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 μM, for Molt-3 was 22.5±2.4 μM, and for Raji was 13.5±2.2 μM. 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 μM, reaching a maximum at 30 μM. In Molt-3, apoptosis was detected at 10 μM, increased thereafter and a plateau effect was observed from 30 to 50 μM Cd 2+. In Raji, apoptosis was detected at 5 μM, while a plateau effect was observed from 20 to 30 μM 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.