Immunology and Infectious Disease Commons^™

Exploring Foundations Of Animal Host-Microbe Interactions In A Freshwater Sponge, Jacob S. Pawley

Electronic Theses and Dissertations

The most ancient eukaryotic immune defense mechanisms evolved in unicellular species. Multicellular eukaryotes, however, expanded these mechanisms to meet challenges unique to multicellular life, including barrier formation, long-distance cell signaling, and coordinated responses that eliminate microbial threats while minimizing damage to the host. As such, animal immune signaling pathways are exceptionally intricate and diverse. Though, most of what is understood about animal host–microbe interactions stems from a small handful of model systems. Here, I evaluate host–microbe interactions and innate immunity in sponges using the highly tractable freshwater sponge, Ephydatia muelleri. I report the discovery of an external host-derived matrix …

Avaren-Fc's Effects On Lymphoma Cells., Jacob Hahn

Electronic Theses and Dissertations

This thesis investigates the therapeutic potential of Avaren-Fc (AvFc), a novel lectin fusion protein that integrates the Fc region of human IgG1 with the engineered lectin Avaren, specifically targeting lymphoma. The study delineates the in vitro binding capabilities of Avaren-Fc with a human B-cell lymphoma cell line, a canine B-cell lymphoma cell line, healthy canine peripheral blood mononuclear cells (PBMCs), and healthy human PBMCs. AvFc was shown to exhibit significant binding to human lymphoma cells. Furthermore, the direct cytotoxicity of Avaren-Fc against canine lymphoma cells, canine lymphoma cells and healthy canine PBMCs was assessed. It was found that there is …

Enzymatic Depletion Of Adenosine To Potentiate Cancer Immunotherapy., Omar Sadi Sarkar

Electronic Theses and Dissertations

Immune checkpoint blockade (ICB) therapies have revolutionized cancer treatment, but many patients still do not respond well. To improve therapeutic outcomes, chemotherapy is often combined with immunotherapy, as chemotherapy is known to promote immunogenicity. However, many patients develop resistance to this combination therapy, and the reasons behind it are not fully understood. In this study, we explored how platinum-based chemotherapy, specifically cisplatin, affects tumor signaling to create an immunosuppressive tumor microenvironment (TME). We found cisplatin triggers ataxia telangiectasia mutated (ATM)-mediated DNA damage signaling and induces higher expression of prostaglandin E₂ (PGE₂) via a cyclooxygenase-2 (COX-2) mediated pathway. We speculate DNA …

Tumor Infiltrating Lymphocytes: From Discovery To Clinical Application., Lewis Clayton Chew

Electronic Theses and Dissertations

This thesis explores the evolution of TIL therapy from its discovery to clinical application, focusing on its use in treating metastatic cancer. Adoptive cell therapy (ACT), particularly TIL therapy, has emerged as a promising alternative to traditional treatments like chemotherapy. This review article traces the historical development of TILs, highlighting key experiments and clinical trials that have shaped its understanding and application as a therapeutic strategy for patients with metastatic and difficult to treat cancers including melanoma. Importantly, this article highlights recent advancements, including the FDA approval of Lifileucel, and explores emerging strategies to enhance therapeutic efficacy of TILs through …

Identifying Correlates Of Protection Of A Pneumonic Plague Vaccine., Caleb Samuel Whitley

Electronic Theses and Dissertations

Pneumonic plague is caused by inhalation of the bacterial pathogen Yersinia pestis. The immune response during Pneumonic plague occurs in two phases; an initial asymptomatic phase followed by a highly inflammatory and destructive phase resulting in 100% mortality if left untreated. The rapid onset of severe disease following the asymptomatic phase makes it difficult to administer antibiotics in time to prevent lethal outcomes. Therefore, the development of an effective vaccine is likely needed to combat pneumonic plague in areas of the world where Y. pestis remains endemic. One candidate subunit vaccine is protective in mice, a natural host for …

Orchestrated Architecture Dismantling: Borrelia Burgdorferi’S Coordinated Destruction Of Adaptive Immune Responses, Craig A. Land

Electronic Theses and Dissertations

Borrelia burgdorferi represents the most prevalent vector-borne bacteria in North America, affecting ~476,000 Americans annually yet persisting despite robust immune responses. This project reveals spirochetes target adaptive immunity through coordinated lymphatic colonization and precision immune dysregulation.

