Immunology and Infectious Disease Commons^™

Pi3kδ Inhibition Alters Cd8 T Cell Differentiation And Reprograms The Tumor Microenvironment Following Adoptive Immunotherapy, Alexandrea Joy Turnquist

Dartmouth College Ph.D Dissertations

T cell exhaustion remains a significant barrier to effective adoptive cell therapy in solid tumors. Here, we demonstrate that in vitro treatment with the PI3Kδ inhibitor CAL-101 generates T cells with enhanced stemness and metabolic fitness, though the stemness of these cells is not dependent on HIF-1α -dependent mechanisms. These cells show increased mitochondrial dependence and spare respiratory capacity while maintaining normal basal metabolism. Under chronic antigen stimulation, CAL-101-treated T cells, including human T cells, resist terminal exhaustion and maintain stem-like properties. Using single-cell RNA sequencing and spatial transcriptomics of B16 melanoma tumors, we found that CAL-101-treated T cells preferentially …

Identification And Characterization Of Novel Immune Modulating Genes In Parkinson's Disease, Kathleen Chaundy Paul Murphy

Dartmouth College Ph.D Dissertations

Parkinson’s disease (PD) is a progressive age-related neurodegenerative disorder characterized by both motor and non-motor symptoms. The poorly understood prodromal period, decades-long progression, and disease-phenotype heterogeneity continue to impede the development of preventive and curative therapies. A growing appreciation of immune system changes during the progression of PD suggests that evaluating peripheral immune cells may help identify signatures relevant to disease etiology. We aimed to expand our understanding of the peripheral immune compartment in PD via two lines of investigation: (1) by employing single-cell RNA sequencing to profile the transcriptomes of peripheral blood mononuclear cells (PBMCs) from a cohort of …

Biologically Informed Negative Samplingfor Antibody Chain Pairing Classification, Ishita Singh

Computer Science Senior Theses

Antibody heavy and light chain (H/L) pairing is fundamental to antigen recognition and stability. While single-cell sequencing preserves native pairing information, widely used bulk repertoire and spatial transcriptomics platforms do not, motivating the need for efficient ML methods to infer H/L pairing. Training a binary classifier for this task faces the methodological challenge of a lack of true biological negatives, since natural selection eliminates B cells with incompatible H/L pairs.

In this thesis, I introduce a biologically informed negative sampling strategy for H/L pairing classification, drawing on known V-gene biases in heavy and light chain pairing. Pseudo-negatives are constructed by …

Understanding The Role Of Toxs As A Bile Sensing Component Of The Toxrs Virulence Regulatory System In Vibrio Spp., Minje Kim

Dartmouth College Ph.D Dissertations

Pathogenic Vibrio bacteria, such as V. cholerae and V. parahaemolyticus, colonize in the human small intestine to cause severe gastrointestinal disease. During the infection, these bacteria encounter bile salts, antimicrobial cholesterol metabolites secreted into the intestine. Pathogenic Vibrio species have evolved to utilize bile salts as signals to regulate virulence. The signaling depends in part on ToxRS, a conserved co-component transmembrane transcription regulator. ToxRS consists of the transcription factor ToxR and its membrane-tethered binding partner ToxS. ToxS is required for ToxR stability and full transcriptional activity. Although bile salts are known to influence ToxRS-dependent virulence gene expression, the molecular …

Mitochondria Dynamics In Microglia During Health, Inflammation, And Aging, Alicia Nicole Pietramale

Dartmouth College Ph.D Dissertations

Microglia continually surveil the brain, allowing for rapid detection of tissue damage or infection. Microglial metabolism is linked to tissue homeostasis, yet how mitochondria are subcellularly partitioned in microglia and dynamically reorganize during surveillance, injury responses, and phagocytic engulfment in the intact brain has remained unclear. In this dissertation, I combine intravital imaging, ultrastructural analyses, and metabolic and cytoskeletal markers to investigate how mitochondrial organization relates to microglial function across health, inflammation, and aging.

