Herndler-Brandstetter,D.; Schwaiger,S.; Veel,E.; Fehrer,C.; Cioca,D.P.; Almanzar,G.; Keller,M.; Pfister,G.; Parson,W.; Wurzner,R.; Schonitzer,D.; Henson,S.M.; Aspinall,R.; Lepperdinger,G.; Grubeck-Loebenstein,B.;

We have recently described an IL-2/IL-4-producing CD8+CD25+ non-regulatory memory T cell population that occurs in a subgroup of healthy elderly persons who characteristically still have a good humoral response after vaccination. The present study addresses this specific T cell subset and investigates its origin, clonal composition, Ag specificity, and replicative history. We demonstrate that CD8+CD25+ memory T cells frequently exhibit a CD4+CD8+ double-positive phenotype. The expression of the CD8 alphabeta molecule and the occurrence of signal-joint TCR rearrangement excision circles suggest a thymic origin of these cells. They also have longer telomeres than their CD8+

J.Immunol. 2005 175(3):1566-1574
PubMed: 16034095