Antigen Discovery In Multiple Myeloma Using Integrated Long-Read Transcriptomics And Immunopeptidomics, Aya Albittar

Dissertations and Theses (Open Access)

Multiple myeloma (MM) remains an incurable plasma cell malignancy, with relapse driven by persistent chemotherapy-resistant cells and residual disease following treatment. Although immunotherapies have transformed MM care, their success depends on identifying tumor-specific antigens that can be safely targeted. While aberrant genomic structural variation and transcriptional dysregulation are increasingly recognized as sources of novel antigens in MM, the HLA-presented antigenic landscape of MM remains incompletely characterized, particularly for non-canonical, structurally-derived peptides, and long-read transcriptome-informed immunopeptidomic data specific to MM remain scarce.

We established an integrated antigen discovery platform combining long-read RNA sequencing (Iso-Seq) with mass spectrometry-based HLA immunoprecipitation and immunopeptidomics …

From Antigen Presentation To Tumor Control: Mechanisms Of Type I Conventional Dendritic Cell-Based Cancer Vaccines, Josue E. Pineda

Dissertations and Theses (Open Access)

Type 1 conventional dendritic cells (cDC1s) are important for generating and sustaining antitumor immunity. Accordingly, the abundance of cDC1s in human tumors correlates with improved outcomes in cancer. Capitalizing on this role, we previously demonstrated that vaccination with in vitro-derived murine cDC1s elicits durable tumor control in multiple preclinical models; however, the immunological mechanisms underlying the efficacy of cDC1 vaccination remain unclear. Here, we examined whether in vitro-derived cDC1s resemble tumor-infiltrating DC populations and whether MHC-I and MHC-II antigen presentation contribute to cDC1-mediated tumor control following vaccination in melanoma.

As expected, MHC-I- or MHC-II-deficiency had minimal impact on …

Understanding Epigenomic Landscapes In Cancer Progression And Immunotherapy Response, Jonathan Schulz

Dissertations and Theses (Open Access)

Nonmutational epigenomic reprogramming has emerged as a key hallmark of cancer that plays crucial roles in tumor evolution during its progression and response to therapy. However, the extent and nature of epigenomic reprogramming remains poorly understood. This dissertation examines how epigenetic regulation shapes cancer progression and response to immunotherapy. Working at the intersection of cancer biology and computational genomics, it develops analytical frameworks for characterizing chromatin structure and DNA methylation across diverse tumor contexts and uses these frameworks to address two complementary biological questions: how promoter-associated chromatin organization varies across cancer types, and how epigenetic perturbation modulates tumor immunogenicity in …

Host-Intrinsic Factors Determine Anti-Tumor Efficacy Of Exercise In Pancreatic Ductal Adenocarcinoma, Sumedha Pareek

Dissertations and Theses (Open Access)

Pancreatic Ductal Adenocarcinoma (PDAC) is the third leading cause of cancer-related deaths with a low 5-year relative survival rate of approximately 13.3% for all stages combined. We have previously shown that exercise can improve quality of life and enhance functional capacity among patients with PDAC. Exercise induces a variety of changes in the tumor microenvironment with beneficial effects in several tumor types. However, our understanding of the clinical effects of exercise and the mechanisms that mediate anti-tumor effects are limited in pancreatic cancer.

In this project, using C57BL/6 mice from Taconic Biosciences (Tac) and Jackson Laboratories (Jax), we established a …

Computational Frameworks To Unravel The Immune Landscape, Shan He

Dissertations and Theses (Open Access)

Recent advances in immunotherapy, including immune checkpoint blockade (ICB) and adoptive cell therapy, face challenges such as resistance and immune-related adverse events, partly due to our limited understanding of the immune signaling pathways. While high- throughput genomic data provide unprecedented resolution into these immune pathways, their full potential is limited by the lack of well-annotated, context-specific immune gene sets. To address this need, I developed a workflow to construct immune gene sets by integrating RNA- seq datasets and performing decomposition. Using this approach, I constructed 28 immune- specific gene sets from 83 bulk RNA-seq datasets and 12 Natural Killer (NK) …

Studies Of The Mechanisms Of Reverse Signaling By Cd40l, Barbara M. Nassif Rausseo

