Life Sciences Commons^™

Lymphatic Filariasis: Host And Parasite Factors And The Pathogenesis Of Systemic Adverse Events Following Treatment, Britt Juul Andersen

Arts & Sciences Electronic Theses and Dissertations

Lymphatic filariasis (LF) is a neglected tropical disease caused by the nematode parasites Wuchereria bancrofti, Brugia malayi and B. timori. The primary tool used by the Global Program to Eliminate LF is mass drug administration (MDA), and some 500 million people take the medications each year. Mild to moderate adverse events (AEs) are common after LF treatment, and these pose a major challenge for the LF elimination program. To better understand the pathogenesis of AEs, we studied patients from LF treatment trials in Côte d’Ivoire and Papua New Guinea, where plasma and leucocytes were collected pre and post-treatment and subjects …

Metabolic Requirements Of Nk Cell Responses To Viral Infection, Annelise Yoo Mah-Som

Arts & Sciences Electronic Theses and Dissertations

In recent years, the field of immunometabolism – the study of how specific changes in cellular metabolism regulate the function of diverse immune cell types—has grown exponentially. Several in vitro studies have examined the metabolic regulation of natural killer (NK) cells, which are first responders for viral infection and malignant transformation; however, much less is known regarding the role of metabolism in directing NK cell responses in vivo, such as during viral infection. In order to examine how NK cell antiviral function is regulated in vivo, we used a wellcharacterized infection with murine cytomegalovirus (MCMV) to assess NK cell cytokine …

Effects Of Toxoplasma Gondii Infection On Nk Cells And Ilc1s, Eugene Park

Arts & Sciences Electronic Theses and Dissertations

Natural killer cells and Type I innate lymphoid cells (ILCs) are subsets of ILCs. In C57BL/6 mice, they share expression of the surface markers NK1. 1 and NKp46, and can produce the cytokine interferon-gamma. These similarities led to the initial classification of natural killer cells and Type I ILCs together under the category of Group 1 ILCs. However, more recent studies found that natural killer cells and ILC1s develop from distinct progenitor cells and utilize transcription factor in distinct manners. Whereas ILC1s require Tbet for their development and are Eomes-independent, natural killer cells require Tbet only for terminal maturation and …

The Enzymatic Function Of The Tir Domain: From Axon Degeneration To Innate Immunity, Kow Essuman

Arts & Sciences Electronic Theses and Dissertations

The Toll/Interleukin-1 Receptor (TIR) domain is an evolutionarily ancient protein domain conserved from bacteria to eukaryotes, and is an essential signaling component of innate immunity pathways. In animal innate immunity, TIR domains have primarily been described for their scaffolding function in assembling protein complexes in host defense. In plant immunity, TIR domains are key components of the intracellular Nucleotide Binding Leucine rich repeat (NLR) immune receptors that confer resistance to pathogens. These NLR receptors trigger cell death and an immune response upon activation, but their mechanism has remained elusive. In bacteria, TIR domain proteins have been suggested to function as …

Effects Of Agonistic Anti-Cd137 Antibody On Chikungunya Virus Infection And B Cell Responses, Jun Hong

Arts & Sciences Electronic Theses and Dissertations

CD137, a member of the tumor necrosis factor receptor superfamily of cell surface proteins, acts as a costimulatory receptor on T cells, natural killer cells, B cell subsets, and some dendritic cells. Agonistic anti-CD137 monoclonal antibody (MAb) therapy has been combined with other chemotherapeutic agents in human cancer trials. Based on its ability to promote tumor clearance, we hypothesized that anti-CD137 MAb might activate immune responses and resolve chronic viral infections. We evaluated anti-CD137 MAb therapy in a mouse infection model of chikungunya virus (CHIKV), an alphavirus that causes chronic polyarthritis in humans and is associated with reservoirs of CHIKV …

Identification And Characterization Of A Novel Non-Homologous End Joining Factor Mri, Putzer Joseph Hung

