Project description:Mouse lung tissue transcriptome response to a wild type infectious clone of H7N9 Influenza virus and mutant H7N9 viruses [microRNA]
Project description:A novel avian-origin H7N9 influenza A virus (IAV) emerged in China in early 2013 causing mild to lethal human respiratory infections. H7N9 originated from multiple reassortment events between avian viruses and carries genetic markers of human adaptation. Determining whether H7N9 induces a host-response closer to human or avian IAV is important to better characterize this emerging virus. Here we compared the human lung epithelial cell response to infection with A/Anhui/01/13 (H7N9) or highly pathogenic avian-origin H5N1, H7N7, or human seasonal H3N2 IAV.
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:The purpose is to obtain samples for mRNA, miRNA, proteomics, lipidomics, metabolomics, and histopathology analysis in mouse lung infected with WT A/Anhui/1/2013 (H7N9; 'AH1'), AH - NS1-103F/106M, and AH1 - 691 (ferret adapted virus). Groups of 22-week-old C57BL/6 mice were infected with the H7N9 Influenza WT A/Anhui/1/2013 (H7N9; 'AH1'), AH - NS1-103F/106M, and AH1 - 691 (ferret adapted virus). Infections were done at 10^4 PFU or time-matched mock infected. Time points were 1, 2, 4 and 7 d.p.i. There were 5 animals/dose/time point. Lung samples were collected for virus load, transcriptional and proteomics analysis. Weight loss and animal survival were also monitored.
Project description:The purpose is to obtain samples for mRNA, miRNA, proteomics, lipidomics, metabolomics, and histopathology analysis in mouse lung infected with WT A/Anhui/1/2013 (H7N9; 'AH1'), AH - NS1-103F/106M, and AH1 - 691 (ferret adapted virus). Groups of 22-week-old C57BL/6 mice were infected with the H7N9 Influenza WT A/Anhui/1/2013 (H7N9; 'AH1'), AH - NS1-103F/106M, and AH1 - 691 (ferret adapted virus). Infections were done at 10^4 PFU or time-matched mock infected. Time points were 1, 2, 4 and 7 d.p.i. There were 5 animals/dose/time point. Lung samples were collected for virus load, transcriptional and proteomics analysis. Weight loss and animal survival were also monitored.
Project description:A novel avian-origin H7N9 influenza A virus (IAV) emerged in China in early 2013 causing mild to lethal human respiratory infections. H7N9 originated from multiple reassortment events between avian viruses and carries genetic markers of human adaptation. Determining whether H7N9 induces a host-response closer to human or avian IAV is important to better characterize this emerging virus. Here we compared the human lung epithelial cell response to infection with A/Anhui/01/13 (H7N9) or highly pathogenic avian-origin H5N1, H7N7, or human seasonal H3N2 IAV. Here, polarized confluent monolayers of Calu-3 cells were infected apically with the avian-origin IAVs A/Anhui/01/2013 (H7N9) [Anhui01], A/Netherland/219/2003 (H7N7) [NL219], A/Vietnam/1203/2004 (H5N1) [VN1203], or a human seasonal virus A/Panama/2007/1999 (H3N2) [Pan99] at an MOI of 1. Time-matched mocks were also included using the same cell stock as the rest of the samples. Culture medium (same as what the virus stock is in) was used for the mock infections. Quadruplicate wells were infected for each virus/timepoint. Measured timepoints were 3, 7, 12 and 24 hours post-inoculation and the RNA was used for transcriptional analysis via microarray.
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.
Project description:Gene transcription effects of mutations in the infuenza virus A/Hong Kong/1/1968(H3N2) nonstructural 1 NS1 gene in infected human A549 (lung epithilium) cells Influenza A/Hong Kong/156/1997(H5N1) virus NS1 gene mutations F103L and M106I both increase IFN antagonism, virulence and cytoplasmic localization but differ in binding to RIG-I and CPSF30 (manuscript submitted to Virology Journal). Human cells were infected with influenza viruses mutants with specific gain of function mutations in the NS1 gene in order to assess the affects of each mutation on host gene expression. Human (A549) and mouse (M1) cells were infected at a multiplicity of infection of 2 (infectious viruses/cell) and incubated for 8 hr before collection of total RNA and microarray anlaysis using the Affymetrix platforms. Samples were compared in triplicate to mock PBS infected (uninfected) cells to detecte dysregulated genes for A/HK/1/1968(H3N2) wt, and the following NS1 gene mutants: F103L, M106I, M106V, and F103L + M106I. Background: The genetic basis for avian to mammalian host switching in influenza A virus is largely unknown. The human A/HK/156/1997(H5N1) virus that transmitted from poultry possesses NS1 gene mutations F103L + M106I that are virulence determinants in the mouse model of pneumonia; however their individual roles have not been determined. The emergent A/Shanghai/1/2013(H7N9)-like viruses also possess these mutations which may contribute to their virulence and ability to switch species. Methods: NS1 mutant viruses were constructed by reverse genetics and site directed mutagenesis on human and mouse-adapted backbones. Mouse infections assessed virulence, virus yield, tissue infection, and IFN induction. NS1 protein proprieties were assessed for subcellular distribution, IFN antagonism (mouse and human), CPSF30 and RIG-I domain binding, effect on host gene transcription (microarray); and the natural prevalence of 103L and 106I mutants was assessed. Results: Each of the F103L and M106I mutations contributes additively to virulence to reduce the lethal dose by >800 and >3,200 fold respectively by mediating alveolar tissue infection with >100 fold increased infectious yields. The 106I NS1 mutant lost CPSF binding but the 103L mutant maintained binding that correlated with an increased general decrease in host gene expression in human but not mouse cells. Each mutation positively modulated the inhibition of IFN induction in mouse cells and activation of the IFN-M-NM-2 promoter in human cells but not in combination in human cells indicating negative epistasis. Each of the F103L and M106I mutations restored a defect in cytoplasmic localization of H5N1 NS1 in mouse cells. Human H1N1 and H3N2 NS1 proteins bound to the CARD, helicase and RD RIG-I domains, whereas the H5N1 NS1 with the same consensus 103F and 106M mutations did not bind these domains, which was partially or totally restored by the F103L or M106I mutations respectively. Conclusions: The F103L and M106I mutations in the H5N1 NS1 protein each increased IFN antagonism and mediated interstitial pneumonia in mice that was associated with increased cytoplasmic localization and altered host factor binding. These mutations may contribute to the ability of previous HPAI H5N1 and recent LPAI H7N9 viruses to switch hosts and cause severe disease in mammals. Triplicate biological replicates of mock PBS treated (uninfected) cells to detecte dysregulated genes for A/HK/1/1968(H3N2) wt, and the following NS1 gene mutants: F103L, M106I, M106V, and F103L + M106I. Cells were infected at a multiplicty of infection of 2 and cells were incubated for 8 hr at 37 C for 8 hrs before RNA extraction and analysis of 3 biological replicates relative to mock PBS infected cells.