I first show that microglial processes diverge in their mitochondrial content, with some containing multiple mitochondria while others are completely void. This heterogeneous partitioning is conserved …

Bridging Bench To Bedside: Developing Sup2-Il-33 Armored Car T Cells For Translational Immunotherapy, Shannon Lynn Ferry

Dartmouth College Ph.D Dissertations

Despite some promising results, CAR T cell therapy elicits limited responses in most patients with solid tumors. Armoring CAR T cells with immunomodulatory cytokines improves efficacy in solid tumors. We previously reported that administering IL-2 superkine (Sup2) and IL-33 cytokine armored CAR T cells without host pre-conditioning is sufficient to broadly activate host immunity to delay growth of B16F10 melanoma in immunocompetent B6 mice. However, lymphodepleting pre-conditioning prior to CAR T cell infusion is routinely utilized to enable engraftment of adoptively transferred cells. Here we assess the efficacy TRP1-specific CAR T cells with or without Sup2 and IL-33 armoring following …

The Impact Of Polymycovirus 1 On Aspergillus Fumigatus Pathogenesis During Lung Infection, Alexander W. Rapp

Dartmouth College Ph.D Dissertations

The genus Aspergillus comprises over 250 species of fungi. Within this genus, only a handful of species cause disease in humans. One species is Aspergillus fumigatus (A.f.), an environmentally ubiquitous, saprophytic fungal pathogen. Lung infections due to A.f. range from invasive infection to allergic forms of the disease. Allergic bronchopulmonary aspergillosis (ABPA) is one of the most severe forms and presents as a hypersensitivity that often results in off-target damage to the surrounding airways. Patients with ABPA are sensitized to fungal antigens and this is commonly seen in cystic fibrosis and genetic predispositions. Recent data from our lab shown how …

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 …

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 …

Strategies To Improve Antibody-Mediated Protection Against Herpes Simplex Virus Infections, Matthew D. Slein

Dartmouth College Ph.D Dissertations

No efficacious vaccine exists for herpes simplex virus and the global burden of disease remains high. Antibodies can serve as potent therapeutics to protect high risk populations such as neonates. Although rare, neonatal HSV (nHSV) infections can result in significant mortality and lifelong neurological morbidity even with antiviral therapy. While HSV-specific maternally derived antibodies significantly reduce the risk of neonatal disease in humans, the mechanisms by which they mediate protection have yet to be described. Using a mouse model of neonatal HSV (nHSV) infections we aimed to determine the mechanisms of antibody-mediated protection using monoclonal antibodies (mAbs) targeting two of …

Mechanisms Of Macrophage Metabolic Activation And Paracrine Wnt Signaling In The Pathogenesis Of Systemic Sclerosis, Emily Ann Morris

Dartmouth College Ph.D Dissertations

Systemic sclerosis (SSc) is a chronic autoimmune disease of unknown etiology. We have previously shown that macrophages (MØs) play a critical role in its pathogenesis; however, the mechanisms driving MØ activation in SSc remain poorly understood. This dissertation investigates the molecular signaling pathways and biochemical mechanisms underlying profibrotic MØ activity in SSc.

First, I identify a novel MØ-specific effect of mycophenolate mofetil (MMF), the standard-of-care treatment for SSc. While MMF is a well characterized lymphostatic, my findings demonstrate that its active metabolite, mycophenolic acid (MPA), is also capable of directly inhibiting myeloid viability and profibrotic MØ activation by suppressing de …

Leveraging Epigenomics And Transcriptomics To Develop High-Dimensional Biomarkers Of Neuroinflammation, Steven C. Pike

Dartmouth College Ph.D Dissertations

Neuroinflammation is a critical physiological phenomenon implicated in most neurological disorders, either as a cause or a consequence of pathology. Our understanding of neuroinflammation is limited by the inability to directly profile the cells of interest. Thus, developing biomarkers of neuroinflammation is clinically urgent as we know neuroinflammation correlates with patient outcomes and treatment success. The recent advances in “omics” technologies, particularly epigenomics and transcriptomics, provides the opportunity for high-dimensional profiling of biospecimens for potential biomarkers. Within this dissertation, I demonstrate that biomarkers obtained from “omics” platforms can detect neuroimmunological phenomena in clinical and preclinical settings. In chapter one, DNA …

Engineering Extracellular Vesicles (Evs) To Combat Infection And Inflammation In Cystic Fibrosis, Sharanya Sarkar

