Role of nitric oxide in cell-mediated tumor cytotoxicity.

Strong and increasing evidence shows that nitric oxide (NO) contributes to immune function, and in particular to 'non-specific host defense'. The aim of the present review was to focus the current understanding of the role of NO as a biochemical effector of L-arginine-dependent cell-mediated immune responses to neoplastic cells in vitro and in vivo. The cytokine-inducible nitric oxide synthase (NOS) seems to mainly be implicated in the cytotoxic activity of almost all the effector cells involved in tumor cell killing.

Effects of cadmium on cytotoxic functions of human natural killer cells.

The effect of cadmium (Cd(2+)) was studied on natural killer (NK) cell-mediated cytotoxicity as well as on antibody-dependent cellular cytotoxicity (ADCC) of human peripheral blood lymphocytes. The results show that cadmium chloride inhibits human NK and ADCC activities against K562 and Ab-coated P815 target cells in a dose- and time-dependent manner. Maximal inhibition (80-90%) was observed in the presence of 100 mum-cadmium chloride, and it does not appear to be due to toxic effects on effector cells.