Premium
Expansion of cytotoxic CD8 + CD28 − T cells in healthy ageing people, including centenarians
Author(s) -
FAGI F. F.,
VESCOVINI R.,
MAZZOLA M.,
BOLOGNA G.,
NIGRO E.,
LAVAGETTO G.,
FRANCESCHI C.,
PASSERI M.,
SANSONI P.
Publication year - 1996
Publication title -
immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.297
H-Index - 133
eISSN - 1365-2567
pISSN - 0019-2805
DOI - 10.1046/j.1365-2567.1996.d01-689.x
Subject(s) - cytotoxic t cell , cd28 , il 2 receptor , cd38 , biology , ageing , cd8 , microbiology and biotechnology , interleukin 21 , flow cytometry , antigen , immunology , in vitro , biochemistry , stem cell , genetics , cd34
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.