Examining The Ligands, Location, And Function Of Toll-Like Receptor 10, Kiefer Keanu Tam

Master's Theses

Toll-like receptors are a class of innate immune pattern recognition receptors that detect pathogen-associated molecular patterns and regulate downstream inflammatory responses. Toll-like receptor 10 remains the only human TLR whose ligand specificity, cellular localization, and immunological function are not fully defined. Emerging evidence suggests that TLR10 may play an anti-inflammatory role and can heterodimerize with TLR2 to modulate immune signaling. Previous studies from our laboratory demonstrated that stimulation with heat-killed Mycobacterium tuberculosis promotes TLR2-TLR10 heterodimerization and trafficking to the cell surface. In this study, we expanded our ligand panel to include additional gram-positive bacteria, particularly anti-inflammatory probiotic species, to further …

The Role Of Tumor Microenvironment In Glioblastoma Multiforme(Gbm) Therapeutic Resistance, Kwesi E. Taylor

Master's Theses or Doctor of Nursing Practice

Despite significant advances in cancer research and treatment, Glioblastoma multiforme (GBM) remains one of the most difficult cancers to treat effectively, with minimal improvement in long-term survival rates over the past few decades. This is largely attributed to tumor heterogeneity and the ability of tumor cells to develop adaptive resistance mechanisms supported by the tumor microenvironment (TME). Although the TME is recognized as a key contributor to tumor progression and therapeutic resistance, the underlying molecular pathways and regulatory genes remain incompletely understood. This study investigated the role of the tumor microenvironment in GBM therapeutic resistance using a bioinformatics approach. Single-cell …

Development Of A Split Deoxyribozyme-Based Assay For Detecting Hepatitis B Virus, Dalila Zovko

Honors Undergraduate Theses

Rapid, accessible nucleic acid-based detection methods are needed for hepatitis B virus (HBV). A split deoxyribozyme assay was developed for sequence-specific fluorescence detection. The assay was evaluated using synthetic target and plasmid-derived material. The assay showed target-dependent fluorescence and low-concentration linear range with a LOD of 1.9 nM. The assay supports detection and semi-quantification of HBV genetic material as shown using plasmid-derived transcript samples from HBV genotypes B, C, and D. The selected target corresponded to nt 363–406 of the HBV genome and was chosen based on sequence alignment showing conservation across most genotypes. Genotype-specific detection remains a future application …

Nanoparticle Carriers Enhance The Prophylactic Antiviral Effects Of Dsrna In Vitro And Ex Vivo, Shayne Oberhoffner, Stephanie Dewitte-Orr, Starla Richardson, Leah Haile, Dominique Daniels, Erin Cooper, Aizah Ijaz, Janet Velasquez Perez, Mathilde Peruzzi, Bertrand Collet, Paul Craig, Kristof Jenik

Theses and Dissertations (Comprehensive)

Aquaculture now outpaces traditional capture fisheries as the world population and demand for sustainable protein sources increases. Wild and farmed species are increasingly susceptible to pathogen spread as global temperatures rise and stocking densities increase. Despite the devastating losses experienced by aquaculture due to viral infections, there remain few effective prophylactic antiviral therapeutics. Long double-stranded (ds)RNA is a uniquely viral molecule produced by nearly all viruses during their replication cycle, and its detection by salmonids like rainbow trout (Oncorhynchus mykiss) and chinook salmon (Oncorhynchus tshawytsha) leads to the establishment of a defensive antiviral state. Previous in vitro studies demonstrated a …

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 …

Next-Generation Salmonella Inactivated Vaccine Platforms And Phytobiotic-Modulated Immune Responses In Poultry, Santiago Uribe Diaz

