This dissertation, "Development of DNA Vaccines Encoding Epstein-Barr Virus (EBV)-specific Antigens Potentially for EBV-associated Nasopharyngeal Carcinoma (NPC) Immunotherapy" by Guangsheng, Ling, 寧珖聖, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Abstract of thesis entitled Development of DNA vaccines encoding Epstein-Barr virus (EBV) - specific antigens potentially for EBV-associated nasopharyngeal carcinoma (NPC) immunotherapy Submitted by Ling Guang Sheng For the degree of Master of Philosophy at the University of Hong Kong in August 2005 Epstein-Barr virus (EBV) is a tumorigenic herpes virus which is ubiquitously present in the adult population. It is associated with several types of lymphoid and epithelial malignancies, including the nasopharyngeal carcinoma (NPC) which is the third most common form of malignancy amongst males in southern China. Although radiotherapy and combination chemotherapy are effective against early stage NPC, there is no effective therapy once the disease recurs or progresses. Given that the presence of EBV in tumor cells provides a potential therapeutic target for NPC, immunotherapy by enhancing the EBV-specific CTL responses may be able to provide benefits for NPC patients. Recently, a study using dendritic cell (DC)-based peptide vaccine has demonstrated that the partial tumor regression in some NPC patients was associated with an enhancement in the EBV-specific latent membrane protein LMP2 cytotoxic T-lymphocyte (CTL) response. However, the time-consuming preparation procedures and the lack of CD4 T helper responses in the above study may limit the success. DNA vaccine is a revolutionary new approach in vaccinology and has been shown to be effective in inducing protective immunity in various animal models. In this study, three novel anti-EBV DNA vaccines, which encode the EBV-specific antigens C-terminus + + EBNA1 (a CD4 T cell immunogen) and the full length LMP2A (a CD8 T cell immunogen), have been designed and prepared. In addition to the EBV antigens, cytokine (GM-CSF) and chemokines (RANTES, MDC) were also incorporated into the DNA vaccines to achieve "in situ" sensitization of the dendritic cells. The efficiency of the vaccine genes expression in mammalian cells has been examined. The secretory gene products were detectable by Western Blot analysis and ELISA. In addition, the chemotatic activity of the encoded chemokines on immature DCs has been demonstrated in vitro using chemotaxis assay. In vivo studies further confirmed the efficacy of these vaccines to recruit leukocytes at the site of DNA inoculation in a mouse model. In summary, the three DNA constructs prepared in this study are functional and the immunogenicity of these anti-EBV vaccines will be null further examined in a human PBMC-NOD/LtSz-Rag1 chimeric mouse model. DOI: 10.5353/th_b3618912 Subjects: DNA vaccines Viral antigens Epstein-Barr virus Nasopharynx - Cancer - Immunotherapy