Arts & Sciences Electronic Theses and Dissertations

Non-homologous end joining (NHEJ) is the predominant DNA double-strand break (DSB) repair pathway in G1-phase cells. In particular, developing lymphocytes utilize NHEJ to repair physiologic DSBs generated during the processes of antigen receptor gene assembly and class-switch recombination (CSR). Thus, proper regulation of NHEJ is important not only for immune repertoire diversification, but also for the prevention of chromosomal translocations or deletions that can arise from misrepaired DSBs. The XRCC4-like factor (XLF) has been strongly implicated in promoting NHEJ, presumably by tethering broken DNA ends together in a sleeve-like complex, but its necessity appears to be cell context-dependent. While XLF …

Generation And Utilization Of Diverse Memory B Cells After Flavivirus Challenges, Rachel Wong

Arts & Sciences Electronic Theses and Dissertations

Over the course of an effective immune response to an infection, two distinct B cell populations are generated to provide protection against reinfection, long-lived plasma cells (LLPCs) and memory B cells (MBCs). LLPCs and MBCs originate from germinal center (GC) B cells that have undergone B cell receptor (BCR) affinity maturation through iterative rounds of somatic hypermutation, proliferation, and selection. Thus, LLPCs and MBCs can bind to their antigen with higher affinity than their naïve B cell precursors. LLPCs constitutively secrete antibodies and can provide sterilizing immunity that pre-exists subsequent infections. MBCs, on the other hand, are quiescent and provide …

T Cell Immunity In Pancreatic Cancer Is Undermined By Dendritic Cell Dysfunction, Samarth Hegde

Arts & Sciences Electronic Theses and Dissertations

Pancreatic cancer carries a dismal prognosis, and desperately needs viable therapeutic interventions beyond chemo-radiation. T cell-dependent immunotherapies have shown great promise in several tumor types, but have not been effective for the vast majority of pancreatic cancer patients. This is, in part, due to our limited understanding of how antigenicity of pancreatic lesions is recognized, and how adaptive immunity is overcome in this disease. We sought to study tumor-immune interactions and identify mechanisms for this immune-failure using several spontaneous and unperturbed mouse models of pancreatic adenocarcinoma. We found that early pancreatic lesions fail to elicit tumor-limiting CD4+ TH1 and CD8+ …

The Transcription Factor Bhlhe40 Regulates Tissue-Resident Macrophages And Type 2 Immunity, Nicholas N. Jarjour

Arts & Sciences Electronic Theses and Dissertations

Transcriptional control of gene expression is essential for life, tailoring protein production to development and environment to maintain organismal homeostasis. A limited set of proteins termed transcription factors are critical to this process. As our understanding of these central regulators has improved, new aspects of cell and organismal biology have been revealed. Herein, we demonstrate the importance of the transcription factor Bhlhe40 to tissue-resident macrophages, T helper type 2 cells, and type 2 immune responses, revealing novel transcriptional control of macrophages and unexpected cytokine regulation of helminth infection. We find that Bhlhe40 is cell-intrinsically required for normal proliferation of large …

Understanding The Transcriptional Mechanisms Underlying Dendritic Cell Development, Prachi Bagadia

Arts & Sciences Electronic Theses and Dissertations

Dendritic cells (DCs) comprise an important immune lineage that plays a critical role in initiating and sustaining the proper immune response. They can be divided into two distinct branches, classical/conventional DCs (cDCs) or plasmacytoid DCs (pDCs). cDCs can further be classified as cDC1 or cDC2. Each DC subset exerts unique functions in vivo and are necessary for a complete immune response. The precise transcriptional programs underlying DC specification and commitment remain unclear. cDC1, cDC2, and pDC all arise from the common DC progenitor (CDP) in the bone marrow. How the CDP gives rise to all three DC subsets in an …

