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Dengue virus

About: Dengue virus is a research topic. Over the lifetime, 12671 publications have been published within this topic receiving 461406 citations. The topic is also known as: DENV.


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Journal ArticleDOI
TL;DR: Results indicate (a) T lymphocytes are activated and produce IL-2 and IFN gamma in vivo during DHF and DF, (b) CD4+ T lymphocyte are activated inDHF andDF, and the level of activation is higher in DHF than in DF, and (c) activation of CD8+T lymphocytes is evident in DH, but not in DF.
Abstract: It has been reported that the severe complication of dengue virus infection, dengue hemorrhagic fever (DHF) is much more commonly observed during secondary dengue virus infections than primary infections. In order to elucidate the role of T lymphocytes in the pathogenesis of DHF, we attempted to determine whether T lymphocytes are activated in vivo during dengue virus infections, by examining the levels of soluble IL-2 receptor (sIL-2R), soluble CD4 (sCD4), soluble CD8 (sCD8), interleukin-2 (IL-2) and interferon-gamma (IFN gamma) in the sera of 59 patients with DHF and 41 patients with dengue fever (DF). The levels of sIL-2R, sCD4, sCD8, IL-2, and IFN gamma were significantly higher in the acute sera of patients with DHF than in the sera of healthy children (P less than 0.001 for all markers). The acute sera of patients with DF contained higher levels of sIL-2R, sCD4, IL-2, and IFN gamma than the sera of healthy children (P less than 0.001 for sIL-2R, IL-2, and IFN gamma; P less than 0.05 for sCD4), but did not have elevated levels of sCD8. The levels of sIL-2R (P less than 0.05), sCD4 (P less than 0.001), and sCD8 (P less than 0.001) were higher in DHF than in DF on days 3-4 after the onset of fever. The levels of IL-2 and IFN gamma in patients with DHF were highest 1 d before defervescence. There were no significant differences in the levels of sIL-2R, sCD4, sCD8, IL-2, and IFN gamma among grades 1, 2, and 3 of DHF. These results indicate (a) T lymphocytes are activated and produce IL-2 and IFN gamma in vivo during DHF and DF, (b) CD4+ T lymphocytes are activated in DHF and DF, and the level of activation is higher in DHF than in DF, and (c) activation of CD8+ T lymphocytes is evident in DHF, but not in DF.

326 citations

Journal ArticleDOI
09 Oct 2015-Science
TL;DR: These findings demonstrate a distinctive viral RNA–host protein interaction to evade the innate immune response for increased epidemiological fitness.
Abstract: The global spread of dengue virus (DENV) infections has increased viral genetic diversity, some of which appears associated with greater epidemic potential. The mechanisms governing viral fitness in epidemiological settings, however, remain poorly defined. We identified a determinant of fitness in a foreign dominant (PR-2B) DENV serotype 2 (DENV-2) clade, which emerged during the 1994 epidemic in Puerto Rico and replaced an endemic (PR-1) DENV-2 clade. The PR-2B DENV-2 produced increased levels of subgenomic flavivirus RNA (sfRNA) relative to genomic RNA during replication. PR-2B sfRNA showed sequence-dependent binding to and prevention of tripartite motif 25 (TRIM25) deubiquitylation, which is critical for sustained and amplified retinoic acid–inducible gene 1 (RIG-I)–induced type I interferon expression. Our findings demonstrate a distinctive viral RNA–host protein interaction to evade the innate immune response for increased epidemiological fitness.

