Fig. 1
TNF-α-induced apoptosis in TN and TCM CD8+ T cells. Activated purified TN and TCM CD8+ T cells subsets were incubated in the absence or presence of TNF-α for 48 h and apoptosis was measured by TUNEL assay using FACSCalibur. Ten thousand cells were acquired. Data for spontaneous and TNF-α-induced apoptosis from 10 young and 10 aged subjects are presented as percent of TUNEL positive cells. A significantly increased (P < 0.001) apoptosis was observed in aged subjects. No significant difference was observed in spontaneous apoptosis between young and aged subjects