Medical Genetics Commons^™

The Role Of Obesity In Macrophage-Mediated Mechanisms Promoting Early-Onset Colon Cancer., Katharina Marietta Scheurlen

Electronic Theses and Dissertations

Early-onset colon cancer (EOCC) is a leading cause of cancer death among people younger than 50 years of age in the United States and is associated with metabolic dysfunction and obesity. Anti-inflammatory tumor-associated macrophages (TAM) and low Peroxisome Proliferator Activated Receptor Gamma (PPARγ) gene expression in colon cancer (CC) tissue promote tumor progression and decreased patient survival. Obesity-related hormones, such as leptin and adiponectin, have the potential to affect gene expression in TAM to promote CC progression and thereby link obesity and EOCC. The aim of this project was to identify target genes in human CC and to investigate the …

Environmental And Genetic Factors Affecting Bone Diseases And Phenotypes In Mouse Models, Wei Dong

Theses and Dissertations (ETD)

Bone diseases and phenotypes are affected in multiple ways. We focused on studying the effects of genetic and environmental factors, especially their impact on bone properties. Firstly, we investigated the effects of β-caryophyllene (BCP), a naturally occurring dietary cannabinoid, on protecting bone from vitamin D deficiency in mice fed on a diet lacking or supplemented with vitamin D (VD). We found that the VD-deficient diet enhanced the length of femur and tibia bones (P<0.05), and increased bone volume (BV; P<0.01) and the trabecular bone volume fraction (BV/TV; P <0.01) compared to the D+ diet. When given BCP-containing diet, mice exhibited higher BV and bone mineral density (BMD; P<0.05) than the control group. The trabecular and cortical bone were also affected by VD and BCP. In addition, the inclusion of dietary BCP improved the serum concentrations of klotho (P < 0.05). In summary, these data indicate that BCP enhances the level of klotho in the serum, leading to improved bone properties and mineralization in an experimental mouse model. Under conditions lacking UV light, the D-deficient diet could affect multiple properties of bone, including trabecular and cortical bone, in mice. The D-deficient diet can also result in weight loss in mice.

My second project is to evaluate the bone properties in a mouse model with Il-1rn mutation. When knockout for IL-1rn, mice of Balb/c genomic background exhibited …

Investigating The Role Of Znf384 Rearrangements In Acute Leukemia, Kirsten Dickerson

Theses and Dissertations (ETD)

Chromosomal rearrangements involving ZNF384 are the defining lesion in 5% of pediatric and adult B-cell acute lymphoblastic leukemia and tumors are characterized by aberrant myeloid marker expression. Additionally, ZNF384 rearrangements are the defining lesion in nearly half of pediatric B/myeloid mixed phenotype acute leukemia. These fusions juxtapose full-length ZNF384 to the N terminal portion of a diverse range of partners, most often, transcription factors or epigenetic modifiers. It has been shown that ZNF384-rearranged tumors have a distinct gene expression profile that is consistent between disease groups and N terminal partners. Genomic analyses of patient tumors has shown that ZNF384 fusions …

Dissecting Drivers Of Basal Immunity And Acute Responses To Viral Infection, Aisha Nadia Hegab Souquette

Theses and Dissertations (ETD)

Heterogeneity in the human immune system can lead to limited vaccine efficacy, poor response to therapeutics, increased susceptibility to immune mediated diseases, and differential outcome to infection. Studies to date have suggested a role for biological, environmental, and genetic factors in immune variation; however, they are often focused on a specific subset of the population (e.g. ancestral group, age range) which can exclude phenotypes unique to a diverse population and bias results. To address this gap, we have utilized samples from healthy or influenza virus infected subjects from 8 distinct populations in 5 countries to conduct an integrative analysis of …

The State Of The Translational Chaperone Icd-1 During Apoptosis In Caenorhabditis Elegans, Kyle Cicalese

