Project description:Dengue virus is an + strand RNA virus. We have carried our infections of human cells with Dengue and analyzed the translation, replication, and localization of the Dengue RNA. This allowed for clear definition of the life cycle of the Dengue virus inside a host cell. We also assessed the host response to Dengue virus, finding that a large fraction of the translational response is due to Interferon function. Translational and transcriptional analysis of the cellular response to Dengue virus infection
Project description:Dengue virus is an + strand RNA virus. We have carried our infections of human cells with Dengue and analyzed the translation, replication, and localization of the Dengue RNA. This allowed for clear definition of the life cycle of the Dengue virus inside a host cell. We also assessed the host response to Dengue virus, finding that a large fraction of the translational response is due to Interferon function.
Project description:Dengue viruses cause two severe diseases that alter vascular fluid barrier functions, dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). While the mechanisms that lead to vascular permeability are unknown, the endothelium plays a central role in regulating fluid and cellular efflux from capillaries. Thus, dysregulation of endothelial cells functions by dengue virus infection may contribute to pathogenesis and severe disease. We used microarrays to investigate the effect of dengue virus infection on gene expression within primary human endothelial cells at various times post infection and identified numerous upregulated antiviral and immune response genes. Early passage primary endothelial cells (HUVECs) were mock infected (no virus) or infected with dengue virus and total RNA collected at 3 timepoints: 12, 24, and 48 hours post infection. Multiple timepoints were analyzed to identify changes in gene expression levels over time. Gene expression from both mock infected and dengue virus infected endothelial cells was evaluated to determine fold induction at each timepoint.
Project description:Here; we have described and tested a microarray based-method for the screening of dengue virus (DENV) serotypes. This DNA microarray assay is specific and sensitive and can detect dual infections with two dengue virus serotypes and single-serotype infections. Other methodologies may underestimate samples containing more than one serotype. This technology can be used to discriminate between the four DENV serotypes. Single-stranded DNA targets were covalently attached to glass slides and hybridised with specific labelled probes. DENV isolates and dengue samples were used to evaluate microarray performance. Our results demonstrate that the probes hybridized specifically to DENV serotypes; with no detection of unspecific signals. This finding provides evidence that specific probes can effectively identify single and double infections in DENV samples. Background Dengue is a mosquito-borne viral infection causing a major public health problem globally. Dengue virus (DENV) is the causative agent of dengue fever (DF) and dengue hemorrhagic fever (DHF) and includes four distinct serotypes (DENV-1, DENV-2, DENV-3, and DENV-4). DENV-2 and DENV-3 have been associated with severe dengue disease, consequently, laboratory testing for DENV is needed to confirm the diagnosis of DENV infection, serotype and to differentiate dengue from other febrile tropical illnesses. In addition, surveillance of mosquitoes infected with DENV is needed to monitor the infection rates within vector mosquito populations harboring specific serotype to provide an early warning sign to predict epidemics. Results In this work we have applied microarray analysis to simultaneously determine the serotype of multiple RNA samples from human or mosquitoes. The proposed microarray method can be used for i) rapid and reliable dengue diagnosis; ii) serotyping and iii) surveillance of mosquitoes infected with dengue. These microarrays were useful to confirm the presence of DENV-2 in 94 serum samples, DENV-3 in three samples from Juchitan, Oaxaca and one case from Juchitan, Oaxaca contained DENV-2 and -3. Moreover by using these microarrays we also determined DENV in pools of gravid females mosquitoes collected in several sites of nineteen Mexican states in 2005. Mosquito pools from 31 cities in the states of Yucatan, Campeche, Tabasco, Chiapas, Veracruz, Oaxaca, Guerrero, Tamaulipas and Colima were infected with DENV-2, six cities in Yucatán, Tabasco, Morelos, Tamaulipas, Colima, and Nayarit with DENV-1, three from Tabasco, Veracruz and Oaxaca with DENV 3 and two with two serotypes simultaneously (Ciudad Mante with DENV-1 and DENV-2, and Tavela with DENV-2 and DENV-3). Conclusion Here we show the success of applying microarrays assay to provide a consistently robust qualitative detection of dengue serotypes (DENV-1, DENV-2, DENV-3 and DENV-4) in serum samples from patients or in pools of gravid female mosquitoes collected in the field of nineteen Mexican states. Interestingly, we did not detect any mosquito or serum sample containing DENV-4.
Project description:Dengue virus infection can result in severe symptoms including shock and hemorrhage, but an understanding of the molecular correlates of disease severity is lacking. Bulk transcriptomics on blood samples are difficult to interpret because the blood is composed of different cell types that may react differently to virus infection. Dengue virus RNA can be detected in human plasma, however identifying the cells carrying dengue virus through the bloodstream in vivo has proven challenging. Here we used our recently developed viscRNA-Seq approach to profile transcriptomes of thousands of single blood peripheral mononuclear cells from 6 human subjects with dengue fever and severe dengue, as well as to characterize the cell types associated with dengue virus in the human blood. We found that although no bulk transcriptome marker for severe dengue exists, the expression of MX2 in naive B cells, of CD163 in CD14+/CD16+ monocytes and of other genes in specific cell types is highly predictive for severe dengue. We detected virus-associated cells in the blood of two severe dengue patients with high viral load and discovered the majority of these to be B cells expressing germline IgM or IgD immunoglobulin chains and naive markers but also showing signs of activation and expression of CD69, CXCR4, and other surface receptors. In bystander B cells we detected signs of strong immune activation, parallel hypersomatic evolution and, in one severe degue subject, an anomalously large clone of highly mutated, IgG1 plasmablasts that could be reactive to dengue virus. This study presents a high-resolution molecular exploration into dengue virus infection in humans and can be generalized to any RNA virus.
Project description:Dengue virus is the most common arbovirus worldwide and represents a significant public health concern. To date, chronic Dengue infections have not been previously reported. While investigating the etiology of central nervous system (CNS) disease in a patient presenting with progressive dementia, we elucidated a chronic dengue infection within the CNS. Comprehensive viral immune responses in both serum and cerebrospinal fluid (CSF) were profiled by a phage-display assay (VirScan). Enrichment of Dengue viral antibodies were detected in the CSF as compared to the serum. No virus was detected in serum or CSF, but post-mortem analysis confirmed Dengue virus in the brain by quantitative polymerase chain reaction (PCR), immunohistochemistry, RNAscope and sequencing. Dengue virus was detectable by PCR and sequencing from brain biopsy tissue collected 33 months ante-mortem, confirming a chronic infection. Comprehensive antibody profiling assays can aid in the diagnosis of encephalitis of unknown etiologies. Our findings suggest that Dengue virus infections may persist in the CNS and should be considered in patients with progressive dementia in endemic regions or with relevant travel history.