Graduate Theses and Dissertations

Here, a comprehensive understanding of immune responses triggered by either a multimeric CD40 receptor-agonistic DNA aptamer-based or mannosylated chitosan-based Salmonella Enteritidis inactivated vaccine platforms, along with phytobiotic supplementation as an immune modulatory strategy in response to Salmonella lipopolysaccharides, is presented. This dissertation supports the development of next-generation Salmonella vaccine platforms that simultaneously stimulate both protective cell-mediated and humoral immune responses, while indicating the potential immunomodulatory effects of phytobiotics supplementation to reduce the immunological impact of Salmonella lipopolysaccharides in chickens. The first chapter describes that both vaccine platforms administered in broiler chickens initiated local inflammatory responses, recruiting heterophils and macrophages from …

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 …

Adiponectin-Regulated Macrophage Responses In Aspergillus Fumigatus Infection: Mechanisms Of Uptake And Killing, Sri Harshini Goli

All-Inclusive List of Electronic Theses and Dissertations

Invasive aspergillosis (IA), caused by Aspergillus fumigatus, is a life-threatening infection in immunocompromised individuals, necessitating novel host-directed therapies. Macrophages are pivotal in antifungal defense, yet their function can be dysregulated; the influence of the adipokine adiponectin (APN) on this process is not fully understood. This thesis investigated the role of APN signaling in alveolar macrophage (AM) and bone marrow-derived macrophage (BMDM) responses to A. fumigatus and assessed the therapeutic potential of the APN receptor agonist, AdipoRon. Initial studies revealed that genetic deficiency in APN or its receptors renders AMs intrinsically pro-inflammatory and significantly impaired fungicidal activity against A. fumigatus. Subsequent …

Exploring Immune System Through Computational Modeling: A Comprehensive Study Of Lymph Nodes And Immune Response Scaling, Vaccine Efficacy, And Large-Scale Extreme First Passage Time, Jannatul Ferdous

Computer Science ETDs

The adaptive immune response is a complex defense mechanism that develops over time to recognize and eliminate pathogens with remarkable precision and durability. This dissertation investigates the dynamics, scaling, and efficiency of the adaptive immune response through a synthesis of computational modeling, mathematical analysis, and agent-based simulations. First, we analyze the topology of the lymphatic network and investigate the T cell search time to find the lymph node that is containing the matching dendritic cell. Second we show how the scaling of lymph node number and volume with body mass, leads to scale-invariant search times for T cells locating antigen-bearing …

Macrophage Heterogeneity And Function In The Lung, Xin Li

Dartmouth College Ph.D Dissertations

Macrophages are critical custodians of the lung, orchestrating immune surveillance, maintaining tissue homeostasis, and coordinating both innate and adaptive responses. This dissertation examines their heterogeneity and specialized functions, focusing on IMs, which reside in the lung interstitium, and AMs, which occupy the airspace. Through comprehensive single-cell transcriptomic profiling of murine and human samples, we identify multiple IM and AM subsets defined by distinct chemokine, cytokine, receptor, and innate immune gene signatures. These subsets display clear divisions of labor, contributing to immune cell recruitment, tertiary lymphoid structure formation, and alveolar homeostasis.

In IMs, coordinated chemokine programs not only recruit inflammatory cells …

Expanding Inducible Epithelial Resistance Against Pneumonia: Novel Virus, Novel Receptor, Michael Longmire

Dissertations and Theses (Open Access)

Pneumonia is the leading infectious cause of death worldwide and presents a continuing risk among immunocompromised patients. Our work has been focused for many years on the phenomenon of inducible epithelial resistance, where activation of the innate immune response in the airway epithelium is necessary and sufficient to produce a pathogen-killing but self-protective environment to prevent severe disease. Inducible resistance is pathogen-agnostic and has been demonstrated against an array of respiratory infections. We achieve this using a combination of pattern recognition receptor agonists – Pam2CSK4 and ODN M362 being the current formulation – which produce synergistic levels of pathogen reduction …

African Sleeping Sickness: From Basic Biology To Future Directions, Riddhi R. Patel

All Theses

African Sleeping Sickness is a Neglected Tropical Disease (NTD) which poses a significant health risk to impoverished populations in 36 Sub-Saharan African countries. It is a devastating disease caused by the protozoan parasite Trypanosoma brucei, which is transmitted to mammals via the bite of infected tsetse flies. The disease manifests in two stages: the hemolymphatic stage and the meningoencephalitic stage. In the latter stage, it invades the Central Nervous System (CNS) and can be fatal if left untreated. It is caused by morphologically indistinguishable species of Trypanosoma brucei in both humans and animals, where in humans it is known as …

