Immunology of Infectious Disease Commons^™

Investigating Regulation Of Neutrophil-Mediated Inflammation In Mycoplasma Pneumoniae Infection, Nathan D. Velazquez

University Scholar Projects

No vaccine exists for Mycoplasma pneumoniae (Mp) infections, largely due to the

gap in understanding in the virulence and immunopathogenesis of this bacterium.

We have recently demonstrated that neutrophils are maladaptive in the context of

Mp infection, and drive disease severity while also impairing bacterial clearance.

Furthermore, we observed that B cells play a regulatory role in limiting disease

severity by modulating neutrophilic inflammation. We investigated this

phenomenon further to elucidate the mechanisms by which B cells regulate

neutrophilic inflammation. We utilized a monoclonal antibody to deplete B cells

during Mp infection and found that B-cell-depleted mice had elevated neutrophil …

Soluble Cd13 Is A Potential Mediator Of Neutrophil-Induced Thrombogenic Inflammation In Sars-Cov-2 Infection, Pei-Suen Tsou, Ramadan A. Ali, Chenyang Lu, Gautam Sule, Carmelo Carmona-Rivera, Serena Lucotti, Yuzo Ikari, Qi Wu, Phillip L. Campbell, Mikel Gurrea-Rubio, Kohei Maeda, Sharon E. Fox, William D. Brodie, Megan N. Mattichak, Caroline Foster, Ajay Tambralli, Srilakshmi Yalavarthi, M Asif Amin, Katarina Kmetova, Bruna Mazetto Fonseca, Emily Chong, Yu Zuo, Michael D. Maile, Luisa Imberti, Arnaldo Caruso, Francesca Caccuri, Virginia Quaresima, Alessandra Sottini, Douglas B. Kuhns, Et Al

School of Medicine Faculty Publications

The soluble variant of the ectopeptidase CD13 (sCD13), released from the cell surface by matrix metalloproteinase 14 (MMP14), is a potent pro-inflammatory mediator, displaying chemotactic, angiogenic, and arthritogenic properties through bradykinin receptor B1 (B1R). We revealed a link between sCD13 and amplified neutrophil-mediated inflammatory responses in SARS-CoV-2 infection. sCD13 was markedly elevated in patients with COVID-19 and correlated with disease severity and variants, ethnicity, inflammation markers, and neutrophil extracellular trap formation (NETosis). Neutrophils treated with sCD13 showed heightened NETosis and chemotaxis, which were inhibited by sCD13 receptor blockade. Meanwhile sCD13 did not induce platelet aggregation. Single-cell analysis of COVID-19 lungs …

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 …

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 …

Antimicrobial Activity Of Cat Flea (Ctenocephalides Felis) Gut Proteins On Different Days After Blood Feeding, Dhruva K. Karnik

Honors College Theses

Cat fleas (Ctenocephalides felis) are a blood-feeding ectoparasitic insect and a common domestic pest found throughout the world. Because of their reliance on host blood, fleas are exposed to blood-borne pathogens; however, the flea gut lumen is a hostile environment for microbial colonization. For example, the gut epithelia differentially express immune genes in response to feeding. In the present study, we measured the antimicrobial activity of gut proteins from cat fleas at different days after feeding (2, 5, 7, and 14). Dissected flea guts were homogenized, passed through a syringe filter, and measured in a protein assay kit. …

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

Electronic Theses and Dissertations

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

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

Evaluation Of Oasl And Herc5’S Role In The Non-Lytic Clearance Of Influenza A Virus From Club Cells, Steve Crisafulli

West Chester University Master’s Theses

Influenza A virus (IAV) is a highly infectious pathogen responsible for causing severe respiratory illness and death in humans and animals worldwide. Due to highly effective strategies to negate host antiviral defenses, IAV leads to the death of nearly all infected cells. Furthermore, IAV induces high levels of genome-damaging oxidative stress within infected cells and suppresses the cellular mismatch repair (MMR) mechanism, thereby inhibiting expression of key antiviral genes, which further contributes to cell death. However, recent studies have demonstrated that a subset of respiratory epithelial cells, called club cells, are able to non-lytically clear IAV and continue to survive …

