Life Sciences Commons^™

Development Of Non-Viral Nano-Carriers For Gene Delivery And Covid-19 Vaccines, Zhongyu Li

Dissertations

Gene therapy is one of the most promising medical fields with the potential to effectively advance the treatment of difficult diseases by producing therapeutic proteins or repairing defective gene sequences. However, gene therapy presents severe challenges in delivery including renal clearance, phagocytosis, enzymatic degradation, protein absorption, and cellular internalization barriers, which have been barriers for translation into the clinic. Naked nucleic acids, with their intrinsic negative charge, electrostatically repulse the anionic cell membrane, preventing cellular uptake. Also, they are considered foreign genetic material when introduced into the body and are rapidly cleared by the reticuloendothelial system or degraded by nucleases, …

Probing Amyloid-Beta Protein Structure And Dynamics With A Selective Antibody, Shikha Grover

Dissertations

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder. The AD brain is characterized by significant neuronal loss and accumulation of insoluble fibrillar amyloid-β protein (Aβ) plaques and tau protein neurofibrillary tangles in the brain. However, over the last decade, many studies have shown that the neurodegenerative effect of Aβ may in fact be caused by various soluble oligomeric forms as opposed to the insoluble fibrils. Furthermore, the data suggest that a pre-fibrillar aggregated form, termed protofibrils, mediates direct neurotoxicity, and triggers a robust neuroinflammatory response.

Antibodies targeting the various conformation of Aβ are important therapeutic agents to prevent the progression …

Investigating The Involvement Of The Tick Vector In The Induction Of Alpha-Galactose Hypersensitivity (Alpha-Gal Syndrome, Red Meat Allergy) In The United States., Gary Crispell

Dissertations

Alpha-gal syndrome (AGS or sometimes called red meat allergy) is a result of the development of specific IgE antibodies to the oligosaccharide galactose-α-1,3-galactose (α-gal) after a person has had exposure to tick bites. This dissertation investigates four common tick species found in North America: the lone-star tick (Amblyomma americanum), the Gulf-Coast tick (Amblyomma maculatum), the American dog tick (Dermacentor variabilis), and the black-legged tick (Ixodes scapularis) for the presence of α-gal by utilizing a combination of immunoproteomic approaches and carbohydrate analysis techniques.

Anti-α-gal IgM antibodies (M86) were used in immunoblotting to detect …

Elucidating The Mechanisms Underlying How Vmp1 Regulates Inflammatory Responses, Stephanie Zack

Dissertations

autophagy, inflammation, mitochondria, NLRP3 inflammasome, SERCA, VMP1

Characterizing Endogenous Dicer Products To Unravel Novel Rnai Biogenesis Pathways, Jacob Oche Peter

Dissertations

ABSTRACT

RNA interference (RNAi) is a pervasive gene regulatory mechanism in eukaryotes based on the action of multiple classes of small RNA (sRNA). Exploiting RNAi pathways in non-model systems have great potential for creating potent RNAi technologies. Here, we accessed RNAi-mediated control of gene expression in the two-spotted spider mite, Tetranychus urticae (T. urticae) using engineered dsRNA designed to modulate the host RNAi pathway and increase RNAi efficacy. Analysis of Dicer (Dcr) generated fragments revealed how exogenous RNAs access the host RNAi pathway in this animal, opening avenues for designing RNAi technology for their control. Further, some organisms …

Repeated Low-Level Blast Induces Chronic Neuroinflammation And Neurobehavioral Changes In Rat Models, Arun Reddy Ravula

Dissertations

Blast-induced neurotrauma (bTBI) is a signature medical concern for military personnel when they are exposed to explosions in active combat zones. However, soldiers as well as law enforcement personnel are also repeatedly exposed to low-level blasts during training sessions with heavy weaponries as part of combat readiness. Service personnel who sustain brain injuries from repeated low-level blasts (rLLBs) do not display overt pathological symptoms immediately but rather develop cognitive impairments, attention deficits, anxiety, and sleep disturbances over time. An improved rat model of rLLB was developed in this thesis by applying controlled low-level blast pressures (10 psi) repeated five times …

