Open AccessPrednisone increases apoptosis in in vitro activated human peripheral blood T lymphocytes
Author(s) -
LANZA L.,
SCUDELETTI M.,
PUPPO F.,
BOSCO O.,
PEIRANO L.,
FILACI G.,
FECAROTTA E.,
VIDALI G.,
INDIVERI F.
Publication year - 1996
Publication title -
clinical & experimental immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.329
H-Index - 135
eISSN - 1365-2249
pISSN - 0009-9104
DOI - 10.1111/j.1365-2249.1996.tb08306.x
Subject(s) - apoptosis , biology , flow cytometry , cd8 , immunology , immune system , t cell , in vitro , peripheral blood mononuclear cell , microbiology and biotechnology , endocrinology , biochemistry
SUMMARY Glucocorticoid hormones (GCH) regulate, through the apoptotic process, the negative selection of immature T cells in the thymus. Because apoptosis seems to occur also in the maintenance of peripheral tolerance, we have investigated whether GCH may induce apoptosis in human mature lymphocytes. Peripheral blood lymphocytes (PBL) or peripheral CD4 + and CD8 + T cell subsets were cultured in the presence of phytohaemaglutinin (PHA) or PHA and prednisone (PDN) at 10 −3 ‐10 −12 M concentrations for 72, 96 and 120h. Cell cycle and membrane antigen expression were evaluated by flow cytometry and DNA degradation was detected by agarose gel electrophoresis. PDN blocks PBL growth in the G 1 phase of cell cycle and inhibits both IL‐2 receptor (IL‐2R) expression and IL‐2 secretion. Apoptosis is clearly increased by PDN in PHA‐activated human PBL, and the apoptotic effect of PDN is stronger on CD8 + than on CD4 + T lymphocytes. All these effects are dose‐ and time‐dependent. The addition of exogenous IL‐2 did not rescue lymphocytes from PDN‐increased apoptosis. These results show that PDN increases apoptosis in mature activated human peripheral blood lymphocytes, suggesting a possible role of GCH in the maintenance of immune tolerance at post‐thymic level.