Modulatory effect of cytokines on natural killer and antibody dependent cellular cytotoxicity directed to squamous cell carcinoma targets by lymphocytes from oral cancer patients

Cells from solid tumours are generally poor targets for natural killer (NK) cytotoxicity and antibody dependent cellular cytotoxicity (ADCC). In this paper, we have analysed NK cytotoxicity and ADCC mediated by peripheral blood mononuclear cells from healthy individuals and oral cancer patients before and after modulation with recombinant interleukin-2 (rIL-2), on target cells derived from two squamous cell carcinoma (SCC) cell lines prior to and after treatment with recombinant interferon-α (rIFNα). Target SCC cell directed monoclonal antibody 3F8E3 was used in ADCC. The results showed that the unmodulated SCC cells were poor targets for NK and ADCC compared to standard targets (K562 cells and chicken red blood cells, respectively). Modulation of targets alone with rIFNα showed moderate increase in their susceptibility while rIL-2 treated effectors could significantly lyse even unmodulated targets. Combined treatment of targets with rIFNα and effectors with rIL-2 showed additive enhancenent in NK and ADCC activity against SCC cells. Lymphocytes from treated patients with recurrent disease could not efficiently lyse SCC targets even after combined modulation.