Dissertations and Theses (Open Access)

CD40 ligand (CD40L) is a transmembrane protein expressed on activated CD4 T cells, traditionally known for its role in forward signaling by engaging CD40 on antigen- presenting cells to promote immune activation. While this pathway is well characterized, there is evidence that CD40L also mediates reverse signaling, acting as a signaling receptor on T cells which enhances T cell function. However, the extent, consequences, and mechanism of CD40L-mediated reverse signaling in CD4 T cells remain poorly defined. This dissertation investigates the mechanisms and effects of CD40L reverse signaling on T cell function using both primary human T cells and the …

Fc Gamma Receptors Facilitate Antigenic Modulation Of Lilrb4 And Function As Predictive Biomarkers In Acute Monocytic Leukemia, Joshua Morse

Dissertations and Theses (Open Access)

Acute monocytic leukemia (monocytic AML) is a subtype of AML marked by a proliferation of abnormal monoblasts. This subtype represents approximately 10% of AML cases. The prognosis of monocytic AML is poor, with a 5-year survival of ~30%. Most patients are diagnosed at an age when they are unlikely to survive first-line non-targeted cytotoxic chemotherapy as a bridge to hematopoietic stem cell transplant (HSCT). Even patients who achieve remission commonly relapse. This population of patients would greatly benefit from precision-targeted therapies but currently there are none approved for monocytic AML.

Leukocyte immunoglobulin-like receptor B4 (LILRB4) is an immune checkpoint expressed …

Expanding Inducible Epithelial Resistance Against Pneumonia: Novel Virus, Novel Receptor, Michael Longmire

Dissertations and Theses (Open Access)

Pneumonia is the leading infectious cause of death worldwide and presents a continuing risk among immunocompromised patients. Our work has been focused for many years on the phenomenon of inducible epithelial resistance, where activation of the innate immune response in the airway epithelium is necessary and sufficient to produce a pathogen-killing but self-protective environment to prevent severe disease. Inducible resistance is pathogen-agnostic and has been demonstrated against an array of respiratory infections. We achieve this using a combination of pattern recognition receptor agonists – Pam2CSK4 and ODN M362 being the current formulation – which produce synergistic levels of pathogen reduction …

Leveraging Innate Immune Sensors To Generate Durable Anti-Glioma Adaptive Immune Responses, Spencer Lea

Dissertations and Theses (Open Access)

Glioblastoma is an aggressive primary brain malignancy harboring a tumor microenvironment that is mostly devoid of T cell effector infiltration but is dominated by immune suppressive microglia, macrophages, and myeloid-derived suppresser cells. These innate immune cells display impaired phagocytosis and antigen presentation and are inadequate for triggering the subsequent immune activating signals needed for anti-tumor adaptive effector responses. Glioblastoma tumors can further restrict phagocytosis and subsequent tumor antigen presentation by the upregulation of the antiphagocytic “don’t eat me” ligand CD47. Here we tested whether activation of multiple conserved innate immune pathways could initiate proinflammatory conversion of suppressive myeloid populations, activation …

Impact Of Tumor Cell Expressed Cd38 On Metastasis And Immune Evasion In Breast Cancer, Tanvi Visal

Dissertations and Theses (Open Access)

Triple-negative breast cancer (TNBC) is a highly metastatic breast cancer subtype. The epithelial-to-mesenchymal transition (EMT) of cancer cells is a key feature of the metastatic cascade and is not a binary process but often generates malignant cells with both epithelial (E) and mesenchymal (M) traits known as hybrid EM cells. Recent studies highlight the enhanced metastatic potential of the hybrid EM cells. However, molecular insights and targetable vulnerabilities within hybrid EM remain elusive. We discovered that hybrid EM murine tumors are enriched in CD38, an immunesuppressive molecule associated with worse clinical outcomes in liquid malignancies but relatively understudied in solid …

Exploring Veto Activity: Dnam-1-Cd155 Axis In Overcoming Nk Cell-Mediated Allo-Rejection And Applications For Car-T Cell Therapy, Wei-Hsin Liu

Dissertations and Theses (Open Access)