Dartmouth College Ph.D Dissertations

Cystic Fibrosis (CF) is a multisystemic genetic disorder caused by mutations in the CFTR gene, resulting in chronic pulmonary infections, hyperinflammation, and progressive lung damage. Among the pathogens that colonize CF lungs, Pseudomonas aeruginosa (P. aeruginosa) is predominant, infecting over 50% of adults with CF and developing antibiotic resistance over time. Current modulator therapies fail to address persistent bacterial infections, chronic inflammation, or irreversible lung damage, underscoring the need for novel therapeutic strategies. In our previous in vitro studies, we demonstrated that extracellular vesicles (EVs) secreted by primary Human Bronchial Epithelial Cells (HBECs) inhibit P. aeruginosa growth by reducing the …

Combination Therapy Of Ido1 Inhibition And Anti-Pd1 Mediates Anti-Tumor Immunity By Promoting Memory Immunity Development And Cytotoxicity Of Γδ T And Nk Cells Via Il-2 Signaling And By Overcoming Pro-Tumor Effects Of Tgf-Β Signaling, Hyuk Jee

Dartmouth College Master’s Theses

Cutaneous melanoma is the most aggressive form of skin cancer even though it takes only about 1% of all skin cancers. Even among all cutaneous melanomas, NRAS-mutant melanoma is more aggressive than any other, and about 10-25% of all cutaneous melanoma cases have mutations in NRAS. NRAS is a member of the RAS family of proto-oncogenic GTPase proteins, and it plays a key role in signal transduction pathways responsible for cellular survival, proliferation, and metabolism. Immunotherapy is the first line of defense against NRAS-mutant melanoma because, despite tremendous efforts made for decades, it has not been successful to develop small …

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 …

Establishment Of Bacteroides In The Gut And Its Role In The Cystic Fibrosis Gut-Lung Axis, Rebecca A. Valls

Dartmouth College Ph.D Dissertations

In the quest to understand the complex interplay between the gut microbiota and cystic fibrosis (CF), a disease characterized by chronic upper respiratory complications and an exacerbated proinflammatory response, our lab engaged in a collaborative study with Dartmouth-Hitchcock Medical Center (DHMC) to characterize the gut microbiota of pediatric CF patients. Initial analyses established a connection between gut microbial composition and respiratory health, particularly highlighting a scarcity of Bacteroides species compared to healthy controls. In following investigations, we utilized random forest models to understand how stool microbiota may influence clinical outcomes of these pediatric CF patients, including: age, upper respiratory infections, …

Hierarchal Single-Cell Lineage Tracing Reveals Differential Fate Commitment Of Cd8 T-Cell Clones In Response To Acute Infection., Leena Abdullah

Dartmouth College Ph.D Dissertations

Generating balanced populations of CD8 effector and memory T cells is necessary for immediate and durable immunity to infections and cancer. Yet, a definitive understanding of CD8 differentiation remains unclear. Here we used CARLIN, a processive lineage recording mouse model with single-cell RNA-seq and TCR-seq to track endogenous antigen-specific CD8 T cells during acute viral infection.

Transcriptional profiling of antigen-specific T cells at the peak of the effector response to Vesicular stomatitis virus uncovered a diverse repertoire of expanded antigen-specific T-cell clones represented by seven transcriptional states. TCR enrichment analysis identified TCR clones with differential memory- or effector-fate biases during …

Regulation And Therapeutic Targeting Of Virus-Specific Resident Memory T Cells, Jordan Fredriksen Isaacs

Dartmouth College Ph.D Dissertations

CD8+ T cells are critical to the immune response to pathogens, as they kill infected cells and generate immunologic memory. Following infection, antigen-specific T cells expand approximately 10,000-fold and migrate to sites of inflammation in order to clear the pathogen. Once infection is resolved, a small pool of memory T cells persist in circulation and within tissues ready to respond rapidly upon re-exposure. Given the importance of CD8+ T cells, significant efforts have been made over the years to better understand how different memory T cell subsets are established, maintained, and regulated. The most recently identified subset, resident memory T …

Heterogeneity And Plasticity Of The Naïve Cd4+ T Cell Compartment, Alia Sajani

Dartmouth College Ph.D Dissertations

Recent studies have illuminated unexpected heterogeneity in the naïve T cell compartment. Using single cell RNA sequencing of mouse naïve CD4⁺ T cells, we identified 5 unique transcriptional subsets within the naïve CD4⁺ T cell compartment. These include a quiescence cluster (T^Q) marked by Klf2, Klf6, Jun and Btg2, a memory-like cluster (T^MEM) marked by Ccr7, Il7r and Tcf7, a TCR reactive cluster (T^TCR) marked by Cd5, Cd6 and Nr4a1, an IFN responsive cluster (T^IFN) marked by Stat1, Irf7 and Ifit1 and …