Senior Honors Projects, 2010-2019

The unfolded protein response (UPR) is a signal transduction cascade that mitigates low levels of misfolded protein stress in the endoplasmic reticulum (ER) in an effort to save the affected cell, while prolonged and/or acute ER stress leads to UPR-initiated apoptosis (programmed cell death). One putative step driving apoptosis is the cleavage of chaperones, proteins tasked to help misfolded proteins refold, by caspases, proteases essential to the execution of apoptosis. We are studying the nascent polypeptide-associated complex (NAC), a heterodimeric chaperone complex essential for viability, to determine if its beta subunit is cleaved by caspases during apoptosis to prevent the …

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

Dissertations & 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 …

Autoimmune Susceptibility Imposed By Public Tcrβ Chains, Yunqian Zhao

Theses and Dissertations (ETD)

The major histocompatibility complex (MHC) is the strongest genetic risk factor for autoimmunity. It acts together with a corresponding TCR repertoire, yet, considering the extent of the repertoire's diversity, how this imposes disease susceptibility on a population is not well understood. We address the hypothesis that shared or public TCR, those present in most individuals, modulate autoimmune risk. High resolution analyses of autoimmune encephalomyelitis-associated T-cell receptor β chain (TCRβ) showed preferential utilization of public TCR sequences, implicating them in pathogenesis. Disease-associated public TCRβ, when transgenically expressed in association with endogenously rearranged T-cell receptor α chain (TCRα), could further endow unprimed …

Systematic Assessment Of The Contribution Of Superantigens To Nasopharyngeal Colonization In A Mouse Model Of Streptococcal Infection, Katherine J. Kasper

Electronic Thesis and Dissertation Repository

Streptococcus pyogenes is adapted for persistence in humans. It typically colonizes the tonsils and skin, and humans are the only known reservoir. S. pyogenes can cause a wide range of mild to serious infections. Most streptococci-related deaths are due to complications of rheumatic fever and invasive infections. S. pyogenes produces virulence factors that contribute to the pathogen’s ability to colonize and cause disease, including streptococcal superantigens (SAgs), also known as streptococcal pyrogenic exotoxins (Spes). SAgs function by cross-linking T cells and antigen presenting cells (APC) which may cause a massive inflammatory response, and as such have been found to contribute …

Signaling Mechanisms Involved In The Generation Of Human Peripheral Itregs, Mary Catherine Reneer

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

Maintaining balance in the human immune system is critical for the body’s ability to discriminate between foreign and self-antigens. This balance is achieved, in part, by a subpopulation of T cells known as induced regulatory T cells (iTregs). Dysregulation of this population may contribute to the onset and progression of cancer, chronic inflammation and autoimmune diseases. Therefore, manipulation of iTreg development holds promising therapeutic potential; however, studying this vital population has proven difficult due to low numbers, heterogeneous cell populations, substantial phenotypic differences between mouse and human cells, and the high plasticity seen in iTregs. These current limitations have prevented …

Regulation Of Hepatic Gene Expression During Liver Development And Disease, Hui Ren

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

My first project was to investigate the role of Hepatocyte Nuclear Factor 1 (HNF1) and Nuclear Factor I (NFI) on alpha-fetoprotein (AFP) promoter activity during liver development. AFP is highly expressed in the fetal liver, silenced at birth, and remains at very low levels in the adult liver. A GA substitution located at -119 of the human AFP promoter is associated with hereditary persistence of AFP (HPAFP) expression in the adult liver (Hum Molec Genet, 1993, 2:379). The -120 region harbors overlapping binding sites for HNF1 and NFI. While it has been shown that the GA substitution increases HNF1 binding, …

Maternal Immunomodulation Of Neonatal Alloantigen Response, Leh Chang

Loma Linda University Electronic Theses, Dissertations & Projects

Remarkable success has been achieved in the transplantation of allogeneic cardiac grafts into newborn infants at Loma Linda University Medical Center. The superior graft survival rate documented in these patients has not correlated with the degree of immunosuppression rendered, or the selection of genetically matched donors. However, the clinical success has correlated with the age of the recipient at the time of receiving a transplant. Patients receiving an allograft within the first few weeks of life are unique in that they seem to accept the alloantigens of their cardiac graft while responding aggressively to antigens in their environment. These observations …