Project description:C57BL/6J (WT) mice were infected with influenza A virus PR/8/34 or mock infected with phosphate buffered saline (PBS). 18 hours later lung tissue was harvested for transcriptional profiling.
Project description:To further understand the molecular pathogenesis of the 2009 pandemic H1N1 influenza virus infection, we profiled cellular miRNAs of lung tissue from BALB/c mice infected with influenza virus BJ501 and a mouse-adapted influenza virus A/Puerto Rico/8/34 (H1N1)(PR8) as a comparison.
Project description:To further understand the molecular pathogenesis of the 2009 pandemic H1N1 influenza virus infection, we profiled cellular miRNAs of lung tissue from BALB/c mice infected with influenza virus BJ501 and a mouse-adapted influenza virus A/Puerto Rico/8/34 (H1N1)(PR8) as a comparison. Five groups of mice were selected, and three of each group were used to profile the miRNA, two were in case for unqualified RNA extraction. Whole lungs from mice infected by BJ501 or PR8 were harvested on 2,5 days post infection (dpi), and compared with lung samples from 5 uninfected mice.
Project description:Recombinant human plasma gelsolin (rhu-pGSN) improves survival and reduces morbidity of mice infected with influenza. The goal of this study was to investigate the transcriptome profile of lung tissue from infected mice, treated with either rhu-pGSN or vehicle.
Project description:Severe bacterial (pneumococcal) infections are commonly associated with influenza and are significant contributors to the excess morbidity and mortality of influenza. Disruption of lung tissue integrity during influenza participates in bacterial pulmonary colonization and dissemination out of the lungs. Interleukin (IL)-22 has gained considerable interest in anti-inflammatory and anti-infection immunotherapy over the last decade. In the current study, we investigated the effect of exogenous IL-22 delivery on the outcome of bacterial superinfection post-influenza. Our data show that exogenous treatment of influenza-infected mice with recombinant IL-22 reduces bacterial dissemination out of the lungs but is without effect on pulmonary bacterial burden. We describe an IL-22 specific gene signature in the lung tissue of IAV-infected (and naïve) mice that might explain the observed effects. Indeed, exogenous IL-22 modulates gene expression profile in a way suggesting a reinforcement of tissue integrity. Our results open the way to alternative approaches for limiting post-influenza bacterial superinfection, particularly systemic bacterial invasion.
Project description:During the 1918 influenza pandemic, children experienced substantially lower mortality than adults, a striking but poorly understood finding. Whether this was due to enhanced resistance (reduced virus load) or better tolerance (reduced impact of infection) has not been defined. We found that prepubertal mice infected with H1N1 influenza virus also showed greater survival than infected pubertal mice, despite similar virus loads. To explore mechanisms for the survival differences, we compared gene expression profiles in lung tissue from mice of both age groups during the course of influenza pneumonia.
Project description:During the 1918 influenza pandemic, children experienced substantially lower mortality than adults, a striking but poorly understood finding. Whether this was due to enhanced resistance (reduced virus load) or better tolerance (reduced impact of infection) has not been defined. We found that prepubertal mice infected with H1N1 influenza virus also showed greater survival than infected pubertal mice, despite similar virus loads. To explore mechanisms for the survival differences, we compared gene expression profiles in lung tissue from mice of both age groups during the course of influenza pneumonia.
Project description:Periodic outbreaks of highly pathogenic avian H5N1 influenza viruses and the current H1N1 pandemic highlight the need for a more detailed understanding of influenza virus pathogenesis. To investigate the host transcriptional response induced by pathogenic influenza viruses, we used a functional-genomics approach to compare gene expression profiles in lungs from wild-type 129S6/SvEv and interferon receptor (IFNR) knockout mice infected with either the fully reconstructed H1N1 1918 pandemic virus (1918) or the highly pathogenic avian H5N1 virus Vietnam/1203/04 (VN/1203). Eight- to 10-week-old female wild-type and IFNR1-/- mice (on a 129S6/SvEv background) were anesthetized by intraperitoneal injection of 0.2 ml of 2,2,2-tribromoethanol in tert-amylalcohol (Avertin; Sigma-Aldrich, Milwaukee, WI). Ten times the 50% lethal dose (LD50), 3.2 × 10^4 PFU (1918) or 7 × 10^3 PFU (VN/1203), in 50 μl of infectious virus diluted in phosphate-buffered saline (PBS) was inoculated intranasally (i.n.). Lung tissue was harvested for microarray analysis from infected animals at 1, 3, and 4 days post-innoculation. For RNA isolation, lungs were frozen in individual tubes and stored in solution D (4 M guanidinium thiocyanate, 25 mM sodium citrate, 0.5% sarcosyl, 0.1 M β-mercaptoethanol). Separate microarrays were run for each infected mouse. This included 2 animals/time point for 1918 virus-infected mice (24 animals total) or 3 animals/time point for VN/1203-infected mice (36 animals total). Lung tissue from three uninfected wild type 129S6/SvEv mice was collected as a mock control. Equal masses of total RNA from the lung tissue of the three mice were pooled prior to being run on microarray. Two-channel microarrays were used to determine gene expression in the lungs. For each individual infected lung, gene expression from an infected lung was compared to gene expression from the pooled RNA from the mock control.
Project description:Disruption of the lung endothelial-epithelial cell barrier during respiratory virus infection causes cell and fluid accumulation in the air spaces and compromises vital gas exchange function. Endothelial cell dysfunction is known to exacerbate tissue damage; however, it is unclear whether the lung endothelium engages in tissue-protective activity during viral infection. Here we show that the environmental sensor aryl hydrocarbon receptor (AHR) is predominantly active in endothelial cells and protects against influenza-induced lung damage. Endothelial-specific AHR deletion caused increased vascular leakage in air spaces and enhanced influenza-induced lung tissue pathology. Global expression profiling revealed limited AHR-dependent regulation of vessels in the steady-state lung. However, following influenza-induced tissue damage and inflammation, AHR engages tissue-protective programmes in endothelia and prevents a dysplastic keratinised and apoptotic signature in the airways of infected lungs.