Cadmium induces apoptosis differentially on immune system cell lines

We investigate the role of cadmium-induced apoptosis in the immune system, studying the apoptotic effect of Cd(2+) in three human cell lines, the T-cell line CCRF-CEM, the B-cell line Raji and the lymphoblastoid cell line Molt-3. Cd(2+) was found to be dose-dependently toxic for these cell lines, after 18 h incubation. The 50% lethal dose (LD(50)) for CCRF-CEM was 25+/-20 mu M, for Molt-3 was 22.5+/-2.4 mu M, and for Raji was 13.5+/-2.2 mu M. DNA electrophoresis and quantitation of apoptosis after 18 h incubation with different Cd(2+) concentrations was carried out. In CCRF-CEM cells, apoptosis was detected at 10 mu M, reaching a maximum at 30 mu M. In Molt-3, apoptosis was detected at 10 mu M, increased thereafter and a plateau effect was observed from 30 to 50 mu M Cd(2+). In Raji, apoptosis was detected at 5 mu M, while a plateau effect was observed from 20 to 30 mu M Cd(2+). The above results indicated that Raji cells were more sensitive to cadmium compared to both CCRF-CEM and Molt-3 cells, suggesting a differential Cd(2+)-induced apoptotic effect, which may disturb the immune system normal growth and development. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.