Age-related events in active T lymphocyte subpopulation. A morphological study.
The incorporation of 5-bromo-2'-deoxyuridine (BrdU) into the DNA of active T lymphocytes from healthy aged donors was evaluated after in vitro PHA stimulation by means of light microscopy, electron microscopy and flow cytometry. The percentage of BrdU-labelled cells differed markedly between aged and young donors after 48 h of PHA stimulation, due to an enlarged early S phase compartment. In contrast, after 72 h the percentage of positive cells was quite similar in both age groups and no significant differences in the distribution within S phase nor changes in the patterns of ultrastructural localization of DNA replicon sites were observed. Our study provides evidence that an altered synchronization and a substantial delay in the in vitro cell proliferation occur in this peculiar T subpopulation as a consequence of the ageing process.
Istituto di Morfologia Umana Normale, Università di Chieti, Italy.
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Rana
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Di Pietro
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Centurione
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Vitale
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Zamai
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Sciscio
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Mazzotti
D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D002478:Cells, Cultured; D004261:DNA Replication / Q000187:drug effects; D005434:Flow Cytometry; D006801:Humans; D008854:Microscopy, Electron; D010835:Phytohemagglutinins / Q000494:pharmacology; D016176:T-Lymphocyte Subsets / Q000166:cytology* / Q000187:drug effects / Q000648:ultrastructure
D010835:Phytohemagglutinins