Project description:Due to the RNA nature of their genomes, influenza viruses have to utilize many RNA-binding proteins (RBPs) of both viral and host origin, for their replication. To uncover the comprehensive vRNA-host protein interactions, we performed affinity purification coupled with mass spectrometry (AP-MS) analysis of influenza vRNA complexes. The eight vRNA segments of H7N9 were transcribed and individually labeled with biotin in vitro and incubated with IAV virus-infected THP-1 cells, and vRNA complexes were enriched streptavidin magnetic beads and analyzed by mass spectrometry
Project description:we identify gene expression patterns associated with three distinct phases (Infiltrating, Early Inflammatory, Late Inflammatory) in the influenza A virus response of recruited alveolar macrophages. In the Early Inflammatory phase, recruited macrophages begin expressing pro-inflammatory genes, driving cytokine-mediated lung damage and contributing to the morbidity observed in influenza-infected wild-type mice. In mice lacking vimentin (Vim-/-), genes associated with the Early Inflammatory phase are suppressed, while the expression of the Infiltrating Phase genes is maintained, which is associated with protection from influenza-induced injury. Using a bone-marrow chimera mouse model, we validate that Vim-/- recruited alveolar macrophages are sufficient to confer protection from influenza-induced mortality. Our results define the temporal dynamics of gene expression in recruited alveolar macrophages, which shape the host response to infection with respiratory viruses.
Project description:We defined the major transcriptional responses in primary human bronchial epithelial cells (HBECs) after either infection with influenza or treatment with relevant ligands. We used four different strategies, each highlighting distinct aspects of the response. (1) cells were infected with the wild-type PR8 influenza virus that can mount a complete replicative cycle. (2) cells were transfected with viral RNA (âvRNAâ) isolated from influenza particles. This does not result in the production of viral proteins or particles and identifies the effect of RNA-sensing pathways (e.g., RIG-I.). (3) Cells were treated with interferon beta (IFNb), to distinguish the portion of the response which is mediated through Type I IFNs. (4) Cells were infected with a PR8 virus lacking the NS1 gene (âDNS1â). The NS1 protein normally inhibits vRNA- or IFNb-induced pathways, and its deletion can reveal an expanded response to infection. HBECs were stimulated with a 15 minute pulse of 1000U/ml IFNÃ (PBL, Piscataway, NJ), 100ng/ml vRNA (purified directly from PR8 virus) with LTX transfection reagent (Invitrogen; Carlsbad, California), wild type H1N1 influenza (A/PR/8/34) or ?NS1 virus (PR8 with a deleted NS1 gene, gift from Dr. Garcia-Sastre). Viruses were used at a multiplicity of infection (moi) of 5. Control samples were incubated with media or LTX under the same conditions. Cells were washed, supplemented with warm media and harvested at 11 timepoints (0, .25, .5, 1, 1.5, 2, 4, 6, 8, 12, and 18 hours post-treatment). HBECs were seeded in 6 well plates at a concentration of 250,000/well 18 hours prior to stimultaion. Cells were stimulated with a 15 minute pulse of IFNb, vRNA, infected with PR8 influenza or NS1 deleted influenza, or mock treated
Project description:We defined the major transcriptional responses in primary human bronchial epithelial cells (HBECs) after either infection with influenza or treatment with relevant ligands. We used four different strategies, each highlighting distinct aspects of the response. (1) cells were infected with the wild-type PR8 influenza virus that can mount a complete replicative cycle. (2) cells were transfected with viral RNA (‘vRNA’) isolated from influenza particles. This does not result in the production of viral proteins or particles and identifies the effect of RNA-sensing pathways (e.g., RIG-I.). (3) Cells were treated with interferon beta (IFNb), to distinguish the portion of the response which is mediated through Type I IFNs. (4) Cells were infected with a PR8 virus lacking the NS1 gene (‘DNS1’). The NS1 protein normally inhibits vRNA- or IFNb-induced pathways, and its deletion can reveal an expanded response to infection.
Project description:Macrophages were infected with low (PR8) and high pathogenic influenza viruses (FPV and H5N1). To our surprise a genome-wide comparative systems biology approach revealed that in contrast PR8 infections with HPAIV H5N1 and FPV result in a reduced immune response of human macrophages contradicting a primary role of this cell type for the cytokine storm. Our data point to a viral strategy of HPAIV to bypass a major amplifier of the initial local inflammatory response thereby hampering antiviral effector mechanisms and facilitating virus spreading and systemic disease. Macrophages were infected with low (PR8) and high pathogenic influenza viruses (FPV and H5N1)
Project description:Analysis of gene expression in human macrophages infected with influenza A viruses expressing full length or truncated NS1 protein. The hypothesis tested was that C-terminal truncations of viral NS1 protein attenuate the capability of NS1 to limit activation of host antiviral and immune response genes. Cells were infected with influenza A/WSN/33 viruses expressing wild type NS1 protein (WSN-230), NS1 protein of 220 aa long (WSN-220) and NS1 protein of 202 aa long (WSN-202) on non-infected (Mock) Total RNA isolated from macrophages after 8 hours of infection with wild type or mutant influenza A virus (multiplicity of infection = 2)
Project description:Persistent HIV-1 reservoirs of infected CD4 T-cells are a major barrier to HIV-1 cure, though the mechanisms by which they are established and maintained in vivo remain poorly characterized. To study host properties that govern productive cellular infection, we analyzed viral mRNA+ (vRNA) CD4 T-cells of untreated SIV-infected macaques by single-cell RNAseq. Transcriptionally active infected cells, defined by spliced vRNA, were highly enriched for vRNA: 10.3% and 7.5% of all mRNA in two animals. These cells expressed diminished FOS, a component of the Activator protein 1 (AP-1) transcription factor, relative to vRNA-low and -negative cells.
Project description:Assembly of infectious influenza A viruses (IAV) is a complex process involving transport from the nucleus to the plasma membrane. Rab11A containing recycling endosomes have been identified as a platform for intracellular transport of viral RNA (vRNA). Using high spatiotemporal resolution light-sheet microscopy (~1.4 volumes/s, 330 nm isotropic spatial resolution), we quantify Rab11A and vRNA movement in live cells during IAV infection. Here we report that IAV infection decreases speed and increases arrest of Rab11A. Unexpectedly, infection with RSV alters Rab11A motion in a manner opposite to IAV, suggesting that Rab11A is a common host component that is differentially manipulated by respiratory RNA viruses. Using two-color imaging we demonstrate co-transport between Rab11A and IAV vRNA in infected cells and provide direct evidence that vRNA-associated Rab11A have altered transport. The mechanism of altered Rab11A movement is likely related to a decrease in dynein motors bound to Rab11A vesicles during IAV infection.
Project description:Analysis of gene expression in human macrophages infected with influenza A viruses expressing full length or truncated NS1 protein. The hypothesis tested was that C-terminal truncations of viral NS1 protein attenuate the capability of NS1 to limit activation of host antiviral and immune response genes. Cells were infected with influenza A/WSN/33 viruses expressing wild type NS1 protein (WSN-230), NS1 protein of 220 aa long (WSN-220) and NS1 protein of 202 aa long (WSN-202) on non-infected (Mock)
Project description:We used the microarray data to analyse the host cell responses on mouse macrophages infected with the three Influenza A viruses The global expression analysis showed increased expression changes in H5N3 infected mouse macrophages compared to H5N2/F118 and H1N1/WSN