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

Mech Ageing Dev. 2006 Mar;127(3):274-81. doi: 10.1016/j.mad.2005.11.001. Epub 2005 Dec 13.


Memory T cells can be classified as central memory (T(CM), CD45RA(neg)CCR7(+)), effector memory (T(EM), CD45RA(neg)CCR7(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.

Publication types

  • Comparative Study

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aging / immunology*
  • CD4-Positive T-Lymphocytes / cytology
  • CD4-Positive T-Lymphocytes / immunology*
  • CD8-Positive T-Lymphocytes / immunology*
  • Cell Differentiation / immunology*
  • Child
  • Child, Preschool
  • Female
  • Humans
  • Immunologic Memory*
  • Infant
  • Male
  • Middle Aged