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Articles 91 - 120 of 1126

Full-Text Articles in Biology

Studying The Dynamics Of Neuromodulators In The Brain By Fluorescence Lifetime Imaging, Pingchuan Ma Dec 2024

Studying The Dynamics Of Neuromodulators In The Brain By Fluorescence Lifetime Imaging, Pingchuan Ma

Arts & Sciences Graduate Student Theses and Dissertations

Neuromodulators in the brain are fundamental to neuronal functions and animal behaviors in health and diseases. The modulatory actions of neuromodulators highly rely on their spatiotemporal dynamics. Recent research has demonstrated the importance of both sustained and transient change in neuromodulators, likely due to tonic and phasic neuromodulator release. However, no traditional methods could simultaneously record both types of dynamics. Fluorescence lifetime of optical reporters could offer a solution because it both allows high temporal resolution and is impervious to sensor expression differences across chronic periods. Nevertheless, no fluorescence lifetime change across the entire classes of neuromodulator sensors was previously …


Technology Development Of High-Resolution Single-Cell Lineage Tracing For Cell Reprogramming Systems, Sadie Vanhorn Dec 2024

Technology Development Of High-Resolution Single-Cell Lineage Tracing For Cell Reprogramming Systems, Sadie Vanhorn

Arts & Sciences Graduate Student Theses and Dissertations

A critical element of cell identity is the cell that created the observed cell. This parent cell dictates many aspects of its identity, whether measured by function, phenotype, or specific assays. The cell’s lineage impacts the ability of the cell to differentiate into final cell types in development or successfully reprogram in direct cell reprogramming. Here, we evolve molecular barcoding techniques to increase the resolution of lineage recording at single-cell resolution. Using single-cell RNA-sequencing as the readout for this measurement, polyadenylated reporter gene transcripts with engineered 3’ untranslated regions were designed to initially label and then record lineage information. While …


Multi-Omic Analysis Of Phototrophic Extracellular Electron Uptake In Novel Rhodovulum Spp. Isolated From A Marine Estuary, Emily J. Davenport Dec 2024

Multi-Omic Analysis Of Phototrophic Extracellular Electron Uptake In Novel Rhodovulum Spp. Isolated From A Marine Estuary, Emily J. Davenport

Arts & Sciences Graduate Student Theses and Dissertations

Microbial metabolisms are incredibly versatile and dynamic, allowing adaptive strategies for growth in even the most limiting environments. For an ever-increasing number of microbes, this includes utilizing soluble or insoluble inorganic mineral species as electron donors, driving geochemical cycles and microbial metabolisms. This metabolic function of transporting electrons derived from the extracellular environment across cell membranes is called extracellular electron uptake (EEU). Within (photo)autotrophs, (p)EEU also sustains CO2 fixation to cell biomass, implicating a potentially fundamental role of microbial carbon cycling in aquatic and soil ecosystems. A model metabolic scheme of pEEU occurring in natural environments is photoferrotrophy, which pairs …


Gene Expression Regulation By Au-Rich Elements And Au-Rich Element Binding Proteins, Courtney Fay Jungers Dec 2024

Gene Expression Regulation By Au-Rich Elements And Au-Rich Element Binding Proteins, Courtney Fay Jungers

Arts & Sciences Graduate Student Theses and Dissertations

The regulation of messenger RNA (mRNA) splicing, stability, and translation efficiency are major modes for controlling gene expression – which is essential for life. RNA-binding proteins (RBPs) and microRNAs (miRNAs) are trans-acting factors that bind to cis-elements influencing the stability and translation of the mRNA transcript. AU-rich elements (AREs) are cis-elements that are targeted by AU-rich element binding proteins (ARE-BPs). Here, I show a novel role for AREs and AU-rich element binding protein 1 (AUF1) during alternative splicing and report on interactions of RBPs and miRNAs to design a new treatment for breast cancer by interrupting these interactions in the …


Aging, Fast And Slow: Gene Expression Signatures Of Physiological Age Vs. Future Lifespan In Caenorhabditis Elegans, Matthew Mosley Dec 2024

