Project description:A NanoString targeted gene panel was used to elucidate the transcriptomic changes occurring in non-human primate whole blood during Crimean Congo Hemorrhagic Fever Virus infection.
Project description:Zaire ebolavirus (ZEBOV) is among the deadliest known human pathogens, causing severe hemorrhagic fever with high case fatality rates ranging from 70-90%. The lack of effective vaccines or treatment available for ZEBOV renders this pathogen as a significant global biodefense threat, as evidenced by the current, highly lethal outbreak of a novel ZEBOV variant in western Africa. Existing mouse models of lethal ZEBOV infection do not reproduce hallmark symptoms of Ebola hemorrhagic fever (EHF) including prolonged blood coagulation, acute hepatitis, disseminated intravascular coagulation (DIC), and death from hemorrhagic shock, thus restricting pathogenesis studies to non-human primates (NHP). This has prevented rapid evaluation of countermeasures in outbreak scenarios, and impeded a comprehensive understanding of how host responses to infection contribute to severe EHF disease. Here we demonstrate that mice from the Collaborative Cross (CC), a panel of reproducible, recombinant inbred animals that span the genetic breadth of three murine subspecies, are susceptible to a spectrum of disease phenotypes following ZEBOV infection. In contrast to C57Bl6/J mice, which develop lethal disease without symptoms of EHF, CC recombinant inbred intercrossed (CC-RIX) lines develop either complete resistance to lethal disease or severe EHF characterized by prolonged coagulation times and 100% mortality. Disease resistance and survival is not dependent on viral tropism, as both resistant and EHF-susceptible lines show similar inflammation and cytopathic effect in target organs. Transcriptomics reveal potential mechanisms for both induction of severe hemorrhage in EHF mediated by IL-6 and vascular activation, and resistance to lethal infection by induction of lymphocyte differentiation and cellular adhesion. These data demonstrate that host responses specific to unique genetic backgrounds determine susceptibility to hemorrhagic syndrome independent of virus replication. The CC represents a novel mouse model for studying EHF pathogenesis, and we anticipate that it will be applied immediately to developing and evaluating therapeutic countermeasures. Microarrays were performed on liver and spleen samples from mice collected at days 1, 3, and 5 post-infection with mouse adapted Zaire ebolavirus or from time-matched mock-infected animals.
Project description:Crimean-Congo hemorrhagic fever virus (CCHFV) is a tick-borne virus that can cause a hemorrhagic fever in humans, with a case fatality rate of up to 50%. Cases of CCHFV have been reported in Africa, Asia, and southern Europe; and recently, due to the expanding range of its vector, autochthonous cases have been reported in Spain. Although it was discovered over 70 years ago, our understanding of the pathogenesis of this virus remains limited. We used RNA-Seq in two human liver cell lines (HepG2 and Huh7) infected with CCHFV (strain Ib 10200), to examine kinetic changes in host expression and viral replication simultaneously at 24 and 72 hours post infection. Through this, numerous host pathways were identified that were modulated by the virus including: antiviral response and endothelial cell leakage. Notably, DDX60, a cytosolic component of the RIG-I signalling pathway and OAS2 were both shown to be dysregulated. Interestingly, the PTPRR gene was induced in Huh7 cells. This has been associated with the TLR9 signalling cascade, and polymorphisms in the TLR9 gene have been associated with poor outcomes in patients. Additionally, we whole-genome sequenced CCHFV to assess viral diversity over time, and its relationship to the host response. As a result, we have demonstrated that through next-generation mRNA deep-sequencing it is possible to not only examine mRNA gene expression, but also to examine viral evolution. This demonstrates a proof-of-principle that specimens can be analyzed to identify both the virus, and host biomarkers that may have implications for prognosis.
