REGULATION OF MACROPHAGE DEVELOPMENT

白细胞分化受荷尔蒙样因子控制， 采取行动调控复杂的基因表达模式。多例白血病 从粒细胞或单核/巨噬细胞分离的细胞系 维甲酸和佛波酯。巨噬细胞发育的各个方面 通过确定分化剂对细胞生长的影响来研究 基因在刺激细胞系中的表达。5-和15- 脂氧合酶(5-LO，15-LO)酶是在成熟的巨噬细胞和 从花生四烯酸中产生白三烯和脂素。发展中的 5-LO和15-LO基因的调节将通过寻找 HL-60、THP-1和U-937细胞治疗后基因表达的变化 使用了差异化试剂。5-LO和15-LO的mRNA水平将是 用Northern杂交和核糖核酸酶保护进行测定 化验。建议进行核运行研究，以研究5-LO和 15-LO转录起始。基因文库的筛选策略 从刺激细胞中的信使核糖核酸衍生出来的基因被建议用来鉴定一个网络 维甲酸和佛波酯诱导的基因。具体的 在分化细胞中激活的cdna克隆最初将 以序列分析和确定组织特异性为特征的 表情。针对这些cDNA编码的多肽产生的抗血清将是 用于免疫荧光研究以确定亚细胞定位。 将对选定的克隆进行进一步分析以确定其功能角色 在正常和病理状态下的巨噬细胞中。的子集 小鼠单核细胞源性泡沫细胞中表达的克隆 动脉粥样硬化病变将被评估其可能的功能 在动脉粥样硬化形成的过程中发挥作用。实验性的操控 改变单个克隆的表达或干扰其蛋白质 将测试产品对巨噬细胞发育的影响， 泡沫中巨噬细胞特性和低密度脂蛋白代谢的表达 细胞。

White blood cell differentiation is controlled by hormone like factors that act to regulate complex patterns of gene expression. A number of leukemia cell lines from the granulocyte or monocyte/macrophage with agents such as retinoic acid and phorbol esters. Aspects of macrophage development will be studied by determining the effects of differentiating agents on the expression of genes in the stimulated cell lines. The 5- and 15- lipoxygenase (5-LO, 15-LO) enzymes are produced in mature macrophages and produce leukotrienes and lipoxins from arachadonic acid. The developmental regulation of the 5-LO and 15-LO genes will be investigated by looking for variable gene expression in HL-60, THP-1, and U-937 cells after treatment with differentiating agents. Levels of 5-LO and 15-LO mRNA will be measured using Northern blot hybridization and ribonuclease protection assays. Nuclear run on studies are proposed to study the rates of 5-LO and 15-LO transcription initiation. Screening strategies for cDNA libraries derived from mRNA in stimulated cells are proposed to identify a network of genes that are induced by retinoic acid and phorbol esters. The specific cDNA clones activated in differentiated cells will be initially characterized by sequence analysis and determining tissue specific expression. Antisera raised against peptides coded by these cDNAs will be used in immunofluorescence studies to determine subcellular localization. Selected clones will be further analyzed to identify their functional roles in macrophages involved in normal and pathologic conditions. The subset of clones expressed in monocyte derived foam cells isolated from atherosclerotic lesions will be assessed for the functions they might perform in the process of atherogenesis. Experimental manipulations that alter the expression of individual clones or interfere with their protein products will be tested for their effects on macrophage development, the expression of specific macrophage properties, and LDL metabolism in foam cells.