Immunity Commons^™

Loss Of Caspase-8 Function In Combination With Smac Mimetic Treatment Sensitizes Head And Neck Squamous Carcinoma To Radiation Through Induction Of Necroptosis., Burak Uzunparmak

Dissertations and Theses (Open Access)

Caspase-8 (CASP8) is one of the most frequently mutated genes in Head and Neck Squamous Carcinomas (HNSCC), and mutations of CASP8 are associated with poor overall survival. The distribution of these mutations in HNSCC suggests that they are likely to be inactivating. Inhibition of CASP8 has been reported to sensitize cancer cells to necroptosis, a unique cell death mechanism. Here, we evaluated how CASP8 regulates necroptosis in HSNCC using cell line models and syngeneic mouse xenografts. In vitro, knockdown of CASP8 rendered HNSCCs susceptible to necroptosis induced by a second mitochondria-derived activator of caspase (SMAC) mimetic, Birinapant, when combined …

Il-6/Jak1 Drives Pd-L1 Phosphorylation And Glycosylation To Promote Cancer Immune Evasion, Li-Chuan Chan

Dissertations and Theses (Open Access)

Glycosylation of immune receptors and ligands, such as T-cell receptor (TCR), major histocompatibility complex (MHC), and co-inhibitory molecules, regulates immune signaling activation, antigen presentation, and immune surveillance. Recent studies revealed that the glycan structures of co-inhibitory molecules are required for receptor-ligand interaction, a critical feature for activating cancer immune evasion. However, it is unclear how oncogenic signaling initiates glycosylation of co-inhibitory molecules to induce immunosuppression. Here we show interleukin (IL)-6-activated Janus kinase 1 (JAK1) phosphorylates programmed death-ligand 1 (PD-L1)-Tyr112, leading to the recruitment of endoplasmic reticulum (ER)-associated N-glycosyltransferase, STT3A, which catalyzes the glycosylation of PD-L1, contributing to its stability. A …

Tumor Immunotherapy: Mechanisms Of Acquired Resistance And Characterization Of Immune Related To Xicities, Ashvin Jaiswal

Dissertations and Theses (Open Access)

Tumor immunotherapy has shown very promising clinical benefit across an array of cancers; however, two major challenges remain unresolved in the field. First, many patients do not respond to therapy at all or relapse after a period of remission. Second, there are often dose-limiting immune related adverse effects associated with immunomodulation.

In order to understand the mechanisms employed by tumors to evade immunotherapeutic responses, we established a murine model of melanoma designed to elucidate the molecular mechanisms underlying immunotherapy resistance. Through multiple in vivo passages, we selected a B16 melanoma tumor line that evolved complete resistance to combination blockade of …

Developing Novel Approaches To Improve Response To T Cell Based Cancer Immunotherapy, Rina M. Mbofung

Dissertations and Theses (Open Access)

Recently, T cell based immunotherapies have moved to the forefront of cancer immunotherapy with the success of Adoptive T cell therapy (ACT) and Immune checkpoint blockade.ACT, where patients are treated with tumour infiltrating T cells (TILs), conferred a clinical response rate of ~50%. Treatment with anti-CTLA4 and anti –PD1 therapy, conferred response rates of up to 50%, greatly improving the overall survival of patients with advanced melanoma amongst other cancer types. Despite the encouraging outcomes, there are relatively low response rates coupled with the delay of weeks to months before tumour shrinkage can be appreciated. Thus, understanding what tumour intrinsic …

Stromal Fibroblasts Restrain The Rate Of Colon Cancer Progression And Metastasis By Suppressing Regulatory T Cells And Colon Cancer Stem Cells, Changsoo Kwak

Dissertations and Theses (Open Access)

The initiation, progression, and metastasis of tumors involve not only cancer cells, but also the tumor microenvironment, which consists of immune or inflammatory cells, fibroblasts, endothelial cells, and extracellular matrix components (ECM). Fibroblasts are ubiquitous stromal cells that can influence other neighboring cell types through the secretion of chemokines, cytokines, ECM, ECM remodeling enzymes, and other metabolites. Myofibroblasts are a distinct subtype of fibroblasts characterized by expression α-smooth muscle actin (αSMA). These cells are a dominant component of the microenvironment, and a FSP1 and FAP could be a different clone of fibroblasts. Myofibroblasts also have been known to contribute to …

Development Of An In Silico Kir Genotyping Algorithm And Its Application To Population And Cancer Immunogenetic Analyses, Howard Rosoff

