Molecular mechanisms of TNF-alpha-induced apoptosis in naïve and memory T cell subsets.

Aging in humans is associated with progressive decline in T cell function, hyperimmunoglobulinemia, increased prevalence of autoantibodies and decline in naïve CD8(+) T cells and accumulation of memory T cells, which appears to be oligoclonal and display feature of senescence, that is, decreased replication, short telomere length and resistance to apoptosis. Recently memory T cells have been further subdivided into central and effector memory T cells, based upon their migratory and homing properties. They are identified by a number of cell surface makers. In this brief review we will discuss molecular mechanisms of apoptosis in naïve and various types of memory T cells to possibly explain the changes observed in aging, which are very similar to certain autoimmune diseases.