[Development of specific immunotherapy for cancer]

We developed CTL therapy against cancer as an cancer specific immunotherapy. The primary CTL therapy showed certain efficacy on advanced cancer patients. However, when ratio of monocyte population in peripheral blood lymphoid cells (PBL) of advanced cancer patients increases more than that of CD8+ T cell population, so that CD8+ T cell/M3 ratio is less than 1, CTL directed to cancer cannot be induced in PBL and the primary CTL therapy is not materialized for these patients. Monocyte-macrophages in these patients release a suppressive factor(s) capable of inhibiting CTL induction and proliferation at induction phase but not inhibiting cytotoxic activity in target cell lysis at effector phase. Furthermore, these monocytes expressed strong message of TGF beta. If most of increased monocytes of PBL from advanced cancer patients are removed by a nylon wool column method from the PBL, CTL directed to cancer cells can be induced even in PBL of advanced cancer patients with high frequency, this improved CTL therapy against cancer showed remarkable efficacy as the cancer specific immunotherapy in various advanced cancer patients without any side effects.