Aging, Fast And Slow: Gene Expression Signatures Of Physiological Age Vs. Future Lifespan In Caenorhabditis Elegans, Matthew Mosley

Arts & Sciences Graduate Student Theses and Dissertations

An outstanding question in the field of aging biology is the origin of variability in lifespans among members of the same species. Traditional wisdom dictates that differences in one individual’s genes or environment, “nature” and “nurture,” could predispose that individual to a long or short life. However, these explanations are radically incomplete. Even in a model system as homogenous as C. elegans, using an isogenic population in a lab-controlled environment, we observe a distribution in lifespans comparable to that seen in outbred human populations. The first part of this dissertation focuses on characterizing this non-genetic, non-environmental variability in the aging …


A Filter-Based Model Of Visual Recognition, Olivia Rose Bockler Dec 2024

A Filter-Based Model Of Visual Recognition, Olivia Rose Bockler

Arts & Sciences Graduate Student Theses and Dissertations

Visual recognition, a key perceptual process, enables primates to identify faces, food, tools, and potential threats in their environment. Cortical neurons along the ventral visual stream—spanning from early visual cortex (V1) through inferotemporal cortex (IT), with long-range projections to ventrolateral prefrontal cortex (vlPFC)—are essential for visual recognition. Traditional models propose that neuronal representations increase in complexity in each stage of this pathway, culminating in object-specific representations in higher-order cortex. However, this hypothesis remains debated, particularly as artificial visual models have countered that individual neurons along this pathway may function more as filters contributing to distributed representations of objects. Thus, this …


Avian Adaptation To Thermal Gradients, Justin Wheeler Baldwin Dec 2024

Avian Adaptation To Thermal Gradients, Justin Wheeler Baldwin

Arts & Sciences Graduate Student Theses and Dissertations

Life on Earth has adapted to extremely different temperatures worldwide. However, across distant branches of the tree of life, animals in similar temperature environments often share similar phenotypic traits. Specifically, traits that bear on the ratio between an individual’s surface area (e.g. appendage length) and its volume (e.g. body size) are particularly important for temperature regulation and are codified in canonical biogeographical rules. Although these global patterns of finding larger-bodied (Bergmann’s Rule) and shorter-limbed (Allen’s Rule) animals in colder regions are widely upheld, they also show substantial variation. It remains poorly understood why some animals conform to these biogeographical rules …


N-Methyl-D-Aspartate (Nmda) Receptors Control Calcium Signaling In Striatal Neurons To Guide Value-Based Learning, Alex Legaria Macal Dec 2024

N-Methyl-D-Aspartate (Nmda) Receptors Control Calcium Signaling In Striatal Neurons To Guide Value-Based Learning, Alex Legaria Macal

Arts & Sciences Graduate Student Theses and Dissertations

N-methyl-D-aspartate receptors (NMDARs) play an essential role in neuronal function. Activation of NMDARs leads to calcium influx into postsynaptic neurons, which regu?late many fundamental aspects of neuronal physiology including synaptic plasticity, gene expression, and excitability. In the striatum, the input region of the basal ganglia, NM?DAR activity has been shown to regulate physiological function of striatal neurons, such as synaptic plasticity and excitability, and they also modulate behavior, particularly op?erant learning. However, there are many fundamental questions about the signaling and effects of NMDARs in vivo that have yet to be resolved. Moreover, the link between the physiological and behavioral …


Understanding Sequence Determinants Of Functional Protein Dynamics Using Biophysical Simulations And Experiments, Upasana Lakshmi Mallimadugula Dec 2024

Understanding Sequence Determinants Of Functional Protein Dynamics Using Biophysical Simulations And Experiments, Upasana Lakshmi Mallimadugula

Arts & Sciences Graduate Student Theses and Dissertations

Mutations in the sequence of proteins associated with a disease often increase its risk or severity. They can also be a barrier to developing effective therapeutics for such diseases. One way in which mutations affect function is by altering dynamics that elude structural studies. Observing these changes requires methods that can report on movements of the protein on various timescales and is an ongoing challenge in biophysics and biochemistry. In this study I will use both experimental and computational techniques that can report on such dynamics to explore how small sequence changes shift the conformational landscape and consequently the function …


