Kioussis Dimitris, Ellmeier Wilfried
Division of Molecular Immunology, National Institute for Medical Research, The Ridgeway, London NW7 1AA, UK.
Nat Rev Immunol. 2002 Dec;2(12):909-19. doi: 10.1038/nri952.
The regulation of gene expression during thymocyte development provides an ideal experimental system to study lineage-commitment processes. In particular, expression of the CD4, CD8A and CD8B genes seems to correlate well with the cell-fate decisions that are taken by thymocytes, and elucidating the molecular mechanisms that underlie the differential expression of these genes could reveal key events in differentiation processes. Here, we review examples of how gene cis elements (such as promoters, enhancers and locus control regions) and trans elements (such as transcription factors, chromatin-remodelling complexes and histone-modification enzymes) come together to orchestrate a finely tuned sequence of events that results in the complex pattern of CD4, CD8A and CD8B gene expression that is observed during thymocyte development.
胸腺细胞发育过程中的基因表达调控为研究细胞谱系定向过程提供了一个理想的实验系统。特别是，CD4、CD8A和CD8B基因的表达似乎与胸腺细胞所做出的细胞命运决定密切相关，阐明这些基因差异表达背后的分子机制可能会揭示分化过程中的关键事件。在这里，我们回顾了基因顺式元件（如启动子、增强子和基因座控制区）和反式元件（如转录因子、染色质重塑复合物和组蛋白修饰酶）如何共同作用，精心编排一系列精确调控的事件，从而导致在胸腺细胞发育过程中观察到的CD4、CD8A和CD8B基因表达的复杂模式。
