. Envelope genes of 42 DENV-2 strains were sequenced in the study. All DENV-2 strains grouped within the Cosmopolitan genotype and further clustered into three lineages; Lineage I, II and III. Lineage III replaced lineage I during dengue fever outbreak of 2013. Further, a novel mutation Thr404Ile was detected in the stem region of the envelope protein of a single DENV-2 strain in 2014. Nucleotide substitution rate and time to the most recent common ancestor were determined by molecular clock analysis using Bayesian methods. A change in effective population size of Indian DENV-2 viruses was investigated through Bayesian skyline plot. The study will be a vital road map for investigation of epidemiology and evolutionary pattern of dengue viruses in India.

  11. Role of human GRP75 in miRNA mediated regulation of dengue virus replication.

    Science.gov (United States)

    Kakumani, Pavan Kumar; Medigeshi, Guruprasad R; Kaur, Inderjeet; Malhotra, Pawan; Mukherjee, Sunil K; Bhatnagar, Raj K

    2016-07-15

    In recent times, RNAi has emerged as an important defence system that regulates replication of pathogens in host cells. Many RNAi related host factors especially the host miRNAs play important roles in all intrinsic cellular functions, including viral infection. We have been working on identification of mammalian host factors involved in Dengue virus infection. In the present study, we identified Glucose Regulated Protein 75kDa (GRP75), as a host factor that is associated with dicer complex, in particular with HADHA (trifunctional enzyme subunit alpha, mitochondrial), an auxiliary component of dicer complex. Knockdown of GRP75 by respective siRNAs in Huh-7 cells resulted in the accumulation of dengue viral genomic RNA suggesting a role of GRP75 in regulating dengue virus replication in human cell lines. To elucidate the mode of action of GRP75, we over expressed the protein in Huh-7 cells and analysed the host miRNAs processing. The results revealed that, GRP75 is involved in processing of host miRNA, hsa-mir-126, that down regulates dengue virus replication. These findings suggest a regulatory role of human miRNA pathway especially GRP75 protein and hsa-mir-126 in dengue virus replication. These results thus provide insights into the role of miRNAs and RNAi machinery in dengue life cycle. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Deeper understanding about the genetic structure of dengue virus using SVM

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    Choi Subin

    2016-01-01

    Full Text Available Dengue fever, mainly found in the tropical and subtropical regions, is carried by mosquitoes. With the help of greenhouse effect, places considered to be a Dengue safe-zone are becoming more and more dangerous. Dengue fever shows similar aspects to MERS, which caused heavy casualties in South Korea; Dengue virus does not have clear treatments nor vaccines like MERS. Development of Dengue vaccine is actively investigated lately. However, it is not easy to succeed; the fact that Dengue’s 4 serotypes have different properties and that repeated infections worsen the symptoms. This research aims to analyze the 4 serotypes (DENV1, DENV2, DENV3, DENV4 using SVM and ANN algorithms to investigate the constraints in the development of Dengue’s vaccines and treatments.

  13. Maternal Zika Virus Disease Severity, Virus Load, Prior Dengue Antibodies, and Their Relationship to Birth Outcomes.

    Science.gov (United States)

    Halai, Umme-Aiman; Nielsen-Saines, Karin; Moreira, Maria Lopes; de Sequeira, Patricia Carvalho; Junior, Jose Paulo Pereira; de Araujo Zin, Andrea; Cherry, James; Gabaglia, Claudia Raja; Gaw, Stephanie L; Adachi, Kristina; Tsui, Irena; Pilotto, Jose Henrique; Nogueira, Rita Ribeiro; de Filippis, Ana Maria Bispo; Brasil, Patricia

    2017-09-15

    Congenital Zika virus (ZIKV) syndrome is a newly identified condition resulting from infection during pregnancy. We analyzed outcome data from a mother-infant cohort in Rio de Janeiro in order to assess whether clinical severity of maternal ZIKV infection was associated with maternal virus load, prior dengue antibodies, or abnormal pregnancy/infant outcomes. A clinical severity assessment tool was developed based on duration of fever, severity of rash, multisystem involvement, and duration of symptoms during ZIKV infection. ZIKV-RNA load was quantified by polymerase chain reaction (PCR) cycles in blood/ urine. Dengue immunoglobulin G (IgG) antibodies were measured at baseline. Adverse outcomes were defined as fetal loss or a live infant with grossly abnormal clinical or brain imaging findings. Regression models were used to study potential associations. 131 ZIKV-PCR positive pregnant women were scored for clinical disease severity, 6 (4.6%) had mild disease, 98 (74.8%) had moderate disease, and 27 (20.6%) severe manifestations of ZIKV infection. There were 58 (46.4%) abnormal outcomes with 9 fetal losses (7.2%) in 125 pregnancies. No associations were found between: disease severity and abnormal outcomes (P = .961; odds ratio [OR]: 1.00; 95% confidence interval [CI]: 0.796-1.270); disease severity and viral load (P = .994); viral load and adverse outcomes (P = .667; OR: 1.02; 95% CI: 0.922-1.135); or existence of prior dengue antibodies (88% subjects) with severity score, ZIKV-RNA load or adverse outcomes (P = .667; OR: 0.78; 95% CI: 0.255-2.397). Congenital ZIKV syndrome does not appear to be associated with maternal disease severity, ZIKV-RNA load at time of infection or existence of prior dengue antibodies. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

  14. Identification of natural antimicrobial agents to treat dengue infection: In vitro analysis of latarcin peptide activity against dengue virus.

