ABSTRACT: DNA microarrays and specific RT-PCR assays were used to reveal transcriptional patterns in the blood of children presenting with dengue shock syndrome (DSS) and well-matched patients with uncomplicated dengue. The transcriptome of patients with acute uncomplicated dengue was characterized by a metabolically demanding "host defense" profile; transcripts related to oxidative metabolism, interferon signaling, protein ubiquination, apoptosis and cytokines were prominent. In contrast, the transcriptome of DSS patients was surprisingly benign, particularly with regard to transcripts derived from apoptotic and type I interferon pathways. These data highlight significant heterogeneity in the type or timing of host transcriptional immune responses precipitated by DENV infection independent of the duration of illness. In particular, they suggest that if transcriptional events in the blood compartment contribute to capillary leakage leading to hypovolemic shock, they occur before cardiovascular decompensation occurs, a finding that has implications for rational adjuvant therapy in this syndrome.
Project description:DNA microarrays and specific RT-PCR assays were used to reveal transcriptional patterns in the blood of children presenting with dengue shock syndrome (DSS) and well-matched patients with uncomplicated dengue. The transcriptome of patients with acute uncomplicated dengue was characterized by a metabolically demanding "host defense" profile; transcripts related to oxidative metabolism, interferon signaling, protein ubiquination, apoptosis and cytokines were prominent. In contrast, the transcriptome of DSS patients was surprisingly benign, particularly with regard to transcripts derived from apoptotic and type I interferon pathways. These data highlight significant heterogeneity in the type or timing of host transcriptional immune responses precipitated by DENV infection independent of the duration of illness. In particular, they suggest that if transcriptional events in the blood compartment contribute to capillary leakage leading to hypovolemic shock, they occur before cardiovascular decompensation occurs, a finding that has implications for rational adjuvant therapy in this syndrome. Whole blood transcriptional profiles of children infected with dengue virus with different clinical outcomes were compared. The subjects including 9 acute dengue shock samples, 9 acute uncomplicated dengue samples, 6 autologous follow up dengue samples and 6 autologous follow up uncomplicated dengue patients. Microarray data was normalised using Genespring GX7 software, statistical analysis was performed in Multiexperiment viewer software. Pathway analysis was performed using Ingenuity Pathway analysis online software.
Project description:Dengue is a pan-tropic public health problem. In children, dengue shock syndrome (DSS) is the most common life-threatening complication. Predicting patients who may develop DSS may improve triage and treatment. To this end, we conducted a nested case-control comparison of the early host-transcriptional features in 24 DSS patients and 56 sex-, age-, virus serotype-matched uncomplicated dengue patients. In the first instance we defined the âearly dengueâ profile. The transcriptional signature in acute versus convalescent samples (â¤72hrs post illness-onset) was defined by an over-abundance of interferon-inducible transcripts (31% of the 551 over-abundant transcripts), and canonical gene ontology terms that included response to virus, immune response, innate immune response and inflammatory response. Pathway and network analysis identified STAT1, STAT2, STAT3, IRF7, IRF9, IRF1, CEBPB and SP1 as key transcriptional factors mediating the early response. Strikingly, the only differences in the transcriptional signatures of early DSS and uncomplicated dengue cases was the greater abundance of several neutrophil-associated transcripts in patients who progressed to DSS, a finding supported by higher plasma concentrations of several canonical proteins associated with neutrophil-degranulation (BPI, ELA2, DEF1A). Elevated levels of neutrophil-associated transcripts were independent of the neutrophil count and also the genotype of the infecting virus, as genome-length sequences of DENV-1 (n=15) and DENV-2 (n=3) viruses sampled from DSS patients were phylogenetically indistinguishable from those sampled from uncomplicated dengue patients (32 DENV-1 and 9 DENV-2). Collectively, these data suggest an hitherto unrecognised association between neutrophil activation, pathogenesis and the development of DSS and point to future strategies for guiding prognosis. 112 patients: 80 with uncomplicated dengue, 32 with dengue shock syndrome
Project description:Dengue is a pan-tropic public health problem. In children, dengue shock syndrome (DSS) is the most common life-threatening complication. Predicting patients who may develop DSS may improve triage and treatment. To this end, we conducted a nested case-control comparison of the early host-transcriptional features in 24 DSS patients and 56 sex-, age-, virus serotype-matched uncomplicated dengue patients. In the first instance we defined the “early dengue” profile. The transcriptional signature in acute versus convalescent samples (≤72hrs post illness-onset) was defined by an over-abundance of interferon-inducible transcripts (31% of the 551 over-abundant transcripts), and canonical gene ontology terms that included response to virus, immune response, innate immune response and inflammatory response. Pathway and network analysis identified STAT1, STAT2, STAT3, IRF7, IRF9, IRF1, CEBPB and SP1 as key transcriptional factors mediating the early response. Strikingly, the only differences in the transcriptional signatures of early DSS and uncomplicated dengue cases was the greater abundance of several neutrophil-associated transcripts in patients who progressed to DSS, a finding supported by higher plasma concentrations of several canonical proteins associated with neutrophil-degranulation (BPI, ELA2, DEF1A). Elevated levels of neutrophil-associated transcripts were independent of the neutrophil count and also the genotype of the infecting virus, as genome-length sequences of DENV-1 (n=15) and DENV-2 (n=3) viruses sampled from DSS patients were phylogenetically indistinguishable from those sampled from uncomplicated dengue patients (32 DENV-1 and 9 DENV-2). Collectively, these data suggest an hitherto unrecognised association between neutrophil activation, pathogenesis and the development of DSS and point to future strategies for guiding prognosis.
