Lymphokine-activated killer cell induction in tumor-infiltrating leukocytes from colon cancer patients

Lymphokine-activated killer (LAK) cell induction was evaluated in the peripheral blood mononuclear cells (PBMC) from 28 colon cancer patients and in the tumor-infiltrating leukocytes (TIL) from 20 of the patients' colon cancer specimens. Modulation of LAK cell induction in TIL and PBMC by inhibitors of arachidonic acid metabolism also was examined. LAK cells were induced in vitro in isolated TIL and PBMC by culturing with 500 U/ml of recombinant interleukin-2 (IL-2) for 3 to 5 days, and this was followed by the assessment of cytolytic activity against natural killer (NK)-resistant Chang hepatoma cells. LAK cell induction in the TIL was depressed significantly, compared with LAK cell induction in the PBMC of colon cancer patients (P less than 0.01). In the majority of cases, indomethacin augmented LAK cell induction in the TIL (P = 0.073 for the entire group, compared with cultures not treated with indomethacin) and nordihydroguaiaretic acid (NDGA) depressed LAK cell induction (P less than 0.05 for the entire group, compared with cultures not treated with NDGA). Further characterization of the mechanisms responsible for modulating LAK cell induction in the TIL of cancer patients may identify ways to optimize their use in adoptive cellular immunotherapy.