Mesothelium-Derived Factors Shape Tissue Resident Macrophage, Chin-Wen Lai

Arts & Sciences Electronic Theses and Dissertations

The studies outlined in this thesis provide several new insights into Msln-related pathways necessary for peritoneal immune responses and mucosal repair. We found that Msln and its binding partner mucin 16 from mesothelium influenced peritoneal and pleural macrophage differentiation. We found that Msln was required for proper tissue repair after colonic biopsy injury and was required for maximal polyp growth in APCMin/+ mice. Overall, this work describes mesothelial and epithelial-derived factors that are important for tissue resident macrophage differentiation and wound repair after colonic mucosal injury. Understanding the complex interactions between stromal cells and immune cells will lead to better …

Secretory Iga Enhances Gut B Cells Priming And Systemic Igg Responses Towards Commensals, You Zhou

Arts & Sciences Electronic Theses and Dissertations

IgA is the primary antibody response at mucosal surfaces and is reported to inhibit adaptive immune responses against gut bacteria. Here, we utilize an in vitro system to expand and screen IgA memory B cells for their ability to recognize gut bacteria in the context of secretory IgA (sIgA) deficiency in polymeric Ig receptor (Pigr–/–) mice. Contrary to the prevailing hypothesis that IgA provides an immune exclusionary function, we found that mice lacking sIgA showed decreased anti-bacterial IgA specificities as assessed using flow cytometry. IgA B cell responses against certain taxa such as those of order Bacteriodales showed greater dependence …

Activation Of Toll-Like Receptor 3 Translates To Long-Term Post-Viral Lung Disease, Xinyu Wang

Arts & Sciences Electronic Theses and Dissertations

Chronic obstructive lung disease (COPD) causes substantial human and economic costs both in the US and worldwide. To identify the molecular mechanisms to allow for targeted therapies for COPD, we developed a high-fidelity mouse model of chronic lung inflammation using the natural rodent pathogen Sendai virus (SeV). While nucleic acid-sensing pattern recognition receptors are important for innate immune responses to viral pathogens, there have been few studies investigating their role in the context of chronic disease. Here we show that Toll-like receptor 3 (Tlr3) signaling is required for the development of chronic lung disease in a postviral mouse model. Activation …

Dissemination Of The Apicomplexan Parasite, Toxoplasma Gondii, Lisa L. Drewry

Arts & Sciences Electronic Theses and Dissertations

The parasitic protist Toxoplasma gondii is a common pathogen of rodents and felines that also infects humans. The most severe clinical manifestations of toxoplasmosis in humans derive from the systemic dissemination of T. gondii, during which the parasite penetrates biological barriers and accesses protected host compartments such as the central nervous system. T. gondii dissemination is enabled by the intrinsic gliding motility of extracellular parasites, which allows for travel to new host cells and tissues, and also powers the invasion of diverse host cells including migratory leukocytes. Dissemination is further advanced when migrating infected leukocytes shuttle intracellular parasites to new …

Development Of Enteric Neurons And Muscularis Macrophages, Marina Avetisyan

Arts & Sciences Electronic Theses and Dissertations

The enteric nervous system (ENS) is a complex interconnected network of neurons and glia in the bowel wall that regulates intestinal motility, blood flow, and epithelial function. The ENS also controls aspects of inflammatory signaling within the bowel. To perform these tasks, there are at least 20 types of enteric neuron and four types of enteric glia. Although much is known about early events in ENS development, signals governing the development of specific neuronal subtypes and communication with neighboring cell types within the bowel remain poorly understood. One fundamental hypothesis is that diverse trophic factors support distinct neuronal populations in …