Immunological Factors Associated With Siv/ Shiv Persistence In Diverse Tissue Niches, Omalla A. Olwenyi

Theses & Dissertations

The significant challenge towards a successful HIV cure lies in eradicating persistent viral reservoirs across diverse tissue niches. As a result, HIV-infected individuals have to resort to lifelong antiretroviral therapy. Recent news of supposed HIV eradication in a second patient has further re-invigorated the fields of HIV cure. However, a few barriers remain, such as the lack of currently available assays to accurately quantify viral reservoirs, limited information on cellular factors associated with persistence, and varied dynamics of the viral reservoir in various body compartments. Lastly, HIV-infected individuals live different lifestyles stemming from comorbid substance abuse including consumption of morphine, …

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 …

Immune Function And Metabolism Of Hibernating North American Bats With White-Nose Syndrome, Briana Nicole Anderson

Graduate Theses/Dissertations

White-nose syndrome (WNS) causes substantial mortality in certain species of hibernating North American bats. The responsible agent is Pseudogymnoascus destructans (Pd), a fungus which causes physiological complications such as increased arousals and energy depletion during the hibernation season. Tricolored bats (Perimyotis subflavus) and northern long-eared bats (Myotis septentrionalis) suffer extensive WNS mortality, while gray bats (Myotis grisescens) and big brown bats (Eptesicus fuscus) are infected, but mortality is rarely observed. It is hypothesized that there is a difference in immune responses and/or hibernation metabolism between these bat species, resulting in this …

Assessment Of Melanocyte-Specific Primary And Memory Autoimmune Responses In Vitiligo-Prone Smyth And Vitiligo-Susceptible, Non-Expressing Brown Line Chickens, Daniel Morales Falcon

Graduate Theses and Dissertations

Vitiligo is an acquired de-pigmentation disorder characterized by the post-natal loss of epidermal melanocytes (pigment-producing cells) resulting in the appearance of white patches in the skin. The Smyth line of chicken is the only model for vitiligo that shares all the characteristics of the human condition including: spontaneous post-natal loss of melanocytes, interactions between genetic, environmental and immunological factors and associations with other autoimmune diseases. In addition, an avian model for vitiligo has the added benefit of an easily accessible target tissue (a growing feather) that allows for the repeated sampling of an individual and thus the continuous monitoring of …

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 …

Validation Of The Pre-B Cell Receptor As A Therapeutic Target In B Cell Precursor Acute Lymphoblastic Leukemia, Michael Frank Erasmus

Biomedical Sciences ETDs

This dissertation is built upon the fundamental idea that the pre-B cell receptor (pre-BCR) is important to leukemia cell survival and a logical therapeutic target in B cell precursor acute lymphoblastic leukemia (BCP-ALL). The pre-BCR is expressed early at a specific stage during B cell development where it plays a central role in survival of healthy B lymphocytes. This receptor is composed of the membrane heavy chain (mIgμ) associated with surrogate light chain components, 5 and VpreB. Through the use of advanced imaging modalities, in particular two-color single particle tracking (SPT), we showed that pre-BCRs formed transient, homotypic interactions. These …

Immune Evasion By Division Of Labor: The Trophic Life Cycle Stage Of Pneumocystis Murina Suppresses Innate Immunity To This Opportunistic, Fungal Pathogen, Heather M. Evans

Theses and Dissertations--Microbiology, Immunology, and Molecular Genetics

Pneumocystis species are opportunistic fungal pathogens that cause severe pneumonia in immunocompromised hosts, including AIDS patients. Pneumocystis species have a biphasic life cycle consisting of single-nucleated trophic forms and ascus-like cysts. Both stages live within the host, and, thus, must contend with threats from the host immune system. The cyst cell wall β-glucans have been shown to stimulate immune responses in lung epithelial cells, dendritic cells and alveolar macrophages. Little is known about how the trophic life forms, which do not have a fungal cell wall, interact with immune cells. In this study, the immune response to the life cycle …

Characterization Of A Putative Hemolysin Expressed By Sneathia Amnii, A Preterm Birth-Associated Pathogen, Lizette Carrasco, Kimberly Jefferson

