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    How does dengue virus reproduce?

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  2. How Dengue Virus Infects Cells | National Institutes of ...

    www.nih.gov/.../how-dengue-virus-infects-cells

    To infect a cell, the dengue virus initially binds to the cell surface. It gains entry into the cell when it becomes enveloped by the cell membrane during the creation of a pouch-like structure known as an endosome.

  3. NIH scientists discover how dengue virus infects cells ...

    www.nih.gov/news-events/news-releases/nih...

    To infect a cell, dengue virus (counterclockwise, from upper left) binds to the cell membrane. The virus is then enveloped in the membrane, which coalesces around it, forming a pouch-like structure called an endosome. Deep inside the cell, the endosome membrane acquires a negative charge, which allows the virus to fuse with the endosomal membrane and release genetic material into the interior.

  4. How the dengue virus replicates in infected cells

    medicalxpress.com/news/2019-05-dengue-virus...

    May 09, 2019 · NS1 is secreted from infected cells, counteracts antiviral immune responses, and contributes to the severe clinical manifestations of dengue. In addition, NS1 is essential for the viral replication...

  5. NS1 is secreted from infected cells, counteracts antiviral immune responses, and contributes to the severe clinical manifestations of dengue. In addition, NS1 is essential for the viral replication...

  6. Receptors and routes of dengue virus entry into the host cells

    academic.oup.com/femsre/article/39/2/155/635122
    • Introduction
    • Structural Overview of Denv Particle and Its Components
    • Virus Binding to Cell Surface
    • Virus Internalization
    • Genome Access to The Cytoplasm
    • Concluding Remarks
    • Funding

    The increasing number of dengue cases and the changes in the geographic distribution of the disease over the last two decades stimulated the scientific community to research on dengue virus (DENV). The disease caused by this member of the Flaviviridae family is a major international health threat now spreading from tropical and subtropical areas to other regions worldwide (Gubler 2006; WHO 2014). There are four distinct DENV serotypes, DENV-1 to 4, which challenges the development of a vaccine for this pathogen. DENV infection cycle initiates with the virus attachment to the target cell through the interaction between viral surface proteins and attachment/receptors molecules on the cell surface. This interaction allows the internalization of the virus particle, generally involving receptor-mediated endocytosis. After virus internalization, the access of viral genome to the cytoplasm is mediated by the fusion between the viral envelope and the endosomal membrane. The viral genome is...

    DENV structure consists of a 50-nm-diameter particle with a lipid envelope to which two structural proteins are associated, the membrane (M) and the envelope (E) proteins (Mukhopadhyay et al., 2005; Perera and Kuhn 2008). The envelope houses a amorphous ribonucleoprotein complex formed by the capsid (C) protein bound to the positive single-strand RNA (ssRNA) genome (Fig. 1) (Kuhn et al., 2002; Zhang et al., 2003a; Freire et al., 2013a). At neutral pH and 28–30°C, the typical temperature range in the mosquito vector, the external glycoprotein shell is formed by 90 E protein head-to-tail homodimers tightly packed in an icosahedral manner (Kuhn et al., 2002; Modis et al., 2003, 2004). On the other hand, at 37°C, the physiological temperature in humans, DENV structure consists of a more heterogeneous expanded particle with loosen E protein intra- and interdimeric interactions that expose patches of the viral membrane (Fibriansah et al., 2013; Zhang et al., 2013a). The E protein is a 53...

    Virus recognition by target cells depends on the interaction between virus surface proteins and cellular plasma membrane components (Fig. 1). The susceptibility of the host tissues to the virus is intimately dependent on the abundance and distribution of cell receptors, rendering the receptors valuable targets for the development of antiviral drugs. In general, attachment factors placed on the surface of the cells are responsible for the first contact with the virus. This binding occurs in a non-specific manner, concentrating the virus on cell surface and facilitating attachment to its specific receptor, a particular molecule that will promote virus entry into the target cell (Grove and Marsh 2011). Despite the efforts to determine the molecule(s) responsible for DENV recognition by target cells, a specific receptor for DENV has not been definitely identified so far (Hidari and Suzuki 2011). However, a number of candidates of distinct nature in mammalian (Table 1) and mosquito (Tabl...

    After DENV recognition by cellular receptors, the particle is internalized through distinct routes, which include clathrin-mediated endocytosis or non-classical clathrin-independent endocytic pathways, depending on the cell host and virus serotype or strain (summarized in Table 3 and Fig. 2). Factors such as virus particle maturation and recognition of viral immunocomplexes by Fcγ receptors also interfere in virus entry.

    For all enveloped viruses, genome access to the cytoplasm depends on the fusion of viral envelope with a cellular membrane, a process triggered by a viral fusion protein anchored at the virion envelope. In the case of DENV, it is currently established in the literature that, despite the different entry routes of viral particle internalization, genome release into the cytoplasm occurs through E protein-mediated membrane fusion (Pierson and Kielian 2013). However, recent data from our group support the hypothesis that C protein also participates in the translocation of DENV RNA into the cytoplasm (Freire et al., 2013a,b, Freire et al., 2014).

    The use of a specific cell surface receptor that might be restricted to certain cells and tissues can limit the ability of a virus to broadly infect the host. In the case of DENV, a number of cell types are susceptible to infection, both in vertebrate and mosquitoes hosts. Thus, it is more likely that DENV do not use a unique, specific receptor for its internalization, but recognizes and binds to diverse molecules, possibly in a serotype- and/or strain-specific manner, potentiating viral dissemination and infection severity. For many viruses, one single infection route was initially proposed, but with continuous research in the field and the advent of high-resolution quantitative techniques, alternative routes of infection for these viruses were discovered and characterized. HIV is a well-documented example of such development. Initially restricted to CD4 and CXCR4/CCR5 receptor binding and class I membrane fusion, several lines of evidence suggest that HIV may also enter the cell t...