As Miller et al. defined veto activity, it enables cells to target host cytotoxic T lymphocyte (CTL) precursors specific to veto cells' antigens, selectively eliminating anti- donor T cell clones without inducing rejection. By leveraging this unique immune property, two key research aims were proposed: “Exploration of the Impact of Veto Activity on Natural Killer (NK) Cell-Mediated Allo-rejection” and “Development of Off-the- shelf Chimeric Antigen Receptor (CAR)-T Therapy: Engineering Anti-Viral Veto CD8+ T Cells”. As demonstrated in our previous research, in a murine model with mild conditioning, anti-third-party central memory CD8+ veto T cells (veto Tcm) can prevent T cell- …

Harnessing The Immunomodulatory Potential Of Radiofrequency Ablation To Improve Therapeutic Outcomes In Pancreatic Ductal Adenocarcinoma, Bhumi Maniyar

Dissertations and Theses (Open Access)

Pancreatic ductal adenocarcinoma (PDAC) continues to rank among the most lethal cancers with poor prognosis. PDAC is characterized by a thick desmoplastic stroma, severe immunological suppression, and resistance tostandard treatments. The need for innovative therapeutic approaches is highlighted by the tumor microenvironment's (TME) critical role in promoting disease development and reducing the effectiveness oftreatment. A promising locoregional treatment that can induce tumor necrosis and modify the TME is endoscopic ultrasound-guided radiofrequency ablation (EUS-RFA). However, there is still minimal understanding around its wider impact on stromal remodeling and immunological activation. This study investigates the immunomodulatory effects of RFA combined with neoadjuvant …

Exploring The Immunologic Consequences Of Atrx Deficiency In Glioma, Benjamin Whitfield

Dissertations and Theses (Open Access)

ATRX is a key chromatin regulator that is frequently mutated across multiple cancer types. One of the most common ATRX-mutated tumor types is the adult-type glioma, IDH-mutant, Astrocytoma. It is known that ATRX mutation leads to increases in DNA damage, replication stress, and global epigenetic regulation at a cell level; however, less is known about the impact of ATRX mutation on immune signaling. Furthermore, little is known about the interaction of ATRX loss with gain-of-function mutations in IDH. In this paper we set out to explore the impact of ATRX loss on immune signaling in gliomas, both in the context …

Stat3, Nf-Κb, And Estrogen Receptor Beta: The Balance Of Inflammation In K-Ras Mutant Lung Adenocarcinoma, Michael J. Clowers

Dissertations and Theses (Open Access)

K-ras mutant lung adenocarcinoma (KM-LUAD) is a difficult-to-treat cancer subtype in which chronic inflammation pervades the tumor immune microenvironment (TIME). Pro-inflammatory pathways dampen the response to treatments, including immune checkpoint inhibitors, necessitating therapies that target this inflammatory signaling network in the TIME. This network is underpinned by interaction and coordination of two inflammatory pathways: signal transducer and activator of transcription 3 (STAT3) and nuclear factor kappa B (NF-κB). The balance of these transcription factors determines the degree of anti- vs. pro-tumor immunity, and a skewing towards STAT3 is known to promote tumor development and a pro-tumor TIME. It is also …

Mhc Class I Tyrosine Phosphorylation Site Y320 Augments Cd8+ T Cell Priming, Effector Function, And Memory Response, Yimo Sun, Gregory A Lizee, Yitao Tang, Priscilla Ortiz, R Eric Davis

Dissertations and Theses (Open Access)

The cytoplasmic domain of MHC class I (MHC-I) molecules contains a single, highly conserved tyrosine residue (Y320). In previous work, we found that mice expressing a Y320F-mutated form of H-2K^b had reduced capacity to generate K^b-restricted cytotoxic T lymphocyte (CTL) responses following viral infection, due (at least in part) to defects in endolysosomal trafficking of H-2K^b and antigen cross-presentation by dendritic cells (DCs). In this study, we investigated whether there are additional, post-presentation dependencies on Y320 for T-cell priming. We engineered both human- and mouse-derived antigen-presenting cells (APCs) to express either wild-type MHC-I or variants of …

