Life Sciences Commons^™

Individual And Social Influences On Cigarette Smoking During Pregnancy, Alexandra Noel Houston-Ludlam

Arts & Sciences Graduate Student Theses and Dissertations

Population-level trends on sociodemographic risk factors for cigarette smoking during pregnancy (SDP) and outcomes for offspring exposed to maternal SDP are well established. However, the more complex task of understanding individual risk-prediction, including differences by maternal race/ethnicity, and its clinical application, remains incomplete. Characterizing the relative influence of environmental and individual characteristics as risk or protective factors for continued SDP is a necessary next step for informing individual- and public health-level interventions to produce successful smoking cessation prior to pregnancy, substantially reducing smoking-related mortality in child-bearing people. In this dissertation, I wanted to explore how multiple levels of influence, from …

The Microbes Within: Pathogen In-Host Adaptation And The Gut Microbiome During Persistent Colonization And Recurrent Infection, Joohee Choi

Arts & Sciences Graduate Student Theses and Dissertations

Microbes not just surround us; they are inside of us. The gut microbiome has emerged in recent years as an important modulator of health and is thought to have co-evolved with us throughout evolutionary history. On the other hand, our immune systems are constantly surveilling and battling infection by external pathogens— some of which still manage to evade our immune response and colonize our bodies long-term. In this Thesis, I investigated microbes inhabiting our bodies in various contexts to understand their impact on human health.In Chapter 2, I discuss the effects of fecal microbiome transplant (FMT) study drug RBX2660 on …

Circumventing Drug Resistance With Small Molecule Inhibitors Of Mycobacterium Tuberculosis, Gregory Alexander Harrison

Arts & Sciences Graduate Student Theses and Dissertations

The disease tuberculosis caused by Mycobacterium tuberculosis (Mtb) remains a global health threat, and the antibiotic resistance crisis challenges our ability to treat Mtb infections. For example, out of the approximately 10 million cases of tuberculosis each year, an estimated 10.7% of new cases and 27.2% of previously treated cases are resistant to the frontline antibiotic isoniazid (INH). There is a clear need for new therapies that enhance our current regimen and target these genetically resistant strains.Identifying ways to enhance the antimicrobial activity of INH has the potential to significantly improve the efficacy of frontline treatment regimens. To this end, …

Function And Regulation Of Virulence-Associated Siderophores In Uropathogenic Enterobacterales, James Robert Heffernan

Arts & Sciences Graduate Student Theses and Dissertations

Siderophores are small molecules created by fungi and bacterial cells to help obtain iron. This may extend to cells in iron-limiting environments within host organisms. Certain siderophores are associated with increased virulence in urinary tract infections (UTIs). Siderophore system activity is typically regulated by feedback inhibition via ferric uptake regulator (Fur) which, in the presence of cytosolic iron, binds to a ~19 base pair inverted DNA repeat (9-1-9) called a Fur box. Once bound to this motif, the iron-Fur complex suppresses siderophore expression when adequate bacterial iron status is achieved. Many organisms produce more than one siderophore, and in the …

Zebrafish Swim Capacity, Gait, And Posture During Innate Spinal Cord Repair, Nicholas Oliver Jensen

Arts & Sciences Graduate Student Theses and Dissertations

Adult zebrafish are capable of anatomical and functional recovery following severe spinal cord injury. Significant advances for understanding the cellular and molecular mechanisms of innate spinal cord repair are best supported by accurate assessment of swim function. This study introduces neuromuscular-associated measurements derived from gait and posture, compares new and classical functional measurements longitudinally, and provides a comprehensive correlative analysis of various functional and cellular regeneration outputs. It also explores trajectories of functional regeneration through tensor decomposition and demonstrates that swim function at 2 weeks post-injury can be used to predict 8-week regeneration outcomes. By establishing swim quality metrics which …

Ribosomes As Sensors: How Cells Utilize The Translational Process To Monitor Cellular Conditions, Kyusik Q. Kim

