Project description:Lassa fever (LF) is a rodent-borne viral disease that can be fatal for human beings. In this study, an attenuated Lassa vaccine candidate, ML29, was tested in SIV-infected rhesus macaques for its ability to elicit immune responses without instigating signs of virulent disease. ML29 is a reassortant between Lassa and Mopeia viruses that causes a transient infection in non-human primates and confers sterilizing protection from lethal Lassa viral challenge. However, since the LF endemic area of West Africa also has high HIV seroprevalence, it is important to determine whether vaccination could be safe in the context of AIDS. SIV-infected and uninfected rhesus macaques were vaccinated with the ML29 virus and monitored for classical and non-classical signs of arenavirus disease. Classical disease signs included viremia, rash, weight loss, high liver enzyme levels, and virus invasion of the central nervous system. Non-classical signs derived from profiling the blood transcriptome of virulent and non-virulent arenavirus infections included increased expression of interferon response genes and decreased expression of COX2, IL-1?, coagulation intermediates and nuclear receptors needed for stress signaling. Here it is demonstrated that SIV-infected and uninfected rhesus macaques responded similarly to ML29 vaccination, and that none developed signs of arenavirus disease or persistence. Furthermore, 5 of 5 animals given a heterologous challenge with a lethal dose of LCMV-WE survived without developing disease signs.
Project description:Lassa fever (LF) is a rodent-borne viral disease that can be fatal for human beings. In this study, an attenuated Lassa vaccine candidate, ML29, was tested in SIV-infected rhesus macaques for its ability to elicit immune responses without instigating signs of virulent disease. ML29 is a reassortant between Lassa and Mopeia viruses that causes a transient infection in non-human primates and confers sterilizing protection from lethal Lassa viral challenge. However, since the LF endemic area of West Africa also has high HIV seroprevalence, it is important to determine whether vaccination could be safe in the context of AIDS. SIV-infected and uninfected rhesus macaques were vaccinated with the ML29 virus and monitored for classical and non-classical signs of arenavirus disease. Classical disease signs included viremia, rash, weight loss, high liver enzyme levels, and virus invasion of the central nervous system. Non-classical signs derived from profiling the blood transcriptome of virulent and non-virulent arenavirus infections included increased expression of interferon response genes and decreased expression of COX2, IL-1?, coagulation intermediates and nuclear receptors needed for stress signaling. Here it is demonstrated that SIV-infected and uninfected rhesus macaques responded similarly to ML29 vaccination, and that none developed signs of arenavirus disease or persistence. Furthermore, 5 of 5 animals given a heterologous challenge with a lethal dose of LCMV-WE survived without developing disease signs. 30 RNA samples from Monkey PBMC: 4 uninf. Monkey PBMC, 8 SIV-infected Monkey PBMC(From 8 Monkeys), 5 SIV+ML29-sc infected week1(Monkey PBMC), 5 SIV+ML29-sc infected week2(Monkey PBMC), 1 SIV+ML29-ig infected week1(Monkey PBMC), 1 SIV+ML29-ig infected week2(Monkey PBMC), 2 SIV+Arm-sc infected week1(Monkey PBMC), 2 SIV+Arm-sc infected week2(Monkey PBMC), 1 only ML29-iv infected week1(Monkey PBMC), 1 only ML29-iv infected week2(Monkey PBMC)
Project description:Transcriptomic comparison of 5 cell types during lethal and non-lethal influenza infection and further use of these signatures in a top-down systems analysis investigating the relative pathogenic contributions of direct viral damage to lung epithelium vs. dysregulated immunity during lethal influenza infection. For acutely lethal influenza infections, the relative pathogenic contributions of direct viral damage to lung epithelium vs. dysregulated immunity remain unresolved. Here, we take a top-down systems approach to this question. Multigene transcriptional signatures from infected lungs suggested that elevated activation of inflammatory signaling networks distinguished lethal from sublethal infections. Flow cytometry and gene expression analysis involving isolated cell subpopulations from infected lungs showed that neutrophil influx largely accounted for the predictive transcriptional signature. Automated imaging analysis together with these gene expression and flow data identified a chemokine-driven feed-forward circuit involving pro-inflammatory neutrophils potently driven by poorly contained lethal viruses. Consistent with these data, attenuation but not ablation of the neutrophil-driven response increased survival without changing viral spread. These findings establish the primacy of damaging innate inflammation in at least some forms of influenza-induced lethality and provide a roadmap for the systematic dissection of infection-associated pathology.
