Molecular characterization of thymic epithelium

描述(申请人提供)：基于父母申请支持的关于成纤维细胞生长因子家族成员在胸腺上皮(TE)发育和功能中的作用的工作，我们提出了一个假设，即多潜能咽内胚祖细胞持续存在于成人胸腺和其他内皮源性器官和组织中。在胸腺内，这些细胞将在维持髓质上皮细胞异质性方面发挥核心作用，而在胸腺外、内皮源性组织中，这些祖细胞可以保持支持胸腺生成环境的能力。由于胸腺和其他上皮组织中上皮细胞的混合性质，传统的基因表达分析方法是不可行的，原位方法过于费力和时间密集，无法快速检测大量基因的表达，而且后一种方法不能识别新的或意外的基因产物。这里提出的活动将开发必要的基础设施和实验方法，以检验这一假说的几个假设。具体地说，我们希望使用激光捕获显微切割来恢复胸腺组织成分，并利用回收的RNA来探测胸腺上皮特定区段的基因表达谱。这种方法已经成功地用于胸腺环境的几个研究，从而说明了该方法的实用性，但由于所需仪器的新颖性，该方法尚未得到广泛应用。这一应用程序需要支持，以带来最先进的技术来探索胸腺微环境的特征和调节。所获得的信息可能为胸腺生物学的几个重要领域提供新的见解，包括胸腺上皮发育的调节，而胸腺上皮发育可能在维持自身耐受和控制与年龄相关的胸腺退化方面发挥核心作用。

DESCRIPTION (provided by applicant): Based on work supported by the parent application concerning the role of FGF family members in thymic epithelium (TE) development and function, we have proposed the hypothesis that multi-potential pharyngeal endodermal progenitor cells persist within the adult thymus and in other endodermally-derived organs and tissues. Within the thymus, these cells would play a central role in maintaining medullary epithelial heterogeneity, while in extrathymic, endodermally-derived tissues, these progenitor cells could retain the capacity to support thymopoietic environments. Because of the commingled nature of the epithelia within the thymus and in other epithelial tissues, traditional approaches to analyze gene expression are not feasible and in situ approaches are too labor and time intensive to rapidly survey the expression of a large number of genes, Furthermore, this latter approach would not identify novel or unanticipated gene products. The activities proposed here will develop the infrastructure and experimental approaches necessary to test several postulates of this hypothesis. Specifically, we wish to employ laser capture micro-dissection to recover thymic tissue components and to utilize the recovered RNA to probe the profiles gene expression by defined compartments of thymic epithelium. This approach has been used successfully in several studies of the thymic environment, thus speaking to the utility of the approach, but has not been widely employed due to the novelty of the required instrumentation. This application requests support to bring state-of the art technologies to explore the character and regulation of the thymic microenvironment. The information gained is likely to provide new insight into several important areas of thymus biology, including the regulation of thymic epithelial development, which in turn is likely to be centrally involved in the maintenance of self tolerance and the control of age-related thymic involution.