Immunology and Infectious Disease Commons^™

The Role Of Lkb1 Spliceoforms In Itreg-Th17 Plasticity And Their Interactions With Pkcθ And Sirt1 Downstream Of Il-6 Signaling, Deeksha Mohan

Doctoral Dissertations

Following activation, CD4 T cells undergo metabolic and transcriptional changes as they respond to external cues and differentiate into T helper (Th) cells. T cells exhibit plasticity between Th phenotypes in highly inflammatory environments, such as colitis, in which high levels of IL-6 promote plasticity between regulatory T (Treg) cells and Th17 cells. Protein Kinase C theta (PKCθ) is a T cell-specific serine/threonine kinase that promotes Th17 differentiation while negatively regulating Treg differentiation. Liver kinase B1 (LKB1), also a serine/threonine kinase and encoded by Stk11, is necessary for Treg survival and function. Stk11 can be alternatively spliced to produce a …

Human Milk: From Covid-19 Immunity To Breast Cancer Risk Assessment, Vignesh Narayanaswamy

Doctoral Dissertations

Breastmilk is a complex biological fluid containing macromolecules including lipids, oligosaccharides, proteins as well as several types of cells. Several studies have reported in detail of these components. My focus is studying the protein component of breastmilk, specifically antibodies, cytokines, and other secreted factors in the setting of different pathogenicity in women. Studies have demonstrated that the levels of numerous cytokines as well as the levels of pathogen-specific antibodies are altered in milk upon either maternal or infant infections. Additionally, there are reports that the levels of certain inflammatory markers are altered in milk among women with breast cancer or …

A Novel Transmembrane Ligand Inhibits T Cell Receptor Activation, Yujie Ye

Doctoral Dissertations

T lymphocytes (T cells) play essential roles in the adaptive immune system. Each mature T cell expresses one type of functional T cell receptor (TCR). The TCR recognizes antigens bound to the major histocompatibility complex (MHC) in antigen presenting cells. The resulting stimulation signal crosses the transmembrane domain of TCR and initiates downstream signaling cascades. The human immune system relies on TCRs to recognize a variety of pathogens. Normally, TCR can distinguish the self-antigens from pathogenic antigens. However, dysfunction or aberrant expression of TCRs causes different inflammatory and autoimmune diseases, which afflict millions of people annually (Chapter I). Current treatments …

Exposure To Endocrine Disrupting Chemicals And The Effects On Inflammation And Mammary Tumor Progression, Stephanie Morin

Doctoral Dissertations

The vast majority of breast cancers, ~70%, are not directly related to an inherited genetic mutation. Environmental factors play a dominant role in the etiology of most breast cancers. There is a subset of chemicals that are able to affect the homeostasis of hormones called endocrine disrupting chemicals (EDCs). Many of these chemicals are pervasive and persistent making the chances for lifetime exposure more prevalent. While many of these chemicals have been deemed safe, a subset of them have come under review to reassess their safety. As estrogen is critical for breast development and can act as a mitogen in …

Chemical Biology Approaches For Tracking And Manipulation Of Macrophage Phenotypes, Javier A. Mas Rosario

Doctoral Dissertations

Macrophages are white blood cells of the innate immune system that have the ability to change phenotypically depending on the stimuli present in their surroundings through a process commonly referred to as polarization. Macrophage phenotypes broadly range from pro-inflammatory, anti-tumor (M1) to immune-suppressing (M2). Of particular interest to this work, breast cancer progression and metastasis rely on the presence of M2-like tumor-associated macrophages (TAMs). While many studies have shown the involvement of macrophages in tumor progression and metastasis, there remains a need to further explore these interactions and the polarization process, including tracking of macrophage subtypes. Toward this end, I …

Enterobactin-Based Immune Interventions Against Gram-Negative Bacterial Infections, Huiwen Wang

Doctoral Dissertations

Enterobactin (Ent)-mediated iron acquisition is critical for many Gram-negative bacteria to survive in the host. Given the bacteriostatic effect of lipocalin-2 resulting from its potent Ent-binding ability, immune interventions directly targeting Ent is a promising antimicrobial strategy against Gram-negative bacterial infections. Moreover, hyperimmune egg yolk antibody is an emerging passive immune agent for the control of bacterial infections. Oral administration of anti-Ent egg yolk antibody may confer passive immune protection against Ent-dependent enteric pathogens. In this dissertation study, multidisciplinary approaches in conjunction with different model systems (in vitro, in vivo, and ex vivo) were used to …

