Immunotherapy with autologous dendritic cells and tumor-specific synthetic peptides for synovial sarcoma

Synovial sarcoma in an 11-year-old Japanese girl relapsed 5 months after autologous stem cell transplantation. Autologous dendritic cells (DCs) were generated from her peripheral blood mononuclear cells using granulocyte/macrophage colony-stimulating factor and IL-4. Dendritic cells were pulsed with synthetic peptides containing a junctional region of SYT-SSX2 fusion protein generated by t(X 18) and were administered once per week. No side effects were observed. Growth of metastatic nodules in the lung was temporally suppressed. The delayed-type hypersensitivity responses in skin were enhanced to tumor lysate but not to peripheral blood mononuclear cell lysate. The CD3(+) cells cultured with pulsed DCs lysed tumor cells in vitro. Immunotherapy using DCs and tumor-specific peptides may be a safe approach in the treatment of childhood cancer.