Arts & Sciences Graduate Student Theses and Dissertations

The discovery that collisions between ribosomes are the key signaling event that triggers quality control and stress response pathways in eukaryotes has changed our understanding of how cells sense and respond to the environment. Collided eukaryotic ribosomes adopt a unique structure, providing a mechanistic basis for how environmental signals can be sensed by the translational machinery and propagated into wider reprogramming of gene expression. Indeed, the use of ribosomes as a signaling hub is quite apt, as ribosomes make intimate contact with both mRNA and tRNAs. This enables them to monitor the integrity of genetic information coming from the nucleus …

Identification And Characterization Of Targets Of Metastasis In High-Grade Serous Ovarian Cancer, Emilee Nicole Kotnik

Arts & Sciences Graduate Student Theses and Dissertations

High-Grade Serous Ovarian Cancer (HGSC) is a highly metastatic cancer with the majority of patients presenting in advanced stages. Currently there are limited targeted treatment options for patients, especially for women with high metastatic tumor burdens. In order to improve patient outcomes, we have aimed to identify and characterize novel targets of metastasis utilizing sequencing from patient tumors and a functional genomic screen. First, we identified genetic alterations of metastasis and short survival by characterizing the genomic and transcriptomic alterations of primary and metastatic tumors in HGSC patients from 23 short-term survivors (overall survival (OS) <3.5 years) and 16 long-term survivors (OS >5 years). We compared somatic …

Iterative Machine Learning Of A Cis-Regulatory Grammar, Ryan Z. Friedman

Arts & Sciences Graduate Student Theses and Dissertations

Gene regulation allows for the quantitative control of gene expression. Gene regulation is a complex process encoded through cis-regulatory sequences, short DNA sequences containing clusters of transcription factor binding sites. Each binding site can occur millions of times in multicellular genomes, and seemingly similar collections of binding sites can have very different activities. A leading model to explain these degeneracies is that cis-regulatory sequences follow a “grammar” defined by the number, identity, strength, arrangement, and/or context of the underlying binding sites. Understanding cis-regulatory grammar requires high-throughput technology, quantitative measurements, and computational modeling. This thesis describes an iterative machine learning approach …

Multi-Omics Understanding Of Heterogeneity, Progression, And Therapeutic Vulnerabilities In Kidney Disease And Cancer, Yize Li

Arts & Sciences Graduate Student Theses and Dissertations

Kidney disease and cancer are both highly heterogeneous diseases, meaning that they exhibit significant variability in their underlying causes, mechanisms, progression, and responses to therapy. Traditional approaches to studying these diseases have focused on individual molecular or cellular pathways, which can provide limited information on the complexity of the disease. By combining multi-omics technologies, we can gain a more comprehensive understanding of the molecular and cellular changes that occur in kidney disease and cancer and identify new therapeutic targets and personalized treatment options.As a kidney disease, clear cell renal cell carcinomas (ccRCCs) represent ~75% of RCC cases and account for …

Fluorescent-Based Approaches For Quantifying Bacterial Transcription Initiation Kinetics, Drake Jensen

Arts & Sciences Graduate Student Theses and Dissertations

All cellular life depends on the precise regulation of its genome to adapt to environmental changes. This thesis focuses on exploring gene expression mechanisms at the level of transcription. Transcription is the process in which the enzyme RNA polymerase (RNAP) uses DNA as a template to generate nascent RNA. RNAP first binds to a regulatory sequence within the DNA called a promoter. The combined processes that occur at the promoter define transcription initiation, including promoter binding, promoter opening around the transcription start site, and initial synthesis of short RNA transcripts. Once RNAP escapes the promoter, it elongates the initial RNA …

Circadian Protein Bmal1 Regulates Astrocyte Activation And Protein Degradation In Health And Disease, Celia Augusta Mckee

Arts & Sciences Graduate Student Theses and Dissertations

The circadian clock regulates gene transcription to control daily rhythms in cellular function, behavior, and disease. Circadian dysfunction is a symptom of aging and neurodegenerative diseases, and recent studies suggest reciprocal regulation between impaired clock function and neurodegeneration. In addition to the clock regulating neuronal activity, non-neuronal glia cells of the brain also possess functional circadian clocks which control their responses to daily oscillations in brain activity, cellular stress, and metabolism. Astrocytes directly support brain function through synaptic interactions, neuronal metabolic support, neuroinflammatory regulation, and control of neurovascular coupling at blood and cerebrospinal fluid (CSF) barriers. Emerging evidence suggests that …

