title: Healthy aging and latent infection with CMV lead to distinct changes in CD8+ and CD4+ T-cell subsets in the elderly.
abstract: Despite general acceptance that immunologic changes are associated with aging and latent infection with Cytomegalovirus (CMV), no clear-cut distinction has so far been made between strictly age-related and CMV-induced changes. We therefore compared CD4+ and CD8+ naïve (CD45RA+CD28+), memory (CD45RA-CD28+), and effector (CD28-) T cells in CMV-positive (n = 164) and CMV-negative (n = 87) elderly persons and correlated CD8+ and CD4+ effector T cells with other T-cell subpopulations. Percentages of CD8+ as well as CD4+ effector T cells were higher, but percentages of naïve and memory cells were lower in CMV-positive compared to CMV-negative elderly persons. Negative correlations within CD8+ T-cell subsets were found to be present in both CMV-positive and CMV-negative elderly individuals. In contrast, correlations within CD4+ T-cell subpopulations and a positive correlation between CD8+ and CD4+ effector T cells were found in CMV-positive individuals only. Our results demonstrate that (a) in the elderly different T-cell subsets compete for space within the CD8+, but not the CD4+ T-cell population; (b) CMV induces changes in the CD4+ compartment that differ from the solely age-related changes seen in CMV-negative elderly population; and (c) the CMV-status of a population has to be taken into account before a conclusion on the effect of aging on the composition of the T-cell pool can be reached.
authors.affiliation: Immunology Division, Institute for Biomedical Aging Research, Austrian Academy of Sciences, Innsbruck, Austria.
authors.forename: Birgit
authors.initials: B
authors.lastname: Weinberger
authors.forename: Lutfan
authors.initials: L
authors.lastname: Lazuardi
authors.forename: Ilka
authors.initials: I
authors.lastname: Weiskirchner
authors.forename: Michael
authors.initials: M
authors.lastname: Keller
authors.forename: Christoph
authors.initials: C
authors.lastname: Neuner
authors.forename: Karl-Heinz
authors.initials: KH
authors.lastname: Fischer
authors.forename: Ber
authors.initials: B
authors.lastname: Neuman
authors.forename: Reinhard
authors.initials: R
authors.lastname: Würzner
authors.forename: Beatrix
authors.initials: B
authors.lastname: Grubeck-Loebenstein
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D003587:Cytomegalovirus / Q000502:physiology*; D003586:Cytomegalovirus Infections / Q000276:immunology*; D005260:Female; D006801:Humans; D007156:Immunologic Memory; D008297:Male; D008875:Middle Aged; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D017735:Virus Latency