Impact Of Temperature And Microbial Infection On The Honey Bee Hemocytes, Michael E. Oeth

Master's Theses

Introduction

Honey bees (Apis mellifera) rely on hemocytes for immunity, wound healing, and hemolymph homeostasis. While 32°C reflects optimal hive conditions, suboptimal temperatures (22°C) and stressors like pathogens (Varroa destructor, bacteria) or pesticides impair hemocyte function. Using clodronate liposomes (CLD) to deplete hemocytes, we assessed how immune suppression interacts with these stressors.

Methods

Newly emerged (5-day-old) and older (15-day-old) bees were assigned to: CLD, control liposomes (LP), PBS, injection wound, or no treatment. Cohorts were exposed to 32°C (optimal) or 22°C (stressful for non-immunosuppressed bees). Fifteen-day-old bees were challenged with Escherichia coli or Staphylococcus aureus. Survival, hemolymph volume, and hemocyte …

Neutrophil Inflammatory Death Regulation By Bacterial Type Iii Secreted Effectors, Arianna D. Reuven

Dartmouth College Ph.D Dissertations

Yersinia and Pseudomonas use a T3SS to secrete effectors into host cells that inhibit phagocytosis and modulate immune responses, such as inflammasome activation. Inflammasomes promote the activation of the proinflammatory protease caspase-1. The activation of an inflammasome sensor in response to a signal or ligand initiates the assembly of the inflammasome leading to activation of caspase-1 which cleaves GSDMD and pro-inflammatory cytokines IL-1β and IL-18 into their mature forms. As neutrophils are recruited in large quantities to sites of infection, they are excellent candidates to drive inflammasome dependent responses. Neutrophils have been shown to produce multiple inflammasomes, like pyrin and …

Characterizing Malaria Infections In Caribbean Lizards: Parasite Niche Expansion & Host Response, Sarah J. Pangburn

Dissertations, Theses, and Capstone Projects

Malaria is historically one of the most severe parasitic human diseases and is still responsible for over half a million deaths annually. Plasmodium species, the causative agents of malaria, are often characterized by two hallmark features of their asexual stages: the invasion of vertebrate red blood cells and the presence of hemozoin pigment as a byproduct of host hemoglobin digestion. Despite their evolutionary relatedness to mammalian Plasmodium, wildlife malaria parasites are understudied, leaving their vast genetic diversity to be explored. Lizard-infective malaria parasites, for example, include over 100 species of Plasmodium and present a diverse array of phenotypes, some …

Functional Analysis Of Ligand Binding Domain 2 Of Outer Surface Protein C Of Borreliella Burgdorferi, Gavin Z. Chambers

Theses and Dissertations

Lyme disease, caused by the spirochete Borreliella burgdorferi, is the most common vector-borne infection in North America. A critical determinant of early mammalian infection is outer surface protein C (OspC), a highly variable lipoprotein that is indispensable for spirochete survival but whose precise function remains unresolved. OspC has been proposed to mediate diverse roles, including complement evasion, adhesion, tissue dissemination, and antiphagocytic activity, supporting the view that it is a multifunctional virulence factor. Structural studies have identified two putative ligand-binding domains (LBD1 and LBD2), with LBD2 forming a solvent-exposed crown at the membrane-distal end of the OspC dimer.