The Effect Of Oxytocin Receptor Genetic Variants On Oxytocin Response, Manasi Malik

Arts & Sciences Graduate Student Theses and Dissertations

Oxytocin is a nonapeptide hormone that modulates social behavior, mediates the lactation reflex, and induces and strengthens uterine contractions. Each year, oxytocin is administered to about half of laboring patients for induction and augmentation, and to almost all patients for prevention of post-partum hemorrhage – a total of four million patients per year in the United States alone. However, response to oxytocin varies widely between individuals, and complications including uterine hyperstimulation, uterine atony, required Cesarean section, and postpartum hemorrhage can arise from either excessive or inadequate oxytocin response. To avoid these adverse events, it is critically important to identify individuals …

The Role Of Mavs And Interferon-Lambda In Regulating Astrovirus And Norovirus Infections, Heyde Makimaa

Arts & Sciences Graduate Student Theses and Dissertations

Although they globally cause viral gastroenteritis in children, astroviruses are understudied due to the lack of well-defined animal models. While muAstVs chronically infect immunodeficient mice, a culture system and understanding of their pathogenesis is lacking. Here, we describe a platform to cultivate muAstV using air–liquid interface (ALI) cultures derived from mouse enteroids, which support apical infection and release. Chronic muAstV infection occurs in the small intestine and correlates with higher IFN-λ expression. MuAstV stimulates IFN-λ production in ALI, recapitulating our in vivo findings. We demonstrate that goblet cells and enterocytes are targets for chronic muAstV infection in vivo, and that …

Examining Therapeutic Targets For Central Nervous System Autoimmune Disease, Sindhu Manivasagam

Arts & Sciences Graduate Student Theses and Dissertations

Multiple sclerosis (MS) is a chronic autoimmune disease of the central nervous system (CNS) that leads to demyelination, axonal damage, and neuronal loss. Patients are typically diagnosed early in adulthood and due to the chronic nature of the disease, will continue to develop symptoms over their lifetime. Currently available therapeutics for MS focus on symptomatic relief and reduce severity of relapses; however, they are unable to prevent disease progression or promote recovery. Therefore, there is a critical need to understand the biological mechanisms driving neuroinflammatory and neurodegenerative processes in MS and to translate these findings into novel therapeutic strategies.Here we …

Development Of Myelin In Wolfram Syndrome, Olga Reine Neyman

Arts & Sciences Graduate Student Theses and Dissertations

Wolfram syndrome is a rare, autosomal recessive disease traditionally characterized by juvenile onset insulin dependent diabetes, optic atrophy, deafness, and neurodegeneration often beginning in childhood and adolescence. The disease is caused by mutations in WFS1, which encodes for the protein wolframin and is associated with endoplasmic (ER) stress-mediated apoptosis. ER stress-related dysfunction may inhibit production of myelin during neurodevelopment in Wolfram syndrome, as active and developing oligodendrocytes are more vulnerable to ER stress than mature ones. It is known that white matter tracts are compromised in the disease, but many questions related to the vulnerability of myelin and its impact …

Roles Of The Transcription Factors Bcl6, Irf2, And Notch2 In Myeloid Development, Kevin William O'Connor

Arts & Sciences Graduate Student Theses and Dissertations

Development of immune cells is orchestrated by expression of transcription factors which function to control differentiation of progenitor populations and survival of mature cells. Nonclassical monocytes are a population of myeloid cells which patrol the bloodstream and are thought to maintain vascular endothelium. Conventional dendritic cells (cDCs) are antigen-presenting myeloid cells which serve to activate naïve T cells during infections. cDCs are further differentiated into cDC1s capable of cross-presenting exogenous antigens to activate CD8 T cells and cDC2s which are thought to play essential roles in activating Th2 and Th17 responses. These disparate cells originate from a shared bone marrow …

