Last data update: Jan 27, 2025. (Total: 48650 publications since 2009)
Records 1-3 (of 3 Records) |
Query Trace: Medina JF[original query] |
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Differences in type I interferon signaling antagonism by dengue viruses in human and non-human primate cell lines
Medina FA , Torres-Malave G , Chase AJ , Santiago GA , Medina JF , Santiago LM , Munoz-Jordan JL . PLoS Negl Trop Dis 2015 9 (3) e0003468 BACKGROUND/OBJECTIVES: In vitro studies have shown that dengue virus (DENV) can thwart the actions of interferon (IFN)-alpha/beta and prevent the development of an antiviral state in infected cells. Clinical studies looking at gene expression in patients with severe dengue show a reduced expression of interferon stimulated genes compared to patients with dengue fever. Interestingly, there are conflicting reports as to the ability of DENV or other flaviviruses to inhibit IFN-alpha/beta signaling. METHODOLOGY/PRINCIPAL FINDINGS: In order to determine the relative inhibition of IFN-alpha/beta signaling by DENVs, a method combining flow cytometry and a four-parameter logistic regression model was established. A representative isolate from DENV-1, -3 and -4 and seventeen representative isolates encompassing all DENV-2 genotypes were evaluated. All of the DENVs evaluated in this study were capable of inhibiting IFN-alpha/beta signaling. Most of the strains were able to inhibit IFN-alpha/beta to a degree similar to DENV strain 16681; however, DENV-2 sylvatic strains demonstrated an increased inhibition of phosphorylated signal transducer and activator of transcription (pSTAT1). Surprisingly, we were unable to observe inhibition of pSTAT1 by DENV-2 sylvatic strains or the Asian strain 16681 in non-human primate (NHP) cell lines. Analysis in primary Rhesus macaque dendritic cells suggests that DENVs are capable of inhibiting IFN signaling in these cells. However, contrary to human dendritic cells, production of IFN-alpha was detected in the supernatant of DENV-infected Rhesus macaque dendritic cells. CONCLUSIONS: The ability of DENVs to inhibit IFN-alpha/beta signaling is conserved. Although some variation in the inhibition was observed, the moderate differences may be difficult to correlate with clinical outcomes. DENVs were unable to inhibit pSTAT1 in NHP cell lines, but their ability to inhibit pSTAT1 in primary Rhesus macaque dendritic cells suggests that this may be a cell specific phenomena or due to the transformed nature of the cell lines. |
Analytical and clinical performance of the CDC real time RT-PCR assay for detection and typing of dengue virus.
Santiago GA , Vergne E , Quiles Y , Cosme J , Vazquez J , Medina JF , Medina F , Colon C , Margolis H , Munoz-Jordan JL . PLoS Negl Trop Dis 2013 7 (7) e2311 ![]() Dengue is an acute illness caused by the positive-strand RNA dengue virus (DENV). There are four genetically distinct DENVs (DENV-1-4) that cause disease in tropical and subtropical countries. Most patients are viremic when they present with symptoms; therefore, RT-PCR has been increasingly used in dengue diagnosis. The CDC DENV-1-4 RT-PCR Assay has been developed as an in-vitro diagnostic platform and was recently approved by the US Food and Drug Administration (FDA) for detection of dengue in patients with signs or symptoms of mild or severe dengue. The primers and probes of this test have been designed to detect currently circulating strains of DENV-1-4 from around the world at comparable sensitivity. In a retrospective study with 102 dengue cases confirmed by IgM anti-DENV seroconversion in the convalescent sample, the RT-PCR Assay detected DENV RNA in 98.04% of the paired acute samples. Using sequencing as a positive indicator, the RT-PCR Assay had a 97.92% positive agreement in 86 suspected dengue patients with a single acute serum sample. After extensive validations, the RT-PCR Assay performance was highly reproducible when evaluated across three independent testing sites, did not produce false positive results for etiologic agents of other febrile illnesses, and was not affected by pathological levels of potentially interfering biomolecules. These results indicate that the CDC DENV-1-4 RT-PCR Assay provides a reliable diagnostic platform capable for confirming dengue in suspected cases. |
Dengue virus: isolation, propagation, quantification, and storage
Medina F , Medina JF , Colon C , Vergne E , Santiago GA , Munoz-Jordan JL . Curr Protoc Microbiol 2012 Chapter 15 Unit15D 2 Dengue is a disease caused by infection with one of the four dengue virus serotypes (DENV-1, -2, -3, and -4). The virus is transmitted to humans by Aedes sp. mosquitoes. This enveloped virus contains a positive single-stranded RNA genome. Clinical manifestations of dengue can have a wide range of outcomes varying from a mild febrile illness to a life-threatening condition. New techniques have largely replaced the use of DENV isolation in disease diagnosis. However, virus isolation still serves as the gold standard for detection and serotyping of DENV and is common practice in research and reference laboratories where clinical isolates of the virus are characterized and sequenced, or used for a variety of research experiments. Isolation of DENV from clinical samples can be achieved in mammalian and mosquito cells or by inoculation of mosquitoes. The experimental methods presented here describe the most common procedures used for the isolation, serotyping, propagation, and quantification of DENV. (Curr. Protoc. Microbiol. 27:15D.2.1-15D.2.24. (c) 2012 by John Wiley & Sons, Inc.) |
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