Differential response of murine CD4+CD25+ and CD4+CD25- T cells to dexamethasone-induced cell death.
To evaluate the in vivo effect of immunosuppressive glucocorticoids on CD4+CD25+ T regulatory cells, we injected dexamethasone (Dex) into BALB/c mice. Administration of Dex enhanced the proportion of CD4+CD25+ cells and the ratio of CD4+CD25+ cells to CD4+CD25- cells in the lymphoid organs, especially in the thymus. This correlates with our in vitro observation that CD4+CD25+ T cells express higher levels of glucocorticoid receptor and Bcl-2, and are therefore more resistant to Dex-mediated cell death than CD4+CD25- T cells. Furthermore, IL-2 selectively protected CD4+CD25+ T cells from Dex-induced cell death, while IL-7 and IL-15 did not exert preferential protective effects. Dex-treated CD4+CD25+ T cells expressed higher levels of intracellular CTLA-4 and surface glucocorticoid-induced TNF receptor than fresh CD4+CD25+ T cells, but still failed to respond to TCR stimulation and inhibited proliferation of CD4+CD25- T cells. These results suggest that, in addition to suppressing cytokine transcription, Dex treatment is permissive for the survival of functional CD4+CD25+ T regulatory cells, and this property may contribute to the anti-inflammatory and immunosuppressive efficacy of glucocorticoids. Our data also suggest that selective protection of CD4+CD25+ T cell from apoptosis may constitute a role in immune tolerance for IL-2.
Basic Research Program, SAIC-Frederick, Inc., Frederick, USA.
Xin
X
Chen
Laboratory of Molecular Immunoregulation, Center for Cancer Research, National Cancer Institute-Frederick, Frederick, USA.
Takaya
T
Murakami
Laboratory of Molecular Immunoregulation, Center for Cancer Research, National Cancer Institute-Frederick, Frederick, USA.
Joost J
JJ
Oppenheim
Laboratory of Molecular Immunoregulation, Center for Cancer Research, National Cancer Institute-Frederick, Frederick, USA.
O M Zack
OMZ
Howard
D000818:Animals; D015703:Antigens, CD; D000943:Antigens, Differentiation / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000187:drug effects / Q000276:immunology*; D060908:CTLA-4 Antigen; D003907:Dexamethasone / Q000494:pharmacology*; D005260:Female; D053450:Glucocorticoid-Induced TNFR-Related Protein; D005938:Glucocorticoids / Q000494:pharmacology*; D016753:Interleukin-10 / Q000378:metabolism; D007376:Interleukin-2 / Q000494:pharmacology; D008213:Lymphocyte Activation / Q000187:drug effects; D051379:Mice; D008807:Mice, Inbred BALB C; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D011965:Receptors, Glucocorticoid / Q000378:metabolism; D015375:Receptors, Interleukin-2 / Q000032:analysis*; D017475:Receptors, Nerve Growth Factor / Q000378:metabolism; D018124:Receptors, Tumor Necrosis Factor / Q000378:metabolism; D013154:Spleen / Q000166:cytology / Q000187:drug effects / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000166:cytology / Q000187:drug effects / Q000276:immunology*; D013950:Thymus Gland / Q000166:cytology / Q000187:drug effects / Q000276:immunology
D015703:Antigens, CD; D000943:Antigens, Differentiation; D060908:CTLA-4 Antigen; C556707:Ctla4 protein, mouse; D053450:Glucocorticoid-Induced TNFR-Related Protein; D005938:Glucocorticoids; D007376:Interleukin-2; D019253:Proto-Oncogene Proteins c-bcl-2; D011965:Receptors, Glucocorticoid; D015375:Receptors, Interleukin-2; D017475:Receptors, Nerve Growth Factor; D018124:Receptors, Tumor Necrosis Factor; C106544:Tnfrsf18 protein, mouse; D016753:Interleukin-10; D003907:Dexamethasone