Dynamics Of Epithelial Differentiation Following Intestinal Villus Injury, Takahiro Erick Ohara

Arts & Sciences Graduate Student Theses and Dissertations

Millions of finger-like structures called villi line the small intestine, providing an enormous surface area for rapid and efficient nutrient absorption. Collapse of the villus architecture, known as villus atrophy, is often observed in response to pathogen invasion, inflammation, medications, and ischemia due to loss of intestinal epithelial cells, resulting in symptoms of diarrhea and malabsorption. Though removal of the inciting agent generally allows for near complete tissue recovery, some individuals take longer to restore their villi, a condition known as persistent villus atrophy, for reasons that are unknown. How intestinal villi cope with tissue damage and re-establish their structure …

An Investigation Of Second-Site Non-Complementation Among Motile Cilia Genes In Chlamydomonas Reinhardtii, Gervette M. Penny

Arts & Sciences Graduate Student Theses and Dissertations

ABSTRACT OF THE DISSERTATIONAn Investigation of Second-Site Non-Complementation among Motile Cilia Genes in Chlamydomonas reinhardtii by Gervette M. Penny Doctor of Philosophy in Biology and Biomedical Sciences Molecular Genetics and Genomics Washington University in St. Louis, 2023 Professor Susan K. Dutcher, ChairMotile cilia are complex microtubule-based organelles used by eukaryotic cells for locomotion or directing fluid flow. In humans, motile cilia defects cause primary ciliary dyskinesia (PCD), characterized by neonatal respiratory distress, recurrent lung infections, bronchiectasis, and low nitric oxide. Situs inversus and/or male infertility are present in about 50% of cases. PCD inheritance is recessive; both copies (alleles) of …

Characterizing The Significance Of Polya Tracks In Gene Regulation And Disease, Geralle Norlene Powell-Rodgers

Arts & Sciences Graduate Student Theses and Dissertations

The regulation of gene expression is essential for all domains of life. Control of gene expression occurs during each of the three steps of mRNA translation into protein. The fidelity and rate of the third step of translation, elongation, has been established as a key regulator of gene expression through its effects on mRNA stability and, thus, protein abundance. Consequently, studies focusing on factors that affect mRNA stability, including mRNA sequence composition and structure, have become integral to understanding the role of translational control in gene regulation. In Chapter 1, I discuss mechanisms of translational control, focusing on the gene …

Identifying Molecular Targets Of Adar1 Dependency In Breast Cancer, Sua Ryu

Arts & Sciences Graduate Student Theses and Dissertations

Innate immunity is a fundamental defense mechanism against non-self. Similar to its role in pathogenic infections, innate immunity is capable of eliminating cancerous cells by activating cytotoxic inflammatory signaling. Adenosine deaminase acting on RNA 1 (ADAR1) is a key regulator of cell-intrinsic innate immunity. ADAR1 converts adenosines to inosines on double-stranded RNAs (dsRNAs), altering dsRNA structure and its interactive properties. This suppresses cytoplasmic sensing of immunogenic dsRNA and activation of the type I interferon (IFN) signaling pathway. Frequently, suppressing endogenous dsRNA from triggering cytotoxic inflammatory signaling is essential for cancer cell survival. This is known as ADAR1 dependency, which has …

Mapping Brain Development And Decoding Brain Activity With Diffuse Optical Tomography, Kalyan Tripathy

Arts & Sciences Graduate Student Theses and Dissertations

Functional neuroimaging has been used to map brain function as well as decode information from brain activity. However, applications like studying early brain development or enabling augmentative communication in patients with severe motor disabilities have been constrained by extant imaging modalities, which can be challenging to use in young children and entail major tradeoffs between logistics and image quality. Diffuse optical tomography (DOT) is an emerging method combining logistical advantages of optical imaging with enhanced image quality. Here, we developed one of the world’s largest DOT systems for high-performance optical brain imaging in children. From visual cortex activity in adults, …

