Matching Items (5)
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- All Subjects: Epidemiology
- All Subjects: Mosquito
- Creators: Blattman, Joseph
- Creators: Huijben, Silvie
- Creators: Bond, Angela
- Member of: Barrett, The Honors College Thesis/Creative Project Collection
Description
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
Among wild rodent populations, vertical transmission is believed to constitute the primary route of infection for Lymphocytic Choriomeningitis Virus (LCMV), a non-lytic arenavirus with both acute and chronic forms. When carrier mice infected at birth with the acute Armstrong strain reproduce, they generate congenital carrier offspring containing a quasispecies of LCMV that includes Armstrong as well as its chronic Clone-13 variant. This study examined the genetic trends in the vertical transmission of LCMV from mothers infected perinatally with Clone-13. Viral isolates obtained from the serum of congenital carrier offspring were partially sequenced to reveal residue 260 in the glycoprotein-encoding region of their S segment, the site of a major amino acid change differentiating the chronic and acute strains. It was found that the phenylalanine-to-leucine mutation associated with Clone-13 was present in 100% of the isolates, strongly indicating that the offspring of Clone-13 carriers contain exclusively the chronic variant. This research has broad implications for the epidemiology of the virus, and, given the predominance of Armstrong in the wild, suggests that there must be a biological cost associated with Clone-13 infection in non-carriers.
ContributorsFrear, Cody Christian (Author) / Blattman, Joseph (Thesis director) / Hogue, Brenda (Committee member) / Holechek, Susan (Committee member) / Barrett, The Honors College (Contributor) / School of Human Evolution and Social Change (Contributor) / School of Life Sciences (Contributor)
Created2015-05
Description
Hundreds of thousands of people die annually from malaria; a protozoan of the genus Plasmodium is responsible for this mortality. The Plasmodium parasite undergoes several life stages within the mosquito vector, the transition between which require passage across the lumen of the mosquito midgut. It has been observed that in about 15% of parasites that develop ookinetes in the mosquito abdomen, sporozoites never develop in the salivary glands, indicating that passage across the midgut lumen is a significant barrier in parasite development (Gamage-Mendis et al., 1993). We aim to investigate a possible correlation between passage through the midgut lumen and drug-resistance trends in Plasmodium falciparum parasites. This study contains a total of 1024 Anopheles mosquitoes: 187 Anopheles gambiae and 837 Anopheles funestus samples collected in high malaria transmission areas of Mozambique between March and June of 2016. Sanger sequencing will be used to determine the prevalence of known resistance alleles for anti-malarial drugs: chloroquine resistance transporter (pfcrt), multidrug resistance (pfmdr1) gene, dihydropteroate synthase (pfdhps) and dihydrofolate reductase (pfdhfr). We compare prevalence of resistance between abdomen and head/thorax in order to determine whether drug resistant parasites are disproportionately hindered during their passage through the midgut lumen. A statistically significant difference between resistance alleles in the two studied body sections supports the efficacy of new anti-malarial gene surveillance strategies in areas of high malaria transmission.
ContributorsPhillips, Keeley Isabella (Author) / Huijben, Silvie (Thesis director) / Gile, Gillian (Committee member) / Young, Steven (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description
The non-native mosquito Aedes aegypti has become a common nuisance in Maricopa county. Associated with human settlement, Ae. aegypti is known to reproduce in standing water sources both indoors and outdoors, within vessels such as tires, flowerpots, and neglected swimming pools (Jansen & Beebe, 2010). Ae. aegypti and the related Ae. albopictus are the primary vectors of the arboviral diseases chikungunya, Zika, yellow fever and dengue. Ae. aegypti tends to blood feed multiple times per gonotrophic cycle (cycle of feeding and egg laying) which, alongside a preference for human blood and close association with human habitation, contributes to an increased risk of Ae. aegypti borne virus transmission (Scott & Takken, 2012). Between 2010-2017, 153 travel-associated cases of dengue were reported in the whole of Arizona (Rivera et al., 2020); while there have been no documented locally transmitted cases of Aedes borne diseases in Maricopa county, there are no apparent reasons why local transmission can’t occur in the future via local Aedes aegypti mosquitoes infected after feeding from travelling viremic hosts. Incidents of local dengue transmission in New York (Rivera et al., 2020) and Barcelona (European Center for Disease Control [ECDC], 2019) suggest that outbreaks of Aedes borne arbovirus’ can occur in regions more temperate than the current endemic range of Aedes borne diseases. Further, while the fact that Ae. aegypti eggs have a high mortality rate when exposed to cold temperatures limits the ability for Ae aegypti to establish stable breeding populations in temperate climates (Thomas, Obermayr, Fischer, Kreyling, & Beierkuhnlein, 2012), global increases in temperature will expand the possible ranges of Ae aegypti and Aedes borne diseases.
ContributorsHon, Ruiheng (Author) / Paaijmans, Krijn (Thesis director) / Bond, Angela (Committee member) / Angilletta, Michael (Committee member) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
Malaria is a deadly, infectious, parasitic disease which is caused by Plasmodium parasites and transmitted between humans via the bite of adult female Anopheles mosquitoes. The primary insecticide-based interventions used to control malaria are indoor residual spraying (IRS) and long-lasting insecticide nets (LLINs). Larvicides are another insecticide-based intervention which is less commonly used. In this study, a mathematical model for malaria transmission dynamics in an endemic region which incorporates the use of IRS, LLINS, and larvicides is presented. The model is rigorously analyzed to gain insight into the asymptotic stability of the disease-free equilibrium. Simulations of the model show that individual insecticide-based interventions will not realistically control malaria in regions with high endemicity, but an integrated vector management strategy involving the use of multiple interventions could lead to the effective control of the disease. This study suggests that the use of larvicides alongside IRS and LLINs in endemic regions may be more effective than using only IRS and LLINs.
ContributorsJameson, Leah (Author) / Gumel, Abba (Thesis director) / Huijben, Silvie (Committee member) / Barrett, The Honors College (Contributor) / School of Mathematical and Statistical Sciences (Contributor) / School of Civic & Economic Thought and Leadership (Contributor)
Created2022-05