Role of GATA-3 During CD4/CD8 Lineage Commitment

描述（由申请人提供）：在这项资助中，我们提出了一些旨在详细了解转录因子加塔-3在胸腺中CD 4/CD 8谱系定型过程中的作用的实验。我们最近发现加塔-3在发育成CD 4谱系的未成熟胸腺细胞中差异表达，并且通过修饰胸腺中的加塔-3活性，我们可以偏向谱系定型。我们现在将： 使用功能获得/功能丧失遗传学方法来鉴定正常DP胸腺细胞中参与此过程的信号转导途径，剖析调节胸腺中TCR诱导的加塔-3上调的机制。 使用重组胎儿胸腺器官培养物（rFTOC）、慢病毒转基因和不同的加塔-3突变体，以绘制加塔-3在CD 4/CD 8谱系定型过程中发挥作用所需的结构区域。 分析加塔-3与两种转录因子Egr-2和Lmo-4的相互作用，我们已经在全基因组筛选中鉴定出这两种转录因子优先在CD 4谱系中间体中表达。 这些研究将使我们更好地了解控制CD 4/CD 8谱系定型的机制，更广泛地说，将提供有关在胸腺中建立细胞命运决定和发育程序的遗传网络的线索。

DESCRIPTION (provided by applicant): In this grant we propose a number of experiments aimed at understanding in detail the role of the transcription factor GATA-3 during CD4/CD8 lineage commitment in the thymus. We have recently shown that GATA-3 is differentially expressed in immature thymocytes that develop into the CD4 lineage, and that by modifying GATA-3 activity in the thymus we can bias lineage commitment. We will now: Dissect the mechanisms that regulate TCR-induced GATA-3 upregulation in the thymus, using a gain-of function/loss-of-function genetic approach to identify the signal transduction pathways involved in this process in normal DP thymocytes. Use reaggregate fetal thymic organ culture (rFTOC), lentiviral transgenesis and different GATA-3 mutants to map the structural regions of GATA-3 required for its effect during CD4/CD8 lineage commitment. Analyze the interactions of GATA-3 with two transcription factors, Egr-2 and Lmo-4, that we have identified as preferentially expressed in CD4 lineage intermediates in a genome-wide screen. These studies should provide us with a better understanding of the mechanisms that control CD4/CD8 lineage commitment, and, more widely, will provide clues about the genetic networks that establish cell fate determination and developmental programs in the thymus.