Sustainable Plastics From Plastic Metabolisms: Leveraging Purple Non-Sulfur Bacteria For Polyhydroxyalkanoate Synthesis, Eric Michael Conners Dec 2024

Sustainable Plastics From Plastic Metabolisms: Leveraging Purple Non-Sulfur Bacteria For Polyhydroxyalkanoate Synthesis, Eric Michael Conners

Arts & Sciences Graduate Student Theses and Dissertations

Purple non-sulfur bacteria (PNSB) are a taxonomically diverse group of gram-negative bacteria representing some of Earth’s most metabolically versatile life, with many genera capable of switching between the four major metabolic modes – chemoheterotrophy, chemoautotrophy, photoheterotrophy, and photoautotrophy. Today, we exploit this diversity to explore fundamental questions about microbial metabolism. At the same time, many researchers are eager to use PNSB as tools for biotechnological innovations. Yet there exists a gap between fundamental biology and applied science. Part of the challenge is that we rely on a handful of model organisms – namely, members of the genera Rhodopseudomonas and Rhodobacter …


Pmp2+ Scs Maintain The Survival And Functioning Of Large-Caliber Motor Axons, Mikolaj Kozlowski Dec 2024

Pmp2+ Scs Maintain The Survival And Functioning Of Large-Caliber Motor Axons, Mikolaj Kozlowski

Arts & Sciences Graduate Student Theses and Dissertations

Neurodegenerative diseases are characterized by selective neuronal vulnerability, a phenomenon in which a specific pathology induces the death of a particular subpopulation of neurons. For example, selective neuronal vulnerability in the peripheral nervous system results in sensory, motor, or mixed peripheral neuropathies. While the intrinsic differences between neuronal subtypes cannot fully explain the basis of selective neuronal vulnerability, it is plausible that it partially stems from neuron extrinsic mechanisms such as the malfunction of distinct Schwann cell (SC) subtypes. Recently, we identified an exciting subpopulation of myelinating SCs characterized by the expression of Adamtsl1, Cldn14, and Pmp2 (hereafter referred to …


Elucidating The Role Of Astrocytes In Norepinephrine Neuromodulation, Katheryn Bry Lefton Dec 2024

Elucidating The Role Of Astrocytes In Norepinephrine Neuromodulation, Katheryn Bry Lefton

Arts & Sciences Graduate Student Theses and Dissertations

Norepinephrine, a wakefulness-associated neuromodulator, profoundly reshapes neural systems, from synaptic circuits to behavior. Through decades of research, a substantial catalogue on the effects of noradrenergic signaling on behavior and networks has been generated. How norepinephrine remodels synaptic circuitry is widely thought to underlie the larger changes in neural networks and behavior, highlighting the need for a more thorough understanding of the circuit effects of norepinephrine neuromodulation. However, the mechanistic details of the norepinephrine on synapses are still unclear. In recent decades, a large body of work has shown that norepinephrine acts not just on neurons, but on glial cells including …


Deciphering Immune Suppression Mechanisms Of Primary And Metastatic Breast Cancer, Seunghyun Lee Dec 2024

Deciphering Immune Suppression Mechanisms Of Primary And Metastatic Breast Cancer, Seunghyun Lee

Arts & Sciences Graduate Student Theses and Dissertations

Immune checkpoint blockade (ICB) has revolutionized cancer treatment, receiving FDA approval for various previously incurable cancers. In breast cancer, the combination of pembrolizumab (an anti-PD-1 antibody) with chemotherapy has become the standard-of-care for early-stage (Keynote-522) and advance-stage (Keynote-355) triple-negative breast cancer (TNBC). Unfortunately, over 30% of TNBC patients fail to respond to the combined chemo-immune therapy treatment, and the causes are unknown. Furthermore, ICB has demonstrated poor results in hormone-receptor positive breast cancer. While it is well-established that breast cancer cells can evade immune responses, the specific mechanisms driving immune evasion remain unclear. Thus, deciphering the immune system's role in …