Quality Of Life For Women With Chronic Lyme Disease: A Socioeconomic Investigation, Dale M. Jones

Doctoral Dissertations

This is a mixed methods investigation of how chronic Lyme disease, including Lyme-like diseases and co-infections, affects the quality of life of women who have chronic Lyme. Both quantitative and qualitative methods were used during three phases of research: a 91-question survey instrument followed by focus group discussions and written narratives. The research considered the socioeconomic impact on quality of life in five areas: obtaining a diagnosis, relationships and personal support systems, struggles with the medical system, the ability to work, and access to treatment. There were 500 responses to the survey, of which 373 were analyzed; 11 participants in …

Cat Covid, Cmv And Chemokines, Oh My!, Trevor Hancock

Doctoral Dissertations

Cytomegalovirus (CMV) is an important pathogen infecting most humans worldwide. CMV infection within immunocompromised individuals can cause severe morbidity and potential mortality. Disease during CMV infection is due to virus dissemination and subsequent inflammation. Host immune cells lie at the intersection potentially mediating both. The CMV-encoded viral chemokine vCXCL-1 is a proposed virulence factor in mouse models increasing immune cell recruitment and disease. However, the primary immune cell mediator is undetermined. To identify targets, Chapter 2 examines CXCR2 expression (receptor for vCXCL-1) among various mouse tissues and human peripheral blood under steady-state conditions. In vitro, isoforms of HCMV’s vCXCL-1 …

Multi-Omic Systems Biological Analysis Of Host-Microbe Interactions, Piet Jones

Doctoral Dissertations

Systems biology offers the opportunity to understand the complex mechanisms of various biological phenomena. The wealth of data that is produced, at an increasing rate, provides the potential to meet this opportunity. Here we take an applied approach to integrate multiple omic level data sources in order to generate biologically relevant hypotheses. We apply a novel analysis pipeline to model both, in concert, the microbial and transcriptomic signature from COVID-19 positive patients. We show patients may suffer from an increased microbial burden, with an increased pathogen potential. Gene expression evidence further shows patients may exhibit a compromised barrier immunity, owing …

Wc1 And Tcr Interactions For Γδ T Cell Activation, Alexandria Gillespie

Doctoral Dissertations

Major subpopulations of gamma delta T cells within ruminant and pigs are defined by expression of WC1, a hybrid pattern recognition receptor/co-receptor to the T cell receptor (TCR). It is known that when WC1 is knocked down cells fail to respond. Showing that WC1 plays an active role in the stimulation of bovine gamma delta T cells. Here we explored the spatio-temporal dynamics of WC1 and TCR interaction using imaging flow cytometry and stochastic optical reconstruction microscopy. We found that in quiescent gamma delta T cells both WC1 and TCR existed in separate protein domains (protein islands) but after activation …

Genomic Organization And Expression Of The Wc1 Hybrid Coreceptor And Pattern Recognition Receptor On Porcine Gamma Delta T Cells, Lauren Le Page

Doctoral Dissertations

gd T cells are a crucial component of the immune response to a number of increasingly relevant and largely zoonotic pathogens to which efficacious vaccination is lacking. In ruminants and swine, gd T cells represent a major population of peripheral blood and epithelial tissue-resident lymphocytes. gdT cells respond to both protein and non-protein antigens independently of MHC presentation and possess immunological memory. Upon activation, gamma delta T cells illicit a variety of effector functions and play an indispensable role of orchestrating the downstream immune response. These characteristics make gamma delta T cells a promising candidate for recruitment by vaccination, however, …

Anti-Inflammatory And Chemopreventive Activity Of Lunasin From Tofu Whey For The Management Of Gastrointestinal Diseases, Cindy Andrea Nieto Veloza

Doctoral Dissertations

Gastrointestinal diseases such as inflammatory bowel diseases (IBD) and colorectal cancer (CRC) are pathological conditions associated with chronic inflammation, characterized by intestinal damage, debilitating symptoms, and detrimental health consequences. The increased risk of CRC in IBD patients, and the adverse effects associated with current therapeutic strategies, point out the need for safer alternatives to reduce chronic inflammation in the bowel. Lunasin is a bioactive peptide naturally occurring in soybeans, with chemopreventive and anti-inflammatory properties demonstrated in several extra-intestinal diseases. However, to date, there is no evidence of the biological activity of lunasin on the gastrointestinal tract as a target site. …