UROP Posters

The gram-negative bacteria Sneathia amnii is a poorly-characterized commensal of the female urogenital tract frequently associated with adverse clinical outcomes such as bacterial vaginosis (BV), amnionitis, and preterm labor. To investigate its potential role in virulence, we sought to identify and characterize virulence determinants produced by S. amnii in an effort to better understand the pathogenesis of infectious preterm birth. Through sequencing of the Sn35 genome (type strain of S. amnii), we identified two genes with amino acid sequence similarity and structural similarity to the filamentous hemagglutinin (FHA) protein of Bordetella pertussis and its Type Vb transporter. Because S. amnii …

The Incidence Of Chagas Coinfections Amongst Acute Dengue Patients In Machala, Ecuador, Elizabeth A. Mcmahon

Renée Crown University Honors Thesis Projects - All

Dengue fever is a febrile illness found throughout the tropics that, in severe cases, can be deadly. The most rapidly spreading of any mosquito-borne disease, dengue is re-emerging as an illness of great concern in Latin America and around the globe. The CDC estimates that as many as 400 million cases of dengue occur each year. The pathogenesis of dengue virus is complicated and acts through modulation of the host immune system. Dengue polarizes the immune system balance of T helper 1 (Th1) and T helper 2 (Th2) cells towards a Th1 inflammatory response. Parasitic infections have also been shown …

Selection Methods For Genetically-Modified T Cells: In Support Of Translational Therapy, David Rushworth

Dissertations and Theses (Open Access)

T cells are blood cells which organize the immune system of the host. These cells are necessary for the host to respond appropriately to threats from foreign organisms and cancerous growth. However, in the case of certain infections and cancer, T cells are unable to respond appropriately to a threat and establish immunity. This leads to disease when the infection or cancer is not sufficiently eliminated. On the other hand, T cells can lack tolerance for healthy tissue and perceive healthy tissue as infected. The ensuing over-reactive immune response also leads to disease. A delicate balance must exist between immunity …

Identification Of Epitopes On Ricin Toxin's Enzymatic Subunit (Rta) Critical For Eliciting Neutralizing Antibodies And Protective Immunity, Joanne Marie O'Hara

Legacy Theses & Dissertations (2009 - 2024)

Ricin toxin's enzymatic subunit (RTA) is a 267 amino acid RNA N-glycosidase that selectively depurinates eukaryotic ribosomal RNA and arrests protein synthesis. The crystal structure of RTA revealed that the protein assumes three distinct folding domains (FD). Residues within FD1 and FD2 form RTA's active site pocket and are proposed to interface with ribosomal proteins, while FD3's primary function is to associate with ricin's B subunit (RTB). In this study I sought to identify the regions of RTA that are important in eliciting toxin-neutralizing antibodies (TNA), as this information is critical for current efforts to develop RTA-based subunit vaccines. I …

Enhancement Of Reactive Oxygen Species Production And Chlamydial Infection By The Mitochondrial Nod-Like Family Member Nlrx1, Ali A. Abdul-Sater, Najwene Saïd-Sadier, Verissa M. Lam, Bhavni Singh, Matthew A. Pettengill, Fraser Soares, Ivan Tattoli, Simone Lipinski, Stephen E. Girardin, Philip Rosenstiel, David M. Ojcius

All Dugoni School of Dentistry Faculty Articles

Chlamydia trachomatis infections cause severe and irreversible damage that can lead to infertility and blindness in both males and females. Following infection of epithelial cells, Chlamydia induces production of reactive oxygen species (ROS). Unconventionally, Chlamydiae use ROS to their advantage by activating caspase-1, which contributes to chlamydial growth. NLRX1, a member of the Nod-like receptor family that translocates to the mitochondria, can augment ROS production from the mitochondria following Shigella flexneri infections. However, in general, ROS can also be produced by membrane-bound NADPH oxidases. Given the importance of ROS-induced caspase-1 activation in growth of the chlamydial vacuole, we investigated the …

Probiotic Therapy - Recruiting Old Friends To Fight New Foes, Roy D. Sleator

Department of Biological Sciences Publications

Against a backdrop of increasing antibiotic resistance, and the emergence of new and evolving pathogens, clinicians are increasingly forced to consider alternative therapies - probiotics are one such alternative.