    This work was supported by Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq, Brazil, Projects 471239/2012-7 and 306669/2013-7), Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ, Brazil, Projects E-26/102.919/2011 and E-26/111.668/2013), Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES, Brazil, Project 171/2012), Fundação para a Ciência e Tecnologia - Ministério da Educação e Ciência (FCT-MEC, Portugal, Project PTDC/QUI-BIQ/112929/2009). Conflict of interest statement.None declared.

    • Christine Cruz-Oliveira, João Miguel Freire, Thaís M. Conceição, Luiza M. Higa, Miguel A.R.B. Castan...
    • 173
    • 2015
  7. Cells in Dengue Virus Infection In Vivo

    www.hindawi.com/journals/av/2010/164878

    With the observation that dengue viral antigens are associated with proplatelets [148, 149] or micromegakaryocytes [137, 150] in blood during acute dengue virus infection (Figure 3), it is likely that a platelet lineage parental cell, megakaryocytes, may be involved in the production of dengue virus during acute infection.

    • Sansanee Noisakran, Sansanee Noisakran, Nattawat Onlamoon, Nattawat Onlamoon, Pucharee Songprakhon, ...
    • 66
    • 2010
  8. Dengue Virus Infects Macrophages and Dendritic Cells in a ...

    academic.oup.com/jid/article/195/12/1808/810106
    • Abstract
    • Materials and Methods
    • Results
    • Discussion

    Dengue is a mosquitoborne viral febrile illness caused by 4 dengue virus serotypes (DENV-1–4) and is currently the most prevalent arthropodborne viral disease worldwide, with an estimated 100 million infections each year in tropical and subtropical regions. As the fever breaks, a percentage of symptomatic infections proceed to a more-severe, life-threatening disease characterized by increased vascular permeability, dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS) [1]. The molecular basis of DENV pathogenesis is not well understood, in part because of the lack of a representative animal model in which to test hypotheses generated by clinical and epidemiological observations. Clinical and autopsy findings in humans, as well as studies involving nonhuman primates, have indicated that cells of the mononuclear phagocyte lineage are the primary cell targets. Human autopsy studies have described DENV antigen—positive cells to be primarily macrophages and lymphocytes located in the...

    Viruses and cell lines. DENV was propagated in the Aedes albopictus cell line C6/36 (American Type Culture Collection [ATCC]) as described elsewhere [27]. DENV-2 strain PL046 is a Taiwanese isolate (obtained from H.-Y. Lei, National Cheng Kung University, Taiwan), and DENV-2 strain D2S10 was derived in our laboratory [26]. DENV-1 strain Mochizuki (mouse-passaged) was obtained from R. Tesh (University of Texas Medical Branch at Galveston), and DENV-4 strain 664 from Thailand was a gift of S. Kliks (Pediatric Dengue Vaccine Initiative). Virus titers were obtained by plaque assay on baby hamster kidney (BHK 21; clone 15) cells, as described elsewhere [27]. Before injection into mice, virus was diluted directly in PBS for low doses or centrifuged at 53,000 gfor 2 h to concentrate the virus for high-dose inocula and then resuspended in PBS. Infection of AG129 and A129 mice. 129/Pas mice lacking receptors for IFN-α/β and -γ are designated AG129, whereas A129 mice lack only the receptor fo...

    Presence of DENV in hematopoetic tissues in AG129 mice. DENV-2 strain PL046 has been shown to replicate to high titers in A/J, AG129, and SCID-K562 mice [16, 21, 24, 27]. Recently, strain D2S10 was derived from PL046 and demonstrated an early death phenotype with increased vascular permeability in AG129 mice after an intravenous injection of 107 pfu [26]. Using these 2 viral strains, we characterized the kinetics and dissemination of DENV-2 in AG129 mice, which are highly susceptible to fatal DENV infection [23, 24] and are currently used for vaccine-testing studies [34, 35]. To approximate the route of introduction of DENV from the bite of a mosquito, mice were infected subcutaneously. After a dose of 107 pfu of either PL046 or D2S10, we tested multiple tissues during the first 6 days after infection by plaque assay and found that DENV-2 spreads to and replicates primarily in hematopoetic tissues during the first week after infection (figure 1). Viral titers in the lymph nodes and...

    Our characterization of the initial tropism of DENV injected subcutaneously into 129/Pas mice lacking IFN-α/β and -γ receptors or the IFN-α/β receptor alone revealed that DENV-2 primarily infects macrophages and dendritic cells during the first 6 days after infection. Using a combination of flow cytometry and magnetic bead separation plus strand-specific RTPCR, we identified DENV antigen—positive cells as primarily CD11b+ (granulocyte/macrophage), CD11c+ (dendritic cell), F4/80+ (macrophage), and, to a lesser extent, CD19+ or B220+(B cell) populations at days 1–3 after infection. The detection of DENV NS1 antigen, a viral protein not present in the virion itself, confirmed the presence of replicating virus in these cell types. Similar results for tissue tropism were observed using 3 serotypes of DENV with relevant doses of virus. These results demonstrate that, early in infection, DENV targets similar cell types in our mouse model as in humans. To our knowledge, these results are th...

    • Jennifer L. Kyle, P. Robert Beatty, Eva Harris
    • 172
    • 2007
  9. Roles for Endothelial Cells in Dengue Virus Infection

    www.ncbi.nlm.nih.gov/pmc/articles/PMC3431041

    Aug 16, 2012 · Dengue virus infection upregulates cell surface markers of EC activation which can trigger the expression and release of various cytokines, chemokines, and complement factors that act on neighboring tissues, ECs, and circulating immune cells.

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