Rapid Cell Phenotyping Using Array-Based Sensors: Applications In Cancer Stem Cell Therapy And High-Content Screening, Yingying Geng

Doctoral Dissertations

Cell surface harbors rich information regarding the status of cell health. Being able to monitor and detect its changes in response to stimuli will provide crucial information in drug discovery, disease diagnosis, and human health. Despite the efforts and breakthroughs made possible through the specific sensing approach, there are significant challenges in extracting the information on the cell surface in a quantitative and reliable way. To address this challenge, I took the approach of array-based, hypothesis-free sensing in which the engineered sensors selectively interact with target analytes, producing a distinct pattern of response that enables analyte identification. This signature-based pattern …

Caprine Γδ T Cell Biology, Alehegne W. Yirsaw

Doctoral Dissertations

CAPRINE gd T CELL BIOLOGY AUGUST 2020 ALEHEGNE W YIRSAW, DVM, ADDIS ABABA UNIVERSITY, ETHIOPIA MSC., ADDIS ABABA UNIVERSITY, ETHIOPIA PHD., UNIVERSITY OF MASSACHUSETTS AMHERST DIRECTED BY: PROFESSOR CYNTHIA L BALDWIN Goats are important food animals and are disseminated globally. Their productivity is impacted by infectious diseases thus impacting the livestock owners and the community. γδ T lymphocytes or T cells have vital roles in immune responses in mammals and thus we identified information gaps regarding these cells in goats. We used genome annotation, PCR amplification of genomic DNA and cDNA, and Sanger and PacBio sequencing for this research to …

Liver Kinase B1 Isoform Expression As A Regulator Of T Cell Phenotypic Stability, Heather Sherman

Doctoral Dissertations

Following activation, CD4 T cells undergo extensive metabolic and transcriptional changes to respond to external cues and differentiate into T helper (Th) cell subsets. This differentiation process was originally perceived to be terminal. However, it has been shown that T cells exhibit plasticity between subsets in the context of highly inflammatory environments. This phenomenon is especially prevalent in autoimmune conditions such as colitis and multiple sclerosis in which high levels of IL-6 promote considerable plasticity between regulatory T (Treg) cells and Th17 cells. Herein we show that Liver Kinase B1 (LKB1), a metabolic sensor that enforces energy-preserving mechanisms such as …

Micro-Physiological Models To Mimic Mucosal Barrier Complexity Of The Human Intestine In Vitro, Abhinav Sharma

Doctoral Dissertations

The mucosal barrier in the intestine is vital to maintain selective absorption of nutrients while protecting internal tissues and maintaining symbiotic relationship with luminal microbiota. This bio-barrier consists of a cellular epithelial barrier and an acellular mucus barrier. Secreted mucus regulates barrier function via in situ biochemical and biophysical interaction with luminal content that continually evolves during digestion and absorption. Increasing evidence suggests that a mucus barrier is indispensable to maintain homeostasis in the gastrointestinal tract. However, the importance of mucus barrier is largely underrated for in vitro mucosal tissue modeling. The major gap is the lack of experimental material …

Defining The Let-7 Microrna-Mediated Molecular Mechanisms Regulating T Cell Differentiation, Constance C. Angelou

Doctoral Dissertations

CD4⁺ and CD8⁺ T cells are lymphocytes of the adaptive immune system that play essential roles in immunity. Both T cell subsets recognize their cognate antigen through the T cell receptor (TCR), which induces the proliferation and differentiation of these antigen-specific cells into effector T cells. CD4⁺ T cells have the potential to differentiate into one of multiple lineages of helper T (Th) cells and participate indirectly in antigen clearance by orchestrating the function of other cells. CD8⁺ T cells differentiate into cytotoxic T lymphocytes (CTL), which directly contributes to the resolution of an infection by …

Let-7 Mirnas Program The Fate Of Cd8 T Cells, Alexandria Wells

Doctoral Dissertations

CD8 T cells are the cytotoxic effectors of the adaptive immune response, clearing virally infected and cancerous cells within the host. CD8 T cells acquire their cytotoxic function by differentiating into cytotoxic T lymphocytes (CTLs). Once the CTLs have cleared the antigen, the majority of responding cells will die during contraction; however, a small population of the antigen-specific responders will remain, differentiating into long-lived memory cells that provide potent protection to the host upon re-encounter with the antigen. These differentiation programs often become disturbed in cases of chronic infection and cancer. Instead, CD8 T cells are subverted into the so-called …