Using comparative host models (C57BL/6 vs. reservoir Peromyscus leucopus), we demonstrate lymph node colonization within 48-hours, with spirochetes exploiting LYVE-1-positive lymphatic structures as dissemination highways while avoiding the interior of follicular regions. Critically, we identify targeted CD4+ T-cell elimination in germinal center border zones at 21-DPI, precisely when these cells should be coordinating protective immunity. Concurrent upregulation of inhibitory receptor CD32b creates molecular …

Sars-Cov-2 Modulates Pla2g2d/Pgd2 Signaling To Manipulate Host Immune Response To Increase Disease Severity., Dante L. Hamiel

Electronic Theses and Dissertations

Background: Previous studies suggested that SARS-CoV-2 infection could cause diverse immune and metabolic dysregulations, although the underlying mechanisms remain poorly understood. In addition, viruses may escape the immune response by modulating cellular metabolism, mitochondria, and protein functions indicating that immune or metabolic components may represent novel targets for anti-viral strategies. However, whether immune and metabolic disorders interact or affect each other waits to be determined. On the other hand, previous investigations identified the critical roles of a cell membrane-bound phospholipase PLA₂G2D and its downstream products PGD₂ in regulating the metabolism and inflammation in respiratory system. More importantly, …

Interactions Of The Sars-Cov-2 Viral Genome 3’-Untranslated Region With Viral And Host Rnas, Caleb Frye, Mihaela Rita Mihailescu

Electronic Theses and Dissertations

This dissertation focuses on the characterization of RNA-RNA interactions within the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) genome and with host microRNAs. As the causative agent of coronavirus disease 2019 (COVID-19), SARS-CoV-2 has evolved rapidly since its appearance. This has warranted prompt characterization of the virus particularly of its single stranded RNA (ssRNA) genome. By using a combination of bioinformatics, biophysics, and/or biological assays, we analyzed the SARS-CoV-2 viral genomic RNA and uncovered interactions of genomic RNA with host RNAs, highlighting an underutilized method of targeting RNA viruses. We showed here that the conserved elements in the viral genomic …

Proteolytic Manipulation Of Neutrophil Responses And The Efferocytic Synapse By Porphyromonas Gingivalis., Kelley N. Cooper

Electronic Theses and Dissertations

Porphyromonas gingivalis (Pg) is etiologically associated with chronic periodontitis, a highly prevalent chronic inflammatory disease characterized by the destruction of hard and soft tissues of the periodontium. Pg is adapted to live in the human oral subgingival niche, a hostile environment dominated by excessive numbers of activated neutrophils and antimicrobial mediators. Its survival is contingent upon prompt and effective inactivation of neutrophil effector functions. In this dissertation, I uncover a novel pathogenic mechanism employed by Pg that disarms the antimicrobial capacity of live neutrophils and simultaneously sequesters them within macrophages. Mechanistically, RgpB, a cysteine protease produced by Pg …

Differential Responses Of Human Neutrophils To Legionella Species., Hannah E. Hanford

Electronic Theses and Dissertations

Legionella species are Gram-negative facultative intracellular bacterial pathogens commonly found in freshwater or soil environments where they survive and replicate within their natural protozoan hosts. Humans serve as an accidental host for Legionella species after inhalation of contaminated aerosolized water droplets or soil particles enabling the bacteria to enter the lungs, infect alveolar macrophages, and result in severe pneumonia. Evasion of degradation and proliferation within alveolar macrophages by Legionella species and manifestation of “Legionnaires’ disease” is dependent on the Dot/Icm type IV secretion system (T4SS). The T4SS apparatus is a needle-like channel for translocation of over ~350 effector proteins, depending …