B Cells In The Gut Associated Lymphoid Tissue (Galt), Ameera Bukhari

Dissertations

The gut-associated lymphoid tissue (GALT) is the largest mass of lymphoid tissue in the body, and it is a unique line of defense where immune cells are in constant contact with gut commensals and pathogens. B lymphocytes constitute most of the lymphatic tissues of the gastrointestinal (GI) tract and they play a critical role in protecting from infections, promoting tolerance, and shaping microbiota in the gut through the production of immunoglobulins (Ig). Previous studies on GALT B cells in human showed that large B cell clones in the body partition into two broad networks: one includes the blood, bone marrow, …

Dicer Represses Antiviral Innate Immunity Pathways In Mouse Embryonic Stem Cells, Chandan Gurung

Dissertations

Recent studies have demonstrated that embryonic stem cells (ESCs) are deficient in expressing type I interferons (IFN), the cytokines that play key roles in antiviral responses. However, the underlying molecular mechanisms and biological implications of this finding are poorly understood. In this study, I used a synthetic RNA-based assay that can simultaneously assess multiple forms of antiviral responses in ESCs. Dicer is an enzyme essential for RNA interference (RNAi), which is used as a major antiviral mechanism in invertebrates but not clear in vertebrates. RNAi activity is detected in wild-type ESCs but is abolished in Dicer knockout ESCs (D−/−ESCs) as …

Livestock Ticks In The Uae: Prevalence, Distribution, Population Dynamics, And Associated Microorganisms, Nighat Perveen

Dissertations

Ticks are important vectors of an array of viral, bacterial, and protozoan pathogens resulting in a wide range of animal and human diseases in the Middle East and North Africa (MENA). In this study, ticks were collected from camels, cows, sheep, and goats in Abu Dhabi, Dubai, and Sharjah in the United Arab Emirates (UAE). The objectives of the study were to (1) identify tick species of livestock through taxonomic keys and using molecular markers, and determine their prevalence and distribution in the UAE, (2) assess Hyalomma dromedarii seasonal population fluctuation over a year under common camel breeding and management …

Investigating The Effects Of Tgf-Β On T Cell Activation-Induced Cell Death, Christina Rose Cunha

Dissertations

Achieving immune homeostasis requires the functions and numbers of suppressive regulatory T cells (Tregs) and effector conventional T cells (conv T) to be balanced and precisely controlled. A decrease in Treg numbers is associated with autoimmune diseases such as type I diabetes and multiple sclerosis, while Treg numbers are increased in the tumor microenvironment. Conversely, an increase in conv inflammatory T cells in the tumor microenvironment is associated with better outcomes for cancer patients. Thus, maintaining the appropriate balance between Treg and conventional T cell populations is essential for controlling immune responses against non-self and self-antigens, as well as tumor …

Molecular Determinants Of Fetal Tolerance And The Transition To Adult Immunity, Yi Wei Lim

Dissertations

The perinatal immune system is highly tolerogenic and is phenotypically and functionally distinct from the adult immune system. This tolerogenic nature is a double-edged sword for newborns. While it is beneficial to prevent excessive inflammation against the vast array of foreign antigens encountered after birth, it also causes a lack of immune responses to life-threatening infections. My dissertation research aims to investigate the mechanisms by which perinatal T cells contribute to immune tolerance in infants. A deeper understanding of the nature of the perinatal immune system will provide pivotal knowledge to develop safe and effective strategies to protect infants from …

Analysis Of Regulatory Mechanisms For T Cell Activation, Aleksandra Vuchkovska

Dissertations

The primary function of the immune system is to seek and eliminate altered or unhealthy cells. T cells are a major component of the immune response and mediate their functions by recognizing specific antigens that allow elimination of infected or neoplastic cells. To avoid inappropriate activation and subsequent immune injuries, T cells have evolved strategies to discriminate self from non-self, or healthy from altered and infected. These strategies rely on the activation of receptors that restrict the T cell response. CD33rSiglecs are a family of mostly inhibitory receptors that bind to sialic acids. Siglecs respond to specific sialic acid patterns …

Suffocated Cd8 T Cells In The Hypoxic Tumor Microenvironment, Lourdes Beatriz Plaza Rojas

Dissertations

Hypoxia is a common feature of solid tumors that plays an important role in angiogenesis, malignant progression and metastatic development. However, its impact on T cell anti-tumor responses is less known. We determined that CD8 tumor infiltrating lymphocytes (TILs) tend to localize to non-hypoxic tumor areas, suggesting a susceptibility to tumor-associated hypoxia. This led us to further study the effects of hypoxia in vitro by culturing spleen-derived mouse T cells in a humidified chamber at 0.5% O2, 5% CO2 and 37 °C. We found that T cell proliferation and effector function are reduced by hypoxia, severely affecting inflammatory cytokine production. …

