Diversity in the lymphocyte recognition repertoire is altered during ageing.
A variety of experiments is discussed, all of which indicate that a major alteration in the degree of diversity of both the B and T lymphocyte recognition repertoire occurs during ageing. This seems to be in part caused by alterations intrinsic to mature lymphocyte precursors themselves, and their responsiveness to environmental signals (e. g. MHC restriction), and in part due to changes in the host differentiation environment. Other changes which contribute to a decline in immune performance with age include altered accessory cell function/activity and alterations in e. g. the affinity of lymphocyte target interactions.
D000375:Aging / Q000276:immunology*; D000818:Animals; D000915:Antibody Affinity; D002454:Cell Differentiation; D008214:Lymphocytes / Q000276:immunology*; D051379:Mice