| Abstract: | This study examined the importance of interleukin 1 (IL 1) in the large granular lymphocyte (LGL)-target cell interaction. K562 target cells when treated with highly purified human IL 1 for 1 hr bound greater numbers of LGL than untreated cells. LGL from patients with hepatocellular carcinoma (HCC) that bound few untreated K562 cells, attached to considerably increased numbers of IL 1-treated target cells. Cytotoxicity of LGL against target cells could similarly be increased by pulsing the latter cells with IL 1, and defective cytotoxicity of LGL from HCC patients could be corrected by treating the target K562 cells with IL 1. Lysis of PLC/PRF/5 cells, Yac-1 cells, and normal skin fibroblasts could also be increased by treatment with IL 1 for 1 hr. The enhanced binding and cytotoxicity of IL 1-treated target cells was only observed when the latter cells were preincubated with IL 1 at 37 degrees C, and was not evident at 4 degrees C. Furthermore, the IL 1-mediated effect could be abolished by treating the target cells with cycloheximide before the IL 1 pulse, or by adding rabbit anti-human IL 1 together with the IL 1. These results indicate that IL 1 affects a variety of target cells and increases their ability to bind and be lysed by enriched LGL. They demonstrate, furthermore, that defective natural cytotoxicity by the LGL of patients with advanced malignant disease can be corrected in vitro by treating the target cells with IL 1. |
