Cell Biology & Molecular Genetics
Permanent URI for this communityhttp://hdl.handle.net/1903/11811
Browse
2 results
Search Results
Item MUCIN-MEDIATED AND INTERFERON-DRIVEN DEFENSE MECHANISMS AGAINST INFLUENZA VIRUS INFECTION IN HUMAN AIRWAY EPITHELIUM(2022) Iverson, Ethan; Scull, Margaret A; Cell Biology & Molecular Genetics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The human airway epithelium represents the primary site of infection for many respiratory viruses, including influenza A virus (IAV). To safeguard this tissue and maintain the functionality of the lung, humans possess a two-layer, extracellular, mucus barrier composed predominantly of individual proteins termed mucins. Additionally, underlying epithelial cells produce interferons upon virus detection that promote the establishment of a local antiviral state through autocrine and paracrine signaling. However, despite these protective measures, IAV continues to cause significant annual morbidity and mortality across the globe. Therefore, we sought to further investigate how specific mucin molecules interact with IAV, and how interferon drives intrinsic antiviral defense in the context of a human airway epithelial (HAE) culture system. By utilizing fluorescently-labeled influenza virus particles we further elucidate the adhesive interactions between mucus and influenza virus while also detailing, for the first time, real-time IAV diffusivity within patient-derived mucus samples. These results reveal that the polymeric structure of mucus greatly influences the mobility of IAV within human secreted mucus. Additionally, we investigate the interaction between influenza virus and tethered mucin 1 (MUC1), finding that MUC1 expression is enhanced by virus-driven inflammation and interferon signaling. Moreover, by establishing a genetically-tractable airway epithelial model, we detail the protective role MUC1 plays in preventing the initial establishment and spread of influenza virus in HAE. Specifically, we find that the loss of MUC1 significantly enhances IAV uptake and spread. Finally, we observe that the directionality of IFN exposure at airway epithelial surfaces impacts the magnitude of protection against IAV and SARS-CoV-2. We then detail the cellular composition of our HAE culture system and define a shared IFN response profile across all HAE component cell types as well as cell type-specific interferon stimulated genes. Together our work provides novel insight into the innate and intrinsic anti-viral properties of the human airway epithelium.Item REASSORTMENT AND GENE SELECTION OF INFLUENZA VIRUSES IN THE FERRET MODEL AND POTENTIAL PLATFORMS FOR IN VIVO REVERSE GENETICS(2014) Angel, Matthew Gray; Perez, Daniel R; Cell Biology & Molecular Genetics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Influenza A virus is a highly infectious agent that cause seasonal epidemics affecting 5-15% of the world population with mild to severe illness and possibly death. While this pathogen represents a significant disease burden to the human population, it can also infect a wide range of animals including swine and land-based poultry, which are thought to serve as intermediate hosts between the human and natural wild aquatic bird reservoir. Here, two viruses, a swine-origin pandemic H1N1 and a seasonal human H3N2 are examined for segment fitness during co-infection of in vivo animal models. In three independent co-infections, reassortment between seasonal and pandemic viruses resulted in the selection of an H1N2 virus with a seasonal PB1 with an otherwise pandemic internal gene constellation. Selection for the seasonal PB1 and NA as well as the pandemic M segment was observed to occur rapidly during segment resolution. As pandemic M gene reassortant strains are being consistently identified in the field, studies were performed to identify the genetic determinants in pandemic M gene selection. Research here shows that both the M1 capsid protein and M2 ion channel from the pandemic virus are sufficient to drive the selection of the entire M segment. As swine represent an important intermediate host for the adaptation of potentially pandemic viruses, including pandemic M gene reassortant strains, alternative DNA and recombinant baculovirus-based platforms are investigated for their ability to generate influenza viruses from porcine polymerase I promoters and serve as potential vaccine candidates. Research here shows that influenza A virus can be rescued de novo using the porcine polymerase I promoter in an eight plasmid system. Furthermore, a single bacmid can be constructed that rescues influenza virus or baculovirus encoding the influenza reverse genetic system in mammalian tissue culture or Sf9 cells, respectively. These represent a new generation of species-tailored vaccine platforms.