Dissertations and Theses (Open Access)

Gene content determination and variant calling in the complex KIR genomic region are useful for immune system function analysis, pathogenesis and disease risk factor elucidation, immunotherapy development, evolutionary investigations, and human migration modeling. Sequence-specific oligonucleotide and sequence-specific primer PCR methods are the de facto standards for KIR presence/absence identification, but the current platforms are unsuitable for SNP calling, impractical for KIR typing large cohorts of DNA samples, and inapplicable for typing repositories in which sequence data, but not cells or cell analytes, are available. Alternative typing methods, such as in silico sequence-based typing, can address the problems associated with amplicon-based …

Rerouting Pre-Existing Host Vaccine-Induced Immunity To Wards Breast Cancer, Bharat Kumar Reddy Chaganty

Dissertations and Theses (Open Access)

For decades, investigators have attempted to activate the immune system to prevent cancer metastasis or recurrence; however, owing to host immune tolerance to cancer antigens and the immunosuppressive environment at tumor sites, many such attempts have failed. The recent success of anti-CTLA4, PD-L1 and PD-1 antibodies targeting immune checkpoint pathways and HPV vaccines has renewed hope that patient survival can be increased through enhancing T-cell responses. We propose to test a novel approach that may bypass host immune tolerance to cancer cells. We hypothesize that host T-cell immunity acquired through vaccination against or natural infection with infectious diseases—e.g., influenza—can be …

Plasmacytoid Dendritic Cell-Mediated Humoral Autoimmunity, Stephanie M. Dorta-Estremera Ph.D.

Dissertations and Theses (Open Access)

Humoral autoimmunity is characterized by the breakdown of B cell immune tolerance to self-antigens and consequent production of pathogenic autoantibodies. Plasmacytoid dendritic cells (pDCs), a potent type I interferon (IFN-I) producer, have been linked to the pathogenesis of systemic lupus erythematosus (SLE), a prototypic systemic humoral autoimmune disease. However, the cellular events that stimulate the development of humoral autoimmunity as a result of pDC activation have not been characterized. Moreover, the B cell subset(s) responsible for the generation of autoantibodies remains to be clearly identified.

The immunization of DNA-containing amyloids into non-autoimmune mice triggers the activation of pDCs and induction …

Determining The Mechanisms Generating Soluble Il-15 Complexes, Scott Anthony

Dissertations and Theses (Open Access)

A diverse assortment of infectious pathogens and TLR agonists enhance the expression of Interleukin (IL)-15. Additionally, inducing lymphopenia enhances anti-tumor responses in an IL-15-dependent manner. Paradoxically, despite the limited expression of IL-15 during homeostasis, the role of IL-15 during the steady state is well-known, while its roles during inflammation and infections remain largely undefined. IL-15 uses a unique method of production and presentation to support the development and homeostasis of NK and CD8 T cells. IL-15 is produced with its high affinity IL-15Rα and this IL-15Rα/IL-15 complex is shuttled to the cell surface where it is presented in-trans or cleaved …

Characterization Of The Roles Of Carma3 And Bcl10 In Virus-Triggered Rig-I/Mavs Signaling Pathway, Zhicheng Zhou Mr

Dissertations and Theses (Open Access)

After RNA virus infection, the innate immunity utilizes RIG-I family of receptors in the cytoplasm to initiate the production of type-I IFNs and proinflammatory cytokines by mitochondrial protein MAVS, which forms a prion-like structure to recruit TBK1and IKK complex to activate IRF3 and NF-κB, respectively. Herein, we revealed the important roles of CARMA3 and BCL10 in RIG-I/MAVS signaling pathway for the first time. CARMA3 or BCL10 deficient cells exhibited partially defective NF-κB activation but hyperactivation of TBK1-IRF3 signaling pathway upon ssRNA virus infection. It led to less production of IL6 but more production of type I IFNs and resulted in …

The Role Of Dual Specificity Phosphatase -11 In Innate And Adaptive Immune Responses, Kalyan Chakravarthy Nallaparaju

Dissertations and Theses (Open Access)

THE ROLE OF DUAL SPECIFICITY PHOSPHATASE -11 IN INNATE AND ADAPTIVE IMMUNE RESPONSES

Kalyan Chakravarthy Nallaparaju, M.S.

Supervisory Professor: Chen Dong, Ph.D.