Characterizing The Humoral Response To Flavivirus Infection, Estefania Fernandez

Arts & Sciences Electronic Theses and Dissertations

Flaviviruses are positive (+) sense, single-stranded RNA viruses of the Flaviviridae family that are transmitted by mosquitoes. For our studies, we focused on Zika virus (ZIKV) and Japanese encephalitis virus (JEV). Most human infections with ZIKV historically resulted in a mild self-limiting febrile illness. However, since 2013, a worldwide spread and increase in ZIKV infections has been observed. Notably, ZIKV has been associated with autoimmune ascending paralysis (Guillain-Barré Syndrome) and ophthalmologic effects in adults and intrauterine growth restriction and microcephaly in developing fetuses. Current vaccine efforts utilize technologies implemented for related flaviviruses (yellow fever virus (YFV), Dengue virus (DENV), and …

A Recombinant Virus And Reporter Mouse System To Study Chronic Chikungunya Virus Pathogenesis, Alissa Roxanne Young

Arts & Sciences Electronic Theses and Dissertations

Chikungunya virus (CHIKV) is an arthritogenic alphavirus that during acute disease causes fever as well as severe joint and muscle pain. Chronic joint and muscle pain persists in a significant subset of patients, yet we still have a poor understanding of what drives this chronic disease. While replicating virus has not been detected in the joints of patients with chronic arthritis or in various animal models at chronic time points, persistent viral RNA can be detected for months after acute infection.

To identify the cells that could be contributing to chronic CHIKV pathogenesis, we developed recombinant viruses that express Cre …

The Role Of Apolipoprotein E In Regulating Tau Pathogenesis And Neurodegeneration In A Tauopathy Mouse Model, Yang Shi

Arts & Sciences Electronic Theses and Dissertations

APOE4 is the strongest genetic risk factor for late-onset Alzheimer's disease (AD). APOE4 increases brain amyloid-β (Aβ) pathology relative to other APOE isoforms. However, whether APOE independently influences tau pathology, the other pathological hallmark of AD and other tauopathies, or tau-mediated neurodegeneration, is not clear. By generating P301S tau transgenic mice on either a human APOE knock in (KI) or APOE knockout (KO) background, we show that the presence of human APOE, regardless of APOE isoforms, leads to various degrees of brain atrophy in 9-month old P301S mice, whereas APOE ablation strongly protects against neurodegeneration. In particular, P301S/E4 mice develop …

Sequence Analysis Methods For The Design Of Cancer Vaccines That Target Tumor-Specific Mutant Antigens (Neoantigens), Jasreet Hundal

Arts & Sciences Electronic Theses and Dissertations

The human adaptive immune system is programmed to distinguish between self and non-self proteins and if trained to recognize markers unique to a cancer, it may be possible to stimulate the selective destruction of cancer cells. Therapeutic cancer vaccines aim to boost the immune system by selectively increasing the population of T cells specifically targeted to the tumor-unique antigens, thereby initiating cancer cell death.. In the past, this approach has primarily focused on targeted selection of ‘shared’ tumor antigens, found across many patients. The advent of massively parallel sequencing and specialized analytical approaches has enabled more efficient characterization of tumor-specific …

Identification Of Bhlhe40 And Irg1 As Essential Regulators Of The Inflammatory Response To Mycobacterium Tuberculosis, Jeremy Peter Huynh

Arts & Sciences Electronic Theses and Dissertations

Protective immune responses to Mycobacterium tuberculosis (Mtb) must induce bactericidal functions while minimizing damage to the lung. Such responses require precise control of pro- and anti-inflammatory factors to regulate the recruitment and function of protective immune cells but the mechanisms by which this control is exerted remain incompletely defined. Basic helix-loop-helix family, member e40 (Bhlhe40) is a transcription factor known to regulate production of pro- and anti-inflammatory cytokines that affect protective immunity to Mtb. Immune-responsive Gene 1 (Irg1) is an enzyme that generates itaconate, a metabolite with potential anti-inflammatory and antibacterial roles during Mtb infection. The impact of Bhlhe40 and …

Cd4 T Cell Interaction With Intestinal Microbes Under Homeostasis And Inflammation, Jiani Chai