Project description:Identification of biological processes that distinguish lethal from non-lethal influenza infection and further use of these signatures in a top-down systems analysis investigating the relative pathogenic contributions of direct viral damage to lung epithelium vs. dysregulated immunity to during lethal influenza infection. For acutely lethal influenza infections, the relative pathogenic contributions of direct viral damage to lung epithelium vs. dysregulated immunity remain unresolved. Here, we take a top-down systems approach to this question. Multigene transcriptional signatures from infected lungs suggested that elevated activation of inflammatory signaling networks distinguished lethal from sublethal infections. Flow cytometry and gene expression analysis involving isolated cell subpopulations from infected lungs showed that neutrophil influx largely accounted for the predictive transcriptional signature. Automated imaging analysis together with these gene expression and flow data identified a chemokine-driven feed-forward circuit involving pro-inflammatory neutrophils potently driven by poorly contained lethal viruses. Consistent with these data, attenuation but not ablation of the neutrophil-driven response increased survival without changing viral spread. These findings establish the primacy of damaging innate inflammation in at least some forms of influenza-induced lethality and provide a roadmap for the systematic dissection of infection-associated pathology.
2013-07-03 | GSE42638 | GEO
Project description:A Top-down Systems Analysis Identifies an Innate Feed-forward Inflammatory Circuit Leading to Lethal Influenza Infection
Project description:Transcriptomic comparison of 5 cell types during lethal and non-lethal influenza infection and further use of these signatures in a top-down systems analysis investigating the relative pathogenic contributions of direct viral damage to lung epithelium vs. dysregulated immunity during lethal influenza infection. For acutely lethal influenza infections, the relative pathogenic contributions of direct viral damage to lung epithelium vs. dysregulated immunity remain unresolved. Here, we take a top-down systems approach to this question. Multigene transcriptional signatures from infected lungs suggested that elevated activation of inflammatory signaling networks distinguished lethal from sublethal infections. Flow cytometry and gene expression analysis involving isolated cell subpopulations from infected lungs showed that neutrophil influx largely accounted for the predictive transcriptional signature. Automated imaging analysis together with these gene expression and flow data identified a chemokine-driven feed-forward circuit involving pro-inflammatory neutrophils potently driven by poorly contained lethal viruses. Consistent with these data, attenuation but not ablation of the neutrophil-driven response increased survival without changing viral spread. These findings establish the primacy of damaging innate inflammation in at least some forms of influenza-induced lethality and provide a roadmap for the systematic dissection of infection-associated pathology. Multiple mice were either sham infected, infected with the seasonal H1N1 influenza A virus TX91 (10^6PFU), or infected with various sublethal or lethal doses of the mouse pathogenic H1N1 strain PR8. Lung tissues were collected at 48h or 72h post infection. 5 different cell types were purified by flow sorting from lungs of individual animals and then processed to yield total RNA that was used for microarray analysis. The dataset contains 75 microarrays covering 25 experimental conditions with 3 biological replicates. This dataset is linked to a dataset containing 138 microarrays of whole lungs covering 20 experimental conditions.
Project description:We report that cells infected with the prototypic arenavirus LCMV are continiously cleared from the infection in a non-cytolytic manner. Non-cytolytic clearance of murine hepatocytes goes along with profound alterations in gene expression.
Project description:Identification of biological processes that distinguish lethal from non-lethal influenza infection and further use of these signatures in a top-down systems analysis investigating the relative pathogenic contributions of direct viral damage to lung epithelium vs. dysregulated immunity to during lethal influenza infection. For acutely lethal influenza infections, the relative pathogenic contributions of direct viral damage to lung epithelium vs. dysregulated immunity remain unresolved. Here, we take a top-down systems approach to this question. Multigene transcriptional signatures from infected lungs suggested that elevated activation of inflammatory signaling networks distinguished lethal from sublethal infections. Flow cytometry and gene expression analysis involving isolated cell subpopulations from infected lungs showed that neutrophil influx largely accounted for the predictive transcriptional signature. Automated imaging analysis together with these gene expression and flow data identified a chemokine-driven feed-forward circuit involving pro-inflammatory neutrophils potently driven by poorly contained lethal viruses. Consistent with these data, attenuation but not ablation of the neutrophil-driven response increased survival without changing viral spread. These findings establish the primacy of damaging innate inflammation in at least some forms of influenza-induced lethality and provide a roadmap for the systematic dissection of infection-associated pathology. Multiple mice were either sham infected, infected with the seasonal H1N1 influenza A virus TX91 (10^6PFU), or infected with various sublethal or lethal doses of the mouse pathogenic H1N1 strain PR8. Lung tissues were collected at various time points (24h, 48h, 72h and 240h post infection) and processed to yield whole lung RNA that was used for microarray analysis. The dataset contains 138 microarrays covering 20 experimental conditions with 7 biological replicates each. As an exception, the alternative non-infectious control condition (Alum treatment) contains 5 biological replicates. This dataset is linked to a dataset comparing the transcriptomes of 5 different cell types isolated from individual lungs of influenza A-infected or control animals (contains 75 microarrays covering 25 experimental conditions).
Project description:Unbiased forward genetic screens to identify host factors for DENV1 and JEV in 293FT cells. Unbiased forward genetic screens to identify host factors for HCoV-229E in Huh7.5.1 cells.