STRUCTURE AND FUNCTION OF THE I REGION GENES

主要组织相容性复合体II类抗原具有作为它们的一种 主要功能是将抗原呈递给T辅助细胞。 的 这些蛋白质在适当的细胞中表达，并在适当的时间， 对免疫系统的有效运作至关重要。 我们 主要的兴趣是研究编码MHCII类的基因是如何 抗原以细胞特异性方式和通过细胞因子调节。 这些基因调控的核心是转录的组装 位于基因上游的顺式作用元件上的因子。 为了 为了更好地了解这些因素是如何工作的，我们建议确定和 鉴定MHCII类基因的转录因子 表情 最初的目标将是确定DNA结合蛋白， MHC II类基因的上游区域，I-Abeta。 由于低 大量的这些蛋白质，我们设计了几种方法 来克隆这些DNA结合因子的基因 一旦基因 克隆，我们将能够产生足够数量的蛋白质， 更详细的蛋白质特征。 基本上，我们希望 为了了解这些DNA结合蛋白是否反映了 I-Abeta基因。 需要调查的可能变化包括 基因的剪接模式和磷酸化状态 proteins. 将测试发现的任何变化对 转录。 很可能存在与DNA结合相关的蛋白质 蛋白质通过蛋白质-蛋白质相互作用。 我们的第二个目标是 来识别这些类型的蛋白质。 的存在或不存在 表达MHC II类基因的细胞中的特定蛋白质可能提供新的 II类基因是如何调控的 如果我们看到一种蛋白质 仅在表达II类基因的细胞中表达，这种蛋白质将被 一个很好的候选人进一步表征。 我们还建议研究患者MHC II类基因的表达 缺乏MHC II类分子表达。 有可能 缺陷的基础在于转录因子。 我们开始 通过检测DNA结合蛋白的基因， 以任何缺陷为特征。 一个基因的激活区发生突变 这些蛋白质的表达可能足以彻底改变 II类基因 最后，我们将在转基因小鼠中测试各种I-Abeta构建体。 的 这些实验的设计是鉴定新的顺式作用元件， 对I-Abeta的发育调节表达很重要， 基因

The major histocompatibility complex class II antigens have as one of their primary functions the presentation of antigen to T helper cells. The expression of these proteins in the proper cells, and at the proper time, is critical for the effective functioning of the immune system. Our primary interest is to examine how the genes coding for the MHC class II antigens are regulated in both a cell specific manner and by cytokines. Central to the regulation of these genes is the assembly of transcription factors on the cis-acting elements located upstream of the genes. In order to better understand how these factors work, we propose to identify and characterize the transcription factors involved in MHC class II gene expression. The initial goal will be to identify DNA binding proteins that bind to the upstream region of the MHC class II gene, I-Abeta. Because of the low quantities of these proteins in cells, we have designed several approaches to clone the genes for these DNA binding factors. Once the genes have been cloned, we will be able to generate sufficient quantities of protein for a more detailed characterization of the proteins. Basically, we would like to know if these DNA binding proteins reflect the transcriptional activity of the I-Abeta gene. Possible changes to be investigated include the splicing pattern of the genes and the phosphorylation status of the proteins. Any change found will be tested for its influence on transcription. It is likely that there are proteins that associate with the DNA binding proteins via protein-protein interactions. A second goal of ours will be to identify these types of proteins. The presence or absence of a particular protein in cells that express MHC class II genes may provide new ideas on how the class II genes are regulated. If we see a protein expressed only in cells that express class II genes, this protein will be an excellent candidate for further characterization. We also propose to study the expression of MHC class II genes in patients with a deficiency in MHC class II expression. It is possible that the deficiency has its basis in a transcription factor. We will begin this study by examining the genes for the DNA binding proteins we have characterized for any defects. A mutation in the activation domain of one of these proteins may be sufficient to alter drastically the expression of the class II gene. Finally, we will test various I-Abeta constructs in transgenic mice. The design of these experiments is to identify new cis-acting elements that may be important for the developmentally regulated expression of the I-Abeta gene.