title: 1 alpha, 25-dihydroxyvitamin D3 (calcitriol) induces apoptosis in stimulated T cells through an IL-2 dependent mechanism.
abstract: 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.
authors.affiliation: Unidad de Investigación, Hospital Reina Sofía, Córdoba, Spain.
authors.forename: C O
authors.initials: CO
authors.lastname: Pintado
authors.forename: J
authors.initials: J
authors.lastname: Carracedo
authors.forename: M
authors.initials: M
authors.lastname: Rodríguez
authors.forename: R
authors.initials: R
authors.lastname: Pérez-Calderón
authors.forename: R
authors.initials: R
authors.lastname: Ramírez
mesh_terms: 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*
chemical_list: D007376:Interleukin-2; D010835:Phytohemagglutinins; D002117:Calcitriol