Abstract
With increasing age, the competence of the immune system to fight infections and tumors declines. Age-dependent changes have been mostly described for human CD8 T cells, raising the question of whether the response patterns for CD4 T cells are different. Gene expression arrays of memory CD4 T cells yielded a similar age-induced fingerprint as has been described for CD8 T cells. In cross-sectional studies, the phenotypic changes were not qualitatively different for CD4 and CD8 T cells, but occurred much more frequently in CD8 T cells. Homeostatic stability partially explained this lesser age sensitivity of CD4 T cells. With aging, naïve and central memory CD8 T cells were lost at the expense of phenotypically distinct CD8 effector T cells, while effector CD4 T cells did not accumulate. However, phenotypic shifts on central memory T cells were also more pronounced in CD8 T cells. This distinct stability in cell surface marker expression can be reproduced in vitro. The data show that CD8 T cells are age sensitive by at least two partially independent mechanisms: fragile homeostatic control and gene expression instability in a large set of regulatory cell surface molecules.
Original language | English (US) |
---|---|
Pages (from-to) | 107-118 |
Number of pages | 12 |
Journal | Clinical Immunology |
Volume | 127 |
Issue number | 1 |
DOIs | |
State | Published - Apr 2008 |
Keywords
- Aging
- CD4
- CD8
- CD85
- Immunosenescence
- Killer immunoglobulin-like receptors
- T-cell homeostasis
- T-cell subset
ASJC Scopus subject areas
- Immunology and Allergy
- Immunology