Cytotoxicity was induced in lymphocytes (CL) from 10 out of 15 patients by autologous mixed lymphocyte tumor cell culture and further cultivation with recombinant interleukin-2. In cells from 3 of the 10 patients, cytotoxicity was suppressed by more than 50% when autologous peripheral blood mononuclear cells (PBMC) from the patients with large tumors were added to the autologous killing system. The cells responsible for suppressing the cytotoxicity in the effector phase were adherent or nonadherent to plastic depending on the patient examined. The T cell fraction from 1 patient significantly suppressed the cytotoxic activity, and this suppression was seen only in the autologous system. On the other hand, plastic adherent cells but not T cells from PBMC of 2 subjects suppressed the cytotoxic activity of CL. The reason why the main cell population suppressing the CL activity differed among the patients is unclear. However, the findings that the suppression was mostly abrogated following resection of the tumor mass suggested that suppressor cells, either of macrophage lineage or T cells, are induced in patients with a large tumor mass. This speculation is supported by the finding that the PBMC from a patient with tumor recurrence regained the suppressive activity.
Peripheral blood lymphocytes drawn by leukapheresis using Haemonetics V50 were mixed and cultured with autologous or allogeneic tumour cell line to activate killer cells by tumour antigenic stimulation, and further with recombinant interleukin-2 (rIL-2). Killer cells were intra-arterially infused, as a primary therapy, in 5 patients with maxillary and one with lingual cancer (squamous cell carcinoma). Effects on reduction of primary tumour size were significantly high without any severe side effects. The effects were interpreted mainly by direct day-by-day observation of the site, findings of CT and histology. Histological findings of the tissue obtained by surgical operation performed after adoptive immunotherapy were remarkable changes, such as infiltration of lymphoid cells around the cancer nets, degeneration of cancer cells, infiltration of scavenger macrophages (giant cells) and so on. The results suggested that adoptive immunotherapy by the killer cells can be a powerful treatment to bring the cancer under control, in with combination of other therapies.
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