Project description:RNA was extracted from whole blood of subjects collected in Tempus tubes. We performed gene expression analysis of dengue seropositive versus dengue seronegative subjects from Singapore.
Project description:RNA was extracted from whole blood of subjects collected in Tempus tubes. We performed gene expression analysis of dengue seropositive versus dengue seronegative subjects.
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:The ability of many viruses to manipulate the host antiviral immune response often results in complex host-pathogen interactions. In order to study the interaction of dengue virus (DENV) with the Aedes aegypti immune response, we have characterized the DENV infection-responsive transcriptome of the immune-competent A. aegypti cell line Aag2. As in mosquitoes, DENV infection transcriptionally activated the cell line Toll pathway and a variety of cellular physiological systems. Most notably, however, DENV infection down-regulated the expression levels of numerous immune signaling molecules and antimicrobial peptides (AMPs). Functional assays showed that transcriptional induction of AMPs from the Toll and IMD pathways in response to bacterial challenge is impaired in DENV-infected cells. In addition, Escherichia coli, a gram-negative bacteria species, grew better when co-cultured with DENV-infected cells than with uninfected cells, suggesting a decreased production of AMPs from the IMD pathway in virus-infected cells. Pre-stimulation of the cell line with gram-positive bacteria prior to DENV infection had no effect on DENV titers, while pre-stimulation with gram-negative bacteria resulted in an increase in DENV titers. These results indicate that DENV is capable of actively suppressing immune responses in the cells it infects, a phenomenon that may have important consequences for virus transmission and insect physiology. Infected (dengue virus or heat-inactivated dengue virus) vs. naive cells. 3 replicates each.
Project description:The goal of this study was to compare the transcriptional profile (RNA-seq) of Dengue virus 2 and mock infected cells at 24 and 36 hours post infection. Dengue virus NS5 protein plays multiple functions in the cytoplasm of infected cells, enabling viral RNA replication and counteracting host antiviral responses. Here, we demonstrate a novel function of NS5 in the nucleus where it interferes with cellular splicing. Using global proteomic analysis of infected cells together with functional studies, we found that NS5 binds spliceosome complexes and modulates endogenous splicing. In particular, we show that NS5 alone, or in the context of viral infection, interacts with core components of the U5 snRNP particle, CD2BP2 and DDX23, alters the inclusion/exclusion ratio of alternative splicing events, and changes mRNA isoform abundance of known antiviral factors. Interestingly, a genome wide transcriptome analysis, using recently developed bioinformatics tools, revealed an increase of intron retention upon dengue virus infection, and viral replication was improved by silencing specific U5 components. Different mechanistic studies indicate that binding of NS5 to the spliceosome reduces the efficiency of pre-mRNA processing, independently of NS5 enzymatic activities. We propose that NS5 binding to U5 snRNP proteins hijacks the splicing machinery resulting in a less restrictive environment for viral replication. A549 cells where infected with Dengue virus 2 or mock and after 24 and 36 hours post infection mRNA was purified. Then the transcriptional profile of these cells was analyzed using RNA-seq.
Project description:Unbiased forward genetic screens to identify host factors for DENV1 and JEV in 293FT cells. Unbiased forward genetic screens to identify host factors for HCoV-229E in Huh7.5.1 cells.
Project description:We investigated the abundances and transcriptomic changes of immune cells at several time points over the course of dengue virus infection. The PBMC samples were obtained from one dengue fever (DF) and one dengue hemorrhagic fever (DHF) patients (8 samples in total). The samples were harvested at two and one days before defervescence (febrile phase), at defervescence (critical phase), and two-week convalescence. Single-cell RNA-seq libraries were prepared using the 10x genomic protocol and were sequenced using the Illumina Hiseq platform. One healthy control sample analysed by the same protocol was included.
Project description:Samples were collected from the DEN210 study, a phase IIb clinical trial evaluating two doses of TAK003, a tetravalent dengue vaccine, administered 90 days apart in healthy adult participants with and without prior DENV infection (NCT03746015). RNA was extracted from whole blood collected in Paxgene tubes from volunteers at Day 1, 4, 6, 90, 94 and 96. Day 1 and Day 90 samples were collected prior to administration of first and second TAK-003 vaccine dose. We performed gene expression analysis in dengue seronegative and seropositive individuals over time.
Project description:Background: We report the detailed development of biomarkers to predict the clinical outcome under dengue infection. Transcriptional signatures from purified peripheral blood mononuclear cells were derived from whole-genome gene-expression microarray data and validated by quantitative PCR and tested in independent samples. Methodology/Principal Findings: The study was performed on patients of a well-characterized dengue cohort from Recife, Brazil. The samples analyzed were collected prospectively from acute febrile dengue patients who evolved with different degrees of disease severity, classic dengue fever or dengue hemorrhagic fever (DHF) and compared with similar samples from other non-dengue febrile illnesses. The DHF samples were collected 2-3 days before the presentation of the plasma leakage symptoms. Differentially-expressed genes were selected by univariate statistical tests as well as multivariate classification techniques. The results showed that at early stages of dengue infection, the genes involved in effector mechanisms of innate immune response presented a weaker activation on patients who later developed hemorrhagic fever, whereas the genes involved in apoptosis were expressed in higher levels. Conclusions/Significance: Some of the gene expression signatures displayed estimated accuracy rates of more than 95%, indicating that expression profiling with these signatures may provide a useful means of DHF prognosis at early stages of infection The samples correspond to blood samples from 26 patients from a cohort in Brazil, divided into three classes, DHF, DF, ND, as follows: 18 were confirmed dengue 3, genotype III cases, among which 10 were diagnosed as dengue hemorrhagic fever (DHF) and 8 as classical dengue fever (DF), and 8 control samples (ND) from febrile patients confirmed to be not infected with dengue. None of the DHF patients presented vasculopathy signs and symptoms at the time the samples used in the functional genomic characterization were collected. At the time of collection the patients referred approximately 5 days of disease and the absence of fever was reported two to three days after enrollment. The samples from the DF, DHF and ND patients were matched to avoid significant differences regarding patient age, gender, dengue infection history and days of symptoms among the groups.