| Autor: |
Raaphorst FM; Department of Pathology, Vrÿe Universiteit University Hospital, Amsterdam, The Netherlands. fm.raaphorst@azvu.nl, Otte AP, van Kemenade FJ, Blokzijl T, Fieret E, Hamer KM, Satijn DP, Meijer CJ |
| Jazyk: |
angličtina |
| Zdroj: |
Journal of immunology (Baltimore, Md. : 1950) [J Immunol] 2001 May 15; Vol. 166 (10), pp. 5925-34. |
| DOI: |
10.4049/jimmunol.166.10.5925 |
| Abstrakt: |
BMI-1 and EZH2 Polycomb-group (PcG) proteins belong to two distinct protein complexes involved in the regulation of hematopoiesis. Using unique PcG-specific antisera and triple immunofluorescence, we found that mature resting peripheral T cells expressed BMI-1, whereas dividing blasts were EZH2(+). By contrast, subcapsular immature double-negative (DN) (CD4(-)/CD8(-)) T cells in the thymus coexpressed BMI-1 and EZH2 or were BMI-1 single positive. Their descendants, double-positive (DP; CD4(+)/CD8(+)) cortical thymocytes, expressed EZH2 without BMI-1. Most EZH2(+) DN and DP thymocytes were dividing, while DN BMI-1(+)/EZH2(-) thymocytes were resting and proliferation was occasionally noted in DN BMI-1(+)/EZH2(+) cells. Maturation of DP cortical thymocytes to single-positive (CD4(+)/CD8(-) or CD8(+)/CD4(-)) medullar thymocytes correlated with decreased detectability of EZH2 and continued relative absence of BMI-1. Our data show that BMI-1 and EZH2 expression in mature peripheral T cells is mutually exclusive and linked to proliferation status, and that this pattern is not yet established in thymocytes of the cortex and medulla. T cell stage-specific PcG expression profiles suggest that PcG genes contribute to regulation of T cell differentiation. They probably reflect stabilization of cell type-specific gene expression and irreversibility of lineage choice. The difference in PcG expression between medullar thymocytes and mature interfollicular T cells indicates that additional maturation processes occur after thymocyte transportation from the thymus. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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