SYNERGISTIC ANTITUMOR EFFECTS OF COMBINATION IMMUNOTHERAPY WITH ACTIV ATED MACROPHAGE AND LYMPHOKINE-ACTIVATED KILLER CELL IN THE TREATMENT OF ESTABLISHED MURINE CANCER MODEL

Lymphokine-activated killer cell (LAK cell) is induced from peripheral blood lymphocytes or splenocytes by coincubation with interleukin-2 (IL-2), and macrophage is activated in vitro by MAF including interferon-γ etc. They have cytotoxic effects on various malignant cells nonspecifically. Recently, many reports have indicated that adoptive immunotherapy (AIT) using effector cells, especially LAK cell, is effective for tumor bearing hosts, but reports concerning AIT combined with activated macrophage and LAK cell are few. In the current study, we investigated the synergistic cytotoxic effect on the X5563 plasmacytoma of the combination of activated macrophage and LAK cell from murine splenocytes. In vivo antitumor effect on tumor growth after AIT showed that the combination group of activated macrophage and LAK cell is most effective of all groups : activated macrophage group, LAK group and splenocyte group. Also, Winn assay showed the same. In vitro cytotoxic assay showed that the combination group is more effective than the other groups, but not significantly. In the mortality assay of metastatic models, the combination group showed the best survival rate. So, combination AIT using activated macrophage and LAK cell can be expected to exert synergistic cytotoxicity in vivo