Natural Killer Activity of Lymphocytes Infiltrating Human Lung Cancers Following Preoperative Systemic Recombinant Interleukin 2

Tumor-infiltrating lymphocytes (TILs) show depressed natural killer (NK) activity compared with peripheral blood lymphocytes (PBLs). To determine if TIL NK function can be reactivated in vivo, 11 patients with tumors metastatic to the lung were treated with systemic recombinant interleukin 2 (rlL-2). Spontaneous TIL NK activity and NK activity after three days' incubation with 100 U/mL of rlL-2 were increased in patients receiving 15000 U/kg of rlL-2 preoperatively compared with those receiving between 1000 and 10000 U/kg. Histologically, higher doses of rlL-2 increased the number of intratumoral lymphocytes, the level of peritumoral lymphocytic transferrin, and the expression of HLA-DR. Spontaneous PBL NK activity in patients receiving between 10000 and 15000 U/kg of rlL-2 was also increased and was further increased by in vitro culture with rlL-2. Thus, PBL NK activity and TIL NK function in vivo can be augmented with 15000 U/kg of systemic rlL-2. Both TIL- and PBL-inducible cytotoxicities were further enhanced by in vitro culture with rlL-2.