Cell Biology Commons^™

Investigating The Role Of Il-10 Producing Nkt Cells In Prevention Of Graft Versus Host Disease, Drew Boagni

Dissertations & Theses (Open Access)

The standard curative treatment for hematologic malignancies is allogeneic stem cell transplantation (ASCT), in which the patient’s immune system is replaced with that of a healthy donor. This can lead to cure through the graft versus leukemia (GVL) effect but can also cause graft versus host disease (GVHD), which is characterized by systemic inflammation and organ damage mediated by dysregulated donor T cells. Preclinical studies have shown invariant natural killer T cells (iNKT) cells can prevent GVHD while preserving GVL. iNKT cells are unconventional T cells which recognize glycolipid antigens presented in the context of CD1d. Upon activation, they secrete …

Adipocytes And Innate Immunity In Systemic Sclerosis, Nancy Wareing

Dissertations & Theses (Open Access)

Systemic sclerosis (SSc; scleroderma) is a chronic systemic autoimmune and connective tissue disorder characterized by vasculopathy, autoimmune phenomena, and widespread fibrosis. Skin thickening and tightening is the cardinal feature of SSc and is responsible, in part, for the considerable morbidity of this disease. There are currently no targeted treatments for skin manifestations in SSc, primarily due to our fragmented understanding of its pathophysiologic mechanisms. In PART I, we report a previously unappreciated link between aberrant expression of the developmental gene sine oculis homeobox homolog 1 (SIX1) in skin-associated adipocytes in SSc skin and the early loss of dermal white adipose …

The Role Of The Hypoxia-Inducible Factor 2 In Pancreatic Cancer: Mechanisms Of Tumor Immunosuppression And Intestinal Radioprotection, Carolina Garcia Garcia

Dissertations & Theses (Open Access)

Pancreatic ductal adenocarcinoma (PDAC) is a devastating disease with dismal prognosis. The only curative option for patients is surgery, but over 80% of patients are not surgical candidates. Unfortunately, PDAC is resistant to the three remaining options. PDAC is characterized by a profoundly hypoxic and immunosuppressive stroma, which contributes to its therapeutic recalcitrance. Alpha-smooth muscle actin+ (αSMA+) cancer-associated fibroblasts (CAFs) are the most abundant stromal component, as well as mediators of stromal deposition. The hypoxia-inducible factors (HIF1 and HIF2) coordinate responses to hypoxia, yet, despite their known association to poor patient outcomes, their functions within the PDAC tumor microenvironment (TME) …

Heterogeneous Nuclear Ribonucleoprotein K (Hnrnp K) Overexpression And Its Interaction With Runx1 Rna In Acute Myeloid Leukemia, Marisa Aitken

Dissertations & Theses (Open Access)

Acute myeloid leukemia (AML) is an often devastating hematologic malignancy with 5-year overall survival lingering near 20%. Acquiring a deeper understanding of molecular underpinnings of leukemogenesis will provide a basis for developing more effective therapeutic strategies for patients with AML.

Here, we identified overexpression of hnRNP K as a recurrent abnormality in a subset (~20%) of AML patients. High levels of this RNA-binding protein associated with inferior clinical outcomes in de novo AML. Thus, to evaluate its putative oncogenic capacity in myeloid disease, we overexpressed hnRNP K in murine hematopoietic stem and progenitor cells isolated from fetal liver cells (FLCs). …

Study Of Regulated Cell Death In Two Systems: Pd-1 In Natural Killer Cells And Rip3 In Neurons, Yu Huang

Dissertations & Theses (Open Access)

Cell death is not only an essential phenomenon in normal development and homeostasis, but also crucial in various pathologies. It is now clear that many types of cell death can be regulated by pharmacological or genetic interventions. These were largely achieved by identifying the molecular mechanisms underlying the regulated cell death (RCD). While in the immune system, RCD needs to be facilitated to help the clearance of pathogens and tumors, in healthy cells, especially the terminally differentiated neurons in the nervous system, it is more desirable to protect cells from dying due to stress under pathological conditions. Thus, understating the …

Preventing Thymus Involution In K5.Cyclin D1 Transgenic Mice Sustains The Naïve T Cell Compartment With Age, Michelle L. Bolner

Dissertations & Theses (Open Access)

The thymus maintains T cell receptor (TCR) repertoire diversity through perpetual release of self-MHC restricted naive T cells. However, thymus involution during the aging process reduces naïve T cell output, leading to defective immune responsiveness to newly encountered antigens. We have found that early thymus involution precipitates the age-associated shift favoring memory T cell dominancy in young control mice. Furthermore, we have shown that age-related thymus involution is prevented in mice expressing a keratin 5 promoter-driven Cyclin D1 (K5.D1) transgene in thymic epithelial cells (TECs). Thymopoiesis occurs normally in K5.D1 transgenic thymi and sustains T cell output to prevent the …

Role Of Stat3 In Human Nk Cell Functions, Prasad V. Phatarpekar

Dissertations & Theses (Open Access)

Natural Killer (NK) cells are cytotoxic lymphocytes, which play a critical role in the immune response against malignant cells and microbial infections. NK cells are equipped with activating receptors, which upon detecting ligands expressed on stressed cells induce cytolytic activity of NK cells. Stimulation of NK cell proliferation and priming of NK cytolytic capability are accomplished by cytokines, which mediate their signals mainly through JAK-STAT signaling pathway. Previously, we found that K562 cells genetically modified to express membrane bound IL-21 (mbIL-21), which predominantly activates STAT3, induce robust expansion and activation of human NK cells. Further investigations revealed role of STAT3 …

Src Homology 2 Domain-Containing 5’-Inositol Phosphatase-2 (Ship2) Is An Effector Of Lymphatic Dysfunction, Germaine D. Agollah

Dissertations & Theses (Open Access)

The lymphatic system is essential for the transport of excess fluid, protein, and foreign materials from interstitial tissues to lymph nodes; for immune surveillance, and to maintain fluid homeostasis. Dysregulated lymphatics can be attributed to pathological conditions including tumor metastasis, inflammation, chronic wounds, obesity, blood vascular disorders, and lymphedema. Of these, lymphedema is the most extreme of lymphatic disorders and is represented by a spectrum of symptoms ranging from mild, subtle presentation to severe, disfiguring, overt presentation. Lymphedema is more manageable in the early stages of disease but severely reduces quality of life with progression. Due to lack of molecular …

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

Dissertations & 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 …

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

Dissertations & 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 & 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), …

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

Dissertations & 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 …

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 & 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 …