The Role Of Ns1 In Flavivirus Immunity And Pathogenesis, Alex W. Wessel

Arts & Sciences Graduate Student Theses and Dissertations

ABSTRACT OF THE DISSERTATIONThe Role of NS1 in Flavivirus Immunity and Pathogenesis by Alex W. Wessel Doctor of Philosophy in Biology and Biomedical Sciences Immunology Washington University in St. Louis, 2023 Professor Michael Diamond, Chair Flaviviruses are a genus of enveloped, arthropod-transmitted RNA viruses that include clinically relevant pathogens such as yellow fever, dengue, Zika, and West Nile viruses. These viruses cause a spectrum of potentially life-threatening diseases including hepatitis, vascular shock, congenital abnormalities, and encephalitis. Dengue virus, alone, infects up to 390 million individuals in any given year, and its endemic regions continue to expand along with the geographical …

Trpm5'S Role In Vascular Development, Megan Goeckel

Arts & Sciences Graduate Student Theses and Dissertations

Blood vessels are composed of two main cell types, endothelial cells (ECs) and mural cells (MCs). Endothelial cells comprise of the inner-most layer of the vessel and sense changes in blood flow to recruit mural cells. The mechanism for how endothelial cells sense these hemodynamic changes is not well understood and deciphering this mechanism is the focus of this thesis. We hypothesize that transient receptor potential melastatin 5 (TRPM5), a transmembrane channel protein, is involved in this process. Here, using cultured human endothelial cells and the zebrafish model, we show that inhibition of TRPM5 decreases vessel formation and increases EC-MC …

Cancer Immunogenomics Approaches To Characterizing And Treating Malignant Brain Tumors, Maximilian Oswald Schaettler

Arts & Sciences Graduate Student Theses and Dissertations

Fueled by a deeper understanding of the fundamental mechanisms of anti-tumor immune responses, cancer immunotherapy has experienced a resurgence over the last decade with remarkable success in the treatment of certain malignancies. However, despite a multitude of treatment approaches ranging from immune checkpoint blockade to adoptive cellular therapy to neoantigen vaccines, certain cancer types have shown limited response to immunotherapy. Glioblastoma multiforme (GBM), the most common primary malignancy of the central nervous system, represents a particularly challenging tumor where new treatment approaches are desperately needed. Despite multimodality treatment consisting of surgical resection, chemotherapy, and radiation therapy, patients with GBM face …

Immunity To Emerging Rna Viruses, Emma Winkler

Arts & Sciences Graduate Student Theses and Dissertations

In the past decade, newly emerged and re-emerged pathogenic RNA viruses such as Ebola, H1N1, and Zika virus have become substantial threats to global health. Two notable examples include the explosive re-appearance of chikungunya virus in the 2000s in Asia and the Western Hemisphere and, more recently, the global COVID-19 pandemic. Therefore, an improved understanding of immunity to emerging RNA viruses is critical for defining host susceptibility and restriction factors to viral infection as well as appropriate vaccine and antiviral therapeutic design. Chikungunya virus (CHIKV) is a mosquito-transmitted alphavirus that is maintained in an urban epidemic transmission cycle. While most …

Evaluating The Function Of Dnmt3a Mutations Associated With Acute Myeloid Leukemia And Dnmt3a Overgrowth Syndrome, Yang Li

Arts & Sciences Graduate Student Theses and Dissertations

Heterozygous loss-of-function mutations in the DNMT3A gene are the most common cause of clonal hematopoiesis, and among the most common initiating events for Acute Myeloid Leukemia (AML). Meanwhile, mutant DNMT3A cause an overgrowth syndrome, DNMT3A Overgrowth Syndrome (DOS, also known as Tatten-Brown-Rahmen syndrome, TBRS). Amino acid R882H mutation is the most frequent variance of DNMT3A, while the rest of the mutations spread out on the entire gene of DNMT3A. Over 70% of DNMT3A mutants cause loss of function change. A reduction of DNMT3A activity causes a canonical, focal hypomethylation phenotype in hematopoietic cells, which is associated with immortalization of hematopoietic …

Influence Of Environmental Gradients On Genomic Variation In Pediatric Commensals And Pathogens, Sanjam Sawhney

