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FUNCTION AND EXPRESSION OF LYB-2

LYB-2的功能和表达

基本信息

批准号：
2065482
负责人：
JANE R PARNES
金额：
$ 23.4万
依托单位：
STANFORD UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
1990
资助国家：
美国
起止时间：
1990-07-01 至 1995-04-30
项目状态：
已结题

项目摘要

Lyb-2 is a B lymphocyte lineage-specific cell surface glycoprotein expressed on early B cell precursors through the stage of mature B cells. Expression is lost upon terminal differentiation into plasma cells. Lyb-2 appears to play an important role in B cell proliferation and activation, and may be a receptor for a lymphokine or growth factor. The major goal of this project will be to define the molecular mechanisms involved in the regulation of expression of Lyb-2 and to further explore the function of the protein. The structure of the Lyb-2 protein will be better characterized by immunoprecipitation studies of B cells and transfectants. A panel of monoclonal antibodies specific for Lyb-2 will be generated and their functional effects upon B cells will be examined. The structure and sequence of he gene will be determined. The level at which expression of the gene is regulated in different cell types and at different stages of B cell development will be examined, and the molecular mechanisms involved int he lineage and stage specificity of expression Lyb-2 will be determined. These studies will begin in tissue culture cells, where the sequence from the Lyb-2 gene that are necessary for proper expression (i.e., the same pattern of expression as Lyb-2 protein and mRNA) of a reporter gene in transfected cells will be determined. Potential regulatory regions will also be identified by analyzing the gene for differences in DNAse hypersensitive sites in cells that express Lyb-2 as compared to cells that do not. The importance of identified sequences will be confirmed by site-specific mutagenesis. Lyb-2 regulation will then be examined in transgenic mice. The aim of these studies is to determine both the sequences necessary for proper expression of Lyb-2 using its own control sequences, and the consequences of inappropriate expression of the protein resulting from use of control regions of other genes, such as immunoglobulins, T cell receptor and beta-actin. For example, will continued expression of Lyb-2 in B lineage cells, using an immunoglobulin promoter and enhancer, lead to lack or proper B cell differentiation in to antibody-secreting cells? Will such continued expression lead to B cell tumors? Similarly, if Lyb-2 is a growth factor or lymphokine receptor, will expression on T cells or other inappropriate cells lead to tumor development because of continued growth stimulation? These studies should enhance our understanding of the normal mechanisms of control of B cell proliferation and differentiation as well as the abnormalities in these pathways that are observed in B cell neoplastic and autoimmune diseases.

Lyb-2 是一种 B 淋巴细胞谱系特异性细胞表面糖蛋白在成熟 B 细胞阶段的早期 B 细胞前体上表达。表达在终末分化为浆细胞时丢失。 LYB-2 似乎在 B 细胞增殖和激活中发挥重要作用，并且可以是淋巴因子或生长因子的受体。主要目标是该项目将定义涉及的分子机制 Lyb-2表达调控并进一步探讨其功能蛋白质。 Lyb-2蛋白的结构会更好以 B 细胞和转染子的免疫沉淀研究为特征。将生成一组针对 Lyb-2 的单克隆抗体，并将检查它们对 B 细胞的功能影响。结构和 he基因的序列将被确定。的表达水平该基因在不同细胞类型和 B 的不同阶段受到调节将检查细胞发育，以及所涉及的分子机制 Lyb-2 表达的谱系和阶段特异性将是决定。这些研究将从组织培养细胞开始，其中 Lyb-2 基因中正确表达所必需的序列（即与 Lyb-2 蛋白和 mRNA 的表达模式相同）转染细胞中的报告基因将被确定。潜在的还将通过分析基因来确定调控区域表达 Lyb-2 的细胞中 DNAse 超敏感位点的差异与没有的细胞相比。已识别序列的重要性可以通过位点特异性诱变来确认。 Lyb-2 调节将是在转基因小鼠中进行了检查。这些研究的目的是确定使用自己的 Lyb-2 正确表达所需的序列控制序列，以及不当表达的后果使用其他基因的控制区域产生的蛋白质，例如免疫球蛋白、T 细胞受体和 β-肌动蛋白。例如，将使用免疫球蛋白在 B 谱系细胞中持续表达 Lyb-2 启动子和增强子，导致 B 细胞分化缺乏或正确抗体分泌细胞？这样的持续表达会导致B细胞吗？肿瘤？同样，如果 Lyb-2 是生长因子或淋巴因子受体， T细胞或其他不适当的细胞上的表达是否会导致肿瘤发展是因为持续的增长刺激？这些研究应该增强我们对 B 细胞控制正常机制的理解增殖和分化以及这些方面的异常在 B 细胞肿瘤和自身免疫性疾病中观察到的途径。