Theses and Dissertations at Montana State University (MSU)
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Item The role of mast cells during influenza A virus infection(Montana State University - Bozeman, College of Letters & Sciences, 2015) Graham, Amy Catherine; Chairperson, Graduate Committee: Josh Obar; Rachel M. Temple and Joshua J. Obar were co-authors of the article, 'Mast cells and influenza A virus: association with allergic responses and beyond' submitted to the journal 'Frontiers in immunology' which is contained within this thesis.; Kimberly M. Hilmer, Julianne M. Zickovich and Joshua J. Obar were co-authors of the article, 'Inflammatory response of mast cells during influenza A virus infection is mediated by active infection and RIG-I signaling' in the journal 'The journal of immunology' which is contained within this thesis.; Julianne M. Zickovich, Kimberly M. Hilmer and Joshua J. Obar were co-authors of the article, 'Differential role of influenza A virus binding preference in mast cell activation' submitted to the journal 'The journal of virology' which is contained within this thesis.Influenza A virus (IAV) is a major cause of seasonal viral respiratory infections and causes ~36,000 deaths and ~1.7 million hospitalizations each year in the United States alone. Moreover, IAV has the potential to cause global pandemics, which have significantly greater morbidity and mortality. Morbidity and mortality associated with IAV infections is thought to be the result of significant pulmonary immunopathology from the inflammatory response rather than viral replication. The initial lines of defense against pathogens in the lungs include alveolar epithelial cells, endothelial cells, tissue resident alveolar macrophages, dendritic cells, and mast cells. Additionally, recruitment of neutrophils and macrophages is required for optimal clearance of IAV. Recent global analysis of lungs from mice infected with highly pathological IAV strains demonstrated enrichment of a mast cell transcriptional response, but the role of mast cells during severe pulmonary viral infections has been under studied. We found that A/WSN/33 causes significant immunopathology in C57Bl/6 mice and viral-induced pathology is mast cell-dependent. A/WSN/33 is able to directly activate bone marrow cultured mast cells (BMCMC) to produce histamine, leukotrienes, inflammatory cytokines, and anti-viral chemokines. Moreover, human H1N1, H3N2, and influenza B virus isolates can activate murine BMCMC in vitro suggesting this pathway could play a role during human infections. BMCMC activation requires infection of mast cells by IAV, which is dependent on the viral hemagglutinin specificity for alpha2,6-linked sialic acids. Cytokine and chemokine production from BMCMC occurs in a RIG-I-dependent fashion that requires the de novo production of vRNA. Conversely, degranulation occurs through a RIG-I-independent mechanism. Reconstitution of mast cell deficient mice with RIG-I -/- BMCMC generates lung pathology similar to wild-type BMCMC, suggesting that mast cell degranulation, rather than production of cytokines, causes A/WSN/33 induced lung pathology. Using recombinant A/WSN/33 strains, we found an association between binding of the A/WSN/33 hemagglutinin to alpha2,6-sialic acids and subsequent interactions with neuraminidase is important for degranulation. Thus, we have identified a unique inflammatory cascade that could be therapeutically targeted to limit morbidity following infection with IAV.Item Insights into the reciprocal communication between Neutrophils and Staphylococcus aureus(Montana State University - Bozeman, College of Letters & Science, 2015) Zurek, Oliwia Wiktoria; Chairperson, Graduate Committee: Jovanka Voyich-Kane; Tyler K. Nygaard, Robert L. Watkins, Kyler B. Pallister, Victor J. Torres, Alexander R. Horswill and Jovanka M. Voyich were co-authors of the article, 'The role of innate immunity in promoting SAER/S-mediated virulence in Staphylococcus aureus' in the journal 'Journal of innate immunity' which is contained within this thesis.; Kyler B. Pallister and Jovanka M. Voyich were co-authors of the article, 'Staphylococcus aureus inhibits neutrophil-derived IL-8 to promote cell death' in the journal 'Journal of Infectious Diseases' which is contained within this thesis.Staphylococcus aureus (S. aureus) is a highly adaptable pathogen that can cause endocarditis, skin abscesses, tissue necrosis, and sepsis. S. aureus success can be partially attributed to its ability to colonize and subsequently infect a wide variety of host tissues. This capacity is dependent on elaborate two-component gene-regulatory systems that control expression of virulence and immunomodulatory factors. The S. aureus exoprotein expression (SaeR/S) system is recognized as a major regulator of virulence that significantly contributes to the pathogen's ability to evade killing by the human neutrophil. However, it is unclear how this system becomes activated and how the SaeR/S system modulates neutrophil function. In this study, we elucidated how S. aureus evades neutrophil killing by studying the reciprocal