Arts & Sciences Electronic Theses and Dissertations

Specific gut commensal bacteria improve host health by eliciting mutualistic regulatory T (Treg) cells responses. However, the bacteria that induce effector T (Teff) cells during inflammation are unclear. Here, we addressed this by analyzing bacterial-reactive T cell receptor (TCR) transgenic cells and TCR repertoires in a murine colitis model. Unexpectedly, we found that mucosal-associated Helicobacter species triggered both Treg responses during homeostasis and Teff responses during colitis, as suggested by an increased overlap between the Teff/Treg TCR repertoires with colitis. In fact, 4/6 Treg TCRs tested recognized mucosal-associated Helicobacter species in vitro and in vivo. By contrast, the marked expansion …

Transcriptional Signatures Of Host Susceptibility In Urinary Tract Infections, Lu Yu

Arts & Sciences Electronic Theses and Dissertations

Urinary tract infections (UTI) caused by uropathogenic Escherichia coli (UPEC) are common and highly recurrent. Two important non-behavioral risk factors for UTI in women are genetics and history of two or more episodes of previous UTI. However, specific mechanisms of how these two factors modulate host susceptibility to UTI remain unclear. Concordantly, inbred mice of various genotypes and with different infection histories exhibit different susceptibilities to acute and chronic bladder infection (cystitis), which recapitulates a range of clinical UTI outcomes observed in women. Early host-pathogen interactions have been shown to determine UTI outcomes in mouse models. Here, we used two …

Viral Mhc Class I Evasion Affects Anti-Viral T Cell Development And Responses, Elvin James Lauron

Arts & Sciences Electronic Theses and Dissertations

Cytotoxic CD8+ T cells (CTLs) play a critical role in protective immunity against viruses, a fact underscored by the evolution of viral CTL evasion mechanisms. For instance, many viruses commonly target the major histocompatibility complex class I (MHCI) antigen presentation pathway to prevent CTLs from recognizing infected cells. A striking example of this is cowpox virus (CPXV), which interferes with MHCI antigen presentation through two distinct mechanisms. One mechanism of CPXV-mediated MHCI inhibition is to retain MHCI molecules in the endoplasmic reticulum (ER). The second mechanism is to prevent antigen peptide loading onto MHCI molecules. When combined these mechanisms result …

Host Determinants Of Protection And Pathogenesis During Chikungunya Virus Infection, Lindsey Elaine Cook

Arts & Sciences Electronic Theses and Dissertations

Chikungunya virus (CHIKV) is a mosquito-transmitted alphavirus that causes acute and chronic polyarthritis. The virus has rapidly emerged over the last decade, and in 2013, CHIKV spread to the Western Hemisphere for the first time, infecting more than 1.8 million people. CHIKV targets the joints and musculoskeletal tissues, resulting in severe myalgia and symmetric polyarthritis that clinically mimics rheumatoid arthritis. Currently, no approved treatment is effective in preventing or controlling CHIKV infection or disease. Pathogenesis of CHIKV is still poorly understood but is thought to reflect an interplay between viral replication and detrimental immune responses. CHIKV patients have increased numbers …

Characterizing The Role Of The T Cell Receptor Repertoire In T Cell Development And Function, Benjamin David Solomon

Arts & Sciences Electronic Theses and Dissertations

Expansion and memory of immune cells in response to stimulation of diversified antigen receptors is the hallmark of adaptive immunity. Here, we use antigen receptor sequencing and in vivo analysis of monoclonal cell populations to elucidate the development and function of two T cell populations: Foxp3+RORγt+ CD4+ T cells and γδ T cells. Foxp3+RORγt+ T cells have recently been characterized as an immunoregulatory population highly enriched in the colon lamina propria. However, their developmental origin and relation to RORγt- Treg and RORγt+ TH17 cells remains unclear. Here, we show that despite sharing a subset of TCR specificities with TH17 cells, …

Innate Lymphoid Cells: Transcriptional Profiles And Cytokine Developmental Requirements, Michelle Lauren Robinette