    Science.gov (United States)

    Rothan, Hussin A; Bahrani, Hirbod; Rahman, Noorsaadah Abd; Yusof, Rohana

    2014-05-31

    Although there have been considerable advances in the study of dengue virus, no vaccines or anti-dengue drugs are currently available for humans. Therefore, new approaches are necessary for the development of potent anti-dengue drugs. Natural antimicrobial peptides (AMPs) with potent antiviral activities are potential hits-to-leads for antiviral drug discovery. We performed this study to identify and characterise the inhibitory potential of the latarcin peptide (Ltc 1, SMWSGMWRRKLKKLRNALKKKLKGE) against dengue virus replication in infected cells. The Ltc 1 peptide showed a significantly inhibitory effect against the dengue protease NS2B-NS3pro at 37°C, a physiological human temperature, (IC50, 12.68 ± 3.2 μM), and greater inhibitory effect was observed at 40°C, a temperature similar to a high fever (IC50, 6.58 ± 4.1 μM). A greater reduction in viral load (p.f.u./ml) was observed at simultaneous (0.7 ± 0.3 vs. 7.2 ± 0.5 control) and post-treatment (1.8 ± 0.7 vs. 6.8 ± 0.6 control) compared to the pre-treatment (4.5 ± 0.6 vs. 6.9 ± 0.5 control). Treatment with the Ltc 1 peptide reduced the viral RNA in a dose-dependent manner with EC50 values of 8.3 ± 1.2, 7.6 ± 2.7 and 6.8 ± 2.5 μM at 24, 48 and 72 h, respectively. The Ltc 1 peptide exhibited significant inhibitory effects against dengue NS2B-NS3pro and virus replication in the infected cells. Therefore, further investigation is necessary to develop the Ltc 1 peptide as a new anti-dengue therapeutic.

  15. Phylogenetic analysis of Dengue virus 1 isolated from South Minas Gerais, Brazil.

    Science.gov (United States)

    Drumond, Betania Paiva; Fagundes, Luiz Gustavo da Silva; Rocha, Raissa Prado; Fumagalli, Marcilio Jorge; Araki, Carlos Shigueru; Colombo, Tatiana Elisa; Nogueira, Mauricio Lacerda; Castilho, Thiago Elias; da Silveira, Nelson José Freitas; Malaquias, Luiz Cosme Cotta; Coelho, Luiz Felipe Leomil

    2016-01-01

    Dengue is a major worldwide public health problem, especially in the tropical and subtropical regions of the world. Primary infection with a single Dengue virus serotype causes a mild, self-limiting febrile illness called dengue fever. However, a subset of patients who experience secondary infection with a different serotype can progress to a more severe form of the disease, called dengue hemorrhagic fever. The four Dengue virus serotypes (1-4) are antigenically and genetically distinct and each serotype is composed of multiple genotypes. In this study we isolated one Dengue virus 1 serotype, named BR/Alfenas/2012, from a patient with dengue hemorrhagic fever in Alfenas, South Minas Gerais, Brazil and molecular identification was performed based on the analysis of NS5 gene. Swiss mice were infected with this isolate to verify its potential to induce histopathological alterations characteristic of dengue. Liver histopathological analysis of infected animals showed the presence of inflammatory infiltrates, hepatic steatosis, as well as edema, hemorrhage and necrosis focal points. Phylogenetic and evolutionary analyses based on the envelope gene provided evidence that the isolate BR/Alfenas/2012 belongs to genotype V, lineage I and it is probably derived from isolates of Rio de Janeiro, Brazil. The isolate BR/Alfenas/2012 showed two unique amino acids substitutions (SER222THRE and PHE306SER) when compared to other Brazilian isolates from the same genotype/lineage. Molecular models were generated for the envelope protein indicating that the amino acid alteration PHE 306 SER could contribute to a different folding in this region located within the domain III. Further genetic and animal model studies using BR/Alfenas/2012 and other isolates belonging to the same lineage/genotype could help determine the relation of these genetic alterations and dengue hemorrhagic fever in a susceptible population. Copyright © 2015 Sociedade Brasileira de Microbiologia. Published by

  16. In silico mutation analysis of non-structural protein-5 (NS5) dengue virus

    Science.gov (United States)

    Puspitasari, R. D.; Tambunan, U. S. F.

    2017-04-01

    Dengue fever is a world disease. It is endemic in more than 100 countries. Information about the effect of mutations in the virus is important in drug design and development. In this research, we studied the effect of mutation on NS5 dengue virus. NS5 is the large protein containing 67% amino acid similarity in DENV 1-4 and has multifunctional enzymatic activities. Dengue virus is an RNA virus that has very high mutation frequency with an average of 100 times higher than DNA mutations, and the accumulation of mutations will be possible to generate the new serotype. In this study, we report that mutation occurs in NS5 of DENV serotype 3, glutamine mutates into methionine at position 10 and threonine mutates into isoleucine at position 55. These residues are part of the domain named S-Adenosyl-L-Methionine-Dependent Methyltransferase (IPR029063).

  17. Application of clustering methods: Regularized Markov clustering (R-MCL) for analyzing dengue virus similarity

    Science.gov (United States)

    Lestari, D.; Raharjo, D.; Bustamam, A.; Abdillah, B.; Widhianto, W.

    2017-07-01

    Dengue virus consists of 10 different constituent proteins and are classified into 4 major serotypes (DEN 1 - DEN 4). This study was designed to perform clustering against 30 protein sequences of dengue virus taken from Virus Pathogen Database and Analysis Resource (VIPR) using Regularized Markov Clustering (R-MCL) algorithm and then we analyze the result. By using Python program 3.4, R-MCL algorithm produces 8 clusters with more than one centroid in several clusters. The number of centroid shows the density level of interaction. Protein interactions that are connected in a tissue, form a complex protein that serves as a specific biological process unit. The analysis of result shows the R-MCL clustering produces clusters of dengue virus family based on the similarity role of their constituent protein, regardless of serotypes.

  18. Antiviral Activity of Novel Quinoline Derivatives against Dengue Virus Serotype 2

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    Carolina de la Guardia

    2018-03-01

    Full Text Available Dengue virus causes dengue fever, a debilitating disease with an increasing incidence in many tropical and subtropical territories. So far, there are no effective antivirals licensed to treat this virus. Here we describe the synthesis and antiviral activity evaluation of two compounds based on the quinoline scaffold, which has shown potential for the development of molecules with various biological activities. Two of the tested compounds showed dose-dependent inhibition of dengue virus serotype 2 in the low and sub micromolar range. The compounds 1 and 2 were also able to impair the accumulation of the viral envelope glycoprotein in infected cells, while showing no sign of direct virucidal activity and acting possibly through a mechanism involving the early stages of the infection. The results are congruent with previously reported data showing the potential of quinoline derivatives as a promising scaffold for the development of new antivirals against this important virus.

