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Memory CD8+ T-cells can persist in the absence of antigen, primed for immediate activation and proliferation if later exposed to the same antigen. These cytotoxic lymphocytes provide long-term immunity following an acute infection. Studies have observed that intermediate levels of general T cell transfer prior to infection may cause an inappropriate response resulting in increased pathology rather than prevention. Therefore, our study focused on a memory CD8 T-cell therapy using lymphocytic choriomeningitis virus (LCMV) specific splenocytes, which activate and proliferate at an accelerated pace compared to that of naive T-cells. LCMV is a natural murine pathogen which also poses a zoonotic infection threat to humans, and the effect of immune cell vaccination therapies for LCMV is not fully understood. We observed the effect of multiple memory CD8 T cell dosage levels on overall disease and memory CD8 T-cell response to the virus. Infection by exposure to a carrier was shown to have a reduced impact on mice receiving higher doses of memory T cells prior to infection compared to mice receiving less or no memory cells. Higher presence of activated memory cells were shown to correlate with less disease-related weight loss and accelerated recovery times. Survival rate after exposure to carriers was not shown to be affected by dosage level, warranting further research regarding the prevalence of the immunopathology observed in other studies in natural murine transmission models.
ContributorsMiller, Charles (Author) / Blattman, Joseph (Thesis director) / Holechek, Susan (Committee member) / Carmen, Joshua (Committee member) / W. P. Carey School of Business (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
Pathogens such as lymphocytic choriomeningitis virus (LCMV) cause abnormalities in the nervous system of developing mice and humans. While humans are able to recover from infection and clear the virus, the mouse immune system tolerates the virus and lifelong infection ensues. In order to understand the factors driving LCMV evolution and evaluate its neuropathogenesis, a mouse model was needed. To establish congenital infection, newborn C57BL/6J mice were intra-cerebrally (i.c.) injected with 1 x 103 PFU LCMV Armstrong. Mice failed to thrive, resulting in a linear reduction in survival over the following two weeks and overall survival of 13%. Surviving mice did not have virus in their circulation after thirty days. As an alternative, 500 PFU of LCMV Armstrong was injected intraperitoneally (i.p.) into other litters. While this was associated with significantly reduced mortality, no mice in this group developed persistent infection either. ELISAs revealed that the mothers of injected pups developed a robust humoral response, confirming earlier reports that contact-associated acute infection occurs (Hotchin, 1971). In addition, the offspring of two litters of mice (out of six tested) also had antibodies to the virus, but at slightly lower titers. This indicates that the humoral response of the mothers may play a role in the neonatal clearance of infection. A higher titer of LCMV in i.p. injections may be necessary to overcome these barriers and establish chronic infection. In contrast, a lower dose of LCMV is recommended for i.c. injections, as the mortality seemed directly linked to the effects of the virus on offspring growth and development. Exposure to the virus in utero may also be necessary to increase survival and the likelihood of chronic infection.
ContributorsMorrow, Kristen Nicole (Author) / Blattman, Joseph (Thesis director) / Holechek, Susan (Committee member) / Franco, Lina (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
Agrobacterium tumefaciens has the ability to transfer its tumor inducing (Ti) plasmid into plant cells. In the last decade, agroinfiltration of Nicotiana benthamiana plants has shown promising results for recombinant protein production. However, A. tumefaciens produce endotoxins in the form of lipopolysaccharides (LPS), a component of their outer membrane that can induce organ failure and septic shock. Therefore, we aimed to detoxify A. tumefaciens by modifying their Lipid A structure, the toxic region of LPS, via mutating the genes for lipid A biosynthesis. Two mutant strains of A. tumefaciens were infiltrated into N. benthamiana stems to test for tumor formation to ensure that the detoxifying process did not compromise the ability of gene transfer. Our results demonstrated that A. tumefaciens with both single and double mutations retained the ability to form tumors. Thus, these mutants can be utilized to generate engineered A. tumefaciens strains for the production of plant-based pharmaceuticals with low endotoxicity.
ContributorsHaseefa, Fathima (Author) / Chen, Qiang (Thesis director) / Mason, Hugh (Committee member) / Hurtado, Jonathan (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
Coronaviruses are a significant group of viruses that cause enteric and respiratory infections in a variety of animals, including humans. Outbreaks of Severe Acute Respiratory Syndrome (SARS) and Middle Eastern Respiratory Syndrome (MERS) in the past 15 years has increased research into coronaviruses to gain an understanding of their structure and function so one day therapies and vaccines may be produced. These viruses have four main structural proteins: the spike, nucleocapsid, envelope, and membrane proteins. The envelope (E) protein is an integral membrane protein in the viral envelope that acts as a viroporin for transport of cations and plays an important role in pathogenesis and viral assembly. E contains a hydrophobic transmembrane domain with polar residues that is conserved across coronavirus species and may be significant to its function. This experiment looks at the possible role of one polar residue in assembly, the 15th residue glutamine, in the Mouse Hepatitis Virus (MHV) E protein. The glutamine 15 residue was mutated into positively charged residues lysine or arginine. Plasmids with these mutations were co-expressed with the membrane protein (M) gene to produce virus-like particles (VLPs). VLPs are produced when E and M are co-expressed together and model assembly of the coronavirus envelope, but they are not infectious as they do not contain the viral genome. Observing their production with the mutated E protein gives insight into the role the glutamine residue plays in assembly. The experiment showed that a changing glutamine 15 to positive charges does not appear to significantly affect the assembly of the VLPs, indicating that this specific residue may not have a large impact on viral assembly.
