Expansion of cytotoxic CD8+ CD28- T cells in healthy ageing people, including centenarians

F. F. Fagnoni, R. Vescovini, M. Mazzola, G. Bologna, E. Nigro, G. Lavagetto, C. Franceschi, M. Passeri, P. Sansoni

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Abstract

Ageing is associated with complex remodelling in the phenotypic and functional profiles of T lymphocytes. We investigated whether expression of CD28 antigen on T cells is conserved throughout adulthood and ageing in humans. For this purpose we analysed T cells obtained from peripheral blood of 102 healthy people of ages ranging from 20 to 105 years. We found an age-related increase of CD28- T cells in percentage and absolute number, predominantly among CD8+ T cells. CD28- T cells from aged donors analysed by flow cytometry appeared as resting cells (not expressing CD25, CD38, CD69, CD71, DR), bearing markers of cytotoxic activity (CD11b and CD57) and with a phenotype compatible with 'memory' cells (up-regulated CD2 and CD11a; CD62L absent). At the functional level, freshly isolated purified CD28-CD8+ T cells showed high anti-CD3 redirected cytotoxic activity against Fc-bearing P815 cells. The same activity tested on freshly isolated bulk T lymphocytes was significantly augmented with age. We found a positive correlation between age, number of CD8+ CD28- T cells and anti-CD3 redirected cytotoxicity by freshly isolated T cells. These data suggest that an activation of unknown nature within the cytotoxic arm of the immune system occurs with age. We speculate that these cytotoxic T lymphocytes (CTL) in vivo may constitute armed effector cells for immediate killing of targets bearing peptides from pathogens of intracellular origin.

Original languageEnglish
Pages (from-to)501-507
Number of pages7
JournalImmunology
Volume88
Issue number4
Publication statusPublished - 1996

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ASJC Scopus subject areas

  • Immunology

Cite this

Fagnoni, F. F., Vescovini, R., Mazzola, M., Bologna, G., Nigro, E., Lavagetto, G., Franceschi, C., Passeri, M., & Sansoni, P. (1996). Expansion of cytotoxic CD8+ CD28- T cells in healthy ageing people, including centenarians. Immunology, 88(4), 501-507.