  19. Detection antigen virus den on monocyts by streptavidin biotin test as early diagnostic for dengue fever hemorrhagic

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    Y NINING SRI WURYANINGSIH

    2007-07-01

    Full Text Available Dengue virus infection is the main cause of morbidity and mortality in the tropical and sub-tropical countries of the world. Clinically it may manifest as asymtomastic,undifferentiated fever,dengue ever,dengue haemorrhagic fever and dengue shock syndrome cases. The mechanism underlying the disease with severe complication is not clear yet,however it has been previosus reported that primary and secondary infections of dengue virus play an important role in the patogenesis of this diseases. Early diagnosis of dengue virus infection has a great contribution for appropriate management of the disease, especialy for the prognosis of the patient. Laboratory investigations for such cases will be methods on serological investigation as well as virus isolation and identification.of dengue virus infection could be made by detection of specific virus ,viral antigen,genomic sequence and or detection of antibodies. These methods are sensitive and precise for detecting dengue virus infection,but there need special equipment,costly and detection of IgM and IgG often positive or negative false the dengue virus in the blood stream There for, this study was performed in order to develop a method to detect dengue virus antigen on the monocytes using Streptavidin biotin technique. The result of Streptavidin biotin study demonstrated that 32 sera from patient suspected with DHF 78,1% were positive DHF,and 21,9% were negative DHF. These results are consistent with the result from WHO criteria as standard .The Chi Square analysis showed that the presentage of sensitivity and specificity of Streptavidin biotin methode were 88% and 87,7% respectively. In conclusions, immunocytochemistry method using streptavidin biotin technique could be used as a method to detect antigen dengue virus on monocytes in the serum patient suspected with DHF. This technique has high sensitivity and specivicity and consistent with the clinical WHO criteria for DHF.

  20. Chikungunya and Zika Virus Cases Detected against a Backdrop of Endemic Dengue Transmission in Vietnam.

    Science.gov (United States)

    Quyen, Nguyen Than Ha; Kien, Duong Thi Hue; Rabaa, Maia; Tuan, Nguyen Minh; Vi, Tran Thuy; Van Tan, Le; Hung, Nguyen Thanh; Tuan, Ha Manh; Van Tram, Ta; Le Da Ha, Nguyen; Quang, Han Khoi; Doanh, Nguyen Quoc; Van Vinh Chau, Nguyen; Wills, Bridget; Simmons, Cameron P

    2017-07-01

    Between 2010 and 2014, four chikungunya and two Zika virus infections were identified among 8,105 febrile children in southern Vietnam. Zika viruses were linked to French Polynesian strains, chikungunya to Cambodian strains. Against a backdrop of endemic dengue transmission, chikungunya and Zika present an additional arboviral disease burden in Vietnam.

  1. Chikungunya and Zika virus cases detected against a backdrop of endemic dengue transmission in Vietnam

    OpenAIRE

    Quyen, NTH; Kien, DTH; Rabaa, M; Tuan, NM; Vi, TT; Van Tan, L; Hung, NT; Tuan, HM; Van Tram, T; Le Da Ha, N; Quang, HK; Doanh, NQ; Van Vinh Chau, N; Wills, B; Simmons, CP

    2017-01-01

    Abstract. Between 2010 and 2014, four chikungunya and two Zika virus infections were identified among 8,105 febrile children in southern Vietnam. Zika viruses were linked to French Polynesian strains, chikungunya to Cambodian strains. Against a backdrop of endemic dengue transmission, chikungunya and Zika present an additional arboviral disease burden in Vietnam.

  2. Molecular mechanisms of dengue virus infection : cell tropism, antibody-dependent enhancement, and cytokines

    NARCIS (Netherlands)

    Flipse, Jacobus

    2015-01-01

    Dengue is the most prevalent mosquito-borne viral disease in humans. Although most infections occur in the (sub)tropical areas, recent outbreaks in Italy and Madeira indicate that the virus is spreading into Europe. Despite its relevance, no vaccine or medications are available against this virus.

  3. Coinfection with influenza A(H1N1)pdm09 and dengue virus in fatal cases.

    Science.gov (United States)

    Perdigão, Anne Carolinne Bezerra; Ramalho, Izabel Letícia Cavalcante; Guedes, Maria Izabel Florindo; Braga, Deborah Nunes Melo; Cavalcanti, Luciano Pamplona Góes; Melo, Maria Elisabeth Lisboa de; Araújo, Rafael Montenegro de Carvalho; Lima, Elza Gadelha; Silva, Luciene Alexandre Bié da; Araújo, Lia de Carvalho; Araújo, Fernanda Montenegro de Carvalho

    2016-09-01

    We report on four patients with fatal influenza A(H1N1)pdm09 and dengue virus coinfections. Clinical, necropsy and histopathologic findings presented in all cases were characteristic of influenza-dengue coinfections, and all were laboratory-confirmed for both infections. The possibility of influenza and dengue coinfection should be considered in locations where these two viruses' epidemic periods coincide to avoid fatal outcomes. Dengue is a mosquito-borne viral infection caused by one of the four dengue viruses (DENV-1 to 4). Each of these viruses is capable of causing nonspecific febrile illnesses, classic dengue fever and dengue haemorrhagic fever (Gubler 1998). As a result, dengue is often difficult to diagnose clinically, especially because peak dengue season often coincides with that of other common febrile illnesses in tropical regions (Chacon et al. 2015). In April 2009, a new virus, influenza A/H1N1/pandemic (FluA/H1N1/09pdm), caused a severe outbreak in Mexico. The virus quickly spread throughout the world, and in June 2009, the World Health Organization declared a pandemic (WHO 2010). In Brazil, the first laboratory confirmed case of FluA/H1N1/09pdm was in July 2009 (Pires Neto et al. 2013). The state of Ceará, in Northeast Brazil, is a dengue endemic area. In this state, the virus influenza A(H1N1)pdm09 has circulated since 2009, and through the first half of 2012, 11 deaths caused by the virus were confirmed (Pires Neto et al. 2013). The influenza and dengue seasons in Ceará overlap, which led to diagnostic difficulties. We report four cases of laboratory-confirmed coinfection of deadly influenza A(H1N1)pdm09 with DENV, which occurred during the dengue and influenza season in 2012 and 2013 in Ceará.

  4. An outbreak of dengue virus (DENV) type 2 Cosmopolitan genotype in Israeli travellers returning from the Seychelles, April 2017.

