Molecular Biology Commons^™

Germinal Center B Cell Expression Of Aire Regulates Antibody Diversification And Autoimmunity, Jordan Zheng Zhou

Wayne State University Dissertations

B cells are a unique subset of immune cells that, in response to antigen, diversify their antibody repertoire to generate progressively higher affinity antibodies of different isotypes through the processes of affinity maturation/somatic hypermutation (SHM) and class switch recombination (CSR). One of the major sites in which this diversification occurs is in T cell dependent microanatomical structures known as germinal centers (GC). Here, we find that GC B cells express the protein, autoimmune regulator (Aire) in a CD40 dependent manner. In these cells, Aire interacts with activation induced cytidine deaminase (AID), the protein responsible for initiating the processes of diversification …

Imbalance Of Uracil Dna Glycosylase And Activation-Induced Cytidine Deaminase Expression In Folate Depleted Human Lymphoblastoids, Elizabeth Zanley

Wayne State University Theses

Background: The DNA base excision repair (BER) pathway is responsible for processing of genomic uracil lesions however, in some tissue types the excisional and gap-filling steps performed by UNG2 and POLβ, respectively, are impaired by folate deficiency in human and murine models in vitro. Genomic uracil damage can be acquired by inadequate conversion of uracil to thymine nucleotide precursors resulting from insufficient folate cofactors, or through activation induced cytosine deaminase (AID) activity during antibody diversification in B-cells in the context of adaptive immunity. The immunoglobulin (Ig) diversification methods in B-cells depend on the coordinated interaction between AID and UNG2, and …

Soy Isoflavones Mediate Radioprotection Of Normal Lung Tissue By Modulating The Radiation-Induced Inflammatory Response, Lisa Marie Abernathy

Wayne State University Dissertations

Radiation-induced lung injury (RILI) is caused by an early inflammatory process triggered by damage to lung parenchyma, epithelial cells, vascular endothelial cells and stroma. Initially, oxidative injuries after radiation induce altered expression of pro-inflammatory cytokines. Infiltrating inflammatory cells are stimulated and activated, producing additional mediators, resulting in a cytokine cascade. The expansion and perpetual activation of inflammatory cells, as well as lung parenchyma, lead to clinical pneumonitis. Activated cells produce molecular mediators and growth factors that affect the proliferation and gene expression of lung fibroblasts. This process leads to increased collagen synthesis and deposition, eventually leading to the development of …

The Transcriptional Regulation Of Flagellin-Induced Innate Protection Of The Cornea: Role Of Irf1 And Atf3, Gi Sang Yoon

Wayne State University Dissertations

Pre-exposure of the cornea to TLR5 ligand flagellin induces profound mucosal innate protection against infections by reprogramming gene expression. This study explored the flagellin-induced modifications of transcription factor expression and function, specifically of IRF1 and ATF3 in corneal epithelial cells to elucidate the transcriptional mechanisms underlying the protective function of flagellin on the cornea.

Initially we used Superarray to screen for transcription factors and identified Interferon Regulatory Factor (IRF) 1 and Activating Transcription Factor (ATF) 3 as the most drastically affected genes by flagellin pretreatment in P. aeruginosa challenged human corneal epithelial cells (CEC). However, flagellin pretreatment had opposite effects …

Modulation Of Anti-Tumor Immune Response By Tgf-Β-Inducible Early Gene 1 (Tieg1), Andi Cani

Wayne State University Theses

Cancer immunotherapy has had limited clinical efficacy partly because regulatory T cells (Treg) suppress the immune response to tumor-associated antigens. Inducible regulatory T cells (iTreg), which are converted from naïve CD4 T cells by TGF-β, an abundant cytokine in the tumor microenvironment, may contribute to this immune suppression. Induction of Foxp3 by TGF-β is mediated by the transcription factor TIEG1 and abrogation of this protein prevents Foxp3 expression. We are testing the hypothesis that blockade of TIEG1 to prevent iTreg conversion will enhance immune response in DNA vaccination to the tumor associated antigen Her-2. Wild type and TIEG1 knockout mice …

Identification Of The Role Of The Sal Locus In Streptococcus Pyogenes Virulence During Host-Pathogen Interactions, Phanramphoei Namprachan-Frantz

Wayne State University Dissertations

The pathogenesis of Streptococcus pyogenes is due to its ability to overcome and adapt to the harsh environment created by the host immune response. The focus of this project was the SalKR two-component regulatory system, which facilitates bacterial adaptation by responding to environmental signals during host pathogen-interactions. The first goal of this project was to determine a role in virulence for the SalKR regulatory system. The complete deletion of the salKR genes in the wild type S. pyogenes strain HSC5 produced a highly attenuated mutant in a Zebrafish infection model. The ΔsalKR mutant appeared to lose the ability to survive …

Post-Transcriptional Regulation Of Vibrio Cholerae Virulence Activator Toxt, Basel Hanna Abuaita

Wayne State University Dissertations

Vibrio cholera, the causative agent of the severe diarreal illness cholera, uses a complex array of gene regulation to induce its virulence determinants. During the early stage of infection, and upon response to unknown signals, virulence genes are turned on. ToxT protein is the primary virulence gene transcription activator. Once ToxT is produced, it amplifies its own expression through an auto-regulatory loop and directly binds and activates expression of various virulence factors including the toxin-coregulated pilus (TCP) and cholera toxin (CT). During the late stage of infection, virulence genes are turned off and the bacteria escape the host to resume …