Epigenetic Mechanisms And Senescence In Aging And Cancer, Alla Karpova Dec 2024

Epigenetic Mechanisms And Senescence In Aging And Cancer, Alla Karpova

Arts & Sciences Graduate Student Theses and Dissertations

Aging is marked by the progressive decline of cellular and organ function. This process often manifests through DNA damage, epigenomic alterations, telomere shortening, and metabolic or mitochondrial dysfunction. As DNA damage and other stressors accumulate, cells take measures to prevent malignant transformation. One such measure is cellular senescence, a state of irreversible cell cycle arrest that halts the growth of pre-malignant cells. When cells are unable to enter senescence due to high levels of genomic alterations, they typically undergo apoptosis or necrosis. However, if mutations affect key driver genes, allowing cells to evade death, they may become malignant, continuing to …


The Challenges Of Diet Generalism In A Microbial Predator, Dictyostelium Discoideum, Shreenidhi Perukkaranai Madabhushi Dec 2024

The Challenges Of Diet Generalism In A Microbial Predator, Dictyostelium Discoideum, Shreenidhi Perukkaranai Madabhushi

Arts & Sciences Graduate Student Theses and Dissertations

Organisms vary widely in their diet breadth, ranging from specialists that feed on few resources to generalists that feed on many. Specialists have honed their ability to catch and process specific prey, but generalists must deal with prey that differ in nutritional quality and defensive mechanisms. Have generalist predators overcome costs associated with consuming multiple prey species or do they experience costly trade-offs when handling different prey? Generalist predators also live in environments that vary in the type and abundance of prey species. How do generalists navigate this variation in prey abundance and profitability and seek out their preferred prey? …


Accumbal Plasticity And Associated Behavioral Adaptations In The Spared Nerve Injury Model Of Chronic Neuropathic Pain, Yu-Hsuan Chang Nov 2024

Accumbal Plasticity And Associated Behavioral Adaptations In The Spared Nerve Injury Model Of Chronic Neuropathic Pain, Yu-Hsuan Chang

Arts & Sciences Graduate Student Theses and Dissertations

Chronic pain is a debilitating neurological disorder that affects hundreds of millions of individuals worldwide. It is associated with cognitive symptoms such as cognitive inflexibility, which is defined as the inability to adaptively update behavior in response to changing environmental conditions. To date, there are no effective treatments for these symptoms, even though they substantially contribute to the decreased quality of life of chronic pain patients and are associated with reduced efficacy of pain management strategies. Therefore, understanding the neural circuit adaptations that drive cognitive symptoms of chronic pain, like cognitive inflexibility, is essential for improving existing treatments for this …


Exploring The Role Of Tissue-Resident T Cells In Neurotropic Viral Infections And Opioid-Induced Immune Disorders During Exposure And Withdrawal, Shenjian Ai Nov 2024

Exploring The Role Of Tissue-Resident T Cells In Neurotropic Viral Infections And Opioid-Induced Immune Disorders During Exposure And Withdrawal, Shenjian Ai

Arts & Sciences Graduate Student Theses and Dissertations

Tissue-resident T cells play a crucial role in the immune response to neurotropic viral infections and opioid-induced immune disorders. Understanding the roles of tissue-resident T cells in these contexts is essential for developing therapeutic strategies to mitigate their detrimental effects while enhancing their protective functions. The chemokine receptor CXCR6 and its ligand CXCL16 are critical in maintaining the population of tissue-resident T cells in the CNS. CXCR6 is expressed on CD8 T cells that persist in the CNS after recovery from West Nile virus infection. Research has shown that CXCL16, produced by microglia and other myeloid cells, binds to CXCR6 …


Clock Hijackers: How Integration Of Glioblastoma Into Circadian Circuits Regulates Tumor Progression And Sensitivity To Current Therapies, Maria Felicita Gonzalez Nov 2024