Dual-specificity phosphatases (DUSPs) constitute a subfamily of protein tyrosine phosphatases characterized by their ability to dephosphorylate both phosphotyrosine and phosphoserine/phosphothreonine residues within a substrate, typically among members of the MAP kinase family. DUSPs have been shown to play a critical role in the regulation of various cellular processes including signal transduction, cell cycle regulation and cellular proliferation via modulation of MAP kinase activities. Also, many members of this family have been demonstrated to be potent immune regulators. …

Potential Roles Of Peroxidases In Caenorhabditis Elegans Innate Immunity, George R. Tiller, George R. Tiller

Dissertations and Theses (Open Access)

The production of ROS (reactive oxygen species) in response to pathogen detection is a rapid, nonspecific response that is evolutionarily conserved from nematodes to humans. ROS serve as direct and indirect effectors of innate and adaptive immunity. In Caenorhabditis elegans, a ROS burst is observed during infection and is mediated by the dual oxidase BLI-3, which produces H₂O₂. RNAi (RNA interference) to reduce the amount of BLI-3 results in a significant increase in susceptibility to pathogens, suggesting BLI-3 has a role in the immune response. However, H₂O₂ by itself is not a …

The Role Of The C5a Receptor In Host Defense Against Listeria Monocytogenes, Daniel Calame

Dissertations and Theses (Open Access)

Listeria monocytogenes (Lm) is a major cause of mortality resulting from food poisoning in the United States. While the complement component C5 is known to be protective in listeriosis, it is unknown how its cleavage fragment C5a participates. Here we show in a model of systemic Lm infection that the C5a receptor is essential for host defense. C5aR-/- mice have reduced survival and increased bacterial burden in the liver and spleen in comparison to WT mice. Surprisingly, C5aR-/- mice also have a dramatic reduction in splenocyte numbers resulting from elevated cell death as indicated by TUNEL staining and caspase 3 …

Natural And Exogenous Genome Editing In Wiskott-Aldrich Syndrome Patient Cells, Tamara J. Laskowski

Dissertations and Theses (Open Access)

Wiskott-Aldrich syndrome (WAS) is an X-linked primary immunodeficiency disease characterized by thrombocytopenia, recurrent infections and increased autoimmunity. This disease is caused by mutations in the WAS gene (WAS) which encodes for the WAS protein (WASp), exclusively expressed in hematopoietic cells and required for proper platelet production and lymphoid cell function. Approximately 11% of patients with WAS exhibit a phenomenon called Somatic Revertant Mosaicism which is characterized by the presence of lymphocytes which naturally revert back to normal phenotype by restoring WASp expression. To date, the mechanisms of this naturally-occurring gene therapy remains poorly understood, and the full extent …

Car-Modified T Cells Capable Of Distinguishing Normal Cells From Malignant Cells, Hillary G. Caruso

Dissertations and Theses (Open Access)

T cells can be redirected to target tumor-associated antigen (TAA) by genetic modification to express a chimeric antigen receptor (CAR), which fuses the specificity derived from an antibody to T-cell activation domains to result in lysis of TAA-expressing cells. Due to the potential for on-target, off-tissue toxicity, CAR⁺ T-cell therapy is currently limited to unique or lineage-restricted TAAs. Glioblastoma, a grade IV brain malignancy, overexpresses epidermal growth factor receptor (EGFR) in 40-50% of patients. EGFR also has widespread normal tissue expression. To target EGFR on glioblastoma while reducing the potential for normal tissue toxicity, EGFR-specific CAR generated from cetuximab, …

Characterization Of Differentiation And Prognostic Biomarkers On Cd8+ Tumor-Infiltrating Lymphocytes In Metastatic Melanoma, Richard C. Wu

Dissertations and Theses (Open Access)

CD8⁺ cytotoxic T lymphocytes (CTL) frequently infiltrate tumors, yet most melanoma patients fail to undergo tumor regression. We studied the differentiation of the CD8⁺ tumor-infiltrating lymphocytes (TIL) from 44 metastatic melanoma patients using known T-cell differentiation markers. We also compared CD8⁺ TIL against the T cells from matched melanoma patients’ peripheral blood. We discovered a novel subset of CD8⁺ TIL co-expressing early-differentiation markers, CD27, CD28, and a late/senescent CTL differentiation marker, CD57. This CD8⁺CD57⁺ TIL expressed a cytolytic enzyme, granzyme B (GB), yet did not express another cytolytic pore-forming molecule, perforin (Perf). In …

Inflammatory Breast Cancer: The Immune Perspective, Evan N. Cohen

Dissertations and Theses (Open Access)

Inflammatory breast cancer (IBC) is the most insidious form of locally advanced disease. Although rare and less than 2% of all breast cancer, IBC is responsible for up to 10% of all breast cancer deaths. Despite the name, very little is known about the role of inflammation or immune mediators in IBC. Therefore, we analyzed blood samples from IBC patients and non-IBC patients, as well as healthy donor controls to establish an IBC-specific profile of peripheral blood leukocyte phenotype and function of T cells and dendritic cells and serum inflammatory cytokines.

