1 alpha, 25-dihydroxyvitamin D3 (calcitriol) induces apoptosis in stimulated T cells through an IL-2 dependent mechanism.
The steroid hormone 1 alpha,25-dihydroxyvitamin D3 (calcitriol) has been shown to inhibit PHA-induced T-cell proliferation. In the present work we show that calcitriol caused a concentration-dependent decrease in the viability of PHA stimulated but not unstimulated T lymphocytes. Under microscopy, nonviable cells exhibit classic features of programmed cell death or apoptosis. In addition, the same concentration of calcitriol induces a blockage in the G1 phase of T cell cycle and decreased secretion of IL-2, which was correlated with the extent of apoptosis. Thus, addition of exogenous IL-2 reverted both the cell cycle block and the apoptotic cell death induced by calcitriol. This data indicates that calcitriol induced apoptosis in PHA-stimulated T cell, and suggests that this action is mediated through suppression of IL-2 secretion.
Pintado
C O
CO
Unidad de Investigación, Hospital Reina Sofía, Córdoba, Spain.
Carracedo
J
J
Rodríguez
M
M
Pérez-Calderón
R
R
Ramírez
R
R
D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D002117:Calcitriol / Q000633:toxicity*; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D005434:Flow Cytometry; D007376:Interleukin-2 / Q000096:biosynthesis*; D051379:Mice; D010835:Phytohemagglutinins / Q000494:pharmacology; D013601:T-Lymphocytes / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*
D007376:Interleukin-2; D010835:Phytohemagglutinins; D002117:Calcitriol