Previous results of ours have demonstrated that the same clonotype can express both a sensitive and a resistant phenotype to Dex-mediated PCD induction depending on its cell cycle phase. In particular, we demonstrated that human T lymphocytes, arrested in the G0/G1 phase of the cell cycle, are susceptible, while proliferating T cells are resistant to Dex-mediated apoptosis, In this paper, we have further characterized the sensitive and resistant phenotypes and investigated whether a different expression of the apoptotic genes Pas, Fast, Bcl-2, Bcl-x and Bar is involved in the regulation of Dex-mediated apoptosis, The results show that the amount of Bcl-2 expression, that changes during cell cycle phases, determines susceptibility or resistance to apoptosis induced by Dex, In fact, undetectable expression of Bcl-2 in sensitive cells favors Dex-mediated apoptosis while high expression of Bcl-2 in proliferating cells counterbalances apoptosis induction. Moreover, the addition of exogenous IL-2, in the presence of Dex, fails to up-regulate Bcl-2 expression and to revert Dex-mediated apoptotic phenomena.
Dexamethasone induces apoptosis in human T cell clones expressing low levels of Bcl-2 / Gilardini Montani, M. S.; Tuosto, Loretta; Giliberti, R.; Stefanini, L.; Cundari, E.; Piccolella, Enza. - In: CELL DEATH AND DIFFERENTIATION. - ISSN 1350-9047. - STAMPA. - 6:1(1999), pp. 79-86. [10.1038/sj.cdd.4400461]
Dexamethasone induces apoptosis in human T cell clones expressing low levels of Bcl-2
M. S. Gilardini Montani;TUOSTO, Loretta;PICCOLELLA, Enza
1999
Abstract
Previous results of ours have demonstrated that the same clonotype can express both a sensitive and a resistant phenotype to Dex-mediated PCD induction depending on its cell cycle phase. In particular, we demonstrated that human T lymphocytes, arrested in the G0/G1 phase of the cell cycle, are susceptible, while proliferating T cells are resistant to Dex-mediated apoptosis, In this paper, we have further characterized the sensitive and resistant phenotypes and investigated whether a different expression of the apoptotic genes Pas, Fast, Bcl-2, Bcl-x and Bar is involved in the regulation of Dex-mediated apoptosis, The results show that the amount of Bcl-2 expression, that changes during cell cycle phases, determines susceptibility or resistance to apoptosis induced by Dex, In fact, undetectable expression of Bcl-2 in sensitive cells favors Dex-mediated apoptosis while high expression of Bcl-2 in proliferating cells counterbalances apoptosis induction. Moreover, the addition of exogenous IL-2, in the presence of Dex, fails to up-regulate Bcl-2 expression and to revert Dex-mediated apoptotic phenomena.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.