Project description:Rhesus macaques (Macaca mulatta) infected with a lethal dose of lymphocytic choriomeningitis virus-strain WE (LCMV-WE) provide a model for Lassa fever virus infection of man. Like Lassa fever in human beings, disease begins with flu-like symptoms but can progress to morbidity fairly rapidly. Previously, we profiled the blood transcriptome of LCMV-infected monkeys (M. Djavani et al. J. Virol. 2007: PMID 17522210) showing distinct pre-viremic and viremic stages that discriminated between virulent and benign infections. In the present study, changes in liver gene expression from macaques infected with virulent LCMV-WE were compared to gene expression in uninfected monkeys as well as to monkeys that were infected but not diseased. We observed gene expression changes that occurred before the viremic stage of the disease, and could potentially serve as biomarkers that discriminate between exposure to a hemorrhagic fever virus and exposure to a benign virus. Based on a functional pathway analysis of differentially expressed genes, virulent LCMV-WE had a much broader effect on liver cell function than non-virulent virus. During the first few days of infection, virulent virus impacted gene expression associated with the generation of energy, such as fatty acid metabolism and glucose metabolism, with the complement and coagulation cascades, and with steroid metabolism, MAPK signaling and cell adhesion. For example, the energy profile resembled that of an organism entering starvation: acetyl-CoA carboxylase, a key enzyme of fatty acid synthesis, was shut down and gene products involved in gluconeogenesis were up-regulated. In conclusion, this study identifies several potential gene markers of LCMV-WE-associated liver disease and contributes to the database of gene expression changes correlated with LCMV pathogenesis in primates. 6 groups: uninfected controls, LCMV-WE infected (pre-viremic; day 1 to day 3), LCMV-WE infected (viremic; day 4 to day 7), LCMV-WE infected (post-viremic; day 8 to day 12), LCMV-Armstrong (LCMV-ARM; non-virulent strain) infected, and LCMV-ARM/LCMV-WE infected but not diseased. Each sample is from the liver of a different rhesus macaque.
Project description:Zaire ebolavirus (ZEBOV) is among the deadliest known human pathogens, causing severe hemorrhagic fever with high case fatality rates ranging from 70-90%. The lack of effective vaccines or treatment available for ZEBOV renders this pathogen as a significant global biodefense threat, as evidenced by the current, highly lethal outbreak of a novel ZEBOV variant in western Africa. Existing mouse models of lethal ZEBOV infection do not reproduce hallmark symptoms of Ebola hemorrhagic fever (EHF) including prolonged blood coagulation, acute hepatitis, disseminated intravascular coagulation (DIC), and death from hemorrhagic shock, thus restricting pathogenesis studies to non-human primates (NHP). This has prevented rapid evaluation of countermeasures in outbreak scenarios, and impeded a comprehensive understanding of how host responses to infection contribute to severe EHF disease. Here we demonstrate that mice from the Collaborative Cross (CC), a panel of reproducible, recombinant inbred animals that span the genetic breadth of three murine subspecies, are susceptible to a spectrum of disease phenotypes following ZEBOV infection. In contrast to C57Bl6/J mice, which develop lethal disease without symptoms of EHF, CC recombinant inbred intercrossed (CC-RIX) lines develop either complete resistance to lethal disease or severe EHF characterized by prolonged coagulation times and 100% mortality. Disease resistance and survival is not dependent on viral tropism, as both resistant and EHF-susceptible lines show similar inflammation and cytopathic effect in target organs. Transcriptomics reveal potential mechanisms for both induction of severe hemorrhage in EHF mediated by IL-6 and vascular activation, and resistance to lethal infection by induction of lymphocyte differentiation and cellular adhesion. These data demonstrate that host responses specific to unique genetic backgrounds determine susceptibility to hemorrhagic syndrome independent of virus replication. The CC represents a novel mouse model for studying EHF pathogenesis, and we anticipate that it will be applied immediately to developing and evaluating therapeutic countermeasures.
Project description:Crimean-Congo hemorrhagic fever (CCHF), caused by Crimean-Congo hemorrhagic fever virus (CCHFV), is on the World Health Organizations list over emerging pathogens and prioritized diseases. With global distribution, high fatality rate and no approved treatment or vaccine, CCHF constitute a treat against the global health. In the current study we show full protection of mice against lethal CCHFV infection due to mRNA-LNP vaccination. IFNAR-/- mice received two immunizations with either mRNA-LNP encoding for the CCHFV nucleoprotein, glycoproteins or a combination of both. While unvaccinated mice showed clear signs of severe disease, vaccinated mice was significantly protected. Vaccine induced immune responses due to vaccination was evaluated both in IFNAR-/- and immunocompetent mice and a strong humoral and cellular immune response was observed in both mouse models with high titers of neutralizing antibodies and primed T-cells. In addition, we conducted a proteomic analysis on liver samples from vaccinated and unvaccinated mice after CCHFV infection to determine the effect of vaccination on the protein profile. Similar to what has been observed in humans due to vaccination, there was an effect on metabolic pathways. In conclusion, this study shows very promising results regarding development of a vaccine against CCHFV.
