[Basic and clinical study of adoptive immunotherapy using cytotoxic T lymphocyte (CTL) against cancers]

Cytotoxic T cells (CTL) have been known to be one of the effector cells responsible for regression of tumors. In tumor-bearing hosts, CTL insufficiently attack the tumor because the suppressor cells inhibit the induction and activation of CTL. In our in vitro study, CTL were induced from peripheral blood lymphocytes (PBL) of cancer patients. These CTL showed the specific cytotoxic activity against autologous tumor in one case and broad specificity against tumors in other cases. A patient with breast cancer was treated with adoptive immunotherapy of CTL because she had severe side effect from antineoplastics . Her breast cancer was histologically scirrhous type adenocarcinoma which was resistant to antineoplastics. Patient's PBL were cocultured with mitomycin C treated-autologous tumor, and they were proliferated with interleukin 2 or T-cell growth factor (TCGF). Then, these CTL were injected to this patient intravenously at the interval of one or two weeks. Before serial injection of CTL, antineoplastics was prescribed in order to inhibit the function of suppressor cells and cancer cells. The sizes of tumors were gradually reduced, suggesting clinical regression. We suggest that combined treatment of adoptive immunotherapy using CTL and antineoplastics (CTL therapy) is very useful in the treatment of cancer patients.