Clock Hijackers: How Integration Of Glioblastoma Into Circadian Circuits Regulates Tumor Progression And Sensitivity To Current Therapies, Maria Felicita Gonzalez

Arts & Sciences Graduate Student Theses and Dissertations

Glioblastoma (GBM) is the most common primary brain tumor in adults with a poor prognosis despite aggressive therapy. A recent, retrospective clinical study found that administering chemotherapy with Temozolomide (TMZ) in the morning increased patient overall survival by 6 months compared to evening. Previous work has shown that murine and human models of GBM have cell-intrinsic circadian rhythms in expression of the core clock genes Bmal1 and Per2 in vitro. This suggests that GBM has circadian rhythms that entrain to the hosts’ central clock. Understanding the mechanisms underlying circadian entrainment and tumor growth in GBM is essential to determine whether …


Treatment Modifications And Development For Mucopolysaccharidosis Type I, Sarah Hurt Oct 2024

Treatment Modifications And Development For Mucopolysaccharidosis Type I, Sarah Hurt

Arts & Sciences Graduate Student Theses and Dissertations

Mucopolysaccharidosis type I (MPS I) is a pediatric lysosomal storage disorder caused by biallelic pathogenic variants in the α-L-iduronidase (IDUA) gene that lead to the loss of a functional form of IDUA enzyme. Loss of this necessary enzyme leads to pathogenic accumulation of glycosaminoglycans (GAG) in lysosomes, leading to cellular distention and dysfunction. IDUA is necessary in every cell of the body and, as a result, a loss of function leads to clinical manifestations of the disease such as developmental delay, cardiac dysfunction, bone disease (dysostosis multiplex), upper respiratory complications, and premature death. A range of severity occurs, with Hurler …


Treatment Modifications And Development For Mucopolysaccharidosis Type I, Sarah Hurt Oct 2024

Treatment Modifications And Development For Mucopolysaccharidosis Type I, Sarah Hurt

Arts & Sciences Graduate Student Theses and Dissertations

Mucopolysaccharidosis type I (MPS I) is a pediatric lysosomal storage disorder caused by biallelic pathogenic variants in the α-L-iduronidase (IDUA) gene that lead to the loss of a functional form of IDUA enzyme. Loss of this necessary enzyme leads to pathogenic accumulation of glycosaminoglycans (GAG) in lysosomes, leading to cellular distention and dysfunction. IDUA is necessary in every cell of the body and, as a result, a loss of function leads to clinical manifestations of the disease such as developmental delay, cardiac dysfunction, bone disease (dysostosis multiplex), upper respiratory complications, and premature death. A range of severity occurs, with Hurler …


Elucidating The Heterogeneity And Epigenetic Determinants Of Memory-Like Natural Killer Cell Differentiation, Jennifer Tran Oct 2024

Elucidating The Heterogeneity And Epigenetic Determinants Of Memory-Like Natural Killer Cell Differentiation, Jennifer Tran

Arts & Sciences Graduate Student Theses and Dissertations

Natural killer (NK) cells are innate lymphoid cells that are a first line of defense against virally infected or malignant cells. Their ability to recognize and kill target cells is controlled by engagement of inhibitory, activating, and cytokine receptors. This leads to release of granules that contain perforin and granzymes, expression of death receptor ligands, and production of cytokines and chemokines. An effective NK cell response results in target cell death, along with changes in the nearby cellular microenvironment to promote immunity. As such NK cells play an essential role in tumor immunosurveillance, and there is an inverse correlation between …


Elucidating The Heterogeneity And Epigenetic Determinants Of Memory-Like Natural Killer Cell Differentiation, Jennifer Tran Oct 2024

Elucidating The Heterogeneity And Epigenetic Determinants Of Memory-Like Natural Killer Cell Differentiation, Jennifer Tran

