Age-related defects in Th1 and Th2 cytokine production by human T cells can be dissociated from altered frequencies of CD45RA+ and CD45RO+ T cell subsets.
Mech Ageing Dev
; 109(2): 97-112, 1999 Aug 30.
Article
em En
| MEDLINE
| ID: mdl-10515660
ABSTRACT
The present study investigated whether age-related changes in the production of Th1 and Th2 cytokines by human T cells might be linked to altered frequencies of naive (CD45RA+) and memory (CD45RO+) T cell subsets. T cells from healthy elderly humans (n = 32) stimulated with anti-CD3epsilon monoclonal antibody OKT3 plus PMA produced significantly lower levels of IL-2 and IFNgamma (Th1 type) and of IL-4 (Th2 type) cytokines compared with T cells from young subjects. Although considerable heterogeneity was observed in the levels of cytokines produced by activated T cells from elderly individuals, linear regression analysis failed to demonstrate any significant shift in Th1 to Th2 type cytokine profiles of human T cells during aging. Sufficient T cells were available from eighteen elderly subjects to quantitate the levels of cytokine production in parallel with flow cytometry analysis of the frequencies of CD45RA+ naive and CD45RO+ memory T cells. Compared with the group of young subjects, the elderly group exhibited significant decreases in the frequencies of naive T cells with reciprocal increases in memory T cells. However, defects in Th1 and Th2 cytokine production were not significantly correlated with altered frequencies of naive/memory T cells among elderly individuals. In addition, those elderly individuals with normal frequencies of naive/memory T cells exhibited decreases in cytokine production comparable to the reductions observed for elderly donors with alterations in the frequencies of naive/memory T cells. These findings suggest that age-related defects in Th1 and Th2 cytokine production cannot be attributed entirely to alterations in the frequencies of naive/memory T cell subsets and point toward intrinsic aberrancies within human T cell cytokine networks during aging.
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Base de dados:
MEDLINE
Assunto principal:
Envelhecimento
/
Interleucina-4
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Interferon gama
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Interleucina-2
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Antígenos Comuns de Leucócito
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Células Th2
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Células Th1
Idioma:
En
Ano de publicação:
1999
Tipo de documento:
Article