Arts & Sciences Electronic Theses and Dissertations

Innate lymphoid cells (ILCs) are a recently discovered lineage of professional cytokine-producing cells that strikingly mirror T cells in transcriptional circuitry and effector functions, but derive from distinct progenitors and do not express recombined antigen-specific receptors. These cells include natural killer (NK) cells, which parallel cytotoxic CD8+ T cells, and three additional classes of ILCs enriched at mucosal surfaces that generate signature cytokines reminiscent of polarized CD4+ helper T cells subsets, called ILC1, ILC2, and ILC3. As ILCs have been implicated in the pathogenesis of colitis, cancer, allergy, and autoimmunity in both human and mouse, understanding the functional capacity of …

Negative Regulators Of Colonic Peripheral Regulatory T Cell Development, Teresa Lei Ai

Arts & Sciences Electronic Theses and Dissertations

Peripheral Treg cells (pTreg cells) maintain immune homeostasis at mucosal interfaces, where they can develop upon activation of naïve CD4+ T cells by bacteria antigen. However, the cellular and molecular requirements that govern their differentiation in inflamed and homeostatic contexts require further elucidation. To circumvent uncertainties in existing methods of distinguishing pTreg cells from thymic Treg cells (tTreg cells), we analyzed monoclonal cell populations of CT2 and CT6 transgenic (Tg) cells that develop into pTreg cells in response to different species of endogenously presented Helicobacter antigen. In our comprehensive assessment of multiple intestinal inflammatory models, including infections and physical injury, …

Tumors Interrupt Irf8-Mediated Dendritic Cell Development To Overcome Immune Surveillance, Melissa Ann Meyer

Arts & Sciences Electronic Theses and Dissertations

Tumors employ multiple mechanisms to evade immune surveillance. One mechanism is tumor-induced myelopoiesis, which expands immune suppressive granulocytes and monocytes to create a protective tumor niche shielding even antigenic tumors. As myeloid cells and immune-stimulatory conventional dendritic cells (cDCs) are derived from the same progenitors, it is logical that tumor-induced myelopoiesis might also impact cDC development. The cDC subset cDC1 is marked by CD141 in humans and CD103 or CD8α in mice. cDC1s act by cross presenting antigen and activating CD8+ T cells. Given these functions, CD103+ cDC1s can support anti-tumor CD8+ T cell responses. However, CD103+ cDC1 numbers are …

Identification And Characterization Of An Interferon Stimulated Gene That Restricts Alphavirus Infection And Pathogenesis, Subhajit Poddar

Arts & Sciences Electronic Theses and Dissertations

Viral infection of host cells induces the Type I interferon (IFN) response, which is

characterized by the production of hundreds of IFN-stimulated genes (ISGs). Altogether, these

ISGs function to induce an antiviral state, hindering or blocking various steps of the viral

lifecycle. Many individual ISGs have potent and broad antiviral functions. However elimination

of a single ISG does not completely abrogate protection, suggesting that other ISGs, although

moderate or moderate when considered alone, must work cooperatively to provide optimal

antiviral activity.

In order to identify and characterize novel ISGs, an attenuated strain of the alphavirus

chikungunya (CHIKV-181/25) was tested against …

Expansion Of Microbial Virology By Impetus Of The Reduction Of Viral Dark Matter, Siddharth Ravindran Krishnamurthy

Arts & Sciences Electronic Theses and Dissertations

Modern metagenomic methods have rapidly accelerated the rate of viral discovery. Currently, to discover a novel virus, deep sequencing reads must align to a known reference virus. While alignment is effective at identifying closely related viruses, highly divergent viruses can often share no discernable sequence alignment with known viruses. Therefore, the accurate classification of viral dark matter – metagenomic sequences that originate from viruses but do not align to any reference virus sequences – is one of the major obstacles in not only discovering novel viruses, but also by extension, comprehensively defining the virome. As viral dark matter results fundamentally …