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Lifespan of T cells: Differential requirements for the survival of young and aged naïve CD4 T cells
Author(s) -
Tsukamoto Hirotake,
Huston Gail E,
Duso Debra K,
Buck Amanda L,
Haynes Laura,
Swain Susan L
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.2_supplement.356
Subject(s) - immune system , homeostasis , t cell receptor , immunology , antigen , biology , microbiology and biotechnology , t cell , cytokine
An age‐associated increase in susceptibility to various infectious diseases results from age‐related changes in the immune systems. We reported that reconstitution of T cells in aged mice partially restored the defects in antigen‐driven expansion and cytokine production of naïve T cells. Thus, it is postulated that thymic involution and the decline in the production of new T cells in elderly result in an accumulation of naïve cells that have persisted for an extended time and that have therefore become dysfunctional. However, our understanding about naïve T cell homeostasis in aged animals remains incomplete. Here we found that turnover of naïve CD4 T cells in aged mice was slower than in young mice, in spite of decreased ability of aged cells to drive homeostatic proliferation. Transfer experiments revealed that the survival advantage of aged naïve CD4 T cells was controlled by T cell‐intrinsic factors and was less dependent on TCR signaling mediated by self‐MHC recognition. Thus, we suggest that the survival advantage of aged naïve CD4 T cells leads to their longer lifespan, which in turn contributes to immune impairments with aging. This has important implications for understanding how and why aged individuals develop defects that prevent their efficient response to vaccination. Supported by grant AG‐21600 and the Trudeau Institute.