BACKGROUND: The effectiveness of gene therapy is closely related to the efficiency of vector transfection and expression. OBJECTIVE: This study was designed to transfect a human brain glioma cell line with recombinant Vaccinia virus expressing the interleukin-2 (rVV-IL-2) gene, and to observe IL-2 expression and glioma cell proliferation potential after transfection. DESIGN: Experimental observation. SETTING: Department of Neurosurgery, Shenyang Military Area Command of Chinese PLA. MATERIALS: The rVV-IL-2 vectors were obtained through homologous recombination and screening in the Second Military Medical University of Chinese PLA. The human brain glioma cell line and IL-2-dependent cells were produced by the Second Military Medical University of Chinese PLA. Human IL-2 was produced by Genzyme Corporation. METHODS: At passage day 1, Vero cells were amplified 1∶1 for virus and cells. A human brain glioma cell line was transfected using amplified Vaccinia viral vectors at varying multiplicities of infection (MOI). At 2, 4, 6, 8, 12, and 24 hours post-transfection, supernatant was collected to determine by MTT assay IL-2 expression levels in IL-2 dependent cells. The transfected and non-transfected cells were divided into 4 groups, namely MOI 1∶1, MOI 5∶1, MOI 10∶1, and control groups. MAIN OUTCOME MEASURES: IL-2 expression at different time points after transfection of human brain glioma cells with varying MOI of Vaccinia viral vectors; in vitro proliferation capacity of human brain glioma cells among the 4 groups. RESULTS: IL-2 expression was detectable 4 hours after Vaccinia viral vector transfection and reached 300 kU/L by 8 hours. There was no significant difference in the proliferating rate of human brain glioma cells among the 4 groups (P > 0.05). CONCLUSION: Vaccinia viral vectors can transfect human brain glioma cells in vitro and express high levels of IL-2. Vaccinia virus and high IL-2 expression do not influence the proliferation rate of human brain glioma cells in vitro. BACKGROUND: The effectiveness of gene therapy is closely related to the efficiency of vector transfection and expression. OBJECTIVE: This study was designed to transfect a human brain glioma cell line with recombinant Vaccinia virus expressing the interleukin-2 (rVV-IL-2) gene SET: Department of Neurosurgery, Shenyang Military Area Command of Chinese PLA. MATERIALS: The rVV-IL-2 vectors were obtained through homologous recombination and The human brain glioma cell line and IL-2-dependent cells were produced by the Second Military Medical University of Chinese PLA. Human IL-2 was produced by Genzyme Corporation. METHODS: At passage day 1, Vero cells were amplified 1:1 for virus and cells. A human brain glioma cell line was transfected using amplified Vaccinia viral vectors at varying multiplication licit of infection (MOI). At 2, 4, 6, 8, 12, and 24 hours post-transfection, supernatant was collected to determine by MTT assay IL-2 expression levels in IL-2 dependent cells. The transfected and non- transfected cells were divided into 4 groups, namely MOI 1: 1, MOI 5: 1, MOI 10: 1, and control groups. MAIN OUTCOME MEASURES: IL-2 expression at different time points after transfection of human brain glioma cells with varying MOI of Vaccinia viral vectors; in vitro proliferation capacity of human brain glioma cells among the 4 groups. RESULTS: IL-2 expression was detectable for 4 hours after Vaccinia viral vector transfection and reached 300 kU / L by 8 hours. There was no significant difference in The proliferating rate of human brain glioma cells among the 4 groups (P> 0.05). CONCLUSION: Vaccinia viral vectors can transfect human brain glioma cells in vitro and express high levels of IL-2. Vaccinia virus and high IL-2 expression do not influence the proliferation rate of human brain glioma cells in vitro.