ContributorsHaller, Sarah S. (Author) / Hogue, Brenda (Thesis director) / Liu, Wei (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor) / Biodesign Institute (Contributor)
Created2017-05
Description
The decline of honeybee colonies around the world has been linked to the presence of the Varroa destructor, a mite acting as a virus vector for the Acute Bee Paralysis Virus. We developed a model of the infestation of the Apis melliifera honeybee colony by the Acute Bee Paralysis Virus, which is transmitted by the parasitic Varroa destructor. This is a four dimensional system of nonlinear ODE's for healthy and virus infected bees, total number of mites in the colony and number of mites that carry the virus. The Acute Bee Paralysis Virus can be transmitted between infected and uninfected bees, infected mite to adult bee, infected bee to phoretic mite, and reproductive mites to bee brood. This model is studied with analytical techniques deriving the conditions under which the bee colony can fight off an Acute Bee Paralysis Virus epidemic.
ContributorsDavis, Talia Lasandra (Author) / Kang, Yun (Thesis director) / Lanchier, Nicolas (Committee member) / Moore, Marianne (Committee member) / School of Mathematical and Statistical Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2015-12
ContributorsPerkins, Caitlin (Author) / Jacobs, Bertram (Thesis director) / Gile, Gillian (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor)
Created2023-05
ContributorsPerkins, Caitlin (Author) / Jacobs, Bertram (Thesis director) / Gile, Gillian (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor)
Created2023-05
Description
This study highlights the significance of zoonotic diseases, which make up almost 60% of infectious diseases in humans, and their origin from animals. Among mammalian viruses, primates, bats, and rodents have been identified as high-risk carriers. Within the rodent family Cricetidae, the species complex of Peromyscus eremicus, Peromyscus californicus, Peromyscus fraterculus, and Osgoodomys banderanus have been found to play a crucial role in disease transmission. These four species are phylogenetically related and share similar physical appearances and ecological niches. They have been identified as carriers of several zoonotic diseases, including Hantavirus, Arenavirus, Yersinia pestis, and Flavivirus, with a history of spread to humans. Despite their implications for public health, many of these species remain understudied. Thus, this study aims to provide a systematic review of the existing literature on these four species to summarize the findings on virus prevalence and distribution. The review shows that sampling efforts have been uneven and recent efforts have been lacking, with potential undiscovered zoonotic diseases. The concentration of sampling efforts in California and gaps in the literature are concerning, especially with changing agriculture and climate change potentially affecting rodent communities.
ContributorsTariq, Muhamamad (Author) / Sterner, Beckett (Thesis director) / Upham, Nate (Committee member) / Barrett, The Honors College (Contributor) / Dean, W.P. Carey School of Business (Contributor) / School of Life Sciences (Contributor)
Created2023-05
Description
In completing this thesis project, I attempted to hypothesize the trigger in my own personal diagnosis of type 1 diabetes through literature research as well as further research on viruses and their contribution to autoimmune disorders. I had previously hypothesized that, based on my own family life, type 1 diabetes could possibly be a non-heritable disease despite its consistent inheritance pattern discovered by researchers; however, the research presented in this thesis project rejects this idea and supports the theory that I may have been previously susceptible to this disorder and would have developed type 1 diabetes naturally. There were multiple viruses discovered during the literature research conducted that could possibly have been triggers in the acceleration of my disease. The major link between enteroviruses and autoimmune disorders was discovered, as well as influenza A and SARS-COV-2 and this is explained further in this project.
ContributorsPerkins, Caitlin (Author) / Jacobs, Bertram (Thesis director) / Gile, Gillian (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor)
Created2023-05
Description
Scorpions are predatory arachnids that are among the most ancient terrestrial invertebrates. They are typically found residing in desert and riparian environments. Viruses associated with scorpions have been explored in the past, unveiling partial RNA virus sequences and polyomaviruses, but more research in this area is necessary. Cycloviruses are non-enveloped viruses with circular single-stranded DNA genomes (~1.7 to 1.9 kb). Cycloviruses were initially identified in mammals and have now been detected in samples from a wide range of mammalian and insect species. Polyomaviruses are double-stranded DNA viruses (~4 to 7 kb). They are known for causing tumors in the host it infects, and have previously been identified in a diverse array of organisms, including scorpions. The objective for this study was to identify known and novel viruses in scorpions. Using high-throughput sequencing and traditional molecular techniques we determine the genome sequences of cycloviruses and polyomaviruses. Sixteen of the forty-three scorpion samples were positive for eight different species of cycloviruses. According to ICTV guidelines, seven of the eight species were novel cycloviruses which were found in bark scorpions, stripe-tailed scorpions, yellow ground scorpions, and giant hairy scorpions (Centruroides sculpturatus, Paravaejovis spinigerus, Paravaejovis confusus & Hadrurus arizonensis) from Maricopa, Pinal, and Pima county in Arizona, USA. Additionally, one previously known cyclovirus species was recovered in bark scorpions (Centruroides sculpturatus) in Pima county which had previously been documented in guano from a Mexican free-tailed bat in Arizona. There were ten scorpions out of forty-three for which we recovered polyomavirus scorpion samples that grouped into four different polyomavirus species. Polyomaviruses were only identified in bark scorpions (Centruroides sculpturatus) from Maricopa, Pinal, and Pima county. Of the polyomavirus genomes recovered three belong to previously identified scorpion polyomavirus 1 and five to scorpion polyomavirus 3, and two represent two new species named scorpion polyomavirus 4 and scorpion polyomavirus 5. The implications of the discovery of cycloviruses and polyomaviruses from this study contributes to our understanding of viral diversity associated with Scorpions.
ContributorsGomez, Magali (Author) / Neil, Julia (Co-author) / Varsani, Arvind (Thesis director) / Kraberger, Simona (Committee member) / Barrett, The Honors College (Contributor) / School of International Letters and Cultures (Contributor) / School of Life Sciences (Contributor)
Created2024-05