Determining The Genetic And Phenotypic Profile Of Cord Blood Derived T Regulatory Cells And The Effect Of Calcitriol On Immune Suppression, Anya Nikolai-Yogerst

Dissertations

Recent outbreaks in vertically transmitted viruses, such as Zika virus and HIV, have rejuvenated interest in fetal and neonatal immune tolerance. Babies are susceptible to vertically transmitted viruses because fetal and neonatal immune systems are considered to be immune-privileged and will tolerate antigens presented to them by their mother. Thus, understanding the mechanisms of this tolerance is important to design effective treatments for infected mothers to protect their offspring. Here, I define a novel Treg, a type of T cell that mediates tolerance, named bidirectional T cells (BiT), found in human umbilical cord blood (UCB). These cells are induced by …

Developing Caspase-1 Biosensors To Monitor Inflammation In Vitro And In Vivo, Sarah Talley

Dissertations

Inflammation is central to the pathogenesis of numerous human diseases. in many contexts, inflammation drives immune responses which are critical to protection against many pathogens. However, uncontrolled inflammation can drive the pathology of numerous diseases, including neurodegenerative diseases, intestinal disorders, cancer, and autoimmune diseases. a primary mediator of inflammation is the inflammasome complex, which drives the release of inflammatory mediators through caspase-1 activation. Our goal was to develop a tool that would allow us to monitor caspase-1 activation in vitro and ultimately in vivo. to this end, we employed a circularly permuted form of luciferase in which the N- and …

The Histoplasma Capsulatum Ddr48 Gene Is Required For Survival Within Macrophages And Resistance To Oxidative Stress And Antifungal Drugs, Logan Blancett

Dissertations

Histoplasma capsulatum(Hc)is a systemic, dimorphic fungal pathogen that affects upwards of 500,000 individuals in the United States annually. Hc grows as a multicellular mold at environmental temperatures; whereas, upon inhalation into a human or other mammalian host, it transforms into a unicellular, pathogenic yeast. The research presented in this dissertation is focused on characterizing the DNA damage-responsive gene HcDDR48. HcDDR48was originally isolated via a subtractive DNA library enriched for transcripts enriched in the mold-phase of Hcgrowth. Upon further analysis we found that HcDDR48is not just expressed in the mold morphotype, but both growth programs …

Binge Alcohol Drinking Exacerbates Ulcerative Colitis Flare, Abigail Cannon

Dissertations

Inflammatory Bowel Disease (IBD) remains a prominent medical concern affecting over 1.4 million people in the U.S. One of the most common forms of the disease is ulcerative colitis (UC), and UC patients will often head doctor's advice to refrain from drinking alcohol. However, whether this phenomenon of alcohol exacerbating UC symptoms occurs is still unknown, which necessitated the generation of a mouse model of UC and binge alcohol. Therefore, we examined a range of DSS concentrations (2-4%) and 2 alcohol paradigms in C57BL/6 mice. Mice receiving 2% DSS ad libitum for five days with a three-day alcohol binge had …

Structure-Guided T Cell Receptor Mutations That Alter Antigen Specificity, Cross-Reactivity, And Polyfunctional Phenotypes In Gene-Modified T Cells, Kendra Foley

Dissertations

Adoptive cell transfer of T cell receptor (TCR) gene-modified T cells targeting specific tumor antigens is currently in clinical trials for patients with advanced malignancies. Despite the clinical responses, there are still hurdles to be overcome in achieving an effective and safe therapy. One of the limitations in the success of this type of therapy is the potential for cross-reactivity and unanticipated off-target reactivity which could lead to autoimmunity. Adverse events encompassing these "off-target, off-tumor" cross-reactivities leading to autoimmunity have been seen in patients in different clinical trials. Here, we demonstrate a novel approach to improve antigen specific reactivity and …

Determination Of Transforming Growth Factor-Β Signaling Targets In Activated T Cells, Ramiah Jacks

