title: Immunological studies of aging. IX. Quantitative differences in T lymphocyte subsets in young and old individuals.
abstract: The enumeration and distribution of T-cell subsets in peripheral blood from young and old humans was studied. The percentage and absolute number of OKT3-reactive lymphocytes was comparable in healthy elderly individuals (65-84 years old) and young individuals (19-31 years old). The number of OKT4-reactive T lymphocytes from peripheral blood was significantly greater in the older group while the number of OKT8-reactive T lymphocytes was significantly lower. The OKT4/OKT8 ratio was significantly greater in old compared to young subjects. The change in the OKT4/OKT8 ratio did not correlate, in either young or old, with the proliferative response of lymphocytes induced by phytohemagglutinin (PHA) or concanavalin A (Con A). Although lymphocytes that form rosettes with autologous erythrocytes, a marker of early T lymphocyte lineage, are increased in old subjects, other markers of early T lineage were found to be absent (OKT6), showed no difference (OKT10), or were comparable in young and old subjects.
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging; D000911:Antibodies, Monoclonal; D005260:Female; D006801:Humans; D007958:Leukocyte Count; D008213:Lymphocyte Activation; D008297:Male; D012397:Rosette Formation; D013601:T-Lymphocytes / Q000145:classification / Q000276:immunology / Q000502:physiology*
chemical_list: D000911:Antibodies, Monoclonal