Uncovering The Hidden Diversity Of Antibody Heavy Chains And Their Implications For Autoantibody Mediated Disease., Easton Earl Ford

Electronic Theses and Dissertations

Understanding the diversity of antibody (IG) molecules at the DNA and RNA level is imperative for understanding immunological processes and disease. Much of the work to uncover IG diversity has been focused on diversity in the variable region of the IG molecule which is crucial for antigen binding. However, the diversity of the constant region responsible for the functions of IG has largely been ignored in the field of immunogenetics. The work presented in this thesis challenges the dogma that the constant region is invariant in terms of genetic diversity. In this thesis we present the development of a long-read …

Molecular Mechanisms Of Exercise-Stimulated Resolution Of Inflammation And Its Dietary Dependence., Ernesto H. Pena Calderin

Electronic Theses and Dissertations

Diet-induced obesity and adipose tissue (AT) inflammation that ensues sets the stage for systemic metabolic inflammation, disrupted insulin signaling, and eventual type 2 diabetes (T2D) development. At the center of this pathology lies a disruption in endogenous inflammation resolution pathways characterized by an imbalance in lipid mediator production (greater abundance of pro-inflammatory to pro-resolving lipids). Additionally, obese states are characterized by adrenergic deficiency, especially in response to physical activity. Inflammatory processes have been experimentally mitigated by either the pharmacological inhibition of pro-inflammatory signals (i.e., Leukotriene B₄ (LTB₄) and its receptor BLT1, which establishes a potent chemotactic stimulus …

Omani Camels From A Cultural And Genomics Perspective, Al Muatasim Al Zadjali

Electronic Theses and Dissertations

The Dromedarian camel, Camelus dromedarius, is native to the Arabian Peninsula, including the Sultanate of Oman. These camels are used for food, milk, as well as show and racing competitions. Despite their economic and cultural importance research on camels in Oman is limited. The goal of this study was to examine their genomic variation, relationship with camels in other parts of the Arabian Peninsula, and to determine if selective breeding has led to the establishment of distinct breeds in Oman. Information was compiled from multiple sources to produce a comprehensive review on the breeding, management, economic and cultural use, …

Investigation Of Avaren-Fc's Therapeutic Potential Against Ovarian Cancer., Katarina Lee Mayer

Electronic Theses and Dissertations

This thesis describes the investigation of Avaren-Fc (AvFc), a novel lectin-based therapeutic fusion protein consisting of the recombinant Avaren lectin and the Fc region of human IgG1, against ovarian cancer. AvFc possesses selectivity toward tumor associated N-linked high-mannose-type glycans. The present study demonstrates AvFc’s in vitro activity against OVCA cell lines via antibody-dependent cell-mediated cytotoxicity and its ability to extend the survival of mice challenged with murine ID8 OVCA cells after repeated systemic administration. Furthermore, AvFc treatment in this model was found to increase the presence of peritoneal leukocytes, suggesting a shift toward an improved antitumor immune response. Another key …

Porphyromonas Gingivalis Inactivates Anti-Viral Immunity At The Oral And Respiratory Epithelium., Carlos J. Rodriguez Hernandez

Electronic Theses and Dissertations

The host microbiome plays an important role in fine-tuning host immune responses in a manner that ultimately impacts outcomes in viral infection. Symbiotic relationships between commensal bacteria and host epithelial and immune cells prime interferon (IFN) signaling, modulating the nature and intensity of the immune response to viral infections at mucosal barrier surfaces. In this doctoral thesis, I explore how dysbiotic shifts in the oral microbial communities modulate antiviral responses at the oral and oro-respiratory mucosal barriers. I identified that in response to a viral challenge, gingival epithelial cells (GECs) preferentially induced type III IFNs (IFN-λ), a newly described family …

