Nickel and vanadium metal ions induce apoptosis of T-lymphocyte Jurkat cells.

Metal alloys are used as prosthetic components in the orthopaedic and dental field. However, there is growing concern over the reported leaching of metal ions from implants. Ions released from metals have been thought to be associated with local immune dysfunction, inflammation, and tissue cell death. The objective of our study was to investigate whether nickel(II) and vanadium(V), present at a smaller percentage in most alloys, are cytotoxic to T-lymphocyte cell models. Jurkat T cells possess characteristics similar to human T-lymphocytes and proliferate at a faster rate. Jurkat T cells were incubated with control media alone or with concentrations of 1, 10, and 100 microg/mL of Ni(II) or V(V) for 24 h. Both types of metal ions reduced cell viability and proliferation in a dose-dependent manner. Ni(II) at 10 microg/mL and V(V) at 100 microg/mL activated Caspase-3 expression. Hoechst 33258 staining and transmission electron microscopy revealed chromatin condensation, as well as nuclear blebbing and fragmentation. Induction of DNA fragmentation by Ni(II) at 100 microg/mL was also indicated by agarose electrophoresis. Our observations indicate that Ni and V ions kill T cells via apoptotic and nonapoptotic pathways.