Induction of Cytotoxic T Lymphocytes by Dendritic Cells Pulsed with Murine Leukemic Cell RNA

Peptide-pulsed dendritic cells can stimulate T cells showing specific cytotoxicity in chronic myelogenous leukemia. We tried to induce a specific cytotoxic T-cell response stimulated by RNA-pulsed dendritic cells in acute myelogenous leukemia. The total RNA of WEHI-3BD⁺, a myelomonocytic leukemia cell line derived from BALB/c mice, was transfected into dendritic cells induced from bone marrow nucleated cells of BALB/c mice with granulocyte macrophage colony-stimulating factor (GM-CSF) and lipopolysaccharide (LPS) using liposome. RNA-pulsed dendritic cells were injected into the peritoneal cavity of BALB/c mice, and splenic T cells were isolated for antigen-stimulated proliferation and leukemia-specific cytotoxicity assay. Cultured bone marrow nucleated cells expressed dendritic cell markers including MHC class II antigen, CD80, CD86, and CD11c. T cells stimulated by RNA-pulsed dendritic cells showed enhanced proliferation than those stimulated by unpulsed dendritic cells (P = 0.05) and showed dose-dependent specific cytotoxicity against WEHI-3BD ⁺ cells. We concluded total RNA-pulsed dendritic cells could induce a specific T-cell cytotoxicity in acute myelogenous leukemia.