ABSTRACT
<p><b>BACKGROUND</b>To study the effects of dendritic cells (DC) transfected with recombinant adenovirus encoding Epstein-Barr virus(EBV)latent membrane protein 2A(LMP2A)gene, and to provide evidence for further investigation on the therapeutic vaccine against EBV-associated malignancies.</p><p><b>METHODS</b>DCs were transfected with EBV-LMP2A recombinant adenovirus (Ad5-LMP2A), which was generated by homologous recombination. The expression of LMP2A protein on mature DC transfected with Ad5-LMP2A at different multiplicity of infection(MOI)was analyzed by fluorescence activated cell sorting(FACS), and the dead cells were counted by trypan blue staining. The alteration of surface markers on mature DC including CD1a, CD83, CD40, CD80, HLA?DR was detected by means of FACS before and after transfection. Meanwhile, the functions including stimulating allogenetic T cells reaction and expressing IL12 P40 mRNA on transfected DC were measured by methods of 3H-thymidine uptake and fluorescent semi?quantitative polymerase chain reaction (PCR), respectively.</p><p><b>RESULTS</b>About 80% mature DC expressed LMP2A protein and >92% cells were viable after transfection at the MOI of 200 No. significant changes in the surface markers and the cytomorphology of mature DCs were detected during the transfection. Transfected DC still have strong potential to stimulate the proliferation of allogenetic T cells and to express IL-12 P40 mRNA.</p><p><b>CONCLUSION</b>EBV-LMP2A gene,which was carried by adenovirus vectors, could be transferred into DC with high efficiency. The function of mature DC was not affected significantly by the transfection of Ad5-LMP2A.</p>
Subject(s)
Humans , Adenoviridae , Genetics , Cells, Cultured , Dendritic Cells , Physiology , Gene Expression , Genetic Vectors , Recombination, Genetic , Transfection , Viral Matrix Proteins , GeneticsABSTRACT
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. [