Résumé
Objective:Generation and functional analysis of EBV LMP2A specific CTL elicited by DC transfected with recombinant adenovirus in vitro .Methods:PBMC were isolated from healthy EBV carriers and NPC patients, and then cocultured with autologous mature Ad5 LMP2A transfected DC at the ratios of 20∶1. Cytotoxicity of LMP2A specific CTL was determined with LDH release assay, the populations of CTL were performed by FACS,the IFN ? secretion and FasL mRNA expression of the CTL were detected by biological activity assays and RT PCR, respectively.Results:The results showed that high cytotoxicity of LMP2A specific CTL could be elicited by autologous transfected DC. The cytotoxicity boosted with the increase of transfected DC stimulation times, but there were no significant changes between two and three stimulations.The phenotypic analysis demonstrated that the LMP2A specific CTL induced at day 14 consisted of a majority of CD4 + and CD8 +T cells, and only a small percentage of CD56 + cells. The IFN ? secreted in the supernatants of cell culture also increased with the stimulation times. In addition, the specific CTL at day 14 from EBV healthy carriers could express FasL mRNA.Conclusion:Strong and functional EBV specific CTL could be generated by autologous mature DC transfected with adenovirus encoding LMP2A, which could provide a rationale for the immunotherapy of EBV associated NPC. [
Résumé
Objective:To generate Epstein-Barr virus(EBV) Latent Membrane Protein 2A(LMP2A) recombinant adenovirus,and provide for further investigation on the therapy vaccine against EBV associated malignancies.Methods:Full length cDNA of encoding LMP2A of EBV had been amplified by reverse transcription-PCR and cloned into pGEM-T vector.The encoding cDNA of LMP2A was inserted into E1,E3-substituted adenovirus vector pAX1CW,then the LMP2A recombinant adenovirus vector was contransfected into 293 cells togetherwith EcoT221 digested Ad5-TPC.The LMP2A recombinant adenovirus was generated by homologous recombination,and primarily identificated by ClaI enzyme digestion.The expression of LMP2A on CV1 cells infected with recombinant adenovirus analyzed by fluorescence-activated cell sorting(FACS) and confocal microscope.Results:The replication-deficient LMP2A recombinant adenovirus was generated efficiently with the titers of 2.3?10 8 pfu/ml.The LMP2A could be seen on CV1 cells membrane with confocal microscope 48 h post infected with recombinant adenovirus and the percentage of CV1 cells expressing LMP2A was 94.4% by means of FACS analysis.Conclusion:These suggested that LMP2A could be expressed efficiently by recombinant adenovirus mediated transfer,and it was the foundation of further researching in its function and developing the suitable genetic engineering vaccine against EBV associated malignancies.