To …

The Role Of Host Factor Sptbn1 In Hiv-1 Capsid Uncoating In Human Microglial Cells, Callie Marie Fry

Graduate Theses/Dissertations

HIV-1 is the virus that causes acquired immunodeficiency syndrome (AIDS), and currently, there is no cure once an individual is infected. The development of new drugs targeting HIV-1 replication steps is essential for keeping viral loads low or undetectable to prevent further transmission. An attractive replication step for new drug targets is viral capsid uncoating, where the virus loses the protein structure encapsulating the genome. The exact mechanism of capsid uncoating is unknown; however, several host-factors may be involved including protein SPTBN1. Recent studies have shown a significant decrease in viral infectivity when SPTBN1 is knocked down, yet its role …

Elucidation Of The Post-Transcriptional Regulation And Role In Iron Homeostasis Of The Outer Membrane Vesicle Protein Ynce In Salmonella, Mira J. Schmidt

Honors Undergraduate Theses

Iron is an essential element for most bacteria as it is a crucial cofactor for enzymes involved in fundamental reactions such as DNA synthesis. Despite being the fourth most abundant element on Earth, bacteria face challenges acquiring iron under aerobic conditions due to the poor solubility of its oxidized form (Fe³⁺). To overcome this, bacteria have developed various strategies of iron acquisition, such as the production of siderophores. Siderophores are small molecules that scavenge free Fe³⁺ in iron-deprived environments. Iron acquisition is tightly regulated due to its capability of promoting hydrogen peroxide formation via the Fenton reaction. In Salmonella Typhimurium, …

Antibody-Induced Multicellular Behaviors Of Salmonella Typhimurium, Samantha K. Lindberg

Electronic Theses & Dissertations (2024 - present)

Salmonella enterica is a globally distributed bacterial pathogen that is commonly acquired through consumption of contaminated food and water. The enterica subspecies includes over 1500 unique subvariants, or serovars, that are classified by antigen presentation. Due to its global environmental prevalence, broad host range, and increasing pathogenicity, serovar Typhimurium is of particular concern for human and animal health, as well as food safety. Once in the gastrointestinal tract, Salmonella Typhimurium (STm) exploits host immune mechanisms, implements an arsenal of virulence factors, and outcompetes the microbiota to invade the intestinal epithelium. While STm infections are generally self-limiting and relatively mild, emerging …

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 …

Lack Of Inflammatory Response In Mouse Embryonic Cells To Listeria Infection, Damilola Oyebode

Master's Theses

Approximately 1 in 5 pregnancies in the United States results in miscarriage, with a significant percentage of these losses attributed to failed implantation due to immunological challenges encountered by the early embryo. Recent research has shown that key cell types within mouse blastocysts, including embryonic stem cells (ESCs) and trophoblast stem cells (TSCs), exhibit remarkable resilience against the cytotoxic effects associated with viral infections and embryotoxic cytokines, such as TNFα and IFNγ, both of which are known to hinder blastocyst development. However, the immune properties of the preimplantation stage embryo, specifically the blastocyst, remain poorly understood. Using mouse cell model, …

Understanding Primate Immunity To African Trypanosomes Through The Characterization Of Trypanosome Lytic Factor Formation And Function, Sara Fresard

Dissertations, Theses, and Capstone Projects

African trypanosomes cause an annual loss of over 1 billion USD due to their economic and agricultural burden in Sub-Saharan Africa. These parasites are unicellular, extracellular parasites, that infect humans, cattle, and other livestock. Humans and some non-human primates are protected against most species of trypanosomes due to an innate immunity factor, Trypanosome Lytic Factor (TLF). This modified High Density Lipoprotein (HDL) contains two unique proteins, Haptoglobin Related Protein (HPR), a ligand to a trypanosome surface receptor, and Apolipoprotein-L1 (APOL1), the lytic component. Our overall goal is to use our understanding of primate immunity to create genetically modified cattle that …

Sounding The Alarm: Local Cues That Drive Functional Specialization Of Brain Resident Memory T Cells, Shawn Christopher Musial Jr.

