RESUMO
The suppressor and cytotoxic activities of mononuclear blood cells (MNC) were studied in 70 cancer patients (melanoma, renal carcinoma) undergoing adoptive immunotherapy (AIT). In the course of AIT the patients' MNC were treated in vitro with the recombinant interleukin-2 (RIL-2) in order to generate the lymphokine-activated killer (LAK) cells. Then patients received i/v 2.5-13.6 10(9) autologous LAK cells and RIL-2 (75000 u). Each course included 2-3 repeated infusions; the patients received 1-5 courses according to their clinical conditions. The cytotoxic activity of MNC was assessed by a routine method; but for evaluation of the suppressor activity we used a new technique based on separation of MNS populations in the Percoll gradient. Twenty-four hours after the completion of each AIT course the suppressor activity of MNC decreased drastically up to the zero level in some patients. The decrease in the suppressor activity inversely correlated with the rise in the cytotoxic activity on Mel-I (LAK-sensitive) and K-562 (natural killer-sensitive) target cells. The level of cytotoxicity in some patients reached 51.2%.