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published_or_final_version / Anatomy / Master / Master of Philosophy

No description available.

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No description available.

ABSTRACT Adenovirus Death Protein (ADP) expression during late stages of a lytic infection releases mature virions to promote viral spread, thus leading to death of the host cell. We sought to investigate ADP expression patterns in persistently infected human lymphocytes cells. We hypothesized that low expression of ADP allows the virus to persist while high expression would promote lytic infection in lymphocytes. Accordingly, we found ADP expressed in low amount in BJAB and KE37 cells, while lytically infected Jurkat cells demonstrated higher ADP expression in both protein and transcript levels. ADP overexpression in persistently infected lymphocytes did not alter the viability of these cells, or their level of ADP expression. In contrast, Jurkat cells infected with an ADP-deleted virus had increased survival and maintained viral DNA for greater than 1-month, suggesting conversion to a persistent infection. Also manipulating ADP expression had minimal impact on the total virus yield from infected lymphocytes.

In addition to their activity against intracellular pathogens, it is now clear that CD8+ T-lymphocytes also mediate anti-tissue responses. In order to manipulate these responses in the setting of tumor immunity or autoimmunity, it is necessary that we understand the parameters that promote CD8+ activation. In the first section of this thesis, a transgenic mouse model was used to explore the effectiveness of peptide/adjuvant-based and dendritic cell (DC)-based vaccination techniques at eliciting CD8-mediated anti-pancreatic responses. It was found that, while peptide vaccines were unable to stimulate autoimmunity, the transfer of DCs promoted autoimmune diabetes in a manner that was dependent upon the toll-like receptor (TLR)-based maturation of the DCs. Furthermore, the diabetes induction was dependent upon the engagement of the immunodominant CD8+ population and a second T-cell specificity, indicating that polyclonal responses may be required for effective tissue destruction. In the second section of this thesis, I explored the requirements for CD28-signaling during the activation of naïve self-reactive CD8+ T-cells. The transfer of mature DCs was insufficient to promote diabetes in CD28-deficient animals, whereas infection with lymphocytic choriomeningitis virus could induce diabetes in the same animals. Anti-tissue responses were further explored in tumor-bearing mice following DC transfer and demonstrated that a critical determinant of the induction of anti-tissue immunity in the absence of CD28-derived costimulatory signals, was the persistence of antigen presentation. In the final section of this thesis, I explored the role of nuclear factor kappa B 1 (NF-κB1) in DC maturation using the DC transfer model described above. Surprisingly, NF-κB1-deficient DCs were capable of inducing diabetes without the need for external stimulation. Furthermore, the absence of NF-κB1 in unstimulated DCs was associated with dysregulated production of tumor necrosis factor alpha (TNF-α), and this cytokine was required for the proper upregulation of the cytotoxic effector molecule granzyme B in CD8+ T-cells that infiltrated the pancreatic islets. This work therefore presents a novel model of autoimmune tissue destruction, in which defined genes and pathways that contribute to DC-T-cell interactions can be explored in an in vivo non-TCR transgenic setting.

In this study, we have analyzed the steady-state kinetics of B lymphocytes in mouse and rat bone marrow using previously published experimental data. Over many years, Prof D.G. Osmond and his colleagues have built up a scheme of B cell development in mouse bone marrow based on the sequential expression of markers associated with the B lineage. The earliest precursor B cells comprise three populations of proliferating pro-B cells, i.e. early, intermediate, and late pro-B cells. The subsequent populations comprise pre-B cells that give rise to nondividing B lymphocytes expressing surface IgM. / In our analysis, we have checked the available published data for consistency with the proliferation of precursor B cells and their death via apoptosis at certain stages of cell development. We made an extensive summary of the existing data on the various B cell precursors and organized it into a comprehensible framework. We built a mathematical model for the proliferation and differentiation of mammalian B lymphocytes in laboratory mice and rats and estimated all of the parameters to explain the existing steady state data. In this context, mathematical modeling acts as a useful tool to analyze hypotheses and experimental results concerning the steady state numbers of B lymphocytes.

Diss. (sammanfattning) Stockholm : Karol. inst., 2003. / Härtill 5 uppsatser.

Thesis (Ph. D.)--Case Western Reserve University, 2008. / [School of Medicine] Department of Pathology. Includes bibliographical references.