Arts & Sciences Graduate Student Theses and Dissertations

Natural killer (NK) cells are innate lymphoid cells that are a first line of defense against virally infected or malignant cells. Their ability to recognize and kill target cells is controlled by engagement of inhibitory, activating, and cytokine receptors. This leads to release of granules that contain perforin and granzymes, expression of death receptor ligands, and production of cytokines and chemokines. An effective NK cell response results in target cell death, along with changes in the nearby cellular microenvironment to promote immunity. As such NK cells play an essential role in tumor immunosurveillance, and there is an inverse correlation between …


The Role Of Group 2 Innate Lymphoid Cells In Restoring Lung Health And Chitinase Function After Epithelial Injury, Haerin Jung Oct 2024

The Role Of Group 2 Innate Lymphoid Cells In Restoring Lung Health And Chitinase Function After Epithelial Injury, Haerin Jung

Arts & Sciences Graduate Student Theses and Dissertations

Alveolar epithelial cells provide oxygen transport and act as a first line of defense against pathogens and environmental triggers that disturb tissue homeostasis. However, in the context of epithelial injury, fibrotic and inflammatory lung diseases develop where regenerative responses may become dysregulated or recurrently engaged. One cause of lung injury is infection with cytopathic respiratory viruses such as influenza and SARS-CoV-2 viruses, which induce lung inflammation, tissue damage, and epithelial cell injury and loss. Restoration of barrier integrity after lung injury is critical for re-establishing healthy lung function but the underlying mechanisms are unclear. In the steady state, lung epithelial …


The Role Of Group 2 Innate Lymphoid Cells In Restoring Lung Health And Chitinase Function After Epithelial Injury, Haerin Jung Oct 2024

The Role Of Group 2 Innate Lymphoid Cells In Restoring Lung Health And Chitinase Function After Epithelial Injury, Haerin Jung

Arts & Sciences Graduate Student Theses and Dissertations

Alveolar epithelial cells provide oxygen transport and act as a first line of defense against pathogens and environmental triggers that disturb tissue homeostasis. However, in the context of epithelial injury, fibrotic and inflammatory lung diseases develop where regenerative responses may become dysregulated or recurrently engaged. One cause of lung injury is infection with cytopathic respiratory viruses such as influenza and SARS-CoV-2 viruses, which induce lung inflammation, tissue damage, and epithelial cell injury and loss. Restoration of barrier integrity after lung injury is critical for re-establishing healthy lung function but the underlying mechanisms are unclear. In the steady state, lung epithelial …


Rapid Unleashing Macrophage Efferocytic Capacity By Transcriptional Pause Release, Turan Tufan Oct 2024

Rapid Unleashing Macrophage Efferocytic Capacity By Transcriptional Pause Release, Turan Tufan

Arts & Sciences Graduate Student Theses and Dissertations

During development, inflammation or tissue injury, macrophages engulf multiple apoptotic cells via efferocytosis to maintain tissue homeostasis. The mechanism by which macrophages rapidly adapt their transcription for continuous corpse uptake is not well understood. Transcriptional pause/release is a conserved mechanism, in which RNA polymerase (Pol) II initiates transcription for 20-60 nucleotides, is paused for minutes to hours and is then released to the elongation phase. We show that macrophages quickly use Pol II pause/release upon encountering corpses to trigger a rapid transcriptional response. This mechanism is essential for continuous efferocytosis but does not affect other forms of phagocytosis. Genomic data …


Rapid Unleashing Macrophage Efferocytic Capacity By Transcriptional Pause Release, Turan Tufan Oct 2024

Rapid Unleashing Macrophage Efferocytic Capacity By Transcriptional Pause Release, Turan Tufan

Arts & Sciences Graduate Student Theses and Dissertations

During development, inflammation or tissue injury, macrophages engulf multiple apoptotic cells via efferocytosis to maintain tissue homeostasis. The mechanism by which macrophages rapidly adapt their transcription for continuous corpse uptake is not well understood. Transcriptional pause/release is a conserved mechanism, in which RNA polymerase (Pol) II initiates transcription for 20-60 nucleotides, is paused for minutes to hours and is then released to the elongation phase. We show that macrophages quickly use Pol II pause/release upon encountering corpses to trigger a rapid transcriptional response. This mechanism is essential for continuous efferocytosis but does not affect other forms of phagocytosis. Genomic data …