Dartmouth College Ph.D Dissertations

Resident memory T cells are a unique subset of memory T cells that persist within tissues throughout the body, including the brain, optimally positioned to exert local immune activation. Broadly, T cells in the CNS are implicated in a range of neurologic disorders, can protect against reinfection, and even participate in normal CNS homeostasis. Despite this, there remain significant gaps in knowledge about how T cells, specifically resident memory T cells (T_RM), are regulated and function in the unique CNS environment. Here, we leverage a mouse model of acute viral infection to dissect the diversity of brain T …

Comprehensive Investigation Into The Molecular Mechanisms Driving The Emergence Of Emm4 Group A Streptococcus, Chioma Odo, Samuel A Shelburne, Anthony R. Flores, Steven J Norris, Anna Konovalova, Blake Hanson

Dissertations and Theses (Open Access)

Abstract

Comprehensive Investigation into the Molecular Mechanisms Driving the Emergence of emm4 Group A Streptococcus

Chioma Modeline Odo, M.S.

Advisory Professor: Samuel A. Shelburne, MD, Ph.D.

The major gram-positive bacterium group A Streptococcus (GAS) is a model organism for studying microbial epidemics as it is well known to cause infections that occur in waves. GAS strains are grouped based on the composition of the N-terminal sequence of the M protein which is encoded by the emm gene. With the advent of large-scale whole genome sequencing, GAS clonal emergence events in emm1, emm3, and emm89 types have been identified …

Adaptive Immune Profiling Of Sin Nombre Hantavirus And Severe Acute Respiratory Syndrome Coronavirus 2 Infection, Tonilynn M. Baranowski

Biomedical Sciences ETDs

Hantaviruses are causative agents of potentially fatal respiratory illness and/or organ failure in humans worldwide. In the United States, the predominant hantavirus species, Sin Nombre hantavirus (SNV), causes a severe disease pathology, called hantavirus cardiopulmonary syndrome (HCPS). Infection with SNV and subsequent clinical manifestations of HCPS lends itself to case fatality rates approaching 40%, even under supportive care. This is partially due to the lack of FDA-approved vaccines and antivirals, in addition to a deficit in our knowledge regarding the human immune response to SNV. Further investigation of the adaptive immune response may reveal key targets to mediate disease outcome. …

Role Of Acute Alcohol Exposure In Klebsiella Pneumoniae-Induced Pneumonia, Prantho Malakar Dipta

LSU Master's Theses

Klebsiella pneumoniae (KP), a Gram-negative bacterium, induces severe pneumonia associated with devastating pathological consequences in the lung, such as substantial parenchymal damage. K. pneumoniae is responsible for causing life-threatening lung infections in patients with alcoholics and diabetics. The need to look for new therapeutic approaches is due to the emergence of Klebsiella pneumoniae strains that are resistant to many drugs. The effects of acute alcohol consumption on the host’s innate immune response to KP during infection remain unclear. Age-matched C57BL/6 female mice were administered 6g/kg of 32% alcohol or same amount of PBS via oral gavage 30 minutes prior to …

Deep Sequence-Coupled Biopanning And Vaccine Development, Julianne Peabody

Biomedical Sciences ETDs

Virus-like particles (VLPs) are nanoparticles comprised of viral structural proteins. They physically resemble the virus from which they are derived but lack genomic material. They are non-infectious, non-replicating, and have a favorable safety profile. VLPs are highly immunogenic with a dense, repetitive structure that is strongly activating for B cells. VLPs can be utilized to develop vaccines and can be used either as direct immunogens or platforms for the display of heterologous antigens. The display of foreign peptides on VLPs can be used to elicit high-titer antibodies against the displayed peptide. A virus-like particle based on the RNA bacteriophage MS2 …

New Insights Into T Lymphocyte-Mediated Immunity To Toxoplasma Gondii, Claire Marie Doherty

Biology ETDs

With nearly a third of the global population infected with the protozoan, Toxoplasma gondii, this parasite sits at a unique, immune-mediated interface of health and disease. In healthy individuals, Toxoplasma results in a chronic yet asymptomatic infection of the central nervous system. This quiescent infection is the result of parasite exploitation of host immune barriers, yet Toxoplasma can quickly become an opportunistic pathogen when immunity is disrupted by illness or immunosuppressive therapies. During the HIV-AIDS pandemic, it was observed that once latent Toxoplasma infections became the cause of severe, even fatal, disease in the absence of an intact T …

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 …}