    Science.gov (United States)

    Lustig, Yaniv; Wolf, Dana; Halutz, Ora; Schwartz, Eli

    2017-06-29

    Dengue virus infection was diagnosed in six Israeli travellers returning from the Seychelles in April 2017. Phylogenetic analysis identified identical sequences belonging to the Cosmopolitan genotype of dengue virus type 2 in all samples sequenced, thus providing evidence for a probable dengue type 2 outbreak in the Seychelles. This report further demonstrates the role of travellers as sentinels for arboviral infections, especially in countries with limited diagnostic capabilities. This article is copyright of The Authors, 2017.

  5. A Physical Interaction Network of Dengue Virus and Human Proteins*

    Science.gov (United States)

    Khadka, Sudip; Vangeloff, Abbey D.; Zhang, Chaoying; Siddavatam, Prasad; Heaton, Nicholas S.; Wang, Ling; Sengupta, Ranjan; Sahasrabudhe, Sudhir; Randall, Glenn; Gribskov, Michael; Kuhn, Richard J.; Perera, Rushika; LaCount, Douglas J.

    2011-01-01

    Dengue virus (DENV), an emerging mosquito-transmitted pathogen capable of causing severe disease in humans, interacts with host cell factors to create a more favorable environment for replication. However, few interactions between DENV and human proteins have been reported to date. To identify DENV-human protein interactions, we used high-throughput yeast two-hybrid assays to screen the 10 DENV proteins against a human liver activation domain library. From 45 DNA-binding domain clones containing either full-length viral genes or partially overlapping gene fragments, we identified 139 interactions between DENV and human proteins, the vast majority of which are novel. These interactions involved 105 human proteins, including six previously implicated in DENV infection and 45 linked to the replication of other viruses. Human proteins with functions related to the complement and coagulation cascade, the centrosome, and the cytoskeleton were enriched among the DENV interaction partners. To determine if the cellular proteins were required for DENV infection, we used small interfering RNAs to inhibit their expression. Six of 12 proteins targeted (CALR, DDX3X, ERC1, GOLGA2, TRIP11, and UBE2I) caused a significant decrease in the replication of a DENV replicon. We further showed that calreticulin colocalized with viral dsRNA and with the viral NS3 and NS5 proteins in DENV-infected cells, consistent with a direct role for calreticulin in DENV replication. Human proteins that interacted with DENV had significantly higher average degree and betweenness than expected by chance, which provides additional support for the hypothesis that viruses preferentially target cellular proteins that occupy central position in the human protein interaction network. This study provides a valuable starting point for additional investigations into the roles of human proteins in DENV infection. PMID:21911577

  6. A physical interaction network of dengue virus and human proteins.

    Science.gov (United States)

    Khadka, Sudip; Vangeloff, Abbey D; Zhang, Chaoying; Siddavatam, Prasad; Heaton, Nicholas S; Wang, Ling; Sengupta, Ranjan; Sahasrabudhe, Sudhir; Randall, Glenn; Gribskov, Michael; Kuhn, Richard J; Perera, Rushika; LaCount, Douglas J

    2011-12-01

    Dengue virus (DENV), an emerging mosquito-transmitted pathogen capable of causing severe disease in humans, interacts with host cell factors to create a more favorable environment for replication. However, few interactions between DENV and human proteins have been reported to date. To identify DENV-human protein interactions, we used high-throughput yeast two-hybrid assays to screen the 10 DENV proteins against a human liver activation domain library. From 45 DNA-binding domain clones containing either full-length viral genes or partially overlapping gene fragments, we identified 139 interactions between DENV and human proteins, the vast majority of which are novel. These interactions involved 105 human proteins, including six previously implicated in DENV infection and 45 linked to the replication of other viruses. Human proteins with functions related to the complement and coagulation cascade, the centrosome, and the cytoskeleton were enriched among the DENV interaction partners. To determine if the cellular proteins were required for DENV infection, we used small interfering RNAs to inhibit their expression. Six of 12 proteins targeted (CALR, DDX3X, ERC1, GOLGA2, TRIP11, and UBE2I) caused a significant decrease in the replication of a DENV replicon. We further showed that calreticulin colocalized with viral dsRNA and with the viral NS3 and NS5 proteins in DENV-infected cells, consistent with a direct role for calreticulin in DENV replication. Human proteins that interacted with DENV had significantly higher average degree and betweenness than expected by chance, which provides additional support for the hypothesis that viruses preferentially target cellular proteins that occupy central position in the human protein interaction network. This study provides a valuable starting point for additional investigations into the roles of human proteins in DENV infection.

  7. Seroprevalence of antibodies to dengue and chikungunya viruses in Thailand.

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    Sompong Vongpunsawad

    Full Text Available The abundance of Aedes mosquito species enabled widespread transmission of mosquito-borne chikungunya virus (CHIKV and dengue virus (DENV in Southeast Asia. Periodic seroprevalence surveys are therefore necessary to assess the viral burden in the population and the effectiveness of public health interventions. Since the current seroprevalence for CHIKV and DENV in Thailand are unknown, we evaluated evidence of past infection among Thais. Eight-hundred and thirty-five serum samples obtained from individuals living in central and southern Thailand were assessed for anti-CHIKV and anti-DENV IgG antibodies using commercial enzyme-linked immunosorbent assays. Overall, 26.8% (224/835 of individuals were seropositive for CHIKV, the majority of whom were also DENV-seropositive (91.1%, 204/224. Approximately half of all adults in their fifth decade of life had attained CHIKV seropositivity. Children under 15 years of age in southern Thailand were significantly more likely to be CHIKV-seropositive compared to those residing in central Thailand. In contrast, 79.2% (661/835 of Thais were DENV-seropositive, 30.9% (204/661 of whom also had antibodies to CHIKV. CHIKV/DENV dual seropositivity among Thais was 24.4% (204/835. The age-standardized seroprevalence for DENV was three times that of CHIKV (80.5% vs. 27.2%. Relatively high CHIKV seroprevalence among adults living in central Thailand revealed an under-recognized CHIKV burden in the region, while the low-to-moderate transmission intensity of DENV (seroprevalence <50% at 9 years is expected to reduce the impact of DENV vaccination in Thailand. This most recent seroprevalence data provide serological baselines for two of the most common mosquito-borne viruses in this region.

