title: Different rates of telomere shortening and telomerase activity reduction in CD8 T and CD16 NK lymphocytes with ageing.
abstract: Telomeres are specialised structures located at the end of eukaryotic chromosomes, that get short during progressive cell divisions. Therefore, telomere may be an indicator of the mitotic history of a cell and it is also a determining factor for the residual cell life span. One mechanism, compensating for the telomere erosion, involves the induction of telomerase, a ribonucleoprotein-enzyme able to synthesize telomeric DNA repeats. In this study, old subjects of two consecutive decades were compared with a group of young controls to investigate whether ageing-related modifications differently affects telomere length and telomerase activity of human peripheral blood CD8 T and CD16 NK lymphocytes. Telomeres in individual cells were measured by flow-FISH and telomerase activity was determined using the TeloTAGGG telomerase PCR ELISA(PLUS) kit. Both CD8 T and NK lymphocytes showed an age-associated loss of telomeres at rates that were different between the subsets together with an age-associated reduction of telomerase activity that was progressive in CD8 and late in NK lymphocytes. We can assume that preserved innate immune response in the elderly is due to the negligible telomere shortening and the maintained telomerase expression that could allow NK cells of octogenarians to delay replicative senescence.
authors.affiliation: Laboratorio di Immunologia e Genetica, Istituto di Ricerca Codivilla Putti, I.O.R., Via di Barbiano 1/10, 40136, Bologna, Italy. marianie@alma.unibo.it
authors.forename: Erminia
authors.initials: E
authors.lastname: Mariani
authors.forename: Alessandra
authors.initials: A
authors.lastname: Meneghetti
authors.forename: Ivan
authors.initials: I
authors.lastname: Formentini
authors.forename: Simona
authors.initials: S
authors.lastname: Neri
authors.forename: Luca
authors.initials: L
authors.lastname: Cattini
authors.forename: Giovanni
authors.initials: G
authors.lastname: Ravaglia
authors.forename: Paola
authors.initials: P
authors.lastname: Forti
authors.forename: Andrea
authors.initials: A
authors.lastname: Facchini
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000235:genetics* / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000201:enzymology* / Q000648:ultrastructure; D002648:Child; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D006801:Humans; D016130:Immunophenotyping; D007694:Killer Cells, Natural / Q000201:enzymology* / Q000648:ultrastructure; D016133:Polymerase Chain Reaction / Q000379:methods; D017452:Receptors, IgG / Q000097:blood; D019098:Telomerase / Q000097:blood*; D016615:Telomere / Q000235:genetics*
chemical_list: D017452:Receptors, IgG; D019098:Telomerase