Inhibition of cytotoxicity to autologous tumor cells by the regional lymph node cells of patients with primary lung cancer.

The regional lymph node (RL) cells of patients with primary lung cancer exhibited no cytotoxicity to autologous tumor cells in a 4-hr 51Cr-release assay, but when cultured in the presence of Interleukin 2 (IL2), the RL cells did become cytotoxic to those target cells. When RL cells were included in a cytotoxic test of IL2-activated RL cells (autologous killer T cells; AKT cells) and autologous target cells, the cytotoxicity of the AKT cells was significantly inhibited in 27 out of a total of 42 cases, but this suppression was observed against neither allogeneic effector cells (seven out of nine cases) nor natural killer cells (all seven cases tested). The cytotoxicity of AKT cells to allogeneic target cells was inhibited by RL cells in three out of six cases. Nylon-wool column separation indicated that the cell population adhering to the nylon wool mediated the suppressive effect of the RL cells. These data suggested the presence of nylon-wool-adherent suppressor cells in the regional lymph nodes of patients with primary lung cancer which suppress the cytotoxicity of autologous killer lymphocytes to autologous tumor cells.