Investigating The Mechanisms For Priming And Maintaining Tumor Ag Specific Cd8+ T Cell Responses In The Context Of Cd4-Depletion, Delaney E. Ramirez

Dartmouth College Ph.D Dissertations

Achieving durable, systemic CD8+ T cell responses against tumors is an imperative goal in treating cancer. However, suppressive cells, including Foxp3+CD4+ regulatory T cells (Tregs) are widely recognized to inhibit CD8+ T cell activity. For nearly two decades, anti-CD4 treatment has been used to eliminate Tregs and induces durable tumor antigen (Ag) specific CD8+ T cells, despite also depleting Foxp3-negative conventional CD4+ T (Tconv) cells. However, the underlying mechanism of anti-CD4 efficacy is not understood. In Chapter Three, we look beyond Treg depletion and investigate the potential contributions of other factors including homeostatic space, depletion of CD4+ APCs, and presence …

Driving Cars Down Memory Lane: Uncovering Car Memory T Cell And Antigenspecific Endogenous T Cells Importance In Durable Responses Against Melanoma, Asmaa Mohamed

Dartmouth College Ph.D Dissertations

Responsiveness to chimeric antigen receptor (CAR) T cell therapy correlates with CAR T cell expansion and persistence in vivo. Multiple working strategies improve CAR T cell persistence by increasing stem-like properties or by sustaining CAR T cell activity with combination therapies. Herein, we describe the intrinsic ability of CAR T cells to differentiate into memory T cells, the effect of cytokine armoring, and neoadjuvant CD4 depletion therapy on CAR and tumor-specific endogenous memory T cells. TRP1-specific CAR T cells alone or in combination with Super2 + IL-33 (S233) armoring and/or CD4 depletion therapy were evaluated in the immunocompetent B16F10 melanoma …

Molecular Mechanisms Governing The Generation Of Tissue Resident Memory Cd8 T Cells In The Setting Of Cancer, Nikhil Khatwani

Dartmouth College Ph.D Dissertations

Although there has been extensive research on T-cell responses to cancer immunotherapy, the understanding of long-lasting memory in visceral organs remains less well understood. Among these, a population of Trm cells was discovered that reside durably within tumor draining lymph nodes (TDLN) and plays a crucial role in protecting against invading melanoma cells, uncovering a new role for Trm cells at critical metastatic sites. However, little is known about the molecular mechanisms promoting Trm establishment in tissues where cancer can develop and metastasize. Here, employing longitudinal T cell receptor (TCR)-lineage-tracing and single-cell transcriptomics, we find that TDLN contain Teff cells …

Genome-Scale Methylation Analysis In Blood And Tumor Identifies Immune Profile, Age Acceleration, And Dna Methylation Alterations Associated With Bladder Cancer Outcomes, Ji-Qing Chen

Dartmouth College Ph.D Dissertations

Bladder cancer patients receive frequent screening due to the high tumor recurrence rate (more than 60%). Nowadays, the conventional monitoring method relies on cystoscopy which is highly invasive and increases patient morbidity and burden to the health care system with frequent follow-up. As a result, it is urgent to explore novel markers related to the outcomes of bladder cancer. Immune profiles have been associated with cancer outcomes and may have the potential to be biomarkers for outcomes management. However, little work has been conducted to investigate the associations of immune cell profiles with bladder cancer outcomes. Here, I utilized the …

Stranger Iggs: Beneficial And Detrimental Sides Of Immunoglobulin G Subclasses, Sweta Shrestha

Dartmouth College Ph.D Dissertations

Understanding antibody responses across various immunological conditions can provide valuable insights for the advancement of therapeutic as well as prophylactic interventions. IgG subclass responses, in particular, have garnered the most attention because of their potential role in disease outcomes and treatment efficacy. The four IgG subclasses differ in their hinge region and “constant region” and these differences in turn modulate their antibody functions. Some subclasses demonstrate robust antibody effector functions, while others exhibit diminished effector functions. The consequences of these differences can either be advantageous or disadvantageous, contingent upon the specific context in which they occur.

