ObjectiveTo detect the expression of indoleamine2, 3-dioxygenase (IDO) and HBV preS mRNA in HepG2 cells and its inhibitory effect on the proliferation of human peripheral blood lymphocyte. MethodsThe AdIDOEGFPpreS was transfected to human hepatocarcinoma cell line HepG2 and the specific fragment of IDO mRNA and HBV preS mRNA in these HepG2 cells were detected by RT-PCR. Then the transfected HepG2 cells were cocultured with human peripheral blood lymphocyte and the inhibitory effect of IDO on the proliferation of human peripheral blood lymphocyte was observed. ResultsThe IDO and HBV preS mRNA were successfully transferred to HepG2 cells, so the specific fragment of IDO and HBV preS mRNA could be found in the transfected HepG2 cells but not in the control group HepG2 cells by RT-PCR. Furthermore, the relative expression intensity of IDO and HBV preS were 1.27 and 1.18, respectively. When co-cultured with human peripheral blood lymphocyte, the counts per minute in the transfected HepG2 cells 〔(7 471±1 375) beats/min〕 was significantly less than that in the control group 〔(13 821±1 997) beats/min〕, Plt;0.001. ConclusionThe target gene IDO and HBV preS can be transferred and expressed in HepG2 cells successfully, which can obviously suppress the proliferation of human peripheral blood lymphocyte.