Arts & Sciences Graduate Student Theses and Dissertations

Microbes interact with humans in a myriad of ways. They come together in the human gut to form complex communities that collectively transform and individually evolve in response to changing environmental conditions. Individual microbes can also cause human infection and escape antibiotic clearance through acquisition and development of novel resistance mechanisms. In this thesis, I chronicle the relationships between microbes and humans across two axes: from complex communities to single isolates, and from targeted studies of pediatric populations vulnerable to microbiome perturbations and pathogen challenge, to broader human and animal cohorts spanning colonizing and diagnostic environments.In Chapter 2, I extensively …

Surfactant Protein A Attenuates Generalized And Localized Neuroinflammation In Neonatal Mice, Caroline E Crocker, Romana Sharmeen, Thu T Tran, Amir M Khan, Wen Li, Joseph L Alcorn

Faculty, Staff and Student Publications

Surfactant protein A (SP-A) has important roles in innate immunity and modulation of pulmonary and extrapulmonary inflammation. Given SP-A has been detected in rat and human brain, we sought to determine if SP-A has a role in modulating inflammation in the neonatal mouse brain. Neonatal wildtype (WT) and SP-A-deficient (SP-A−/−) mice were subjected to three models of brain inflammation: systemic sepsis, intraventricular hemorrhage (IVH) and hypoxic-ischemic encephalopathy (HIE). Following treatment, RNA was isolated from brain tissue and expression of cytokine and SP-A mRNA was determined by real-time quantitative RT-PCR analysis. In the sepsis model, expression of most cytokine mRNAs was …

Correction Of T-Cell Repertoire And Autoimmune Diabetes In Nod Mice By Non-Myeloablative T-Cell Depleted Allogeneic Hsct, Rakefet Sidlik Muskatel, Bar Nathansohn-Levi, Shlomit Reich-Zeliger, Michal Mark, Liat Stoler-Barak, Chava Rosen, Irit Milman-Krentsis, Esther Bachar Lustig, Robert Pete Gale, Nir Friedman, Yair Reisner

Faculty, Staff and Student Publications

The induction of partial tolerance toward pancreatic autoantigens in the treatment of type 1 diabetes mellitus (T1DM) can be attained by autologous hematopoietic stem cell transplantation (HSCT). However, most patients treated by autologous HSCT eventually relapse. Furthermore, allogeneic HSCT which could potentially provide a durable non-autoimmune T-cell receptor (TCR) repertoire is associated with a substantial risk for transplant-related mortality. We have previously demonstrated an effective approach for attaining engraftment without graft versus host disease (GVHD) of allogeneic T-cell depleted HSCT, following non-myeloablative conditioning, using donor-derived anti-3rd party central memory CD8 veto T cells (Tcm). In the present study, we investigated …

Immunologic Predictors For Clinical Responses During Immune Checkpoint Blockade In Patients With Myelodysplastic Syndromes, Sung-Eun Lee, Feng Wang, Maison Grefe, Abel Trujillo-Ocampo, Wilfredo Ruiz-Vasquez, Koichi Takahashi, Hussein A Abbas, Pamella Borges, Dinler Amaral Antunes, Gheath Al-Atrash, Naval Daver, Jeffrey J Molldrem, Andrew Futreal, Guillermo Garcia-Manero, Jin S Im

Faculty, Staff and Student Publications

PURPOSE: The aim of this study is to determine immune-related biomarkers to predict effective antitumor immunity in myelodysplastic syndrome (MDS) during immunotherapy (IMT, αCTLA-4, and/or αPD-1 antibodies) and/or hypomethylating agent (HMA).

EXPERIMENTAL DESIGN: Peripheral blood samples from 55 patients with MDS were assessed for immune subsets, T-cell receptor (TCR) repertoire, mutations in 295 acute myeloid leukemia (AML)/MDS-related genes, and immune-related gene expression profiling before and after the first treatment.

RESULTS: Clinical responders treated with IMT ± HMA but not HMA alone showed a significant expansion of central memory (CM) CD8+ T cells, diverse TCRβ repertoire pretreatment with increased clonality and …