Project description:Background Deciphering host responses contributing to dengue shock syndrome (DSS), the life-threatening form of acute viral dengue infections, is required to improve both the differential prognosis and the treatments provided to DSS patients, a challenge for clinicians. Methodology/Principal Findings Based on a prospective study, we analyzed the genome-wide expression profiles of whole blood cells from 48 matched Cambodian children: 19 progressed to DSS while 16 and 13 presented respectively classical dengue fever (DF) or dengue hemorrhagic fever grades I/II (DHF). Using multi-way analysis of variance (ANOVA) and adjustment of p-values to control the False Discovery Rate (FDR<10%), we identified a signature of 2959 genes differentiating DSS patients from both DF and DHF, and showed a strong association of this DSS-gene signature with the dengue disease phenotype. Using a combined approach to analyse the molecular patterns associated with the DSS-gene signature, we provide an integrative overview of the transcriptional responses altered in DSS children. In particular, we show that the transcriptome of DSS children blood cells is characterized by a decreased abundance of transcripts related to T and NK lymphocyte responses and by an increased abundance of anti-inflammatory and repair/remodeling transcripts. We also show that unexpected pro-inflammatory gene patterns at the interface between innate immunity, inflammation and host lipid metabolism, known to play pathogenic roles in acute and chronic inflammatory diseases associated with systemic vascular dysfunction, are transcriptionnally active in the blood cells of DSS children. Conclusions/Significance We provide a global while non exhaustive overview of the molecular mechanisms altered in of DSS children and suggest how they may interact to lead to final vascular homeostasis breakdown. We suggest that some mechanisms identified should be considered putative therapeutic targets or biomarkers of progression to DSS. Whole blood genome-wide expression profiles of Cambodian children (3-15 year old) infected with dengue virus, having different clinical outcomes were compared. The studied cohort included 16 acute dengue fever samples, 13 acute dengue hemorrhagic fever samples and 19 acute dengue shock syndrome samples, classified according to the 1997 WHO criteria and randomised for age, gender, viral serotype and day of blood sampling after onset of fever. Microarray data were normalised using the quantile method. Multi-way ANOVA was used to compared the three clinical groups, at several False Discovery Rate of 10. Unsupervised Hierarchical Clustering (TreeView) showed that DSS patients clustered together (17 out of 19), identifying a gene-signature of DSS. Bio-informatics-based analysis using the demonstration version 7.1 of Ingenuity Pathway Analysis software (IPA; Ingenuity Systems, www.ingenuity.com) associated with manual and litterature-based analysis was carried out to identify the most relevant functional processes associated with the identified DSS gene expression profile. This was done by combining most informative canonical pathways identified using IPA, genes having the strongest association with the disease phenotype based on ANOVA analysis, and similarities to molecular patterns altered in other systemic inflammatory processes associated with endothelial dysfunction.
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.
Project description:Background Deciphering host responses contributing to dengue shock syndrome (DSS), the life-threatening form of acute viral dengue infections, is required to improve both the differential prognosis and the treatments provided to DSS patients, a challenge for clinicians. Methodology/Principal Findings Based on a prospective study, we analyzed the genome-wide expression profiles of whole blood cells from 48 matched Cambodian children: 19 progressed to DSS while 16 and 13 presented respectively classical dengue fever (DF) or dengue hemorrhagic fever grades I/II (DHF). Using multi-way analysis of variance (ANOVA) and adjustment of p-values to control the False Discovery Rate (FDR<10%), we identified a signature of 2959 genes differentiating DSS patients from both DF and DHF, and showed a strong association of this DSS-gene signature with the dengue disease phenotype. Using a combined approach to analyse the molecular patterns associated with the DSS-gene signature, we provide an integrative overview of the transcriptional responses altered in DSS children. In particular, we show that the transcriptome of DSS children blood cells is characterized by a decreased abundance of transcripts related to T and NK lymphocyte responses and by an increased abundance of anti-inflammatory and repair/remodeling transcripts. We also show that unexpected pro-inflammatory gene patterns at the interface between innate immunity, inflammation and host lipid metabolism, known to play pathogenic roles in acute and chronic inflammatory diseases associated with systemic vascular dysfunction, are transcriptionnally active in the blood cells of DSS children. Conclusions/Significance We provide a global while non exhaustive overview of the molecular mechanisms altered in of DSS children and suggest how they may interact to lead to final vascular homeostasis breakdown. We suggest that some mechanisms identified should be considered putative therapeutic targets or biomarkers of progression to DSS.
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:We measured fever-day-specific genome-wide transcript abundance patterns in 105 peripheral blood mononuclear cell (PBMC) samples collected from 41 children hospitalized with dengue virus (DENV) infection in Nicaragua, and from 8 healthy controls. DF1 = primary DF; DF2 = secondary DF; DHF = Dengue Hemorrhagic Fever; DSS = Dengue Shock Syndrome. Samples were collected from pediatric patients with DENV infection at the Hospital Infantil Manuel de Jesus Rivera (HIMJR) in Managua, Nicaragua. Enrollment criteria consisted of hospitalized patients younger than 15 years of age whose parents or guardians completed the informed consent process, and for children 6 years and older who provided assent, and who presented with acute febrile illness of less than 7 days duration with one or more of the following symptoms or signs at the time of evaluation: headache, arthralgia, myalgia, retro-orbital pain, positive tourniquet test, petechiae, and signs of bleeding. Children were considered to have dengue if DENV was detected by RT-PCR or by isolation in cell culture, if an IgM ELISA indicated seroconversion between the acute and convalescent sample, and/or if there was a > 4-fold increase in DENV-specific antibodies between the acute and convalescent phase. Peripheral blood mononuclear cells (PBMCs) were isolated from whole blood within four hours of collection and stored in Trizol at -80 oC disease_state_design