TRANSCRIPTIONAL CONTROL OF HUMAN T CELL RECEPTOR GENES

描述（改编自申请人的摘要）：正常 需要T淋巴细胞的发育和活化， 宿主对病毒和肿瘤病原体的适当反应，以及 防止宿主组织的自身免疫性破坏。 前四 在该R 01的10年中，申请人使用TCR α和β基因作为 识别和表征转录因子的模型系统 参与调节T细胞发育和激活。 这些研究 已经允许鉴定几种新的转录因子 在调节T细胞中发挥重要作用的家族， 特异性基因表达 这些包括Ets原癌基因， 加塔锌指蛋白和碱性亮氨酸的CREB/ATF家族 拉链转录因子 至少有5种Ets蛋白 在T细胞中表达：Ets-1、Elf-1、Fli-1、Ets-2和GABPa。 的 现有证据表明，淋巴限制因子Ets-1 在调节基因表达方面起着重要作用， 发育中的胸腺细胞和静息T细胞中的TCR α和β。 在 相比之下，Elf-1似乎在调节一组 包括GM-CSF、IL-3、IL-2 R α， HIV-2。 申请人先前的研究表明，Elf-1是 在至少3个翻译后水平调节：（i）通过激活- 特异性磷酸化，这是其DNA结合所必需的 活性，（ii）通过与特异性AP 1和NF-κ B的协同结合 转录因子，和（iii）通过调节的相互作用， 视网膜母细胞瘤（Rb）基因产物或相关口袋蛋白。 Elf-1 似乎代表了激活特异性基因 表达和T细胞中的细胞周期进展。 类似的还有 至少6种ATF/CREB蛋白在T细胞中表达。 以前的研究 已经表明这些蛋白质在调节 TCR α和β基因的表达，以及在控制 激活特异性表达的分子，如增殖的 细胞核抗原（PCNA）是细胞周期中必不可少的 T细胞活化后的进展。 在研究中， 在本申请中，建议使用遗传和 为了更精确地阐明Ets-1的作用， Elf-1和CREB/ATF转录因子调节T细胞发育 和激活。 具体而言，计划（一）阐明 T细胞活化后Elf-1活化的分子基础，（ii） 在小鼠中产生Ets-1和Elf-1的靶向破坏，并研究其 对T细胞发育和活化的影响，和（iii）使用转基因 过表达CREB转录的显性阴性形式的小鼠 因子，以更好地确定CREB/ATF蛋白在调节T细胞中的作用。 细胞发育和活化。 这些研究应该具有重要意义。 对我们理解Ets和CREB/ATF作用的影响 转录因子在调节T细胞发育和 功能 此外，它们可能有助于阐明 参与协调调节基因表达和细胞 响应于受体介导的信号传导事件的周期进展。

DESCRIPTION (Adapted from the applicant's abstract): The normal development and activation of T lymphocytes are required both to ensure appropriate host responses to viral and neoplastic pathogens, and to prevent autoimmune destruction of host tissues. During the first four years of this R01 the applicant used the TCR alpha and beta genes as model systems to identify and characterize the transcription factors involved in regulating T cell development and activation. These studies have allowed the identification of several novel transcription factor families that appear to play important roles in regulating T cell- specific gene expression. These include the Ets protooncogenes, the GATA zinc finger proteins, and the CREB/ATF family of basic-leucine zipper transcription factors. There are at least 5 Ets proteins expressed in T cells: Ets-1, Elf-1, Fli-1, Ets-2, and GABPalpha. The available evidence suggests that the lymphoid-restricted factor, Ets-1 plays an important role in regulating the expression of genes such as TCR alpha and beta in developing thymocytes and resting T cells. In contrast, Elf-1 appears to play an important role in regulating a set of activation-specific T cell genes including GM-CSF, IL-3, IL-2Ralpha, and HIV-2. The applicant's previous studies have shown that Elf-1 is regulated at at least 3 post-translational levels: (i) by activation- specific phosphorylation, which is required for its DNA binding activity, (ii) by cooperative binding with specific AP1 and NF- kappaB transcription factors, and (iii) by regulated interactions with the retinoblastoma (Rb) gene product or related pocket proteins. Thus, Elf-1 appears to represent a functional link between activation-specific gene expression and cell cycle progression in T cells. Similarly, there are at least 6 ATF/CREB proteins expressed in T cells. Previous studies have suggested important roles for these proteins in regulating the expression of the TCR alpha and beta genes, and in controlling the activation-specific expression of molecules such as the proliferating cell nuclear antigen (PCNA), which is essential for cell cycle progression following T cell activation. In the studies described in this application, it is proposed to use a combination of genetic and biochemical approaches to more precisely elucidate the roles of Ets-1, Elf-1 and CREB/ATF transcription factors in regulating T cell development and activation. Specifically it is planned to (i) elucidate the molecular basis of Elf-1 activation following T cell activation, (ii) produce targeted disruptions of Ets-1 and Elf-1 in mice and study their effects on T cell development and activation, and (iii) use transgenic mice overexpressing a dominant-negative form of the CREB transcription factor to better define the role of CREB/ATF proteins in regulating T cell development and activation. These studies should have important implications regarding our understanding of the role of Ets and CREB/ATF transcription factors in regulating both T cell development and function. In addition, they may help to shed light on the molecular mechanisms involved in coordinately regulating gene expression and cell cycle progression in response to receptor-mediated signaling events.