Investigating Metabolic And Mitochondrial Adaptations Triggered By Blood Flow During The Endothelial-To-Hematopoietic Transition, Paulina Horton

Dissertations and Theses (Open Access)

Hematopoietic stem cell (HSC) transplant is the standard of care for many hematologic diseases. However, many patients cannot benefit from this potentially curative treatment because they cannot find a suitable donor, contributing to a high level of unmet need. Recently, bona fide HSCs capable of robust engraftment and differentiation have been generated from iPSCs utilizing wall shear stress (WSS) to help promote HSC generation. However, the mechanisms through which WSS regulates hematopoiesis remain poorly understood. Scientists, therefore, continue to look for the mechanotransduction pathways that promote hematopoiesis, and key answers may lie in examining the role of extrinsic factors that …

Differential Progression Of Pancreatic Premalignancy In Geographically Distant Murine Transgenic Cohorts Uncovers Key Role Of Microbial Metabolites, Rian M. Howell

Dissertations and Theses (Open Access)

Cancer is a leading cause of death worldwide. Despite recent advances in diagnostic and therapeutic modalities, pancreatic ductal adenocarcinoma (PDAC) is an aggressive cancer that remains highly lethal. Efforts have been made to increase the understanding of the underlying mechanisms driving early stages of tumor development, when the cancer is most susceptible to intervention. To this end, genetically engineered mouse models (GEMMs) have been developed with the mutations most commonly seen in the patient population. Expression of these mutations in select cellular compartments has resulted in the ability to recapitulate characteristics of human pancreatic cancer such as the development of …

Timigp: A Computational Framework To Determine The Tumor Immune Microenvironment Associated With Prognosis And Immunotherapy Response, Chenyang Li

Dissertations and Theses (Open Access)

Accumulating evidence has suggested that the tumor immune microenvironment (TIME) drastically impacts cancer patients’ clinical outcomes, including prognosis and immunotherapy response. However, understanding TIME remains challenging due to its complexity and heterogeneity. In this dissertation, we introduce TimiGP (Tumor Immune Microenvironment Illustration based on Gene Pairs), a computational framework designed to address this challenge. Leveraging single-cell RNA-seq (scRNA-seq) and bulk gene expression data alongside clinical information, TimiGP constructs a cell-cell interaction network that elucidates the relationship between immune cell function and relevant clinical outcomes, such as prognosis and treatment response. With immunological insights, these cell-cell interactions also facilitate the development …

The Role Of Lifr Signaling In Innate Immunity, Laura Kahn Serrudo

Dissertations and Theses (Open Access)

The localized signals that bone marrow (BM) hematopoietic stem cells (HSCs) and immune cells receive are critical in regulating their responses in the steady state and inflammation. Monocytes are an abundant and key population in the innate immune response that originates in the BM, and they circulate to monitor the periphery. Monocytes are composed of many subsets that have essential and specific functions, including swift egress from the BM, production of pro-inflammatory cytokines, and differentiation into monocyte-derived dendritic cells (MoDCs), which are required for efficient pathogen eradication.

Here, we uncovered LIFR (leukemia inhibitory factor receptor) restrains low-grade chronic inflammation in …

Oncolytic Viruses Enhance Long-Term Nk Cell Anti-Tumor Cytotoxicity Through Ap-1 And Irf Pathway Activation, Xin Ru Jiang

Dissertations and Theses (Open Access)

Natural killer (NK) cell therapeutics have emerged as a promising strategy in adoptive cellular therapy. While genetic modifications of NK cells can enhance their antitumor activity, modulating the tumor to augment NK cell recognition and function remains underexplored. In this study, we investigated the combination of NK cells with oncolytic viruses to treat solid tumors, specifically pancreatic ductal adenocarcinoma and glioblastoma. We demonstrated that infecting tumor cells with the oncolytic adenovirus Delta-24-RGD significantly increases their susceptibility to NK cell cytotoxicity, driven by a hyperactivated NK cell phenotype characterized by elevated expression of activating receptors and cytotoxicity markers. In a patient-derived …

Local Or Systemic Antibody-Targeted Sting Activation Drives Pro- Inflammatory Stromal Metabolic Changes And Downregulates C-Myc Oncoprotein, Akash Boda

