Lymphokine‐activated killer cell activity of peripheral blood, spleen, regional lymph node, and tumor infiltrating lymphocytes in gastric cancer patients

Lymphokine-activated killer (LAK) cell activity of peripheral blood mono-nuclear cells (PBM), spleen cells (SPC), regional lymph node cells (LNC), and tumor-infiltrating lymphocytes (TIL), induced by activation with in-terleukin 2 (IL 2) for 4 days, was evaluated in patients with gastric carcinoma. TIL exhibited the lowest LAK activity and the cytotoxicity of LNC was significantly lower than that of either PBM or SPC. There was no difference between PBM and SPC. Then, there were significant correlations of LAK activity among PBM, SPC, and LNC, whereas poor correlations were observed in the cytotoxicity between TIL and PBM, SPC, or LNC. Phenotypic analysis of each cell population was performed before and after activation with IL 2. Before culture, the cells mediating natural killer (NK) activity such as CD16+, CD56+, and CD57+ cells were few in LNC and TIL. However, CD56+ and CD57+ cells in TIL were increased after culture. Then, CD4+ Leu8+ and CD8+ CD11+ cells, which identify suppressor cell function, were not elevated in LNC or TIL, as compared to that in PBM or SPC. Further, the proportions of OKIa1+ and CD25+ cells expressing T-cell activation and IL 2 receptor were uniformly increased in all cell populations after culture. These results indicate the differential reactivity of each lymphocyte population to IL 2 and fundamental dysfunction of LNC and, especially TIL, suggesting the specific influence of the local tumor environment on the lymphocyte function in the area in patients with gastric carcinoma. © Wiley-Liss, Inc.