Comparative investigation of the effects of specific antigen-sensitized DC-CIK and DC-CTL cells against B16 melanoma tumor cells

The use of personalized adoptive immunotherapy as a potential novel approach is promising in the treatment of tumors resistant to conventional therapies. In the present study, dendritic cell (DC)-cytokine-induced killer (CIK) and DC-cytotoxic lymphocyte (CTL) cells were cultured to examine their phenotype, proliferation and cytotoxicity against B16 melanoma tumor cells. In addition, comparative investigations of the effect of specific antigen-sensitized DC-CIK and DC-CTL cells against B16 melanoma tumor cells were performed in vitro and in vivo. The results showed that the phenotypes of the co-cultured cells were altered, and DCs promoted DC-CIK cell and DC-CTL cell differentiation and maturation in vitro. Lactate dehydrogenase cytotoxic analysis indicated that the cytotoxicity increased as the effector to target ratio increased between 10:1 and 40:1, and the cytotoxic effect towards B16 melanoma cells by DC-CTL cells was significantly higher, compared with that of DC-CIK cells. To further examine the antineoplastic efficacy of DC-CIK and DC-CTL cells in vivo, the present study performed tail-intravenous injection of DC-CIK cells and DC-CTL cells, which attenuated B16 melanoma cell-engrafted tumor growth, induced G(0)/G(1) cell cycle arrest and accelerated cell apoptosis. Taken together, these results suggested that the use of DC-CTL or DC-CIK cell therapy as a personalized adoptive immunotherapy may regulate immune status and inhibit tumor growth in vivo. In addition, the experiments indicated that DC-CTL cells offer superior antineoplastic activity, compared with DC-CIK cells against B16 melanoma tumor cells.