Inhibition Of Pro-Inflammatory Lipid Mediators By Yersinia Pestis., Amanda Brady

Electronic Theses and Dissertations

Yersinia pestis causes the human disease known as plague. A key manifestation of plague is a delayed inflammatory response. Because this delay in inflammation is required for virulence, I was interested in defining the molecular mechanisms used by Y. pestis to evade immune recognition. Eicosanoids are produced early during infection and necessary to initiate a rapid inflammatory response. Despite the importance of these lipids in mediating inflammation, the role of eicosanoids during plague has not been previously investigated. Using an intranasal mouse model infection, I determined the kinetics of eicosanoid synthesis during pneumonic plague. I further demonstrated that LTB_{4 …}

Regulation Of Cd4 T Cell Functions By Ncrna-Mediated Signaling Pathways During Chronic Viral Infections, Lam Nguyen

Electronic Theses and Dissertations

CD4 T cell homeostasis and competency are critical for the effectiveness of antiviral immunity. However, CD4 T cells derived from people living with HIV (PLWH) and individuals with chronic HCV infection often exhibit an inflammaging phenotype, evidenced by persistent inflammation, immune activation, exhaustion, senescence, and cellular apoptosis. Despite intensive investigations, the molecular mechanisms underlying CD4 T cell dysfunction in antiretroviral therapy (ART)-controlled PLWH and HCV-infected patients remain poorly understood. By investigating the roles of non-coding (nc)RNA transcripts in regulating the functions of CD4 T cells derived from PLWH and HCV-infected patients, we demonstrated that long non-coding (lnc)RNA - growth arrest-specific …

Role Of The Anti-Viral Immune Response In Neural Cell Modulation And Neurological Sequelae Of Childhood Viral Infections, Yashika Kamte

Electronic Theses and Dissertations

Viral infections of the central nervous system (CNS) often result in neurological sequelae and are considered a risk factor for the development of neurological disease. Moreover, the outcomes of a viral infection are largely dependent on the age of the host, with younger hosts developing more profound neuropathology. Perhaps the developing brain coupled with an immature immune system contributes to worse outcomes in the very young. Children suffering from brain infections are more prone to develop enduring neurological impairments even after recovery from the infection. Although majority of the brain growth occurs in utero, neurodevelopment continues throughout the juvenile …

Intestinal Microbiome, Fecal Fermentation Profile, And Health Indices In Hiv Infected Men Versus Non-Infected Controls, Mary Andreae, Mary C. Andreae Mrs

Electronic Theses and Dissertations

Many HIV-positive (HIV+) males on Highly Active Anti-Retroviral Therapy (HAART) experience metabolic abnormalities, including Non-Alcoholic Fatty Liver Disease (NAFLD) and lipodystrophy. The intestinal microbiota and short chain fatty acids (SCFA), participate in bidirectional communication with their host. Dysbiosis in HIV+ males on HAART demonstrate a Prevotella-rich enterotype shaped by multiple factors including, medications, adiposity, diet, intestinal permeability, and lifestyle; our objective was to investigate these factors. 19 HIV+ and 21 HIV- males were enrolled. BMI and hip-to-waist ratio (H:W) were obtained, and FibroScan for liver health. Intestinal permeability markers Claudin-21, flagellin, and intestinal fatty acid binding protein (IFABP) in …

Effect Of Macrophage Expressed Α7 Nicotinic Acetylcholine Receptor (Α7nachr) On Migration Of Macrophages During Inflammation, Kasey Keever

Electronic Theses and Dissertations

Sepsis is a life-threatening condition characterized by overwhelming inflammation, resulting in organ system damage, leading to a high mortality rate. Care in the clinical setting is supportive, and there are no approved sepsis-specific treatments. In septic mice, activation of the cholinergic anti-inflammatory pathway decreases cytokine secretion by leukocytes and improves survival. The cholinergic anti-inflammatory pathway is a reflex of the parasympathetic nervous system, converging on the α7 nicotinic acetylcholine (α7nAChR) at the surface of macrophages. Signaling through the receptor blocks NF-kB activation, thus cytokine secretion. Receptor activation has other effects on macrophages, including modulating their migration to …

Multiphasic Molecular Mechanisms Regulate Expression Of Interleukin 1Β, As Well As Other Immediate-Early Genes, In Monocytes And Macrophages, David Macar

