Apoptotic capability in ageing T cells

The ageing immune system shows a gradual decline in responsiveness to antig ens and tumours due to the emergence of immunosenescence. The main function s of T cells are activation, anergy and apoptosis and these are all affecte d during ageing. Apoptosis is vital in controlling cell numbers, deleting s elf-reactive T cells and maintaining immune surveillance. One of the princi ple instigators of death involves the CD95:CD95-ligand interaction and as T cells age both receptor and ligand levers increase. This view will describ e the current knowledge of the apoptotic susceptibility of ageing T cells a nd evaluate the factors that may affect the apoptotic capability of immunos enescent T cells. (C) 2000 Elsevier Science Ireland Ltd. All rights reserve d.