To augment specific cytotoxic T lymphocyte (CTL) lysis is a promising strategy for cancer therapy. In this study, we examined the boosting effect of CTLs upon autologous lymphoblastoid B cell lines (LCLs) transfected with diverse plasmids, to explore the possible CTL-based immunotherapy of nasopharyngeal carcinoma (NPC). FCM analysis displayed rather high ratio (>30%) of successfully transfected LCLs by utilizing the DMRIE-C kit. CTL assays demonstrated that substantially higher ratio of CTL specific lysis was observed upon the LCLs transfected with both expression vectors encoding EBV-specific epitopes and their presentation molecule HLA-A2, in contrast with those transfected separately. By transfecting the vector encoding HLA-A2 alone, only the LCLs of HLA-A2(+) donors elicited markedly higher CTL lysis. CTL assays also showed that there existed no marked differences upon transfection by either different vectors (pcDNA3, pNGVL3 or pNGVL3-hFlex), or different EBV-derived peptides (LMP(2)Pep1 or LMP(2)Pep2), or with or without the doubled DNA sequence encoding peptides. This study indicated a promising immunotherapy strategy on NPC through boosting and eliciting the EBV-specific CTL activation by transferring vectors encoding both EBV-specific epitopes and their presentation molecule HLA-A2 into autologous LCL, the presentation cells of MHC/peptide tetrameric complex.