  8. Dengue virus capsid protein usurps lipid droplets for viral particle formation.

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    Marcelo M Samsa

    2009-10-01

    Full Text Available Dengue virus is responsible for the highest rates of disease and mortality among the members of the Flavivirus genus. Dengue epidemics are still occurring around the world, indicating an urgent need of prophylactic vaccines and antivirals. In recent years, a great deal has been learned about the mechanisms of dengue virus genome amplification. However, little is known about the process by which the capsid protein recruits the viral genome during encapsidation. Here, we found that the mature capsid protein in the cytoplasm of dengue virus infected cells accumulates on the surface of ER-derived organelles named lipid droplets. Mutagenesis analysis using infectious dengue virus clones has identified specific hydrophobic amino acids, located in the center of the capsid protein, as key elements for lipid droplet association. Substitutions of amino acid L50 or L54 in the capsid protein disrupted lipid droplet targeting and impaired viral particle formation. We also report that dengue virus infection increases the number of lipid droplets per cell, suggesting a link between lipid droplet metabolism and viral replication. In this regard, we found that pharmacological manipulation of the amount of lipid droplets in the cell can be a means to control dengue virus replication. In addition, we developed a novel genetic system to dissociate cis-acting RNA replication elements from the capsid coding sequence. Using this system, we found that mislocalization of a mutated capsid protein decreased viral RNA amplification. We propose that lipid droplets play multiple roles during the viral life cycle; they could sequester the viral capsid protein early during infection and provide a scaffold for genome encapsidation.

  9. Detection of Hepatitis C Virus Coinfection in Patients with Dengue Diagnosis

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    Carlos Machain-Williams

    2014-01-01

    Full Text Available Coinfection produced by dengue virus (DENV and hepatitis C virus (HCV is a serious problem of public health in Mexico, as they both circulate in tropical zones and may lead to masking or complicating symptoms. In this research, we detected active coinfected patients by HCV residing in the endemic city of Mérida, Yucatán, Mexico, with positive diagnosis to dengue during the acute phase. We performed a retrospective analysis of 240 serum samples from dengue patients. The IgM-ELISA serological test was used for dengue diagnosis, as well as viral isolation to confirm infection. DENV and HCV were detected by RT-PCR. Thus, 31 (12.9% samples showed DENV-HCV coinfection, but interestingly the highest frequency of coinfection cases was found in male patients presenting hemorrhagic dengue in 19/31 (61.29%, with a predominance of 12 : 7 in males. Firstly, coinfection of DENV-HCV in Mérida, Mexico, was detected in young dengue patients, between 11 and 20 years old (38.7%, followed by those between 21 and 30 years old (32%; only 16.13% were between 0 and 10 years of age. Diagnosis of HCV infection in patients with dengue is highly recommended in order to establish potential risk in clinical manifestations as well as dictate patients' special care.

  10. Optical diagnosis of dengue virus infected human blood using Mueller matrix polarimetry

    Science.gov (United States)

    Anwar, Shahzad; Firdous, Shamaraz

    2016-08-01

    Currently dengue fever diagnosis methods include capture ELISAs, immunofluorescence tests, and hemagglutination assays. In this study optical diagnosis of dengue virus infection in the whole blood is presented utilizing Mueller matrix polarimetry. Mueller matrices of about 50 dengue viral infected and 25 non-dengue healthy blood samples were recorded utilizing light source from 500 to 700 nm with scanning step of 10 nm. Polar decomposition of the Mueller matrices for all the blood samples was performed that yielded polarization properties including depolarization, diattenuation, degree of polarization, retardance and optical activity, out of which, depolarization index clusters up the diseased and healthy in to different separate groups. The average depolarized light in the case of dengue infection in the whole blood at 500 nm is 18%, whereas for the healthy blood samples it is 13.5%. This suggests that depolarization index of polarized light at the wavelengths of 500, 510, 520, 530 and 540 nm, we find that in case of depolarization index values are higher for dengue viral infection as compared to normal samples. This technique can effectively be used for the characterization of the dengue virus infected at an early stage of disease.

  11. Factors contributing to the disturbance of coagulation and fibrinolysis in dengue virus infection

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    Yung-Chun Chuang

    2013-01-01

    Full Text Available Hemorrhage is one of the hallmarks of dengue hemorrhagic fever. However, the mechanisms that cause hemorrhage are unclear. In this review we focus on the possible factors that may be involved in the disturbance of coagulation and fibrinolysis during dengue virus (DENV infection. Factors such as autoantibodies and cytokines induced by DENV infection as well as hemostatic molecules expressed on DENV-infected cells, and DENV viral proteins may all contribute to the defect of hemostasis during DENV infection. It is the combination of these viral and host factors that may tilt the balance of coagulation and fibrinolysis toward bleeding in dengue patients.

  12. Complete genetic characterization of a Brazilian dengue virus type 3 strain isolated from a fatal outcome

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    Marize Pereira Miagostovich

    2006-05-01

    Full Text Available We have determined the complete nucleotide and the deduced amino acid sequences of Brazilian dengue virus type 3 (DENV-3 from a dengue case with fatal outcome, which occurred during an epidemic in the state of Rio de Janeiro, Brazil, in 2002. This constitutes the first complete genetic characterization of a Brazilian DENV-3 strain since its introduction into the country in 2001. DENV-3 was responsible for the most severe dengue epidemic in the state, based on the highest number of reported cases and on the severity of clinical manifestations and deaths reported.

  13. Optical diagnosis of dengue virus infection in human blood serum using Raman spectroscopy

    Science.gov (United States)

    Saleem, M.; Bilal, M.; Anwar, S.; Rehman, A.; Ahmed, M.

    2013-03-01

    We present the optical diagnosis of dengue virus infection in human blood serum using Raman spectroscopy. Raman spectra were acquired from 18 blood serum samples using a laser at 532 nm as the excitation source. A multivariate regression model based on partial least-squares regression is developed that uses Raman spectra to predict dengue infection with leave-one-sample-out cross validation. The prediction of dengue infection by our model yields correlation coefficient r2 values of 0.9998 between the predicted and reference clinical results. The model was tested for six unknown human blood sera and found to be 100% accurate in accordance with the clinical results.

