OBJECTIVE: To determine the effect of activation of specific anti-tumor cytotoxic T lymphocytes (CTL) and the ability of cross-presentation in vitro by fusion of HLA-A2+ human dendritic cells (DCs) with HLA-A2- melanoma cells. METHODS: The HLA-A2+ human dendritic cells and HLA-A2- melanoma cells were fused by PEG and were cultivated in complete RPMI1640 media containing FCS (10%) and GM-CSF for 24-48 h, and then co-cultured fusion cells with Melan-A specific T cells. HLA-A2- melanoma cells were negative control,While T2 cells and DC+Pts were positive control. The activation of anti-tumor CTL elicited by the fusion cells was detected by intracellular cytokine staining. RESULTS: The immature DC could express CD80, CD83, CD86, HLA-DR, and HLA-ABC,but the mature DC induced by TNF-alpha, PGE-2, and CD40L further highly expressed above molecules. The rate of specific CTL cells primed by the fusion cells was 16.72%+/-4.26%, negative control was 0.21%+/-1.84%,and positive control was 28.60%+/-5.67%. The CTL from vaccine by fusing DC and LAR6 induced lysis of HLA-A2+ LAR1 cells. CONCLUSION: The HLA-A2 restricted specific anti-tumor CTL can be induced in vitro by fusion of HLA-A2+ human dendritic cells with HLA-A2- melanoma cells.