This thesis explores the …

Complement System In Multiple Sclerosis: Its Role In Disease Course And Potential As A Therapeutic Target, Michael R. Linzey

Dartmouth College Ph.D Dissertations

Multiple sclerosis (MS) is a clinically heterogeneous neurological condition characterized by neuroinflammation and neurodegeneration. Relapsing-remitting MS, defined by inflammatory attacks, is the most common initial form of MS and there are currently 23 FDA-approved treatments for these patients. These therapies work primarily by reducing inflammation in the CNS; they do not work well in progressive disease. Therefore, an unmet medical need exists for effective therapeutic options to treat progressive MS (PMS).

In MS, intrathecal immunoglobulins synthesis (IIgS) correlates with disease progression. My goals for this dissertation were to establish the pathological role of IIgS and identify new potential therapeutic …

Cell-Typing And Interaction Analysis Of The Immune Compartment Of The Tumor Microenvironment Using High-Resolution Omics Modalities, Courtney Taylor Schiebout

Dartmouth College Ph.D Dissertations

Single-cell RNA-sequencing (scRNA-seq) has provided a new frontier for the investigation of complex tissues. One ideal candidate for the utilization of this method is the tumor microenvironment (TME). The TME is often host to a complex set of cell populations and behaviors that can be highly influential for cancer inhibition or progression. This is especially true of the immune compartment of the TME: the presence of certain types of immune cells in the TME and their expression profiles can significantly affect cancer prognosis in some cases. By providing individual cell-level gene expression data, scRNA-seq can be highly informative for characterizing …

The Immune Modulation On Innate Immunity, From Pathogen Recognition To Fungal Clearance., Ko-Wei Liu

Dartmouth College Ph.D Dissertations

The human lung is not sterile but a complex environment with various microorganisms. Besides commensals in the lung, hundreds to thousands of individual microbiomes enter the lung every day but without causing the symptom. Host innate immunity plays an important role in maintaining homeostasis of the lung environment and as the first defense line against pathogens. Aspergillus fumigatus (A. fumigatus) is a saprophytic filamentous fungus that can cause human disease in immune compromised patients. However, with functional innate immunity, immune cells can quickly recognize pathogen associated molecular patterns (PAMPs) from A. fumigatus through pattern recognition receptors (PRRs). The activation of …

Response And Molecular Control Of Cd8 T Cells During Infection And Cancer, Nicholas K. Preiss Dr.

Dartmouth College Ph.D Dissertations

CD8 T cells are potent immune effector cells capable of vast clonal expansion and clearance of infected or cancerous cells. After control of the pathogenic insult, CD8 T cells develop into quiescent, long-lived memory populations that are poised to mediate rapid protection upon reencounter with cognate antigen. These properties make control of CD8 T cell responses a highly desirable outcome of vaccine strategies and immunotherapy. Therefore, understanding how the effector function and memory differentiation of CD8 T cells are controlled at a molecular level is of great importance. In the context of infection with gammaherpesviruses (γHV), which form a latent …

In Situ Vaccination Using Plant Viral Particles As A Novel Approach For Cancer Immunotherapy, Chenkai Mao

Dartmouth College Ph.D Dissertations

Non-infectious to mammals, genetically, and physically stable plant virus-based nanoparticles have been increasingly studied as a novel platform for cancer vaccine and adjuvants due to their immunogenic properties. Our prior work showed that, empty cowpea mosaic virus (eCPMV), a plant virus-like particle (VLP) that is composed of a separated capsid, is an excellent in situ vaccine (ISV) for cancer immunotherapy; however, little is known about the mechanisms linked to their activities regarding recognition and antigen presentation.

In the present studies, we report cowpea mosaic virus (CPMV) and RNA-lacking CPMV (empty, eCPMV) are both toll like receptor (TLR) agonists for TLRs …

Profiling Durable Anti-Tumor Memory T Cell Responses In Long-Term Melanoma Survivors, Jichang Han

Dartmouth College Ph.D Dissertations

While T-cell responses to cancer immunotherapy have been avidly studied,

long-lived memory has been poorly characterized. Of melanoma patients who

receive immunotherapy, long-term survivors are frequently found to develop

melanoma-associated vitiligo. Our prior work showed in a preclinical model that

vitiligo skin sustained a long-lived CD8+ resident memory T cell (TRM) population,

playing key roles in perpetuating anti-tumor immunity. However, the characteristics

and longevity of these memory T cells in melanoma survivors have not been defined.

In the present studies, we probed both the CD8+ and CD4+ T cell responses,

focusing on memory T cell responses in a cohort of …