In vitro killing of human glioblastoma by interleukin-2-activated autologous lymphocytes.

Culture of peripheral blood lymphocytes (PBL) from brain-tumor patients with recombinant interleukin-2 (IL-2) results in the activation of lymphokine-activated killer cells (LAK) with the capacity to lyse autologous and allogeneic glioblastoma. In this study, PBL obtained from brain-tumor patients were cultured with or without IL-2 for 3 to 7 days and then tested for their ability to lyse target cells in a 4-hour chromium release cytotoxicity assay. The PBL were drawn 1 to 2 weeks following operative tumor debulking. Cells used as targets included fresh brain-tumor cells obtained at the time of craniotomy, fresh brain-tumor cells grown from 1 to 3 weeks in tissue culture, fresh autologous PBL, and allogeneic glioblastoma cells grown in tissue culture. Peripheral blood lymphocytes from brain-tumor patients that were cultured without IL-2 did not significantly lyse autologous or allogeneic glioblastoma. However, when these PBL were cultured with IL-2, LAK were generated which produced marked lysis of autologous as well as allogeneic tissue-culture glioblastoma in all of eight cases. Significant lysis of autologous fresh tumor by patient LAK was observed in four of five experiments. By contrast, patient LAK did not kill autologous normal PBL. The ability to generate LAK was not influenced by the patient's age, previous therapy, or the administration of steroids.