Electronic Theses and Dissertations

Interleukin 1β (IL-1β), an important cytokine in both health and disease, functions as a major proinflammatory mediator of pathological challenges, including involvement in the cytokine storm associated with Macrophage Activation Syndrome, Hemophagocytic Lymphohistiocytosis and the severe secondary effects of SARS-CoV-2 infection. Therapeutic approaches to limiting the effects of IL-1β protein have focused either on specific protein neutralization before release from activated macrophages (by general metabolic inhibitors and inflammasome inhibition) or after release by ligand and receptor obstruction (e.g., Canakinumab, Anakinra and Rilonacept). Although these approaches are efficacious, they inhibit steps after gene expression. Since a single gene expresses …

Characterization Of The Immunoglobulin Lambda Chain Across Diverse Human Populations., William Gibson

Electronic Theses and Dissertations

The adaptive immune system relies on a diverse set of over one hundred immunoglobulin (IG) genes across three genomic loci that are variably combined to form antibodies (Ab). The IG Lambda locus is one of two loci which encodes the IG light chain. The complexity of the IGL locus severely limits the effective use of standard short-read sequencing, limiting our knowledge of population diversity in these loci. We leveraged single molecule real-time (SMRT) long-read sequencing in conjunction with IGL-targeted DNA capture to develop the method IG-Cap for accurate and high-throughput sequencing of the IGL locus. We benchmarked this method using …

Illuminating Underappreciated Mechanisms Of Receptor Regulation In Human Lymphocytes., Cassandra Woolley

Electronic Theses and Dissertations

A thorough understanding of receptor regulation is imperative to predict expression in varying contexts of disease or treatment. Lymphocyte surface receptors are often used as biomarkers and drug targets, making them particularly important for study. For receptors of debated functionality, such as the Fc receptor for IgM (FcMR), understanding regulation can also help to predict expression in vivo to supplement hypotheses of biological roles. Various mechanisms exist for altering receptor surface expression, including direct feedback mechanisms such as ligand-induced endocytosis and broader mechanisms such as transcriptional and translational control. In this dissertation, we explore selected underappreciated mechanisms of lymphocyte receptor …

Microsporidian Spores And The Integrin Binding Loop Of The Madam Protein Are Important For Integrin Signaling And Attachment To Host Cells, Cindy L. Barrett

Electronic Theses and Dissertations

Microsporidia are a distant fungal pathogen that have severe clinical consequences for the immunocompromised. Previous work identified a microsporidian pathogen protein termed Microsporidian ADAM or MADAM. This protein has close sequence homology to other ADAM proteins (A Disintegrin and Metalloproteinase) in two microsporidian species, Encephalitozoon intestinalis and E. cuniculi. ADAM proteins have a wide range of functions, including binding to integrins and host signaling. It is known that many pathogens manipulate integrins to invade host cells, and it is predicted that microsporidia are also exploiting this host target. Previous work with the MADAM protein demonstrated that this protein has a …

Met Alterations In Glioblastoma: Characterization Of Patient-Derived Xenografts And Therapeutic Strategies, Anna Musket

Electronic Theses and Dissertations

Glioblastoma is the most commonly diagnosed central nervous system primary malignancy and it is considered a terminal diagnosis with few treatment options available. Glioblastoma tumors frequently develop treatment resistance due in part to their highly heterogenic nature. The heterogeneity of glioblastoma is partially attributed to the presence of glioma stem-like cells (GSC), which are highly invasive and resistant to chemotherapy and irradiation treatments. Signaling of the receptor tyrosine kinase MET is a known regulator of GSC. Glioblastoma patients have an increasingly poor prognosis that corresponds with increasing MET expression. Both GSC and MET are known to contribute to treatment resistance …

Comparative Characteristics Of Integrin Αdβ2 Binding To Native Fibrinogen And Fibrinogen Modified By Dha Oxidation During Inflammation, Ajibola Ilesanmi