Dissertations and Theses (Open Access)

The past decade has witnessed remarkable advances in the field of cancer immunotherapy. Immune checkpoint blockade (ICB) has emerged as a cornerstone, achieving long-lasting tumor regression in several types of cancer. However, its effectiveness is often limited, particularly in certain tumor types. Immunologically "cold" tumors, such as pancreatic ductal adenocarcinoma (PDAC), remain clinically unresponsive to ICB, presenting a significant challenge in oncology. Amidst these challenges, the stimulation of the STING pathway via small molecule synthetic agonists has surfaced as a promising strategy. Acting as an in-situ vaccine, STING activation has the potential to transform the immune landscape of cold tumors …

The Role Of Ganglioside Gd2 And Gd3 Synthase (St8sia1) In The Regulation Of Immune Suppression In Breast Cancer, Bolutyfe Oderinde

Dissertations and Theses (Open Access)

Gangliosides are acidic glycosphingolipids involved in cell adhesion, proliferation, and modulation of signal transduction pathways. It has been reported that tumor-shed gangliosides influence the activity of immune cells including macrophages, NK cells, and T cells. GD3 synthase (GD3S) is the key enzyme that regulates the biosynthesis of the b and c series gangliosides, particularly GD3 and GD2, and studies have shown that GD3S is upregulated in most tumors and plays a role in tumor progression. Similarly, we have previously found GD3S to be significantly upregulated in GD2+ breast cancer stem cells (BCSC) compared to GD2- cells, and the knockdown of …

Comprehensive Investigation Into The Molecular Mechanisms Driving The Emergence Of Emm4 Group A Streptococcus, Chioma Odo, Samuel A Shelburne, Anthony R. Flores, Steven J Norris, Anna Konovalova, Blake Hanson

Dissertations and Theses (Open Access)

Abstract

Comprehensive Investigation into the Molecular Mechanisms Driving the Emergence of emm4 Group A Streptococcus

Chioma Modeline Odo, M.S.

Advisory Professor: Samuel A. Shelburne, MD, Ph.D.

The major gram-positive bacterium group A Streptococcus (GAS) is a model organism for studying microbial epidemics as it is well known to cause infections that occur in waves. GAS strains are grouped based on the composition of the N-terminal sequence of the M protein which is encoded by the emm gene. With the advent of large-scale whole genome sequencing, GAS clonal emergence events in emm1, emm3, and emm89 types have been identified …

Tsyn-Seq: A T Cell Synapse-Based Antigen Identification Platform, Yimei Jin

Dissertations and Theses (Open Access)

Tools for genome-wide rapid identification of peptide–major histocompatibility complex targets of T-cell receptors (TCRs) are not yet universally available. We present a new antigen screening method, the T-synapse (Tsyn) reporter system, which includes antigen-presenting cells (APCs) with a Fas-inducible NF-κB reporter and T cells with a nuclear factor of activated T cells (NFAT) reporter. To functionally screen for target antigens from a cDNA library, productively interacting T cell–APC aggregates were detected by dual reporter activity and enriched by flow sorting followed by antigen identification quantified by deep sequencing (Tsyn-seq). When applied to a previously characterized TCR specific for the E7 …

The Role Of An Ultraconserved Long Non-Coding Rna In B-Cell Lymphomagenesis, Swati Mohapatra

Dissertations and Theses (Open Access)

Ultraconserved regions (UCRs) are genomic segments with perfect (100%) conservation between the orthologous regions of human, rat, and mouse genomes. UCRs can be transcribed into mono-exonic long non-coding RNAs (lncRNAs) known as transcribed ultraconserved regions (T-UCRs). These regions, despite lacking protein-coding potential, are increasingly recognized for their regulatory roles in gene expression, including the modulation of non-coding RNA (ncRNA) transcripts. NcRNAs play crucial roles in cellular processes, including oncogenic transformation, with emerging evidence revealing their ability to encode small peptides known as ncRNA-encoded peptides (ncPEPs). These peptides, originating from small open reading frames (smORFs), contribute to diverse cellular functions and …

The Role Of Micrornas On Systemic And Central Nervous System- Inflammation In Aged Mice, Anik Banerjee

