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).
Project description:Himanshu Manchanda, Nora Seidel, Andi Krumbholz, Andreas Sauerbrei, Michaela Schmidtke & Reinhard Guthke. Within-host influenza dynamics: a small-scale mathematical modeling approach. Biosystems 118 (2014).
The emergence of new influenza viruses like the pandemic H1N1 influenza A virus in 2009 (A(H1N1)pdm09) with unpredictable difficulties in vaccine coverage and established antiviral treatment protocols emphasizes the need of new murine models to prove the activity of novel antiviral compounds in vivo. The aim of the present study was to develop a small-scale mathematical model based on easily attainable experimental data to explain differences in influenza kinetics induced by different virus strains in mice. To develop a three-dimensional ordinary differential equation model of influenza dynamics, the following variables were included: (i) viral pathogenicity (P), (ii) antiviral immune defense (D), and (iii) inflammation due to pro-inflammatory response (I). Influenza virus-induced symptoms (clinical score S) in mice provided the basis for calculations of P and I. Both, mono- and biphasic course of mild to severe influenza induced by three clinical A(H1N1)pdm09 strains and one European swine H1N2 virus were comparatively and quantitatively studied by fitting the mathematical model to the experimental data. The model hypothesizes reasons for mild and severe influenza with mono- as well as biphasic course of disease. According to modeling results, the second peak of the biphasic course of infection is caused by inflammation. The parameters (i) maximum primary pathogenicity, (ii) viral infection rate, and (iii) rate of activation of the immune system represent most important parameters that quantitatively characterize the different pattern of virus-specific influenza kinetics.
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:In this work we generated a no-letal mice model infected with pandemic H1N1 virus in order to study the mechanisms implicated in the resolution of uncomplicated pneumonia by using gene expression profiles of lung tissues.
Project description:To study the effects of secondary bacterial infection during 1918 pandemic H1N1 influenza virus infection, BALB/c mice were inoculated with the fully reconstructed 1918 influenza virus followed by inoculation with pneumococcus 72h later. To study the effects of secondary bacterial infection during 1918 pandemic H1N1 influenza virus infection, BALB/c mice were inoculated with the fully reconstructed 1918 influenza virus followed by inoculation with pneumococcus 72h later.
Project description:Modulating the host response is a promising approach to treating influenza, a virus whose pathogenesis is determined in part by the host response it elicits. Though the pathogenicity of emerging H7N9 influenza virus has been reported in several animal models, these studies have not included a detailed characterization of the host response following infection. To this end, we characterized the transcriptomic response of BALB/c mice infected with H7N9 (A/Anhui/1/2013) virus and compared it to the responses induced by H5N1 (A/Vietnam/1203/2004), H7N7 (A/Netherlands/219/2003) or H1N1 (A/Mexico/4482/2009) viruses. We found that responses to the H7 subtype viruses were intermediate to those elicited by H5N1 and H1N1 early in infection, but that they evolved to resemble the H5N1 response as infection progressed. H5N1, H7N7 and H7N9 viruses were pathogenic in mice, and this pathogenicity correlated with increased cytokine response, decreased lipid metabolism and decreased coagulation signaling. This three-pronged signature has previously been observed in mice infected with pathogenic H1N1 strains such as the 1918 virus, indicating that it may be predictive of pathogenicity across multiple influenza strains. Groups of 6- to 8-week-old BALB/c mice were infected with either A/Anhui/01/2013 (H7N9), A/Netherlands/219/2003 (H7N7), A/Vietnam/1203/2004 (H5N1), or pandemic H1N1 human virus, A/Mexico/4482/2007 (H1N1). Infections were done at 10^5 PFU or time-matched mock infected. Time points were 1, 3 and 5 d.p.i. There were 4-5 infected and 3 mock infected animals/time point. Lung samples were collected for virus load and transcriptional analysis. Weight loss and animal survival were also monitored.
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: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 whole blood leukocytes from normal, uninfected mice of both age groups.
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.