Accumulation of memory T cells from childhood to old age: Central and effector memory cells in CD4 + versus effector memory and terminally differentiated memory cells in CD8 + compartment

• Published in: Mechanisms of ageing and development 2006-03, Vol.127 (3), p.274-281
• Main Authors: Saule, Pasquine, Trauet, Jacques, Dutriez, Virginie, Lekeux, Véronique, Dessaint, Jean-Paul, Labalette, Myriam
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Aged; Ageing; Aging - immunology; Biological and medical sciences; CCR7; CD28; CD4-Positive T-Lymphocytes - cytology; CD4-Positive T-Lymphocytes - immunology; CD8-Positive T-Lymphocytes - immunology; Cell Differentiation - immunology; Child; Child, Preschool; Development. Metamorphosis. Moult. Ageing; Female; Fundamental and applied biological sciences. Psychology; Humans; Immunologic Memory; Infant; Male; Middle Aged; Naive T cell; T cell memory; Vertebrates: anatomy and physiology, studies on body, several organs or systems
• ISSN: 0047-6374; 1872-6216
• DOI: 10.1016/j.mad.2005.11.001

Memory T cells can be classified as central memory (T CM, CD45RA negCCR7 +), effector memory (T EM, CD45RA negCCR7 neg), and terminally differentiated cells (T TD, CD45RA +CCR7 neg) with different homing and effector capacities. In 101 healthy subjects aged from 5 to 96 years, distinct dynamics were evidenced between circulating CD4 + and CD8 + T cell populations. Naive CD4 + and CD8 + T cells decreased linearly with age, CD8 + twice more rapidly. Memory cells outnumbered naive cells on average at 37.4 in the CD4 + and 29.5 years of age in the CD8 + pool. CD4 + T CM and T EM cells were positively correlated and increased linearly at a similar rate with age, while CD4 + T TD remained rare. CD8 + T EM and T TD accumulated linearly with age, while T CM increased only slightly, and each memory subset was negatively correlated to the two others. Almost all CD8 + T TD and some CD8 + T EM had lost CD28 expression. Despite different dynamics, each individual CD4 + naive and memory subset was correlated to the synonymous CD8 + subset. Half of the subjects aged 65 years or older were characterized by extremely reduced CD8 + naive and increased CD8 + T TD cell counts, which could indicate an acceleration of the decay of the immune system from this age onward.