Project description:Viable T cells (CD3+ CD19-) and B cells (CD3- CD19+) were sorted from PBMC samples obtained from 1 individual experiencing a natural secondary DENV infection. Single cell RNA sequencing analysis was performed on 3 time points
Project description:Controlled dengue human challenge studies present a unique opportunity to address many longstanding questions in the field of flavivirus biology. These fundamental questions include defining the early immunological signatures of infection, the host/environmental factors that impact disease severity, and the role of preexisting immunity on the development of symptomatic viral infection. However, while several controlled dengue human challenge studies have been performed and appear to clinically recapitulate may features of mild natural DENV infection, limited data are available on how the immunological and transcriptional response elicited by these attenuated challenge viruses compares to the profile associated with a natural, unattenuated DENV infection. To bridge this knowledge gap, we performed scRNAseq analysis on longitudinally collected PBMC samples obtained from 3 individuals (8 time points per subject) enrolled in the SUNY/WRAIR DENV-1 controlled human challenge study. In addition, 3 time points (two acute infection time points, one control time point) from two individuals experiencing a natural DENV-1 infection were analyzed and computationally integrated with the challenge model dataset. This temporally integrated dataset contains a total of 171,208 cells and 22 statistically distinct populations corresponding to all major anticipated leukocyte subsets. While all identified cell populations demonstrated significant and consistant perturbations in their transcriptional profile in response to either natural or experimental DENV infection, conventional monocytes respond most robustly to infection across all subjects and study groups from an unbiased transcriptional perspective. Using these data, core sets of genes that were consistently induced by either natural or experimental DENV were identified, and the overlap between the two arms of the study assessed.
Project description:Dengue virus can infect and cause systemic damage in many organs, resulting in organ failure. Here, we present a novel report showing a tailored stem cell-based therapy which can aid in viral clearance and rescue liver and blood vessels cells from further damage during dengue infection by administering combination of hematopoietic stem cells, endothelial progenitor cells and dental pulp stem cells in a dengue virus-infected BALB/c mouse model. To analyze the molecular level changes induced by DENV infection and stem cell treatment in dengue-infected mice, RNA sequencing (RNA-seq) using MiSeq next-generation sequencing was employed in this study. Transcriptomics analysis was performed comparing gene expression patterns in different experimental groups. Methods: Liver mRNA profiles of 21-day-old healthy, Dengue virus infected, and dengue infected plus stem cells treated BALB/C mice were generated by sequencing, in triplicate, using Illumina Miseq V3 150. The sequence reads that passed quality filters were assembled and analyzed using Tuxedo software. The results were analyzed using Cuffdiff to identify differentially expressed genes and transcripts. The relative expression of genes was determined based on FPKM (total fragments per kilobase of exon per million mapped reads) values Results: After analysis, it was found that 59 genes were significantly up-regulated in the DVI group, and in the DVI-SCT group, 47 of the genes were successfully corrected to the level similar to that of control group, while the remaining genes showed down-regulation Conclusion: In the recent years, the incidence of dengue has continued to increase, but there is currently no rapid and effective treatment available. This study demonstrates stem cell therapy as a promising management to reduce the global burden of dengue.
Project description:Zika virus (ZIKV), a pathogen of global health concern, is transmitted to humans by Aedes mosquitoes. However, the molecular interactions between the vector and the virus remain largely unexplored. We demonstrated that ZIKV and dengue virus (DENV) have similar tropism and infection kinetics in two mosquito strains with different degrees of susceptibility to infection. Comparison of Aedes aegypti’s molecular responses to ZIKV and DENV infection indicated that around 40% of the mosquito’s infection-responsive transcriptome is virus-specific. Regulated genes also included key factors of the mosquito’s anti-viral immunity, pointing to the possible involvement of the Toll innate immune pathway. Comparison of ZIKV and DENV infection-responsive transcriptome data to those for yellow fever virus and West Nile virus identified 26 genes likely to play key roles in virus infection of Aedes mosquitoes. Through reverse genetic analyses, we showed that the Toll and the Jak/Stat innate immune pathways mediate increased resistance to ZIKV infection, and the virus use vATPase and inosine-5’-monophosphate dehydrogenase as mosquito’s host factors.
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 (DENV) is a major human pathogen that belongs to the flavivirus genus. Among non-structural viral proteins, NS1 is an enigmatic factor that is exclusively encoded by members of the flavivirus genus within the Flaviviridae family and accomplishes different functions during DENV infection. To gain insight into the molecular and cellular function of NS1 in viral replication, we generated a tagged NS1 DENV replicon and identified the associated host proteins during active viral replication. Replicons are self-replicating flavivirus RNAs containing large in-frame deletions in the structural genes and are useful tools to study translation and RNA amplification of several flaviviruses. To establish a global map of NS1-host protein interactions occurring during DENV replication, we stably expressed a DENV2 replicon encoding NS1 tagged with N-terminal FLAG and HA epitopes (FH-NS1) or the untagged version (WT) in three different human cell lines (Raji, HeLa and HAP1). Interactors of NS1 were identified by AP-MS/MS from these three different cell lines.
Project description:Infection with dengue viruses (DENVs) leads to a spectrum of disease outcomes. The pathophysiology of severe versus non-severe manifestations of DENV infection may be driven by host responses, which could be reflected in the transcriptional profiles of peripheral blood immune cells. We conducted genome-wide microarray analysis of whole blood RNA from 34 DENV-infected children in Nicaragua collected on days 3–6 of illness, with different disease manifestations. Gene expression analysis identified genes that are differentially regulated between clinical subgroups. The most striking transcriptional differences were observed between dengue patients with and without shock, especially in the expression of mitochondrial ribosomal proteins associated with protein biosynthesis. In the dengue hemorrhagic fever patients, one subset of differentially expressed genes encode neutrophil-derived anti-microbial peptides associated with innate immunity. We analyzed 44 HEEBO arrays on which were hybridized RNA amplified from whole blood collected into PAXgene tubes. 34 samples were collected from DENV-infected patients who presented between days 3-6 of illness. Six convalescent samples collected 14-19 days after onset of symptoms were from two dengue fever patients, one dengue hemorrhagic fever patient and three dengue shock syndrome patients. Additionally, samples from four normal healthy individuals were also analyzed.
Project description:Viable T cells (CD3+ CD19-) and B cells (CD3- CD19+) were sorted from PBMC samples obtained from 6 individuals experiencing either natural primary or natural secondary DENV infection. Single cell RNA sequencing analysis was performed on 2-3 time points per subject
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:Dengue virus (DENV) causes widespread mosquito-borne infection. While most symptomatic patients experience mild disease, a fraction progresses to severe dengue (SD)--a life-threatening condition whose pathogenesis remains largely unknown. We integrated virus-inclusive single cell RNA-Seq 2 (viscRNA-Seq 2) with functional assays to determine the immunological hallmarks of SD progression in children’s blood. We show that beyond myeloid cells, in natural infection, B cells harbor replicating DENV capable of infecting permissive cells. Alterations in cell abundance, gene and protein expression and secretion, and cell-cell communications suggesting increased migration and inflammation in SD progressors, yet concurrent: i) impaired interferon responses and antigen presentation, in part DENV-modulated, by antigen presenting cells (APCs) in face of intact uptake; ii) activation, regulation, and exhaustion of effector responses, enhanced IFNγ-responses, and appearance of HLA-DR-expressing NK cells possibly compensating for APCs impairments. These observations reveal the target cells of DENV in human blood and provide insight into SD pathogenesis beyond antibody-mediated enhancement.