Note:

published_or_final_version / Anatomy / Doctoral / Doctor of Philosophy

published_or_final_version / Medical Sciences / Master / Master of Medical Sciences

No description available.

No description available.

No description available.

Approximately 10% of all gastric cancer cases worldwide are associated with Epstein-Barr virus (EBV) infection. This subgroup differs from non-infected equivalents through a distinct mutational and epigenetic signature, which is crucial for the establishment and maintenance of the viral latent state. Disruption of the latent state and subsequent induction of the lytic cycle, called reactivation, can be used as a therapeutic strategy for this cancer type through either combination with antiviral agents or by induction of an EBV-specific immune response. In this study, epigenetic inhibitors were tested for their potential to reactivate EBV using a novel screening method based on the expression of Zebra, a key regulator of EBV reactivation. Histone deacetylase inhibitors (HDACis), more specifically benzamide-based HDACis, were the most potent group of reactivating agents in this screen. Those HDACis induced the expression of lytic cycle genes as well as targeted cell killing in combination with antiviral agents. Moreover, the reactivation through those agents was sufficient to activate cytotoxic T-cells and thereby ensured a supportive role of the immune system in targeted cell killing. In an additional screen, topoisomerase inhibitors and other chemotherapeutic agents showed synergistic effects on Zebra expression together with HDACis, which was linked to the induction of p53 expression through those compounds. While p53 is known to be involved in the expression of Zebra, the viral DNA processivity factor Ea-D and the viral DNA binding protein DNBI were identified as a potential novel binding protein of p53 and could thus point towards a novel role of p53 in EBV lytic replication. Taken together, this study identifies potential novel therapeutic compound combinations for the treatment of EBV-associated epithelial cancers that could be translated into the clinic after further assessment.

Thesis (Ph. D.)--University of Virginia, 2006. / Includes bibliographical references. Also available online through Digital Dissertations.

Cytokines are known to be involved in mastitis, yet their production by bovine epithelial cells has so far not been reported. In this research a bovine mammary alveolar cell line (MAC-T) was used as a simplified model for mammary glands. Cultured MAC-T cells were stimulated with 1, 10 and 20 mug/ml of a bacterial cell wall component (lipopolysaccharide) to verify the production of epithelially derived bovine cytokines. Cytokine mRNA production was assessed by reverse transcriptase polymerase chain reaction (RT-PCR) using RNA samples isolated during the first 24 hrs of lipopolysaccharide stimulation. Interleukin-1alpha/beta, interleukin-6 and interleukin-8 mRNA production seemed to be time and dose dependent. Restriction enzyme analysis of PCR products confirmed the identity of the cytokines. Enzyme linked immunosorbent assays for interleukin-1 and interleukin-8 showed that the respective mRNA's were translated into proteins. Interleukin-8 protein was detectable 6 hrs after lipopolysaccharide stimulation; maximal levels of approximately 55 pg/ml were reached at 48 hrs post stimulation. Interleukin-1 was detected 1hr after stimulation; concentrations peaked between 500 and 600 pg/ml at 2, 5 and 12 hrs for 20, 10 and 1 mug/ml of lipopolysaccharide respectively. The amount of protein produced by the MAC-T cell line was relatively low and required high concentrations of lipopolysaccharide. Nevertheless, this model demonstrated a time and dose dependent cytokine production. These results suggest that bovine epithelial cells could be a source of cytokine production during mammary infection.

Diss. (sammanfattning) Umeå : Univ., 2003. / Härtill 5 uppsatser.