Browsing by Author "Tilston-Lunel, Natasha L."

Now showing 1 - 4 of 4
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    FeMV is a cathepsin-dependent unique morbillivirus infecting the kidneys of domestic cats
    (National Academy of Sciences, 2022) Nambulli, Sham; Rennick, Linda J.; Acciardo, Andrew S.; Tilston-Lunel, Natasha L.; Ho, Gregory; Crossland, Nicholas A.; Hardcastle, Kathy; Nieto, Betsy; Bainbridge, Graeme; Williams, Tracey; Sharp, Claire R.; Duprex, W. Paul; Microbiology and Immunology, School of Medicine
    Feline morbillivirus (FeMV) has been classified as a morbillivirus despite lacking several biological features shared by all other known viruses in the genus. We confirm that FeMV uses CD150 as a cellular receptor and employs a different protease to furin to process the fusion glycoprotein. As such, FeMV may represent an important evolutionary intermediate between morbilliviruses and the zoonotic henipaviruses. Feline chronic kidney disease is the leading cause of morbidity and mortality in cats and has no clear etiology. FeMV has been postulated to be a causative agent. We dissected FeMV pathogenesis using recombinant, fluorescent protein expressing viruses based on an unpassaged clinical isolate. This sheds light on the primary target cells infected and possible mechanisms of host-to-host transmission.
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    Inhalable Nanobody (PiN-21) prevents and treats SARS-CoV-2 infections in Syrian hamsters at ultra-low doses
    (American Association for the Advancement of Science, 2021-05-26) Nambulli, Sham; Xiang, Yufei; Tilston-Lunel, Natasha L.; Rennick, Linda J.; Sang, Zhe; Klimstra, William B.; Reed, Douglas S.; Crossland, Nicholas A.; Shi, Yi; Duprex, W. Paul; Microbiology and Immunology, School of Medicine
    Globally, there is an urgency to develop effective, low-cost therapeutic interventions for coronavirus disease 2019 (COVID-19). We previously generated the stable and ultrapotent homotrimeric Pittsburgh inhalable Nanobody 21 (PiN-21). Using Syrian hamsters that model moderate to severe COVID-19 disease, we demonstrate the high efficacy of PiN-21 to prevent and treat SARS-CoV-2 infection. Intranasal delivery of PiN-21 at 0.6 mg/kg protects infected animals from weight loss and substantially reduces viral burdens in both lower and upper airways compared to control. Aerosol delivery of PiN-21 facilitates deposition throughout the respiratory tract and dose minimization to 0.2 mg/kg. Inhalation treatment quickly reverses animals' weight loss after infection, decreases lung viral titers by 6 logs leading to drastically mitigated lung pathology, and prevents viral pneumonia. Combined with the marked stability and low production cost, this innovative therapy may provide a convenient and cost-effective option to mitigate the ongoing pandemic.
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    Sustained Replication of Synthetic Canine Distemper Virus Defective Genomes In Vitro and In Vivo
    (American Society for Microbiology, 2021) Tilston-Lunel, Natasha L.; Welch, Stephen R.; Nambulli, Sham; de Vries, Rory D.; Ho, Gregory W.; Wentworth, David E.; Shabman, Reed; Nichol, Stuart T.; Spiropoulou, Christina F.; de Swart, Rik L.; Rennick, Linda J.; Duprex, W. Paul; Microbiology and Immunology, School of Medicine
    Defective interfering (DI) genomes restrict viral replication and induce type I interferon. Since DI genomes have been proposed as vaccine adjuvants or therapeutic antiviral agents, it is important to understand their generation, delineate their mechanism of action, develop robust production capacities, assess their safety and in vivo longevity, and determine their long-term effects. To address this, we generated a recombinant canine distemper virus (rCDV) from an entirely synthetic molecular clone designed using the genomic sequence from a clinical isolate obtained from a free-ranging raccoon with distemper. rCDV was serially passaged in vitro to identify DI genomes that naturally arise during rCDV replication. Defective genomes were identified by Sanger and next-generation sequencing techniques, and predominant genomes were synthetically generated and cloned into T7-driven plasmids. Fully encapsidated DI particles (DIPs) were then generated using a rationally attenuated rCDV as a producer virus to drive DI genome replication. We demonstrate that these DIPs interfere with rCDV replication in a dose-dependent manner in vitro. Finally, we show sustained replication of a fluorescent DIP in experimentally infected ferrets over a period of 14 days. Most importantly, DIPs were isolated from the lymphoid tissues, which are a major site of CDV replication. Our established pipeline for detection, generation, and assaying DIPs is transferable to highly pathogenic paramyxoviruses and will allow qualitative and quantitative assessment of the therapeutic effects of DIP administration on disease outcome. IMPORTANCE: Defective interfering (DI) genomes have long been considered inconvenient artifacts that suppressed viral replication in vitro. However, advances in sequencing technologies have led to DI genomes being identified in clinical samples, implicating them in disease progression and outcome. It has been suggested that DI genomes might be harnessed therapeutically. Negative-strand RNA virus research has provided a rich pool of natural DI genomes over many years, and they are probably the best understood in vitro. Here, we demonstrate the identification, synthesis, production, and experimental inoculation of novel CDV DI genomes in highly susceptible ferrets. These results provide important evidence that rationally designed and packaged DI genomes can survive the course of a wild-type virus infection.
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    Type-2 diabetes mellitus enhances Klebsiella pneumoniae pathogenesis
    (bioRxiv, 2024-05-31) Todd, Katlyn; Gunter, Krista; Bowen, James M.; Holmes, Caitlyn L.; Tilston-Lunel, Natasha L.; Vornhagen, Jay; Microbiology and Immunology, School of Medicine
    Klebsiella pneumoniae is an opportunistic pathogen and an important cause of pneumonia, bacteremia, and urinary tract infection. K. pneumoniae infections are historically associated with diabetes mellitus. There is a fundamental gap in our understanding of how diabetes mellitus, specifically type 2 diabetes, influences K. pneumoniae pathogenesis. K. pneumoniae pathogenesis is a multifactorial process that often begins with gut colonization, followed by an escape from the gut to peripheral sites, leading to host damage and infection. We hypothesized that type 2 diabetes enhances K. pneumoniae pathogenesis. To test this, we used well-established mouse models of K. pneumoniae colonization and lung infection in conjunction with a mouse model of spontaneous type 2 diabetes mellitus (T2DM). We show that T2DM enhances susceptibility to both K. pneumoniae colonization and infection. The enhancement of gut colonization is dependent on T2DM-induced modulation of the gut microbiota community structure. In contrast, lung infection is exacerbated by the increased availability of amino acids in the lung, which is associated with higher levels of vascular endothelial growth factor. These data lay the foundation for mechanistic interrogation of the relationship between K. pneumoniae pathogenesis and type 2 diabetes mellitus, and explicitly establish T2DM as a risk factor for K. pneumoniae disease.