Aging-associated subpopulations of human CD8+ T-lymphocytes identified by their CD28 and CD57 phenotypes.
BACKGROUND
During organismal aging, human T-cells shift towards less functional phenotypes, often called senescent cells. As these cells have not been well characterized, we aimed to relate surface markers of human T-cell senescence with characteristics of in vitro cellular aging and to further characterize these cells.


METHODS
We identified, by flow cytometry, subpopulations of CD8+ T-cells based on CD57 and CD28 expression, and tested them for some markers of cellular senescence, apoptosis, differentiation and homing.


RESULTS
Elderly persons presented significantly higher proportions not only of CD28-CD57+, but also of CD28+CD57+ cells. CD28+CD57+ cells had the highest expression of p16, p21, Bcl-2, CD95, CD45RO, CCR5 and PD-1, thereby arguing in favor of a senescent phenotype.


CONCLUSIONS
Among CD8+ T-lymphocytes, CD28+CD57+ cells represent a subset with some senescent features that are distinct from the CD28-CD57+ cells.
Gerontology Department and Frailty in Aging Research (FRIA) Group, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Laarbeeklaan 103, B-1090 Brussel, Belgium.
Oscar Okwudiri
OO
Onyema
Gerontology Department and Frailty in Aging Research (FRIA) Group, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Laarbeeklaan 103, B-1090 Brussel, Belgium.
Rose
R
Njemini
Gerontology Department and Frailty in Aging Research (FRIA) Group, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Laarbeeklaan 103, B-1090 Brussel, Belgium.
Louis Nuvagah
LN
Forti
Gerontology Department and Frailty in Aging Research (FRIA) Group, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Laarbeeklaan 103, B-1090 Brussel, Belgium.
Ivan
I
Bautmans
Laboratory of Molecular and Cellular Therapy, Vrije Universiteit Brussel, Laarbeeklaan 103, B-1090 Brussel, Belgium.
Joeri L
JL
Aerts
Laboratory of Hematology, Universitair Ziekenhuis Brussel, Laarbeeklaan 101, B-1090 Brussel, Belgium.
Marc
M
De Waele
Gerontology Department and Frailty in Aging Research (FRIA) Group, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Laarbeeklaan 103, B-1090 Brussel, Belgium; Department of Geriatrics, Universitair Ziekenhuis Brussel, Laarbeeklaan 101, B-1090 Brussel, Belgium. Electronic address: tmets@vub.ac.be.
Tony
T
Mets
D000368:Aged; D000375:Aging / Q000235:genetics / Q000276:immunology*; D015415:Biomarkers / Q000032:analysis; D018106:CD28 Antigens / Q000032:analysis; D018959:CD57 Antigens / Q000032:analysis; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D002454:Cell Differentiation / Q000235:genetics; D016922:Cellular Senescence; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000032:analysis; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000032:analysis; D005434:Flow Cytometry; D006801:Humans; D016130:Immunophenotyping / Q000379:methods; D010641:Phenotype
D015415:Biomarkers; D018106:CD28 Antigens; D018959:CD57 Antigens; D019941:Cyclin-Dependent Kinase Inhibitor p16; D050759:Cyclin-Dependent Kinase Inhibitor p21
CD28; CD57; CXCR2; Cellular aging; p16; p21