Hybridized Polymeric Nano-Assemblies: Key Insights Into Addressing Mdr Infections, Ryan Landis

Doctoral Dissertations

Multidrug-resistant (MDR) bacteria contribute to more than 700,000 annual deaths world-wide. Millions more suffer from limb amputations or face high healthcare treatment costs where prolonged and costly therapeutic regimens are used to counter MDR infections. While there is an international push to develop novel and more powerful antimicrobials to address the impending threat, one particularly interesting approach that has re-emerged are essential oils, phytochemical extracts derived from plant sources. While their antimicrobial activity demonstrates a promising avenue, their stability in aqueous media, limits their practical use in or on mammals. Inspired by the versatility of polymer nanotechnology and the sustainability …

Nascent Dna Proteomics Analysis Uncovers Dna Replication Dynamics In The Human Pathogen Trypanosoma Brucei, Maria Rocha Granados

Doctoral Dissertations

DNA is the substrate of many cellular processes including DNA replication, transcription and chromatin remodeling. These processes are coordinated to maintain genome integrity and ensure accurate duplication of genetic and epigenetic information. Genome-wide studies have provided evidence of the relationship between transcription and DNA replication timing. A global analysis of DNA replication initiation in T. brucei showed that TbORC1 (subunit of the origin recognition complex, ORC) binding sites are located at the boundaries of transcription units. Although recent studies in T. brucei indicate functional links among DNA replication and transcription, the underlying mechanisms remain unknown. In this study, we adapted …

Regulation Of Expression Of The  T Cell Wc1 Co-Receptor And Pattern Recognition Receptor Multigene Family, Payal Damani-Yokota

Doctoral Dissertations

WC1 molecules are hybrid PRR/co-receptors exclusively expressed on gd T cells of ruminants while humans and mice have related receptors. Bovine WC1 molecules bind pathogens directly and specifically and augment TCR-mediated signals. Using NGS, we found all 13 WC1 genes transcribed by blood gd T cells with no significant differences at birth although by adulthood the relative proportions of transcripts was somewhat altered perhaps attributable to immunological experience. WC1+ gd T cells form two main subpopulations in blood, WC1.1 and WC1.2, distinguished by reactivity with various anti-WC1 mAbs. Their WC1 molecules also differ in their ability to bind particular microbes …

Canonical Notch Signaling Positively Regulates Mir-155 Transcription In A Nfκb-Dependent Manner, Joe Torres

Doctoral Dissertations

MicroRNA-155 (miR-155) is an important pro-inflammatory molecule that controls immune responses in both physiological and pathological settings. Although miR-155 is well studied, little is known about its transcriptional regulation in T cells. We sought to further understand the mechanisms by which miR-155 transcription is induced following T cell activation. We found that miR-155 transcription is dependent on the activity of the Notch and NFkB signaling pathways. It was determined that the canonical Notch signaling pathway was involved in this regulation and that it was dependent upon the activation of NFkB. Additional work confirmed that both NFkB and Notch1 directly bind …

Defining And Manipulating The Function Of Protein Kinase C-Theta In Graft Versus Host Responses, Emrah Ilker Ozay

Doctoral Dissertations

Immune-mediated tissue destruction of graft-vs-host disease (GvHD) remains a major barrier to greater use of bone marrow transplantation (BMT). It is found that alloreactive donor-derived T cells activated through their T cell receptor (TCR) are primarily the major contributors to the immunopathobiology of GvHD. Protein kinase C-theta (PKCtheta), a crucial, early downstream kinase of TCR signaling, enhances T cell activation, thereby promoting alloreactive responses such as differentiation, proliferation, migration, and cytotoxicity. Thus, delineating specific ways of interfering PKCtheta signaling is beneficial for the GvHD treatment or prevention. Here, we investigated the molecular mechanisms driven by PKCtheta in T cells by …

Polymeric Peptide Mimics For Protein Delivery, Coralie Backlund

Doctoral Dissertations

The plasma membrane is a major obstacle in the development and use of biomacromolecules for intracellular applications. Consequently, proteins with intracellular targets represent an enormous, yet under studied avenue for therapeutics. Extended research has aimed at facilitating intracellular delivery of exogenous proteins using protein transduction domains (PTDs), which allow transport of bioactive molecules into cells. Synthetic polymers, inspired by PTDs, provide a well-controlled platform to vary molecular architecture for structure activity relationship studies. Specifically, this thesis focuses on the use of ring-opening metathesis, a facile and efficient polymerization technique, through which we can vary structural parameters to optimize delivery of …

