title: A reduced peripheral blood CD4(+) lymphocyte proportion is a consistent ageing phenotype.
abstract: Peripheral blood leukocyte composition was measured in young, middle-aged and old C57BL/6J (B6) and BALB/cByJ (BALB) mice by flow cytometry to test the hypothesis that ageing is associated with declines in the proportions of peripheral blood T lymphocytes. In both B6 and BALB mice, increasing age is associated with a significant and continuous decline in the proportions of CD4(+) lymphocytes, a moderate decline in the proportion of CD8(+) lymphocytes, a significant increase in the proportion of Gr1(+) granulocytes and an almost unchanged proportion of B lymphocytes. As expected, the proportion of CD44(low) naive T lymphocytes decreased with age. Expression of Fas (CD95(+)) on CD4(+) and CD8(+) lymphocytes showed no consistent change with age. We also measured peripheral blood CD4(+) and CD8(+) lymphocyte proportions in young and old A/J, CBA/CaJ, DBA/2J, DW/J and (DWxC3H) F1 mice. The CD4(+) lymphocyte proportion decreased from young to old age in these strains by 56,65,72,78 and 68%, respectively. The CD8(+) lymphocyte proportion decreased moderately with age in all the inbred strains tested but not in the (DWxC3H) F1 hybrid. Thus, a reduced proportion of peripheral blood CD4(+) lymphocytes is a consistent ageing phenotype in a wide range of Mus musculus strains.
authors.affiliation: The Jackson Laboratory, Bar Harbor, ME 04609, USA.
authors.forename: Jichun
authors.initials: J
authors.lastname: Chen
authors.forename: Kevin
authors.initials: K
authors.lastname: Flurkey
authors.forename: David E
authors.initials: DE
authors.lastname: Harrison
mesh_terms: D000375:Aging / Q000097:blood / Q000276:immunology*; D000818:Animals; D015415:Biomarkers; D018791:CD4 Lymphocyte Count; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology*; D018960:Hyaluronan Receptors; D007963:Leukocytes, Mononuclear / Q000166:cytology; D018655:Lymphocyte Count; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008815:Mice, Inbred Strains; D010641:Phenotype; D013045:Species Specificity; D019014:fas Receptor / Q000096:biosynthesis
chemical_list: D015415:Biomarkers; D018960:Hyaluronan Receptors; D019014:fas Receptor