Is immune senescence reversible?

Many genes have been shown to be involved in the decline in immune function of the elderly. However, normal numbers of myeloid and lymphoid colonies c an be grown from elderly bone marrow under optimal conditions and some thym ic function is preserved well into adult life. It may also be possible to r everse partially declining thymic function by IL-7 treatment. Peripheral B and T cells show evidence of dysregulation with production of large clones, changes in subset distribution and altered signalling and cytokine product ion, particularly decreased IL-2 production in the mouse. The identificatio n of these defects may lead to relatively simple procedures to improve vacc ination for the elderly. (C) 2000 Elsevier Science Ltd. All rights reserved .