Long term in vitro culture of clonally expanded CD8+ T cells, generally found within the CD57+ or CD28- subset, has generally been unsuccessful, suggesting that these cells may have a limited replicative potential. Telomeric shortening may reflect the action of a 'mitotic clock' regulating the number of divisions a cell can undergo. In this study, we have compared the telomeric lengths of CD28-CD8+ and CD28+CD8+ T cells in 10 normal individuals to assess their replicative history. Overall, the telomeric lengths were found to be significantly shorter in the CD28-CD8+ T cell subset compared with the CD28+CD8+ subset. Furthermore, clonally expanded TCRBV11+CD8+ T cells from an individual exhibited telomeric lengths that were 2.9 kb shorter than those found in the polyclonal CD28+CD8+ T cell subset. These findings indicate that clonally expanded CD28-CD8+ T cells have undergone many more rounds of replication than CD28+CD8+ T cells, and consistent with the loss of CD28 expression, they may have reached a state of replicative senescence.
|Original language||English (US)|
|Number of pages||4|
|Journal||Journal of Immunology|
|State||Published - May 15 1996|
ASJC Scopus subject areas
- Immunology and Allergy