communication between the host and pathogen. We demonstrated that only select SaeR/S-regulated genes (as opposed to all targets) were transcriptionally up-regulated in response to stimulation by neutrophils as well as alpha-defensin and show that the mouse skin environment (that lacks alpha-defensin) promoted transcription of specific saeR/S-targets, different from the expression profile elicited following neutrophil interaction or alpha-defensin. These results were unexpected and demonstrated differential activation of saeR/S targets was dependent on specific stimuli. Furthermore, we studied the influence of SaeR/S on neutrophil function and showed that this system promoted accelerated cell death by decreasing NF-kB activity, and in-turn IL- 8 production, to promote neutrophil lysis. These findings underscored the importance of neutrophil signaling demonstrating that neutrophil-derived production of IL-8 was necessary for this cell to kill S. aureus effectively. It follows that treatment of human neutrophils with recombinant IL-8 significantly increased neutrophil staphylocidal activity. Finally, we propose that both timing and magnitude of inflammation in neutrophils play major roles in dictating the outcome of staphylococcal disease and that alteration in the innate ability of neutrophils to produce IL-8 may increase susceptibility to S. aureus infections. Taken together, the findings define novel pathogen- and host-derived factors that play pivotal roles in the course of S. aureus infection.Item Regulation of the immune response to polyvinylpyrrolidone(Montana State University - Bozeman, College of Agriculture, 1977) Lake, Jeffrey PeterItem A critical analysis of bone marrow-spleen cell interaction in the immune response(Montana State University - Bozeman, College of Agriculture, 1970) Sieckmann, Donna GailItem Dark areas and the immune response to the cestode, Hymenolepis diminuta in mice and rats(Montana State University - Bozeman, College of Agriculture, 1978) Larson, Michael AllenItem The influence of lipopolysaccharide (LPS) on cellular activities in LPS-unresponsive C3H/HeJ mice(Montana State University - Bozeman, College of Agriculture, 1976) Rampy, Patricia Anne NelsonItem Adaptive immunity to Chlamydia pneumoniae respiratory infection(Montana State University - Bozeman, College of Agriculture, 2000) Day, Thomas GordonItem The antibody response of congenitally thymusless (nude) mice to thymus-independent antigens(Montana State University - Bozeman, College of Agriculture, 1972) Manning, Judith KleinItem Alteration by Concanavalin A or silica of the immune response of mice to polyvinylpyrrolidone(Montana State University - Bozeman, College of Agriculture, 1978) Bier, Dennis EarlItem Proteomic host response to Toxoplasma gondii strains of distinct viruence phenotypes(Montana State University - Bozeman, College of Letters & Science, 2014) Tanaka, Naomi; Chairperson, Graduate Committee: Sandra HalonenToxoplasma gondii is an obligate intracellular protozoan parasite that can infect all warm-blood animals. In humans, it is estimated that one-third of world's population is infected with T. gondii. Most T. gondii strains can be classified into three genotypes; type I, II and III. Type I strains (e.g. RH) are virulent strains with features of rapid growth. Type II (e.g. Me49) and type III strains (e.g. CTG) are avirulent, with slower growth and more readily form cysts in the brain in the chronic infection. In infected host cells, the parasite modulates the host immune system for their successful replication and dissemination. To investigate the host response to three different virulence phenotypes, we proposed to use a two dimensional-differential gel electrophoresis (2D-DIGE) based proteomic approach. Though preliminary studies, it was concluded that Me49 was not appropriate for this study due to their significantly slower growth rate within 24 hours p.i.. Subsequent studies were then done comparing the type I RH strain vs. the type III CTG strain. Using the RH strain, kinetic analysis of the host cell response to infection was done, analyzing samples at 2, 12 and 24 hours p.i.. Few protein changes were observed at 2 and 12 h p.i., and thus only 24 hours p.i. was analyzed via 2D-DIGE analysis. For 2D-DIGE analysis, quadruplicates of protein extracts were separated in 2DDIGE based on pH and molecular weight. For RH strain, we found a total of 439 protein spots were found to be significantly affected by infection, with 247 spots with increased expression and 187 spots with decreased expression and fold-changes ranging from 0.16 to 13.1. For CTG straina total of 175 protein spots were found with significant expression changes. Among them, 48 spots were increased and 127 were decreased with expression changes ranging between 0.66 and 2.41. Interestingly, many decreased spots were seen in trains of spots indicating these may be due to a post-translational modification such as phosphorylation. For the further studies, the identification of protein spots is necessary to elucidate the interactions between host cell and T. gondii strains of distinct virulence phenotypes.