  14. Optical diagnosis of dengue virus infection in human blood serum using Raman spectroscopy

    International Nuclear Information System (INIS)

    Saleem, M; Bilal, M; Anwar, S; Rehman, A; Ahmed, M

    2013-01-01

    We present the optical diagnosis of dengue virus infection in human blood serum using Raman spectroscopy. Raman spectra were acquired from 18 blood serum samples using a laser at 532 nm as the excitation source. A multivariate regression model based on partial least-squares regression is developed that uses Raman spectra to predict dengue infection with leave-one-sample-out cross validation. The prediction of dengue infection by our model yields correlation coefficient r 2 values of 0.9998 between the predicted and reference clinical results. The model was tested for six unknown human blood sera and found to be 100% accurate in accordance with the clinical results. (letter)

  15. Laboratory-Based Surveillance and Molecular Characterization of Dengue Viruses in Taiwan, 2014.

    Science.gov (United States)

    Chang, Shu-Fen; Yang, Cheng-Fen; Hsu, Tung-Chieh; Su, Chien-Ling; Lin, Chien-Chou; Shu, Pei-Yun

    2016-04-01

    We present the results of a laboratory-based surveillance of dengue in Taiwan in 2014. A total of 240 imported dengue cases were identified. The patients had arrived from 16 countries, and Malaysia, Indonesia, the Philippines, and China were the most frequent importing countries. Phylogenetic analyses showed that genotype I of dengue virus type 1 (DENV-1) and the cosmopolitan genotype of DENV-2 were the predominant DENV strains circulating in southeast Asia. The 2014 dengue epidemic was the largest ever to occur in Taiwan since World War II, and there were 15,492 laboratory-confirmed indigenous dengue cases. Phylogenetic analysis showed that the explosive dengue epidemic in southern Taiwan was caused by a DENV-1 strain of genotype I imported from Indonesia. There were several possible causes of this outbreak, including delayed notification of the outbreak, limited staff and resources for control measures, abnormal weather conditions, and a serious gas pipeline explosion in the dengue hot spot areas in Kaohsiung City. However, the results of this surveillance indicated that both active and passive surveillance systems should be strengthened so appropriate public health measures can be taken promptly to prevent large-scale dengue outbreaks. © The American Society of Tropical Medicine and Hygiene.

  16. Discovery of Dengue Virus NS4B Inhibitors

    Science.gov (United States)

    Wang, Qing-Yin; Dong, Hongping; Zou, Bin; Karuna, Ratna; Wan, Kah Fei; Zou, Jing; Susila, Agatha; Yip, Andy; Shan, Chao; Yeo, Kim Long; Xu, Haoying; Ding, Mei; Chan, Wai Ling; Gu, Feng; Seah, Peck Gee; Liu, Wei; Lakshminarayana, Suresh B.; Kang, CongBao; Lescar, Julien; Blasco, Francesca; Smith, Paul W.

    2015-01-01

    ABSTRACT The four serotypes of dengue virus (DENV-1 to -4) represent the most prevalent mosquito-borne viral pathogens in humans. No clinically approved vaccine or antiviral is currently available for DENV. Here we report a spiropyrazolopyridone compound that potently inhibits DENV both in vitro and in vivo. The inhibitor was identified through screening of a 1.8-million-compound library by using a DENV-2 replicon assay. The compound selectively inhibits DENV-2 and -3 (50% effective concentration [EC50], 10 to 80 nM) but not DENV-1 and -4 (EC50, >20 μM). Resistance analysis showed that a mutation at amino acid 63 of DENV-2 NS4B (a nonenzymatic transmembrane protein and a component of the viral replication complex) could confer resistance to compound inhibition. Genetic studies demonstrate that variations at amino acid 63 of viral NS4B are responsible for the selective inhibition of DENV-2 and -3. Medicinal chemistry improved the physicochemical properties of the initial “hit” (compound 1), leading to compound 14a, which has good in vivo pharmacokinetics. Treatment of DENV-2-infected AG129 mice with compound 14a suppressed viremia, even when the treatment started after viral infection. The results have proven the concept that inhibitors of NS4B could potentially be developed for clinical treatment of DENV infection. Compound 14a represents a potential preclinical candidate for treatment of DENV-2- and -3-infected patients. IMPORTANCE Dengue virus (DENV) threatens up to 2.5 billion people and is now spreading in many regions in the world where it was not previously endemic. While there are several promising vaccine candidates in clinical trials, approved vaccines or antivirals are not yet available. Here we describe the identification and characterization of a spiropyrazolopyridone as a novel inhibitor of DENV by targeting the viral NS4B protein. The compound potently inhibits two of the four serotypes of DENV (DENV-2 and -3) both in vitro and in vivo. Our

  17. Complete Genome Sequence of a Highly Divergent Dengue Virus Type 2 Strain, Imported into Australia from Sabah, Malaysia.

    Science.gov (United States)

    Pyke, Alyssa T; Huang, Bixing; Warrilow, David; Moore, Peter R; McMahon, Jamie; Harrower, Bruce

    2017-07-20

    In 2015, a female patient returning to Australia from Sabah, Malaysia, was diagnosed with a suspected sylvatic dengue virus type 2 (DENV-2) infection, becoming the second case of imported highly divergent dengue virus infection recorded in Australia. We describe here the complete genome sequencing of the DENV-2 strain isolated from this patient. © Crown copyright 2017.

  18. Satellite based hydroclimatic understanding of evolution of Dengue and Zika virus

    Science.gov (United States)

    Khan, R.; Jutla, A.; Colwell, R. R.

    2017-12-01

    Vector-borne diseases are prevalent in tropical and subtropical regions especially in Africa, South America, and Asia. Vector eradication is perhaps not possible since pathogens adapt to local environment. In absence of appropriate vaccinations for Dengue and Zika virus, burden of these two infections continue to increase in several geographical locations. Aedes spp. is one of the major vectors for Dengue and Zika viruses. Etiologies on Dengue and Zika viruses are evolving, however the key question remains as to how one species of mosquito can transmit two different infections? We argue that a set of conducive environmental condition, modulated by regional climatic and weather processes, may lead to abundance of a specific virus. Using satellite based rainfall (TRMM/GPM), land surface temperature (MODIS) and dew point temperature (AIRS/MERRA), we have identified appropriate thresholds that can provide estimate on risk of abundance of Dengue or Zika viruses at least few weeks in advance. We will discuss a framework coupling satellite derived hydroclimatic and societal processes to predict environmental niches of favorability of conditions of Dengue or Zika risk in human population on a global scale.