Dissertations and Theses (Open Access)

MicroRNAs play a crucial role in multiple biological processes, including development, cell differentiation, proliferation, metabolism, and cell death. Aberrant regulation of microRNAs is seen in many diseases, such as sepsis, cardiovascular disease, neurological diseases such as stroke, and metabolic disorders. Because of their involvement in disease processes, microRNAs have been investigated as both potential biomarkers, and as therapeutic targets. Age-related inflammatory diseases including diabetes, obesity, and atherosclerosis are important risk factors for infection and sepsis. Intestinal barrier impairment occurs with aging and after brain injuries, including stroke. Both aging and stroke increase the risk of infection and sepsis and are …

Mismatch Repair Deficient Neoantigen And Associated Circulating T-Cell Receptor Repertoires In Lynch Syndrome, Ana Bolivar

Dissertations and Theses (Open Access)

Lynch Syndrome (LS) is the most common inherited colorectal cancer (CRC) syndrome. It constitutes the perfect model to understand DNA mismatch repair deficient (MMRd) carcinogenesis, which underlies 15% of early-stage CRC. LS patients develop MMRd tumors with high loads of shared neoantigens (neoAgs), which are recognized by the immune system. Previous research has concentrated on discovering neoAgs and their potential as targets for vaccines in LS patients. However, these studies have primarily identified shared neoAgs from cancers, lacking detailed information on targetable neoAgs present in precancerous lesions. Understanding this landscape of pre-cancer derived neoAgs is crucial for intercepting cancer development …

Oxidative Phosphorylation In Melanoma Brain Metastases: A Regulator Of The Tumor Immune Landscape, Renato A. Guerrieri

Dissertations and Theses (Open Access)

Previously, we demonstrated via RNA-sequencing analysis of murine intracranial melanoma tumors that pharmacologic inhibition of oxidative phosphorylation (OXPHOS) results in increased expression of genes consistent with activated anti-tumor immune responses. The central hypothesis of this dissertation is that OXPHOS plays a critical role in the pathogenesis and immune regulation of melanoma brain metastases (MBMs).

The functional significance of OXPHOS was assessed through genetic inhibition, involving knockout (KO) of key regulatory genes such as Ppargc1a (PGC1a) and Ndfus4 (NDUFS4), a component of mitochondrial complex I. PGC1a KO in an RCAS-TVA mouse model of autochthonous lung and brain tumors developing from primary …

The Role Of Anti-Viral Immune Response On The Therapeutic Efficacy Of Oncolytic Virotherapy For High-Grade Gliomas, Dong Ho Shin Phd

Dissertations and Theses (Open Access)

Currently, there is no effective treatment for high-grade gliomas that are resistant to conventional treatments and immune checkpoint blockade therapies. Oncolytic viruses offer a new treatment modality by selectively replicating in cancer cells and inducing anti-tumor immunity. Among these viruses, the oncolytic adenovirus Delta-24-RGD has shown safety and efficacy in clinical trials for high-grade gliomas. Strategies to improve the efficacy of oncolytic virotherapy have aimed to heighten the immunogenicity of oncolytic viruses, either by incorporating immune-stimulating transgenes or by combining treatments with immune checkpoint blockades. However, such strategies may inadvertently trigger heightened immune responses to viral antigens, which may not …

Loss Of Ptdss1 In Tumor Cells Improves Anti-Pd-1 Therapy, Jielin Liu

Dissertations and Theses (Open Access)

PTDSS1 (Phosphatidylserine synthase 1) encodes an enzyme that facilitates production of phosphatidylserine (PS), which mediates a global immunosuppressive signal. Here, based on in vivo CRISPR screen, we identified PTDSS1 as a target to improve anti-PD-1 therapy. Depletion of PTDSS1 in tumor cells increased expression of IFNγ-regulated genes, including B2m, Cxcl9, Cxcl10, and Stat1. Loss of PTDSS1 in tumor cells also led to increased expression of MHC-I, which was associated with increased expression of cytolytic function related genes in CD8⁺ T cells and increased frequency of an iNOS⁺ myeloid subset. A gene signature derived from the iNOS⁺ myeloid …