Abstract
The aim of this study is to evaluate the effects of interleukin 2 (IL-2) on natural killer (NK) cell activity against renal cell carcinoma cell lines, Caki 1 and KU-2, which had been confirmed to be insensitive to NK cells, and against freshly prepared renal carcinoma cells. This study also aims to compare IL-2 induced cytotoxicity, known as lymphokine-activated killer (LAK) activity, with interferon (IFN)-γ cytotoxicity in vitro, using 51Cr-release assay technique.
The results showed that IL-2 did enhance the cytotoxicity of peripheral blood lymphocytes (PBL) significantly when incubated with a low concentration of 4IU/ml for 72hr (p<0.01) or when incubated with 100IU/ml for a short time (24hr) (p<0.01). The effects of IL-2 on cytotoxicity were dose and time dependent. It was also demonstrated that this lymphokine induced killer lympho-cytes, LAK cells, which showed higher cytotoxicity on renal carcinoma cells than those induced by IFN-γ.
In conclusion, a concentration of 100IU/ml of IL-2 and an incubation time of 72hr were the optimum conditions required in order to induce LAK cells which could lyse not only NK sensitive but resistant tumor cells, and LAK phenomenon produced a higher cytotoxicity than IFN-γ.