Emerging evidence suggests that host factors in the microenviromement …

The Cytoplasmic Tail Of Mhc Class I Molecules Plays A Critical Role In Dendritic Cell-Induced T Cell Immunity, Tania G. Rodriguez-Cruz

Dissertations and Theses (Open Access)

The presentation of MHC class I (MHC-I)/peptide complexes by dendritic cells (DCs) is critical for the maintenance of central tolerance to self and for the regulation of cytotoxic T lymphocytes (CTL)-mediated adaptive immune responses against pathogens and cancer cells. Interestingly, several findings have suggested that the cytoplasmic tail of MHC class I plays a functional role in the regulation of CTL immune responses. For example, our previous studies demonstrated that exon 7-deleted MHC-I molecules not only showed extended DC cell surface half-lives but also induced significantly increased CTL responses to viral challange invivo. Although exon 7-deleted variant of MHC-I does …

Determining The Roles Of Dendritic Cells And Icam-1 In The Transpresentation Of Il-15 To Cd8 T Cells, Spencer W. Stonier

Dissertations and Theses (Open Access)

The maintenance and generation of memory CD8 T cells is dependent on the cytokine IL-15. IL-15 is delivered by a novel mechanism termed transpresentation: IL-15 is presented by a cell expressing IL-15Ralpha to the CD8 T cell which responds via IL-2Rbeta/gamma_c. The identity of what cells transpresent IL-15 to support the survival and homeostatic proliferation of memory CD8 T cells is unknown. Using a transgenic mouse model that limits IL-15 transpresentation to DCs, I have demonstrated that DCs transpresent IL-15 to CD8 T cells. DCs transpresent IL-15 to CD8 T cells during the contraction of an immune response …

Enforced Expression Of Tbx1 In Fetal Thymic Epithelial Cells Antagonizes Thymus Organogenesis, Kim T. Cardenas

Dissertations and Theses (Open Access)

Enforced expression of Tbx1 in fetal thymic epithelial cells antagonizes

thymus organogenesis

Kim T. Cardenas

The thymus and parathyroid glands originate from organ-specific domains of 3rd pharyngeal pouch (PP) endoderm. At embryonic day 11.5 (E11.5), the ventral thymus and dorsal parathyroid domains can be identified by Foxn1 and Gcm2 expression respectively. Neural crest cells, (NCCs) play a role in regulating patterning of 3rd PP endoderm. In addition, pharyngeal endoderm influences fate determination via secretion of Sonic hedgehog (Shh), a morphogen required for Gcm2 expression and generation of the parathyroid domain. Gcm2 is a downstream target of the transcription factor Tbx1, …

Stat3 Controls The Neutrophil Migratory Response To Cxcr2 And Its Ligand Mip-2 (Cxcl2), Hoainam Nguyen-Jackson

Dissertations and Theses (Open Access)

Among the first white blood cells to respond to bacterial and fungal infections, neutrophils are produced in the bone marrow, released into circulating blood, and recruited to inflamed tissue. The cytokine granulocyte colony-stimulating factor (G��CSF) is used clinically to induce neutrophil mobilization from the marrow. This process was previously demonstrated to require the STAT3 transcription factor (signal transducer and activator of transcription 3), the principal signaling molecule activated upon G-CSF-binding of its receptor, but the mechanism was unknown. The chemokines KC (Cxcl1) and MIP-2 (Cxcl2), and their shared receptor CXCR2 (l8rb), also stimulate neutrophil mobilization, in contrast to SDF-1 (Cxcl12), …

Molecular Mechanisms Underlying The Transcriptional Regulation Of T Helper 17 And Regulatory T Cells, Gustavo Javier Martinez

Dissertations and Theses (Open Access)

