title: Aging and cytomegalovirus infection differentially and jointly affect distinct circulating T cell subsets in humans.
abstract: The impact of intrinsic aging upon human peripheral blood T cell subsets remains incompletely quantified and understood. This impact must be distinguished from the influence of latent persistent microorganisms, particularly CMV, which has been associated with age-related changes in the T cell pool. In a cross-sectional cohort of 152 CMV-negative individuals, aged 21-101 y, we found that aging correlated strictly to an absolute loss of naive CD8, but not CD4, T cells but, contrary to many reports, did not lead to an increase in memory T cell numbers. The loss of naive CD8 T cells was not altered by CMV in 239 subjects (range 21-96 y), but the decline in CD4(+) naive cells showed significance in CMV(+) individuals. These individuals also exhibited an absolute increase in the effector/effector memory CD4(+) and CD8(+) cells with age. That increase was seen mainly, if not exclusively, in older subjects with elevated anti-CMV Ab titers, suggesting that efficacy of viral control over time may determine the magnitude of CMV impact upon T cell memory, and perhaps upon immune defense. These findings provide important new insights into the age-related changes in the peripheral blood pool of older adults, demonstrating that aging and CMV exert both distinct and joint influence upon blood T cell homeostasis in humans.
authors: Arizona Center on Aging, University of Arizona College of Medicine, Tucson, AZ 85724;
authors: Anne M
authors: AM
authors: Wertheimer
authors: Michael S
authors: MS
authors: Bennett
authors: Byung
authors: B
authors: Park
authors: Jennifer L
authors: JL
authors: Uhrlaub
authors: Carmine
authors: C
authors: Martinez
authors: Vesna
authors: V
authors: Pulko
authors: Noreen L
authors: NL
authors: Currier
authors: Dragana
authors: D
authors: Nikolich-Žugich
authors: Jeffrey
authors: J
authors: Kaye
authors: Janko
authors: J
authors: Nikolich-Žugich
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000097:blood / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D003587:Cytomegalovirus / Q000276:immunology*; D003586:Cytomegalovirus Infections / Q000097:blood / Q000276:immunology*; D005260:Female; D006801:Humans; D007156:Immunologic Memory; D008297:Male; D008875:Middle Aged