Project description:There are very few studies exploring the genetic diversity of tick-borne encephalitis complex viruses. Most of the viruses have been sequenced using capillary electrophoresis, however, very few viruses have been analyzed using deep sequencing to look at the genotypes in each virus population. In this study, different viruses and strains belonging to the tick-borne encephalitis complex were sequenced and genetic diversity was analyzed. Shannon entropy and single nucleotide variants were used to compare the viruses. Then genetic diversity was compared to the phylogenetic relationship of the viruses.
Project description:Zika virus (ZIKV) is a mosquito-transmitted positive-sense RNA virus in the family Flaviviridae. Live attenuated vaccines have been successfully used to combat infection by flaviviruses, such as yellow fever and Japanese encephalitis viruses. A Zika virus harboring combined mutations in the envelope protein glycosylation site and in the nonstructural 4B protein amino acid 36 (ZE4B-36) was generated and assessed for stability, attenuation, and protection against infection. To determine the genetic stability of its RNA genome, ZE4B-36 was serially passaged in vitro in Vero cells. Virus harvested from passages (P)1 to P6 was subjected to next generation sequencing and downstream analysis to determine its nucleotide sequence variability. Specifically, single nucleotide variant analysis showed that the ZE4B-36 genome decreased its genetic diversity and resulted in a more stable nucleotide sequence. Thus, in addition to showing attenuation and protection, ZE4B-36 is a stable live attenuated virus that possesses characteristics important for a vaccine to combat Zika disease.
Project description:Ebola virus can cause a severe and often fatal hemorrhagic fever in humans and other mammals, known as Ebola virus disease (EVD),the mechanism of how this pathogenesis comes about is not well understood, It is assumed that miRNA may have important roles in virus infection response. To better understand the function of miRNA in EBOV infection disease, we undertook a miRNA profiling analysis using the whole blood of EBOV infection patients.
Project description:The Rift Valley Fever (RVF) is an arthropod-borne disease present in several countries of Africa and Middle East. It is caused by RVF virus which can infect both humans and animals. In humans, it leads to various manifestations including hepatitis, encephalitis and death, while in domestic animals it usually causes miscarriage in pregnant females and it is often fatal for the newborn. Not all people or animal infected by the virus present the same disease. Some patients exhibit unapparent or moderate febrile reactions, while others develop severe symptoms. This observation suggests that host genetic factors play a role in controlling the outcome of infection. In this work, we compare the response of two different inbred strains of mice, MBT/Pas and BALB/cByJ, to infection with RVF virus. These strains exhibit different profiles of susceptibility to RVF virus infection. Indeed, MBT/Pas mice rapidly develop high viraemia and die soon after infection, while BALB/cByJ mice have a lower viraemia and die later. Interestingly, mouse embryonic fibroblasts (MEFs) obtained from MBT/Pas foetuses allows higher viral production than BALB/cByJ MEFs. Keywords: expression profiling The experiment was designed to include ARN samples from MBT/Pas and BALB/cByJ MEFs infected with the Rift Valley Fever (RVF) virus, and their respective mock-infected controls; each one of those in triplicate. Therefore, we have used 12 different samples for the study, divided as follows: 3 samples of RVF virus-infected BALB/cByJ MEFs, 3 samples of mock-infected BALB/cByJ MEFs, 3 samples of RVF virus-infected MBT/Pas MEFs and 3 samples of mock-infected MBT/Pas MEFs. Each RNA was extracted from a different culture well.
Project description:Dengue virus (DENV) infection is one of the most serious public health problems worldwide. A recent dengue outbreak in Paraguay (2007-2009) presented unusual manifestations such as hepatitis, encephalitis, pulmonary as well as cardiac disorders associated with 50% of deaths caused by dengue in the country. Despite the knowledge on inflammatory responses observed during the course of disease, the role of innate immune cells in the control of virus replication influencing clinical outcome is poorly defined. Using two clinical isolates of the virus, a non-fatal case of classical DF (DENV3/290) and a fatal case of DF with visceral complications (DENV3/5532), we sought to determine the profile of dengue infection in human dendritic cell, a major innate immune cell population. Compared to classical DENV3/290, the strain DENV3/5532 displayed higher replicative ability in mdDCs. In addition, DENV3/5532 was found to induce elevated production of pro-inflammatory cytokines associated with higher rates of programmed cell death. The observed phenotype was due to viral replication in mdDCs and TNF appeared to display a protective effect on virus-induced mdDCs apoptosis. These results suggest that the fatal case DENV3/5532 isolate modulates dendritic cell survival as well as inflammatory mediator’s synthesis.
Project description:The Rift Valley Fever (RVF) is an arthropod-borne disease present in several countries of Africa and Middle East. It is caused by RVF virus which can infect both humans and animals. In humans, it leads to various manifestations including hepatitis, encephalitis and death, while in domestic animals it usually causes miscarriage in pregnant females and it is often fatal for the newborn. Not all people or animal infected by the virus present the same disease. Some patients exhibit unapparent or moderate febrile reactions, while others develop severe symptoms. This observation suggests that host genetic factors play a role in controlling the outcome of infection. In this work, we compare the response of two different inbred strains of mice, MBT/Pas and BALB/cByJ, to infection with RVF virus. These strains exhibit different profiles of susceptibility to RVF virus infection. Indeed, MBT/Pas mice rapidly develop high viraemia and die soon after infection, while BALB/cByJ mice have a lower viraemia and die later. Interestingly, mouse embryonic fibroblasts (MEFs) obtained from MBT/Pas foetuses allows higher viral production than BALB/cByJ MEFs. Keywords: expression profiling
Project description:Chikungunya virus (CHIKV) is a mosquito-borne virus that causes acute, subacute, and chronic human diseases and can cause neurological complications and death. Here, we combined epidemiological, virological, histopathological, cytokine, molecular dynamics, metabolomics, proteomics, and genomic analyses to investigate viral and pathophysiologic factors that contribute to deaths caused by chikungunya (CHIK). Our results indicate that CHIK-deaths presented multiple organs infection, central nervous system damage, and exhibited significantly elevated serum levels of pro-inflammatory cytokines and chemokines compared to survivors. The histopathology, metabolite, and proteomic signatures of CHIK-deaths revealed hemodynamic disorders and dysregulated immune system response. CHIKV East-Central-South-African lineage caused fatal and survivor cases, and CHIKV crosses the blood–brain barrier without tight junction alterations. IFN-λ3 was highly expressed in fatal cases but did not present a direct antiviral effect on CHIKV replication in vitro. In summary, our results reveal insights to improve understanding of CHIK pathogenesis, especially the pathophysiology of fatal infections.