Immunology and Infectious Disease Commons^™

The Role Of A Glycosyltransferase, St6gal I In Regulating Viral Specific T And B Cell Responses, Junwei Zeng

Doctoral Dissertations

Glycosylation is one of the most abundant post-translational modifications of proteins. Glycoproteins participate in virtually all aspects of cellular functions. ST6Gal I is a glycosyltransferase highly expressed by B and T cells. Here, we interrogated the role of ST6Gal I in viral specific B and T cell immune responses, as well as examined how loss of this enzyme impacted viral pathogenesis.

First, to understand how loss of ST6Gal I expression impacted viral specific humoral responses, we infected ST6Gal I^-/- mice with influenza virus. We discovered that loss of ST6Gal I expression results in both reduced influenza specific antibodies levels …

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

Dissertations & 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 & 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 …

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), …

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, …

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

Dissertations & 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 …

The Role Of Granulocyte Colony-Stimulating Factor In The Intestinal Immune System And The Response To Probiotics, Andrew J. Martins

Electronic Thesis and Dissertation Repository

Loss of immunoregulation in the intestine results in inflammation, such as is observed in the chronic, relapsing, inflammatory bowel diseases (IBD), Crohn's disease and ulcerative colitis. However, our understanding of this process remains incomplete. The cytokine granulocyte-colony stimulating factor (G-CSF) is an important stimulator of granulopoiesis in steady-state and during inflammation, but has also been shown to have anti-inflammatory effects and is a potential therapeutic for IBD. In addition, certain strains of bacteria, termed probiotics, have been postulated to have anti-inflammatory effects in the intestine. The mechanisms by which these strains of bacteria elicit anti-inflammatory effects are not fully understood. …

Role Of Pi3k-Akt Pathway In The Age Associated Decline In Tlr Mediated Activation Of Innate And Adaptive Immune Responses, Mosoka Papa Fallah

University of Kentucky Doctoral Dissertations

Immunosenescence results in reduced immune response to infections with Streptococcus pneumoniae as well as to pneumococcal polysaccharide vaccines. The antibody response to the capsular polysaccharide (CPS) provides protection against S. pneumoniae infection. CPS immunoresponse is T cell independent and needs the macrophage-derived cytokines such as IL-12, IL-6 and IL-1β to elicit an antibody response. We showed a cytokine dysregulation, i.e. a decrease in IL-12, IL-6 and TNF-α but an increase in IL-10, in the aged (18-24 months old comparable to >65 years in human) compared to young adult mouse (8-12 weeks less than 65 years old) splenic macrophages (SM) or …

The Impact Of Tricaine Methanesulfonate, 2-Phenoxyethanol, And Carvone-Methyl Salicylate On The Innate Immune Response Of Zebrafish (Danio Rerio), Charles R. Wulff

Honors Theses

Anesthesia plays a vital role in the maintenance of aquaculture species, where it is used to minimize stress during complex handling tasks such as transport, assessment, and harvesting. However, anesthetics have been shown to suppress the innate immune response, which could impact immunity and increase risk of infection. Tricaine methanesulfonate (MS-222) and 2-Phenoxyethanol (2-PE) represent two of the most commonly used anesthetics in aquaculture, with R-(+)-carvone, in the form of carvone-methyl salicylate (CMS) has recently been proposed as an alternative anesthetic for food fish. These three anesthetics were used to assess the influence of anesthetics on the immune system of …