Injury to Autologous Normal Tissues and Tumors Mediated by Lymphokine-Activated Killer (LAK) Cells Generated In Vitro from Peripheral Blood Mononuclear Cells of Glioblastoma Patients

Abstract

Activation of peripheral blood mononuclear cells (PBMC) with IL-2 generates lymphokine-activated killer (LAK) cells that show a broad target cell range. In adoptive immunotherapy using in vitro-generated LAK cells, the intensity and specificity of their cytotoxic activity affect the prognosis of cancer patients. The present study was designed to examine the tumor-specific spectrum of T lymphocytes generated from the PBMC of patients with recurrent glioblastoma by in vitro propagation with IL-2 plus either soluble or solid-phase anti-CD3 monoclonal antibody (MAb) in short-term or long-term cultures. Both short-term and long-term culturing with solid-phase anti-CD3 MAb plus IL-2 yielded broad-reactivity CD8+ alpha beta T and gamma delta T lymphocytes, both of which were non-MHC restricted, as shown by the fact that they were able to lyse autologous glioblastoma cells, MHC class I+II- allogeneic glioblastoma cells, and MHC class I-II-NK-sensitive K562 target cells. More importantly, these cells from patients failed to lyse fresh autologous PBMC. These results demonstrate that cells generated using this approach are non-MHC-restricted LAK cells and exhibit marked tumor specificity. In contrast, incubation with soluble anti-CD3 MAb generated T lymphocytes that after long-term culture, were either CD4+ or CD8+. These caused significant lysis of both allogeneic and autologous glioblastoma target cells, the extent of lysis being greater than that using cells produced by culturing with the solid-phase MAb. However, both the CD4+ and CD8+ cells also caused greater lysis of autologous normal PBMC, indicating that cells generated using this approach may cause significant adverse reactions in cancer patients if used for immunotherapy.