321 citations

Journal ArticleDOI
TL;DR: Transgenic mosquitoes with reduced vector competence have been proposed as tools for the control of dengue virus transmission by hybridization in situ patterns of 30 transcripts expressed in the salivary glands of adult Ae.
Abstract: Background: Aedes aegypti mosquitoes are the main vectors of dengue viruses to humans. Understanding their biology and interactions with the pathogen are prerequisites for development of dengue transmission control strategies. Mosquito salivary glands are organs involved directly in pathogen transmission to vertebrate hosts. Information on the spatial distribution of gene expression in these organs is expected to assist in the development of novel disease control strategies, including those that entail the release of transgenic mosquitoes with impaired vector competence. Results: We report here the hybridization in situ patterns of 30 transcripts expressed in the salivary glands of adult Ae. aegypti females. Distinct spatial accumulation patterns were identified. The products of twelve genes are localized exclusively in the proximal-lateral lobes. Among these, three accumulate preferentially in the most anterior portion of the proximal-lateral lobe. This pattern revealed a salivary gland cell type previously undescribed in Ae. aegypti, which was validated by transmission electron microscopy. Five distinct gene products accumulate in the distal-lateral lobes and another five localize in the medial lobe. Seven transcripts are found in the distal-lateral and medial lobes. The transcriptional product of one gene accumulates in proximal- and distal-lateral lobes. Seven genes analyzed by quantitative PCR are expressed constitutively. The most abundant salivary gland transcripts are those localized within the proximal-lateral lobes, while previous work has shown that the distal-lateral lobes are the most active in protein synthesis. This incongruity suggests a role for translational regulation in mosquito saliva production. Conclusions: Transgenic mosquitoes with reduced vector competence have been proposed as tools for the control of dengue virus transmission. Expression of anti-dengue effector molecules in the distal-lateral lobes of Ae. aegypti salivary glands has been shown to reduce prevalence and mean intensities of viral infection. We anticipate greater efficiency of viral suppression if effector genes are expressed in all lobes of the salivary glands. Based on our data, a minimum of two promoters is necessary to drive the expression of one or more anti-dengue genes in all cells of the female salivary glands.

320 citations

Journal ArticleDOI
TL;DR: This outbreak underscores the importance of maintaining surveillance and control of potential disease vectors even in the absence of an imminent disease threat.
Abstract: Autochthonous dengue infections were last reported in Hawaii in 1944. In September 2001, the Hawaii Department of Health was notified of an unusual febrile illness in a resident with no travel history; dengue fever was confirmed. During the investigation, 1,644 persons with locally acquired denguelike illness were evaluated, and 122 (7%) laboratory-positive dengue infections were identified; dengue virus serotype 1 was isolated from 15 patients. No cases of dengue hemorrhagic fever or shock syndrome were reported. In 3 instances autochthonous infections were linked to a person who reported denguelike illness after travel to French Polynesia. Phylogenetic analyses showed the Hawaiian isolates were closely associated with contemporaneous isolates from Tahiti. Aedes albopictus was present in all communities surveyed on Oahu, Maui, Molokai, and Kauai; no Ae. aegypti were found. This outbreak underscores the importance of maintaining surveillance and control of potential disease vectors even in the absence of an imminent disease threat.

320 citations

Journal ArticleDOI
TL;DR: Quantitative RT-PCR experiments indicate that IFN inhibits DV infection by preventing the accumulation of negative-strand viral RNA.
Abstract: A role for interferon (IFN) in modulating infection by dengue virus (DV) has been suggested by studies in DV-infected patients and IFN receptor-deficient mice. To address how IFN modulates DV type 2 infection, we have assayed IFN-α, -β, and -γ for the ability to enhance or diminish antibody-independent and antibody-dependent cell infection using a competitive, asymmetric reverse transcriptase-mediated PCR (RT-PCR) assay that quantitates positive and negative strands of viral RNA, a flow cytometric assay that measures viral antigen, and a plaque assay that analyzes virion production. Our data suggest that IFN-α and -β protect cells against DV infection in vitro. Treatment of hepatoma cells with IFN-α or -β decreases viral RNA levels greater than 1,000-fold, the percentage of cells infected 90 to 95%, and the amount of infectious virus secreted 150- to 100,000-fold. These results have been reproduced with several cell types and viral strains, including low-passage isolates. In contrast, IFN-γ has a more variable effect depending on the cell type and pathway of infection. Quantitative RT-PCR experiments indicate that IFN inhibits DV infection by preventing the accumulation of negative-strand viral RNA.

319 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023546
20221,066
2021780
2020912
2019849
2018930