Source:http://linkedlifedata.com/resource/pubmed/id/15374448
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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
2-3
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| pubmed:dateCreated |
2004-9-17
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| pubmed:abstractText |
Advanced age in humans and experimental animal models has been consistently associated with declines in the in vivo and in vitro responsiveness of T lymphocytes. The declines in vitro responses cannot be explained by decrease in numbers of differentiated T cells or by age-associated changes in the proportion of CD4+ 'helper' to CD8+ 'cytotoxic/suppressor' T cells. However, recent studies have demonstrated a decline with age in numbers of what appear to be antigenically 'naive' or 'virgin' T cells, accompanied by a proportionate increase in 'memory' T cells which mediate anemnestic or recall responses to previously encountered antigens. The findings lead to the hypothesis that thymic involution leads to decline in input of newly differentiated 'naive' T cells, while T cell number in peripheral tissues is maintained by accumulation of longer lived 'memory' T cells due to lifetime antigen exposure. So far, limited data suggest that increasing average biological age of the memory T cells which accumulate with age is largely responsible for declines in vitro activation responses of human peripheral blood T cells and that a subset of these memory T cells becomes refractory to activation stimuli as a consequence of in vivo cellular aging. Approaches to testing this hypothesis are presented and the implications of these findings for use of memory T cells as a model for investigating the mechanisms of in vivo cellular aging, are discussed.
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| pubmed:language |
eng
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| pubmed:journal | |
| pubmed:status |
PubMed-not-MEDLINE
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| pubmed:issn |
0167-4943
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| pubmed:author | |
| pubmed:issnType |
Print
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| pubmed:volume |
12
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| pubmed:owner |
NLM
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| pubmed:authorsComplete |
Y
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| pubmed:pagination |
199-218
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| pubmed:articleTitle |
Aging and lymphocyte function: a model for testing gerontologic hypotheses of aging in man.
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| pubmed:affiliation |
Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN 55455, U.S.A.
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| pubmed:publicationType |
Journal Article
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