  19. Evidence of dengue virus transmission and factors associated with the presence of anti-dengue virus antibodies in humans in three major towns in Cameroon.

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    Maurice Demanou

    2014-07-01

    Full Text Available Dengue is not well documented in Africa. In Cameroon, data are scarce, but dengue infection has been confirmed in humans. We conducted a study to document risk factors associated with anti-dengue virus Immunoglobulin G seropositivity in humans in three major towns in Cameroon.A cross sectional survey was conducted in Douala, Garoua and Yaounde, using a random cluster sampling design. Participants underwent a standardized interview and were blood sampled. Environmental and housing characteristics were recorded. Randomized houses were prospected to record all water containers, and immature stages of Aedes mosquitoes were collected. Sera were screened for anti-dengue virus IgG and IgM antibodies. Risk factors of seropositivity were tested using logistic regression methods with random effects. Anti-dengue IgG were found from 61.4% of sera in Douala (n = 699, 24.2% in Garoua (n = 728 and 9.8% in Yaounde (n = 603. IgM were found from 0.3% of Douala samples, 0.1% of Garoua samples and 0.0% of Yaounde samples. Seroneutralization on randomly selected IgG positive sera showed that 72% (n = 100 in Douala, 80% (n = 94 in Garoua and 77% (n = 66 in Yaounde had antibodies specific for dengue virus serotype 2 (DENV-2. Age, temporary house walls materials, having water-storage containers, old tires or toilets in the yard, having no TV, having no air conditioning and having travelled at least once outside the city were independently associated with anti-dengue IgG positivity in Douala. Age, having uncovered water containers, having no TV, not being born in Garoua and not breeding pigs were significant risk factors in Garoua. Recent history of malaria, having banana trees and stagnant water in the yard were independent risk factors in Yaounde.In this survey, most identified risk factors of dengue were related to housing conditions. Poverty and underdevelopment are central to the dengue epidemiology in Cameroon.

  20. Reciprocal tripartite interactions between the Aedes aegypti midgut microbiota, innate immune system and dengue virus influences vector competence.

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    Jose Luis Ramirez

    Full Text Available Dengue virus is one of the most important arboviral pathogens and the causative agent of dengue fever, dengue hemorrhagic fever, and dengue shock syndrome. It is transmitted between humans by the mosquitoes Aedes aegypti and Aedes albopictus, and at least 2.5 billion people are at daily risk of infection. During their lifecycle, mosquitoes are exposed to a variety of microbes, some of which are needed for their successful development into adulthood. However, recent studies have suggested that the adult mosquito's midgut microflora is critical in influencing the transmission of human pathogens. In this study we assessed the reciprocal interactions between the mosquito's midgut microbiota and dengue virus infection that are, to a large extent, mediated by the mosquito's innate immune system. We observed a marked decrease in susceptibility to dengue virus infection when mosquitoes harbored certain field-derived bacterial isolates in their midgut. Transcript abundance analysis of selected antimicrobial peptide genes suggested that the mosquito's microbiota elicits a basal immune activity that appears to act against dengue virus infection. Conversely, the elicitation of the mosquito immune response by dengue virus infection itself influences the microbial load of the mosquito midgut. In sum, we show that the mosquito's microbiota influences dengue virus infection of the mosquito, which in turn activates its antibacterial responses.

  1. Reciprocal Tripartite Interactions between the Aedes aegypti Midgut Microbiota, Innate Immune System and Dengue Virus Influences Vector Competence

    Science.gov (United States)

    Ramirez, Jose Luis; Souza-Neto, Jayme; Torres Cosme, Rolando; Rovira, Jose; Ortiz, Alma; Pascale, Juan M.; Dimopoulos, George

    2012-01-01

    Dengue virus is one of the most important arboviral pathogens and the causative agent of dengue fever, dengue hemorrhagic fever, and dengue shock syndrome. It is transmitted between humans by the mosquitoes Aedes aegypti and Aedes albopictus, and at least 2.5 billion people are at daily risk of infection. During their lifecycle, mosquitoes are exposed to a variety of microbes, some of which are needed for their successful development into adulthood. However, recent studies have suggested that the adult mosquito's midgut microflora is critical in influencing the transmission of human pathogens. In this study we assessed the reciprocal interactions between the mosquito's midgut microbiota and dengue virus infection that are, to a large extent, mediated by the mosquito's innate immune system. We observed a marked decrease in susceptibility to dengue virus infection when mosquitoes harbored certain field-derived bacterial isolates in their midgut. Transcript abundance analysis of selected antimicrobial peptide genes suggested that the mosquito's microbiota elicits a basal immune activity that appears to act against dengue virus infection. Conversely, the elicitation of the mosquito immune response by dengue virus infection itself influences the microbial load of the mosquito midgut. In sum, we show that the mosquito's microbiota influences dengue virus infection of the mosquito, which in turn activates its antibacterial responses. PMID:22413032

  2. Virus de dengue en personas asintomáticas del poblado de Yariguá

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    Meidis del Rio Bolmey

    2014-08-01

    Full Text Available Se realizó un estudio observacional descriptivo de corte transversal, para determinar la seroprevalencia de anticuerpos Inmunoglobulinas M (IgM Dengue en personas que tuvieron una infección asintomática por el virus del dengue, en la localidad de Yariguá en el municipio Las Tunas, Cuba, donde se presentó un brote en el período de diciembre 2006 a enero 2007. Se analizaron 156 muestras de personas asintomáticas. Se realizó interrogatorio a los pacientes y la detección de IgM Dengue, utilizando la técnica UMELISA (del inglés Ultra Micro Enzyme-Linked ImmunoSorbent Assay. En los resultados se obtuvo que 60 de las personas asintomáticas fueron infectadas con el virus del dengue, prevaleciendo el sexo masculino y los convivientes con los enfermos de dengue. La seroprevalencia de la infección en personas asintomáticas fue de 38,5% y los riesgos de contraer la infección ascendieron a 10,7 por cada mil habitantes de la localidad de Yariguá. Se concluyó que el riesgo de seroprevalencia del virus del dengue en la población fue cuatro veces mayor que el identificado por los sistemas de vigilancia

  3. Dengue

    Science.gov (United States)

    ... emerged as a worldwide problem only since the 1950s. Although dengue rarely occurs in the continental United ... OIG 1600 Clifton Road Atlanta , GA 30329-4027 USA 800-CDC-INFO (800-232-4636) , TTY: 888- ...