Aging Drives Cd8 T Cells To Functional Extremes: From Non-Specific Cytotoxicity To Tissue-Mediated Exhaustion, Irina Shchukina Sep 2024

Aging Drives Cd8 T Cells To Functional Extremes: From Non-Specific Cytotoxicity To Tissue-Mediated Exhaustion, Irina Shchukina

Arts & Sciences Graduate Student Theses and Dissertations

CD8 T cells are a crucial component of the immune system, primarily responsible for executing the effector response against viral infections and cancer. Aging significantly impacts most immune cell types, with particularly dramatic changes observed in CD8 T cells. One major age-related difference is the marked decline in thymus activity, which leads to a substantial reduction in naive CD8 T cells and an increased abundance of memory CD8 T cells. Furthermore, recent work from our lab demonstrated that while young memory CD8 T cells are relatively homogeneous, memory CD8 T cells diverge into two subpopulations: PD1- memory CD8 T cells …


Aging Drives Cd8 T Cells To Functional Extremes: From Non-Specific Cytotoxicity To Tissue-Mediated Exhaustion, Irina Shchukina Sep 2024

Aging Drives Cd8 T Cells To Functional Extremes: From Non-Specific Cytotoxicity To Tissue-Mediated Exhaustion, Irina Shchukina

Arts & Sciences Graduate Student Theses and Dissertations

CD8 T cells are a crucial component of the immune system, primarily responsible for executing the effector response against viral infections and cancer. Aging significantly impacts most immune cell types, with particularly dramatic changes observed in CD8 T cells. One major age-related difference is the marked decline in thymus activity, which leads to a substantial reduction in naive CD8 T cells and an increased abundance of memory CD8 T cells. Furthermore, recent work from our lab demonstrated that while young memory CD8 T cells are relatively homogeneous, memory CD8 T cells diverge into two subpopulations: PD1- memory CD8 T cells …


Mechanisms Of Uropathogenic E. Coli Reservoir Formation In The Gastrointestinal Tract, Philippe Nimma Azimzadeh Sep 2024

Mechanisms Of Uropathogenic E. Coli Reservoir Formation In The Gastrointestinal Tract, Philippe Nimma Azimzadeh

Arts & Sciences Graduate Student Theses and Dissertations

Urinary tract infections (UTI) are an extremely common affliction affecting 150 million people worldwide each year. UTIs are a leading cause of antibiotic therapy among otherwise healthy adult women, accounting for 15% of all outpatient antibiotic prescriptions. Uropathogenic Escherichia coli (UPEC) cause over 80% of community-acquired UTIs. Even when infection is cleared from the urine by clinical antibiotic regimens, 27% of women will experience recurrent UTI (rUTI) within months. Greater than 60% of rUTIs are caused by the same strain of E. coli that caused the initial infection, suggesting that one or more host-associated reservoirs of UPEC can re-inoculate the …


Mechanisms Of Uropathogenic E. Coli Reservoir Formation In The Gastrointestinal Tract, Philippe Nimma Azimzadeh Sep 2024

Mechanisms Of Uropathogenic E. Coli Reservoir Formation In The Gastrointestinal Tract, Philippe Nimma Azimzadeh

Arts & Sciences Graduate Student Theses and Dissertations

Urinary tract infections (UTI) are an extremely common affliction affecting 150 million people worldwide each year. UTIs are a leading cause of antibiotic therapy among otherwise healthy adult women, accounting for 15% of all outpatient antibiotic prescriptions. Uropathogenic Escherichia coli (UPEC) cause over 80% of community-acquired UTIs. Even when infection is cleared from the urine by clinical antibiotic regimens, 27% of women will experience recurrent UTI (rUTI) within months. Greater than 60% of rUTIs are caused by the same strain of E. coli that caused the initial infection, suggesting that one or more host-associated reservoirs of UPEC can re-inoculate the …