INTERLEUKIN-12-MEDIATED KILLER ACTIVITY IN LUNG-CANCER PATIENTS

The authors investigated the interleukin (IL)-12-inducible killer acti vity of blood mononuclear cells (MNC) from 30 untreated primary lung c ancer patients and 24 control subjects. Cytotoxicity was assayed as 4- h Cr-51 release from Daudi lymphoma cells or lung cancer cells (H-69, N-291 and PC-9), MNC from lung cancer patients exhibited similar kille r activity to those from control subjects after in vitro incubation wi th IL-12 for 4 days, Effective killer induction by IL-12 was observed even in MNC from advanced lung cancer patients and patients with small cell lung cancer. IL-12 and a suboptimal dose of IL-2 had additive ef fects in inducing killer activity in MNC from both lung cancer patient s and control subjects, On the other hand, with an optimal dose of IL- 2, IL-12 suppressed killer induction, Addition of IL-12 alone or in co mbination with IL-2 resulted in interferon (IFN)-gamma production by M NC from lung cancer patients as well as control subjects, These observ ations suggest that IL-12 could be useful for immunotherapy of lung ca ncer in humans. (C) 1997 Academic Press Limited.