The role of the Ets2 transcription factor in the proliferation, maturation, and survival of mouse thymocytes.
In this study, we investigated the effects of Ets2 expression on the proliferation, maturation, and survival of thymocytes by establishing transgenic mice that specifically express Ets2 or a dominant negative form of Ets2, Deltaets2, in the thymus. We show that, in young animals, there are fewer T cells in Deltaets2 transgenic thymi and that the maturation of these T cells is affected at the CD4(-)CD8(-) double-negative to CD4(+)CD8(+) double-positive transition compared with wild-type littermate mice. Partial recovery in the number of thymocytes and full T cell maturation are restored with increasing age of Deltaets2 transgenic animals. However, thymocytes from adult Deltaets2 transgenic mice cultured ex vivo are more sensitive to cell death and to glucocorticoid-induced apoptosis than are T cells from control littermate mice. We also show that T cells from adult ets2 transgenic mice proliferate faster than their wild-type littermates. The proliferation and survival of these T cells are clearly affected upon apoptotic signals: glucocorticoid-induced apoptosis induces T cells from ets2 transgenic mice to continue to proliferate in vivo and to survive better ex vivo than T cells from control littermates. It has been shown that c-Myc expression is required for thymic proliferation and improves thymocyte survival of dexamethasone-treated animals. We show that the expression of c-Myc, an Ets2 target, is elevated in T cells freshly isolated from thymi of ets2 transgenic mice pretreated with dexamethasone. Together, these results show that Ets2 plays a role in the proliferation and survival of thymocytes, implicating a Myc-dependent pathway.
Zaldumbide
Arnaud
A
Institute of Signaling, Developmental Biology and Cancer Research, Center de Biochimie, Université de Nice, Parc Valrose, France.
Carlotti
Françoise
F
Pognonec
Philippe
P
Boulukos
Kim E
KE
D000818:Animals; D000831:Animals, Newborn / Q000235:genetics / Q000276:immunology; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics / Q000276:immunology; D002454:Cell Differentiation / Q000187:drug effects / Q000235:genetics / Q000276:immunology; D002455:Cell Division / Q000187:drug effects / Q000235:genetics / Q000276:immunology; D002470:Cell Survival / Q000187:drug effects / Q000235:genetics / Q000276:immunology; D002478:Cells, Cultured; D004268:DNA-Binding Proteins; D003907:Dexamethasone / Q000494:pharmacology; D005260:Female; D016259:Genes, myc / Q000187:drug effects / Q000276:immunology; D006801:Humans; D018655:Lymphocyte Count; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D050787:Proto-Oncogene Protein c-ets-2; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D012097:Repressor Proteins; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000166:cytology* / Q000187:drug effects / Q000276:immunology*; D013950:Thymus Gland / Q000166:cytology* / Q000187:drug effects / Q000276:immunology*; D015534:Trans-Activators / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D014157:Transcription Factors; D019076:Transgenes / Q000187:drug effects / Q000276:immunology; D015854:Up-Regulation / Q000187:drug effects / Q000235:genetics / Q000276:immunology
D004268:DNA-Binding Proteins; C107465:ERF protein, human; C494069:ETS2 protein, human; C494070:Ets2 protein, mouse; D050787:Proto-Oncogene Protein c-ets-2; D011518:Proto-Oncogene Proteins; D012097:Repressor Proteins; D015534:Trans-Activators; D014157:Transcription Factors; D003907:Dexamethasone