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:Background: Dengue virus (DENV) spread widely, causing not only dengue fever, dengue haemorrhagic fever, and dengue shock syndrome but also renal damage, which results in a poor prognosis. MicroRNA (miRNA) has attracted attention in recent years due to its regulatory functions in the transcriptomes of viral and host genomes. However, research on the function of miRNAs in the pathogenesis of dengue and dengue-associated nephropathy is still in the early stages. Methods: We investigated the miRNA libraries from uninfected and DENV-infected mouse kidney tissue with high-throughput miRNA-seq technology, performed genomic analysis, and subsequently, practiced target gene prediction and enrichment analysis of differentially expressed miRNAs (DEmiRNAs). Result: We identified 32 DEmiRNAs, including 19 with upregulated and 13 with downregulated expression, with miR-206-3p, miR-206, and miR-135a-5p showing significantly upregulated expression, the first two were associated with AKT phosphorylation, and the latter was associated with inflammation, however, those factors have been rarely investigated. MiR-122-5p, a potential biomarker in dengue, was downregulated in the kidney, in contrast to previous studies. Subsequently, we predicted 2209 potential target genes of the differentially expressed miRNAs and explored the Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis, showing the pathogenic mechanisms of dengue in which the factors participated, which included viral replication and inflammatory response. Conclusion: The current study investigates overall miRNA expression in mouse kidneys as a result of DENV-2 infection in vivo. These results may broaden the scope of knowledge about how miRNAs regulate the occurrence and development of DENV infection and in turn enhance the prevention and treatment of severe dengue and associated renal disease. In this study, RNA-Seq analysis of kidney tissues from a mouse model after DENV infection was performed to identify differential miRNA expression profiles, predicted target genes, and analyzed the biological functions and pathways involved in the regulation of differential miRNAs.
Project description:Background: Organ dysfunction, especially liver injury, caused by dengue virus (DENV) infection has been associated with fatal cases in dengue patients around the world. However, the pathophysiological mechanisms of liver involvement in dengue remain unclear. There is accumulating evidence that miRNAs are playing an important role in regulating viral pathogenesis, and it can help in diagnostic and anti-viral therapies development. Methods: We collected liver tissues of DENV-infected for small RNA sequencing to identify significantly different express miRNAs during dengue virus infection, and the identified target genes of these miRNAs were annotated by biological function and pathway enrichment. Results: 31 significantly altered miRNAs were identified, including 16 up-regulated and 15 down-regulated miRNAs. By performing a series of miRNA prediction and signaling pathway enrichment analyses, the down-regulated miRNAs of mmu-miR-484, mmu-miR-1247-5p and mmu-miR-6538 were identified to be the crucial miRNAs. Further analysis revealed that the inflammation and immune responses involving Hippo, PI3K-Akt, MAPK, Wnt, mTOR, TGF-beta, Tight junction, and Platelet activation were modulated collectively by these three key miRNAs during DENV infection. These pathways are considered to be closely associated with the pathogenic mechanism and treatment strategy of dengue patients. Conclusion: The miRNAs identified by sequencing, especially miR-484 may be the potential therapeutic targets for liver involvement in dengue patients which involves the regulation of vascular permeability and expression of inflammatory cytokines. In this study, RNA-Seq analysis of liver tissues from a mouse model after DENV infection was performed to identify differential miRNA expression profiles, predicted target genes, and analyzed the biological functions and pathways involved in the regulation of differential miRNAs, contributing to the understanding of the mechanisms of liver tissue involvement after DENV infection.
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
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.