Project description:Rhesus macaques (Macaca mulatta) infected with a lethal dose of lymphocytic choriomeningitis virus-strain WE (LCMV-WE) provide a model for Lassa fever virus infection of man. Like Lassa fever in human beings, disease begins with flu-like symptoms but can progress to morbidity fairly rapidly. Previously, we profiled the blood transcriptome of LCMV-infected monkeys (M. Djavani et al. J. Virol. 2007: PMID 17522210) showing distinct pre-viremic and viremic stages that discriminated between virulent and benign infections. In the present study, changes in liver gene expression from macaques infected with virulent LCMV-WE were compared to gene expression in uninfected monkeys as well as to monkeys that were infected but not diseased. We observed gene expression changes that occurred before the viremic stage of the disease, and could potentially serve as biomarkers that discriminate between exposure to a hemorrhagic fever virus and exposure to a benign virus. Based on a functional pathway analysis of differentially expressed genes, virulent LCMV-WE had a much broader effect on liver cell function than non-virulent virus. During the first few days of infection, virulent virus impacted gene expression associated with the generation of energy, such as fatty acid metabolism and glucose metabolism, with the complement and coagulation cascades, and with steroid metabolism, MAPK signaling and cell adhesion. For example, the energy profile resembled that of an organism entering starvation: acetyl-CoA carboxylase, a key enzyme of fatty acid synthesis, was shut down and gene products involved in gluconeogenesis were up-regulated. In conclusion, this study identifies several potential gene markers of LCMV-WE-associated liver disease and contributes to the database of gene expression changes correlated with LCMV pathogenesis in primates.
Project description:Ebola (EBOV) virus causes severe and often lethal hemorrhagic fever in humans and nonhuman primates (NHP), and has been classified as a Category A bioweapon agent. There are currently no approved preventive vaccines or postexposure treatments for EBOV hemorrhagic fever. The mechanisms of EBOV pathogenesis are only partially understood, but the dysregulation of normal host immune responses (including destruction of lymphocytes, increases in levels of circulating proinflammatory cytokines, and development of coagulation abnormalities) is thought to play a major role. Accumulating evidence suggests that much of the observed pathology is not the direct result of virus-induced structural damage but rather is due to the release of soluble immune mediators from EBOV-infected cells. It is therefore essential to understand how the candidate therapeutic may be interrupting the disease process and/or targeting the infectious agent. Identification of effective treatment strategies may greatly benefit based on identification of molecular features of the host response to infection and treatment. In order to identify these gene signatures related to correlates of protection, we used a DNA microarray-based approach to compare the host genome-wide responses of EBOV-infected NHP responding to candidate therapeutics. With this approach, we have identified genes that appear to correlate with survival, including chemokine ligand 8 (CCL8/MCP-2), and revealed a subset of distinctly differently expressed genes that may provide possible targets for future diagnostics or therapeutics. These analyses will assist us in understanding the pathogenic mechanisms of EBOV infection as well as identify improved therapeutic strategies. Transcriptional analysis of global gene expression changes in Zaire Ebola Virus (ZEBOV)-infected rhesus macaques that were treated with either recombinant nematode anticoagulant protein c2 (rNAPc2) or recombinant human activated protein C (rhAPC). Animals were infected with 1000pfu ZEBOV, then subsequently treated with rNAPc2 or rhAPC. Four animals were left untreated for controls. Blood samples were taken at specified days post-infection and PBMCs were isolated from the samples and inactivated in TRIzol reagent. Total RNA was isolated from the samples, then linearly amplified and hybridized to a whole genome long-oligonucleotide microarray in a two color comparative format with a commercially available human reference RNA from Stratagene as a consistent control in dataset comparisons.