Age associated decline in CD25 and CD28 expression correlate with an increased susceptibility to CD95 mediated apoptosis in T cells.

Immunosenescence is believed to contribute to increase susceptibility to infectious diseases and cancer in the elderly, and is caused mainly by changes in the T cell compartment. Longitudinal studies were undertaken to examine T cell surface receptor expression and apoptotic susceptibility using Staphylococcal enterotoxin B (SEB) activated human T cells as an in vitro model of an ageing T cell culture. An intracellular stain Carboxyfluorescein diacetate succinimidyl ester (CFSE) was used to assess the number of population divisions (PD) occurring in the ageing T cell culture.