Lymphokine-activated killer (LAK) cells. Analysis of factors relevant to the immunotherapy of human cancer

Abstract

Lymphokine‐activated killer (LAK) cells can be generated by incubating fresh peripheral blood lymphocytes (PBL) in Interleukin‐2 (IL‐2). LAK cells kill fresh autologous and allogeneic human tumor cells in vitro. This study analyzes aspects of LAK cells that make them a promising candidate for the adoptive immunotherapy of human cancer. LAK cells can be generated from PBL of normal individuals and tumor‐bearing patients. Pure, recombinant IL‐2 generates LAK cells capable of killing a wide variety of tumors including sarcomas and cancers of the colon, pancreas, adrenal gland, and esophagus. Thirty‐six of 41 (88%) fresh, noncultured, human tumor cell suspensions prepared from surgical specimens were lysed by LAK cells in a standard 4‐hour chromium‐release assay. Normal PBL were not killed. LAK cells can be expanded in vitro for periods longer than 2 months, potentially more than 10²⁰‐fold, while maintaining lytic ability. These results and the demonstrated efficacy of LAK cells in the therapy of murine tumors make LAK cells a candidate for clinical use in the adoptive immunotherapy of human cancer. Cancer 55:1327‐1333, 1985.