CD4⁺ T helper (Th) lymphocytes are vital for integrating immune responses by orchestrating the function of other immune cell types. Naïve Th cells can differentiate into different effector subsets that are characterized by their cytokine profile and immune regulatory functions. These subsets include Th1, Th2, Th17, natural and inducible regulatory T cells (nTreg and iTreg respectively), among others. We focused our investigation on two Th lineages, Th17 and regulatory T cells, with opposing functions in the immune system. These subsets have been suggested to be reciprocally regulated since they both require TGF-b for their development. We investigated the role …

Plasmacytoid Dendritic Cells Sense Skin Injury And Promote Wound Healing Through Type I Interferons, Josh D. Gregorio

Dissertations and Theses (Open Access)

Plasmacytoid dendritic cells (pDCs) are a rare population of circulating cells, which selectively express intracellular Toll-like receptors (TLR)-7 and TLR-9 and have the capacity to produce large amounts of type I IFNs (IFN-a/b) in response to viruses or host derived nucleic acid containing complexes. pDCs are normally absent in skin but accumulate in the skin of psoriasis patients where their chronic activation to produce IFN-a/b drives the disease formation. Whether pDCs and their activation to produce IFN-a/b play a functional role in healthy skin is unknown. Here we show that pDCs are rapidly and transiently recruited into healthy human and …

Defining The Role Of Il-15 Trans-Presentation By Distinct Cell-Types During The Development And Homeostasis Of Natural Killer And Invariant Natural Killer T Cells, Eliseo F. Castillo

Dissertations and Theses (Open Access)

The immuno-regulatory functions displayed by NK and iNKT cells have highlighted their importance as key lymphocytes involved in innate and adaptive immunity. Therefore, understanding the dynamics influencing the generation of NK and iNKT cells is extremely important. IL-15 has been shown to provide a critical signal throughout the development and homeostasis of NK and iNKT cells; however, the cellular source of IL-15 has remained unclear. In this investigation, I provide evidence that the cell-type providing IL-15 to NK and iNKT cells via trans-presentation is determined by the tissue site and the maturation status of NK and iNKT cells. For NK …

Immune Recognition Of Self Nucleic Acids Driven By Endogenous Antimicrobial Peptides: Role In Autoimmunity, Dipyaman Ganguly

Dissertations and Theses (Open Access)

Innate immune recognition of extracellular host-derived self-DNA and self-RNA is prevented by endosomal seclusion of the Toll-like receptors (TLRs) in the dendritic cells (DCs). However, in psoriasis plasmacytoid dendritic cells have been found to be able to sense self-DNA molecules in complex with the endogenous cationic antimicrobial peptide LL37, which are internalized into the endosomal compartments and thus can access TLR9. We investigated whether this endogenous peptide can also interact with extracellular self-RNA and lead to DC activation. We found that LL37 binds self-RNA as well as self-DNA going into an electrostatic interaction; forms micro-aggregates of nano-scale particles protected from …

Efficacy And Mechanism Of Â-Defensin2 Fused Antigen Protein Vaccines, Hyun J. Park

Dissertations and Theses (Open Access)

Vaccines which use the strategy of fusing adjuvant murine â-defensin2 (mBD2) to an antigen in order to elicit stronger anti-antigen immune responses are referred to as murine â-defensin2 (mBD2) vaccines. Previous studies have validated the potential of mBD2 vaccines, thus in this study we focus on increasing vaccine efficacy as well as mechanism elucidation. Initially, we demonstrate superior IFN-ã release levels by antigen specific effector T cells when antigen is crosspresented by dendritic cells (DC) which absorbed mBD2 vaccine (mBD2 fused antigen protein) over antigen alone. We move unto an in vivo model and note significant increases in the expansion …

Characterization And Optimization Of Antigen-Specific T Cell Responses During Ex Vivo Expansion Of Melanoma Tumor-Infiltrating Lymphocytes, Yufeng Li

Dissertations and Theses (Open Access)

Treatment of metastatic melanoma with tumor reactive T cells (adoptive T cell therapy, ACT) is a promising approach associated with a high clinical response rate. However, further optimization of this treatment modality is required to increase the clinical response after this therapy. ACT in melanoma involves an initial phase (pre-REP) of tumor-infiltrating lymphocyte (TIL) expansion ex vivo from tumor isolates followed by a second phase, “rapid expansion protocol” (REP) generating the billions of cells used as the TIL infusion product. The main question addressed in this thesis was how the currently used REP affected the responsiveness of the CD8+ T …