Dissertations

T lymphocytes are a critical component of the adaptive immune system and their responses in pathogenic and steady state conditions require strict regulation. One mechanism involved in this regulation is Transforming Growth Factor-β (TGF-β) signaling. TGF-β can act on activated T cells to facilitate the differentiation of TGF-β dependent T helper subsets or the suppression of T cell activation and proliferation. However, the molecular mechanism(s) by which TGF-β signaling controls T cell differentiation vs T cell suppression remain poorly understood.TGF-β signaling is propagated by initially binding to the TGF-β type II receptor, which subsequently activates TGF-β type I receptor (TGF-βRI) …

Modulating The Tumor Microenvironment To Induce Cross-Priming For Cancer Immunotherapy, Erica Fleming-Trujillo

Dissertations

Adoptive cell transfer (ACT) using T cells engineered to express tumor-specific T cell receptors (TCR) holds great promise in treating cancer patients. ACT involves the in vitro generation of large numbers of tumor-specific T cells, which are then administered back to the patient, to establish an in vivo response and effective tumor control. Our lab conducted a phase I clinical trial in which metastatic melanoma patients received systemic infusions of autologous T cells transduced to express a tyrosinase-specific TCR (TIL 1383I). We observed tumor regression in one of seven patients and the development of vitiligo, indicative of T cell-mediated killing …

Protection From Staphylococcus Aureus Bloodstream Infection By Probiotic Exopolysaccharide, Wonbeom Paik

Dissertations

Staphylococcus aureus is known to cause severe systemic infection with high mortality rates. Antibiotics are the only approved therapy for patients, but the widespread prevalence of antibiotic resistant strains limits treatment efficacy, and many patients succumb to the disease. Many probiotic agents are commercially available, but the mechanisms by which they benefit are not known. Understanding these mechanisms will help develop novel therapeutics that can improve healthcare, including systemic infections by S. aureus. Bacillus subtilis is a probiotic bacterium that produces an exopolysaccharide (EPS) that induces anti inflammatory macrophages (MΦ). We tested if EPS could be used for systemic S. …

The Ecology And Feeding Behavior Of Mosquitoes In The Galapagos Islands, Samoa S. Asigau

Dissertations

Mosquitoes remain important vectors in transmitting wildlife diseases. This dissertation aims to understand the role that mosquitoes play in transmitting wildlife diseases such as avian malaria, a protozoan parasite belonging to the genus Plasmodium. Using data from wild-caught mosquitoes captured in multiple years and across multiple islands on the Galapagos Archipelago, we describe distributional patterns of mosquitoes, their range limits and assess whether there exists a disease-free refuge as occurs in Hawaii. We show that altitudinal ranges for disease transmission of avian malaria may not be bounded by a stable disease-free refuge, since mosquitoes are found at all elevations, …

Taxonomy And Systematics Of Plagioporus (Trematoda), With Descriptions Of 10 New Species From Freshwater Fishes Of The Nearctic, Thomas John Fayton

Dissertations

The Opecoelidae Ozaki, 1925 is one of the largest families of digenetic trematodes of fishes. While the family is mostly marine/estuarine, invasion of freshwater hosts has occurred at least two times. The only representative freshwater plagioporine sequenced to date is Plagiocirrus loboides Curran, Overstreet, & Tkach, 2007, which previous phylogenetic analyses resolved as being related to deep water marine opecoelids. The taxonomy of the freshwater plagioporines, particularly Plagioporus, has long been confused; homoplasy is rife within the family and has complicated the delineation of species and genera, and the freshwater species from marine forms. Here, I hypothesize that the …

A Novel Role For Osteopontin In Facilitating West Nile Virus Neuroinvasion, Amber M. Paul

Dissertations

West Nile virus (WNV) is a positive-sensed, single-stranded RNA flavivirus that can cause human neuroinvasive diseases, including encephalitis, meningitis, and flaccid paralysis. The mechanisms by which WNV enters the central nervous system and the host-factors that are involved in WNV-neuroinvasiveness are not completely understood. Osteopontin (OPN), a multifunctional glycoprotein, has been implicated as a bio-marker for a number of neuroinflammatory diseases. In particular, secreted (s)OPN has been implicated to participate in recruitment of polymorphonuclear neutrophils (PMN) to sites of its expression, while PMNs have been suggested to act as WNV reservoirs. Therefore, sOPN recruitment of PMNs may contribute to neuroinvasive …

Elucidating The Role Of Interleukin-17a In West Nile Virus Infection, Dhiraj Acharya