Electronic Theses and Dissertations

2-ω-carboxyethylpyrrole (CEP) is a product of docosahexaenoic acid (DHA) oxidation, which forms covalent adducts with different proteins. CEP-modified proteins can interact with macrophage receptor, integrin αDβ2. This study aims to compare αDβ2 binding to its physiological ligand, fibrinogen, and CEP-modified fibrinogen, which is formed during inflammation. We hypothesize that modification of fibrinogen changes its ligand-binding properties to integrin αDβ2 which can affect macrophage migration and retention. Recombinant αD I-domain and αDβ2-transfected HEK293 cells were used for the experiments. Using biolayer interferometry, we found that the affinity of αD I-domain binding to fibrinogen-CEP was higher than fibrinogen and inhibited by the …

The Mechanisms Of Mitochondrial Dysfunction In T Cell Aging During Chronic Viral Infection, Madison B. Schank

Electronic Theses and Dissertations

Human immunodeficiency virus (HIV) and hepatitis C virus (HCV) infections induce a myriad of disturbances to CD4 T cell functions, including mitochondrial compromise, excessive inflammation, increased telomeric DNA damage and attrition, cellular exhaustion and senescence, and accelerated aging. In this dissertation, the mechanisms underlying metabolic failure, accelerated aging, and cellular dysfunctions were evaluated in CD4 T cells from healthy subjects (HS) treated with a telomere-targeting drug (KML001) or HCV-infected individuals or people living with HIV (PLHIV) compared to HS. We observed that KML001-induced telomere injury resulted in mitochondrial swelling and decreased mitochondrial membrane potential, cellular respiration, mitochondrial DNA (mtDNA) copy …

Investigating The Pi3k/Akt/Atm Pathway, Telomeric Dna Damage, T Cell Death, And Crispr/Cas9-Mediated Gene Editing During Acute And Chronic Hiv Infection, Sushant Khanal

Electronic Theses and Dissertations

Human Immunodeficiency Virus (HIV) infection initiates major metabolic and cell- survival complications. Anti-retroviral therapy (ART) is the current approach to suppress active HIV replication to a level of undetected viral load, but it is not a curative approach. Newer and sophisticated gene editing technologies could indeed be a potent antiviral therapy to achieve a clinical sterilization/cure of HIV infection. Chronic HIV patients, even under a successful ART regimen, exhibit a low-grade inflammation, immune senescence, premature aging, telomeric DNA attrition, T cell apoptosis, and cellular homeostasis. In this dissertation, we investigated CD4 T cell homeostasis, degree of T cell apoptosis, an …

A Functional Study Of Topological Dna Problem In Human T Cells During Chronic Viral Infection, Xindi Dang

Electronic Theses and Dissertations

T cells play an important role in adaptive immune system against viral infections, while premature aging and dysfunction of T cells induced by unrepaired DNA damages are always non-negligible snags during the long-term of fighting with chronic viral infections, such as Hepatitis B virus (HBV), Hepatitis C virus (HCV) or Human Immunodeficiency Virus (HIV) infection. In this dissertation, we investigated the role of topological DNA damage in reprogramming telomeric DNA damage responses (DDR), mitochondrial metabolisms, and T cell functions using CD4+ T cells derived from individuals with chronic viral infections or healthy subjects treated with topoisomerase inhibitors. The healthy human …

Investigating Host Defenses Of North American Salamanders Against The Recently Emerged Chytrid Pathogen, Batrachochytrium Salamandrivorans, Kenzie Pereira

Electronic Theses and Dissertations

A recently emerged chytrid fungal pathogen, Batrachochytrium salamandrivorans (Bsal) threatens salamander biodiversity. Bsal susceptibility varies between and within salamander species, but little is known about the mechanisms underlying these differences. Susceptibility is likely influenced by numerous interacting factors, but my dissertation studied the role of host immune responses.

My first aim investigated between species differences by studying the bioactive properties of salamander skin peptides against Bsal and the related pathogen, B. dendrobatidis (Bd). Skin peptides were collected from five salamander species, used for in vitro assays, and analyzed by RP-HPLC. While skin peptides from one …