FUNCTION AND EXPRESSION OF LYB 2/CD72

LYB 2/CD72的功能和表达

• 批准号: 6312464
• 负责人: JANE R PARNES
• 金额: $ 6.66万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-07-01 至 2000-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6312464
• 关键词: B lymphocyte; calcium flux; cell differentiation; gene expression; genetic manipulation; genetic polymorphism; genetic regulatory element; genetically modified animals; immunoprecipitation; laboratory mouse; laboratory rat; monoclonal antibody; nucleic acid sequence; phosphatidylinositols; protein structure function; reporter genes; site directed mutagenesis; surface antigens; tissue /cell culture; transfection

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淋巴细胞系特异性细胞表面糖蛋白 在早期B细胞前体细胞上表达，直至成熟B细胞阶段。 在终末分化为浆细胞时表达丢失。LYB-2 似乎在B细胞的增殖和激活中起着重要的作用， 可能是淋巴因子或生长因子的受体。的主要目标是 这个项目将定义涉及到的分子机制 LYB-2的表达调控及进一步探讨其功能 蛋白质。LYB-2蛋白的结构会更好 以B细胞和转染体的免疫沉淀研究为特征。 将产生一组针对LYB-2的单抗，并 我们将研究它们对B细胞的功能影响。它的结构和 他的基因序列将被确定。表达的级别 该基因在不同的细胞类型和B细胞的不同阶段受到调控 我们将研究细胞发育，以及相关的分子机制。 表达LYB-2的谱系和阶段特异性将是 下定决心。这些研究将从组织培养细胞开始，在组织培养细胞中 正确表达所必需的LYB-2基因的序列 (即与LYB-2蛋白和mRNA相同的表达模式) 将确定转基因细胞中的报告基因。潜力 还将通过分析该基因来确定调控区域 表达LYB-2 AS的细胞中DNA酶敏感部位的差异 与不具有这种功能的细胞相比。识别出的序列的重要性将 通过定点突变得到确认。届时将对LYB-2进行监管 在转基因小鼠身上进行了检测。这些研究的目的是确定两者 利用LYB-2自身正确表达所需的序列 控制序列，以及不适当表达 通过使用其他基因的控制区而产生的蛋白质，如 免疫球蛋白、T细胞受体和β-肌动蛋白。例如，Will 利用免疫球蛋白在B系细胞中持续表达LYB-2 启动子和增强子，导致TO中缺乏或适当的B细胞分化 抗体分泌细胞？这种持续表达会不会导致B细胞 肿瘤？同样，如果LYB-2是一种生长因子或淋巴因子受体， T细胞或其他不适当细胞上的表达是否会导致肿瘤 因为持续的增长刺激而发展？这些研究应该 加深对B细胞正常调控机制的认识 增殖和分化以及这些细胞的异常 在B细胞肿瘤和自身免疫性疾病中观察到的通路。