Abstract: Objective To investigate the antitumor immune efficiency of mouse dendritic cells (mDCs) by using adenovirus-mediated tumor necrosis factor-alpha (AdV-TNF-α) gene transfer. Methods MDCs infected with AdV-TNF-α and AdV-pLpA (no gene insert) at 100 multiplicity of infection (MOI) were analyzed by Rnase protection assay for their cytokine secretion. Mixed lymphocyte reactions were also performed to analyze their capacity for alloantigen-presentation. C57BL/6 mice were challenged with R3LL tumor cells (Lewis lung carcinoma line) 10 days after vaccination with different engineered DCs and regular DCs as well.Results Compared to AdV-pLpA and mock-infected DCs, AdV-TNF-α-infected DCs displayed up-regulated expression of alpha tumor necrosis factor, interleukin-12 (IL-12), interleukin-18 (IL-18) and granulocyte macrophage colony stimulation factor (GM-CSF), and indicated stronger allogeneic T cell proliferative responses. Furthermore, vaccination of mice with dendritic cell tumor necrosis factor-alpha (DCTNF-α) pulsed with Mut1 peptide induced more efficient tumor-specific cytotoxic T lymphocyte (CTL) cytotoxicity against R3LL tumor cells in vitro and with efficient antitumor immunity in vivo. Conclusion This type of engineered DCs could be applied in clinical settings of DC-based cancer vaccines.