Effects Of Floral Phytochemicals On Growth And Evolution Of A Parasite Of Bumble Bees, Evan Palmer-Young

Doctoral Dissertations

Background: Nectar and pollen are rich in phytochemicals, some of which can reduce disease in pollinators, including agriculturally important honey and bumble bees. Floral phytochemicals could influence the ecological and evolutionary relationships between plants, their pollinators, and parasites that cause pollinator disease. Antiparasitic effects of phytochemicals could be exploited to ameliorate pollinator disease and decline, and thereby sustain pollinator-dependent agricultural production. However, prior studies showed variable effects of phytochemicals on infection in live bees, where differences in bee genotype, abiotic conditions, and parasite strain could influence results. Approach: I used cell cultures of the intestinal trypanosome parasite of bumble bees, …

On The Construction And Interpretation Of Fitness Landscapes For Hiv: A Computational Perspective, Elizabeth Grace Johnson

Doctoral Dissertations

To identify vulnerable viral targets to incorporate into an immunogen, fitness landscapes for the viral proteome have been constructed. These landscapes describe the sum or synergistic replicative cost exacted on the virus for any combination of non-synonymous mutations. Here we attempt to assess the robustness of current computational methods for measuring the fitness cost of HIV polymorphisms in these landscapes. We also address in the following chapters assumptions and shortcomings that may underlie current landscape's uneven ability to predict fitness effects.

In the first chapter, I appraise the robustness of current frame-works that derive fitness costs from patient sequence data. …

Transmission Pattern Of Major Clonal Lineages Of Toxoplasma Gondii, Pooja Saraf

Doctoral Dissertations

Toxoplasma gondii is the most successful zoonotic pathogen known today. One-third of people are chronically infected worldwide. Different strains of T. gondii shows variability in mouse virulence which may potentially correlate with disease manifestation in humans. As a result, mouse is used as the model organism to study the virulence of T. gondii strains. To study the virulence on a global scale, it is necessary to establish a standardized approach for mice virulence assays. Thus, we review the methodologies used in different labs and put forth standardized approaches to study the T. gondii virulence in mice (Chapter 1). Recent …

Notch1 Modification And Signaling In T Helper Cell Differentiation, Karthik Chandiran

Doctoral Dissertations

Notch signaling modulates the developmental program of multiple cell types. The cleaved intracellular region of the receptor possess the functional domain which influences T cell activation, proliferation and differentiation. However, in naïve CD4 T cells the mechanistic details underlying cleavage of Notch1 is not clearly understood. Notch functions by acting as a signaling hub and interacting with its canonical (CSL) and non-canonical (NFkB, mTOR, Akt) binding partners to cross-talk with other signaling pathways. Notch signaling drives the differentiation program of multiple T helper cell subsets (Th1, Th2, Th17, Th9, iTreg and TFH). Recent discoveries also demonstrated a role for microRNAs …

Characterization Of Protein A And Sortase A In Staphylococcus Pseudintermedius: Potential Targets For Novel Therapeutic Approaches, Manasi Balachandran

Doctoral Dissertations

Staphylococcus pseudintermedius is an opportunistic pathogen in dogs and is the most frequent cause of canine pyoderma. The recent emergence of methicillin resistance and multidrug resistance has made it increasingly difficult to treat infections using conventional antibiotics. There is an urgent need for alternative strategies to prevent S. pseudintermedius infections. The development of a successful vaccine against S. pseudintermedius is complicated by several virulence and immune evasion factors. The objective of this project was to identify new targets for treatment and prophylaxis of methicillin-resistant and multidrug-resistant S. pseudintermedius infection. This was achieved using two strategies (a) understanding the roles of …

Anthrax Models Involving Immunology, Epidemiology And Controls, Buddhi Raj Pantha

Doctoral Dissertations

This dissertation is divided in two parts. Chapters 2 and 3 consider the use of optimal control theory in an anthrax epidemiological model. Models consisting system of ordinary differential equations (ODEs) and partial differential differential equations (PDEs) are considered to describe the dynamics of infection spread. Two controls, vaccination and disposal of infected carcasses, are considered and their optimal management strategies are investigated. Chapter 4 consists modeling early host pathogen interaction in an inhalational anthrax infection which consists a system of ODEs that describes early dynamics of bacteria-phagocytic cell interaction associated to an inhalational anthrax infection.

First we consider a …