RESUMEN
BACKGROUND: This study was done to assess the feasibility of dendritic cell generation from murine bone marrow and the efficacy of dendritic cells pulsed with total RNA to induce specific cytotoxic T lymphocyte response against leukemic cells. METHODS: Nucleated cells of inbred BALB/c mice were obtained and cultured with granulocyte/macrophage colony-stimulating factor (GM-CSF) and lipopolysaccharide (LPS) to induce dendritic cells. Total RNA of WEHI-3BD+, a myelomonocytic leukemia cell line from BALB/c, was transfected into the dendritic cells using liposome. RNA pulsed dendritic cells were irradiated and administered to the BALB/c mice intraperitoneally and splenic T lymphocytes were harvested. After restimulation with leukemic cells, T cell proliferation and specific cytotoxicity was assessed. RESULTS: Cells cultured with GM-CSF and lipopolysaccaride were found to have prominent dendritic processes. The percentage of cells showing high expression of both MHC class II and CD80, CD86, or CD11c was 69.6 %, 63.7%, and 41.8%, respectively. T cells stimulated by WEHI-3BD+ total RNA pulsed dendritic cells using DOTAP showed enhanced proliferation than those stimulated by total RNA or media only (P=0.05). When T cells were cocultured with WEHI-3BD+ as target cells, T cells stimulated by WEHI-3BD+ total RNA pulsed dendritic cells using DOTAP showed much increased cytotoxicity than controls. CONCLUSION: Dendritic cells pulsed with total leukemic RNA could stimulate T cells to induce specific cytotoxic effect.