  4. MAIT cells are activated in acute Dengue virus infection and after in vitro Zika virus infection.

    Science.gov (United States)

    Paquin-Proulx, Dominic; Avelino-Silva, Vivian I; Santos, Bianca A N; Silveira Barsotti, Nathália; Siroma, Fabiana; Fernandes Ramos, Jessica; Coracini Tonacio, Adriana; Song, Alice; Maestri, Alvino; Barros Cerqueira, Natalia; Felix, Alvina Clara; Levi, José Eduardo; Greenspun, Benjamin C; de Mulder Rougvie, Miguel; Rosenberg, Michael G; Nixon, Douglas F; Kallas, Esper G

    2018-01-01

    Dengue virus (DENV) and Zika virus (ZIKV) are members of the Flaviviridae and are predominantly transmitted via mosquito bites. Both viruses are responsible for a growing number of infections in tropical and subtropical regions. DENV infection can cause lethargy with severe morbidity and dengue shock syndrome leading to death in some cases. ZIKV is now linked with Guillain-Barré syndrome and fetal malformations including microcephaly and developmental disorders (congenital Zika syndrome). The protective and pathogenic roles played by the immune response in these infections is unknown. Mucosal-associated invariant T (MAIT) cells are a population of innate T cells with potent anti-bacterial activity. MAIT cells have also been postulated to play a role in the immune response to viral infections. In this study, we evaluated MAIT cell frequency, phenotype, and function in samples from subjects with acute and convalescent DENV infection. We found that in acute DENV infection, MAIT cells had elevated co-expression of the activation markers CD38 and HLA-DR and had a poor IFNγ response following bacterial stimulation. Furthermore, we found that MAIT cells can produce IFNγ in response to in vitro infection with ZIKV. This MAIT cell response was independent of MR1, but dependent on IL-12 and IL-18. Our results suggest that MAIT cells may play an important role in the immune response to Flavivirus infections.

  5. MAIT cells are activated in acute Dengue virus infection and after in vitro Zika virus infection.

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    Dominic Paquin-Proulx

    2018-01-01

    Full Text Available Dengue virus (DENV and Zika virus (ZIKV are members of the Flaviviridae and are predominantly transmitted via mosquito bites. Both viruses are responsible for a growing number of infections in tropical and subtropical regions. DENV infection can cause lethargy with severe morbidity and dengue shock syndrome leading to death in some cases. ZIKV is now linked with Guillain-Barré syndrome and fetal malformations including microcephaly and developmental disorders (congenital Zika syndrome. The protective and pathogenic roles played by the immune response in these infections is unknown. Mucosal-associated invariant T (MAIT cells are a population of innate T cells with potent anti-bacterial activity. MAIT cells have also been postulated to play a role in the immune response to viral infections. In this study, we evaluated MAIT cell frequency, phenotype, and function in samples from subjects with acute and convalescent DENV infection. We found that in acute DENV infection, MAIT cells had elevated co-expression of the activation markers CD38 and HLA-DR and had a poor IFNγ response following bacterial stimulation. Furthermore, we found that MAIT cells can produce IFNγ in response to in vitro infection with ZIKV. This MAIT cell response was independent of MR1, but dependent on IL-12 and IL-18. Our results suggest that MAIT cells may play an important role in the immune response to Flavivirus infections.

  6. Coinfection with influenza A(H1N1pdm09 and dengue virus in fatal cases

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    Anne Carolinne Bezerra Perdigão

    2016-01-01

    Full Text Available Abstract We report on four patients with fatal influenza A(H1N1pdm09 and dengue virus coinfections. Clinical, necropsy and histopathologic findings presented in all cases were characteristic of influenza-dengue coinfections, and all were laboratory-confirmed for both infections. The possibility of influenza and dengue coinfection should be considered in locations where these two viruses’ epidemic periods coincide to avoid fatal outcomes. Dengue is a mosquito-borne viral infection caused by one of the four dengue viruses (DENV-1 to 4. Each of these viruses is capable of causing nonspecific febrile illnesses, classic dengue fever and dengue haemorrhagic fever (Gubler 1998. As a result, dengue is often difficult to diagnose clinically, especially because peak dengue season often coincides with that of other common febrile illnesses in tropical regions (Chacon et al. 2015. In April 2009, a new virus, influenza A/H1N1/pandemic (FluA/H1N1/09pdm, caused a severe outbreak in Mexico. The virus quickly spread throughout the world, and in June 2009, the World Health Organization declared a pandemic (WHO 2010. In Brazil, the first laboratory confirmed case of FluA/H1N1/09pdm was in July 2009 (Pires Neto et al. 2013. The state of Ceará, in Northeast Brazil, is a dengue endemic area. In this state, the virus influenza A(H1N1pdm09 has circulated since 2009, and through the first half of 2012, 11 deaths caused by the virus were confirmed (Pires Neto et al. 2013. The influenza and dengue seasons in Ceará overlap, which led to diagnostic difficulties. We report four cases of laboratory-confirmed coinfection of deadly influenza A(H1N1pdm09 with DENV, which occurred during the dengue and influenza season in 2012 and 2013 in Ceará.

  7. Luteolin restricts dengue virus replication through inhibition of the proprotein convertase furin.

    Science.gov (United States)

    Peng, Minhua; Watanabe, Satoru; Chan, Kitti Wing Ki; He, Qiuyan; Zhao, Ya; Zhang, Zhongde; Lai, Xiaoping; Luo, Dahai; Vasudevan, Subhash G; Li, Geng

    2017-07-01

    In many countries afflicted with dengue fever, traditional medicines are widely used as panaceas for illness, and here we describe the systematic evaluation of a widely known natural product, luteolin, originating from the "heat clearing" class of herbs. We show that luteolin inhibits the replication of all four serotypes of dengue virus, but the selectivity of the inhibition was weak. In addition, ADE-mediated dengue virus infection of human cell lines and primary PBMCs was inhibited. In a time-of-drug-addition study, luteolin was found to reduce infectious virus particle formation, but not viral RNA synthesis, in Huh-7 cells. During the virus life cycle, the host protease furin cleaves the pr moie