[An experiment study of in vitro induced antitumor immune responses by vaccination of tumor lysate-pulsed dendritic cells to kill SO-RB(50)].

OBJECTIVE: To investigate induced antitumor immune responses by vaccination of tumor lysate-pulsed dendritic cells (DC) to kill retinoblastoma cells SO-RB(50). We hope to offer new approach for the treatment of patients with retinoblastoma. METHODS: DC was pulsed with RB tumor lysates in vitro and incubated with autologous lymphocytes to induce antigen specific CTL (cytotoxic T lymphocyte, CTL). SO-RB(50) cells were used as target cells and Raji cells were used as control target cells. Cytotoxicity of CTL was evaluated by MTT method (methyl thiazolyl letrazolium). The specific cytotoxicity of CTL to SO-RB(50) and Raji cells was compared. The cytotoxicity of CTL from RB and normal subjects was compared between these two groups. RESULTS: Antigen specific CTL showed greater cytotoxicity to SO-RB(50) than Raji cells, the difference was statistically significant, P < 0.01. The cytotoxicity was dose-dependent to the ratio of CTL/target cell. The nonspecific cytotoxicity to Raji cells was the same in CTL from RB patients and normal subjects, P > 0.05. The specific cytotoxicity of CTL from RB patients to SO-RB(50) was weaker than that from the healthy subjects, P < 0.01. CONCLUSION: DC pulsed with RB tumor lysate in vitro can induce antigen specific CTL which can kill the SO-RB(50) target cells specifically. This method may have potential value of therapy for the RB patients.