Dissertations

West Nile virus (WNV) is a neurotropic flavivirus of significant public health importance for which no therapeutics and vaccine are currently available. Interleukin-17A (IL-17A) is an inflammatory cytokine that regulates diverse immune functions, while its role is unclear in host’s immune response to WNV. Furthermore, CD8⁺ T cells are crucial components of immunity and play a vital role in recovery from WNV infection. Here, we report a previously unrecognized function of IL-17A in regulating CD8⁺ T cell cytotoxicity. We show that WNV induces the expression of IL-17A in both mouse splenocytes and human peripheral blood mononuclear cells cultured …

Study Of Rickettsia Parkeri Colonization And Proliferation In The Tick Host Amblyomma Maculatum (Acari: Ixodidae), Khemraj Budachetri

Dissertations

Amblyomma maculatum (Gulf coast tick) ticks are prevalent across the Atlantic to Gulf Coast region of United States. These ticks are recognized vectors of Rickettsia parkeri, a spotted fever group of Rickettsia (SFGR) known to cause American boutonneuse fever associated with fever and eschar rashes localized to the site of bites. We hypothesized that Rickettsia parkeri colonization and proliferation in the tick vector involve pathogen-symbiont dynamics and tick-pathogen interactions, which influence rickettsial transmission to the victims after tick bites. The rickettsial infection is maintained across the tick life cycle for many generations due to transovarial and transstadial transmission of …

Role Of The Interleukin-22 And Stat3 Signaling Pathway In Gut Barrier Maintenance Following Intoxication And Burn Injury, Adam M. Hammer

Dissertations

More than half of patients admitted to burn centers for treatment have measurable alcohol levels in their blood. Intoxication that precedes a traumatic burn injury leads to worsened patient outcomes, including higher rates of infection and sepsis. The intestines harbor the largest concentration of bacteria in the human host. Any disruption of the intestinal barrier as a result of intoxication and burn injury could contribute to infection and/or sepsis from gut-derived microbes. Previous work has demonstrated that the intestinal barrier becomes leaky, and that administration of interleukin-22 (IL-22) significantly reduces gut barrier leakiness following alcohol and burn injury. However, the …

A Microbiomic Approach To The Characterization Of The Impacts And Influences Of Viral, Bacterial, And Harmful Algal Bloom Toxins On The Bottlenose Dolphin, Corey David Russo

Dissertations

As apex predators that display high site fidelity Tursiops truncatus (bottlenose dolphin) are indicators of marine ecosystem health. Bottlenose dolphins, additionally, display pathogenesis and immune response similar to that of humans. Humans and coastal bottlenose dolphins, in particular, are constantly exposed to the same industrial, agricultural and domestic toxins and pathogens, contaminants and pollutants. Thus, studies on the bottlenose dolphin are also valuable in bridging the gap between ocean and human health. Bottlenose dolphins are susceptible to viral bacterial and toxin infection. Infection in the bottlenose dolphin manifests itself in the form of mass stranding events, unusual mortality events, chronic …

Inhibition Of B Lymphopoiesis By Adipocytes And Myeloid-Derived Suppressor Cells, Domenick Kennedy

Dissertations

B lymphopoiesis declines with age in humans, mice, and rabbits. Impaired B lymphopoiesis correlates with increased fat in the bone marrow (BM), suggesting that adipocytes negatively regulate this process. In fact, adipocyte factors were found to inhibit B cell development in BM cultures.

Our goal was to understand the mechanism by which adipocytes inhibit B cell development. Through culturing mouse BM cells on OP9 stromal cells in the presence of adipocyte-conditioned medium (ACM), we found that adipocytes promote the accumulation of CD11b+Gr1+ myeloid-derived suppressor cells (MDSCs). These cells were not simply bystanders, as we report for the first time that …

Mechanism By Which Commensal Bacteria Limit Inflammation, Mallory Paynich

Dissertations

Trillions of bacteria live within the gastrointestinal tract and are critical for maintaining intestinal homeostasis; however, the mechanisms utilized by specific bacterial molecules to contribute to homeostasis are not well understood. We utilize a mouse model in which a single oral dose of the probiotic, Bacillus subtilis, protects mice from acute colitis induced by the enteric pathogen Citrobacter rodentium. Our goal is to elucidate the mechanism by which B. subtilis prevents inflammation.

We identified exopolysaccharides (EPS) to be the active molecule of B. subtilis, and a single dose of EPS protects mice from disease. EPS binds F4/80+CD11b+ peritoneal macrophages, and …