GLYCOSPHINGOLIPIDS IN ONCOGENESIS AND DIFFERENTIATION

我们以前的工作主要集中在结构表征 人类白细胞和白血病细胞抗原。 我们建立 人类白细胞表达谱系特异性鞘糖脂 抗原，并且几种白细胞特异性单克隆抗体 与鞘糖脂携带的碳水化合物序列结合。 的 两个复杂的骨髓特异性 由这些抗体识别的鞘糖脂抗原具有 最近被确定。 最后，白血病的存在- 相关的鞘糖脂抗原GD 3也被 确立了习 在当前的提案中，我们将通过使用 包括TLC在内的生化和化学技术 用碳水化合物序列特异性单克隆抗体免疫染色 抗体和快速原子轰击质谱法（FAB/MS）， 以确定其他鞘糖脂抗原的结构 其携带由骨髓特异性抗体识别的表位， Vim-8 通过这些技术和结合了 薄层色谱的分离能力与灵敏度 的FAB/MS，我们建议获得结构信息的高度 复合骨髓特异性（Vim-2）神经节苷脂。 我们亦建议 实验来测量活性和特异性， 合成白细胞的糖基转移酶， 特异性和白血病相关的鞘糖脂抗原， 之前已经被确认。 一种新的基于抗体的ELISA方法 程序将用于确定表达水平， 这些糖基转移酶在正常人白细胞和白血病 细胞 这些拟议的实验将（1）提供以下信息 正常人白细胞表面标志物的结构 和白血病细胞，和（2）建立其酶的基础， 生物合成 需要这些基本信息来确定 导致特定细胞表达的机制 正常分化和白血病发生过程中的表面标记。

Our previous work has focused on the structural characterization of human leukocyte and leukemia cell antigens. We have established that human leukocytes express lineage-specific glycosphingolipid antigens, and that several leukocyte-specific monoclonal antibodies bind to carbohydrate sequences carried by glycosphinoglipids. The complete structures of two complex myeloid-specific glycosphingolipid antigens recognized by these antibodies have recently been determined. Finally, the existence of a leukemia- associated glycosphingolipid antigen, GD3, has also been established. In the current proposal, we will extend this work by using biochemical and chemical techniques which include TLC immunostaining with carbohydrate sequence-specific monoclonal antibodies and fast atom bombardment mass spectrometry (FAB/MS), to determined the structure of other glycosphingolipid antigens that carry the epitope recognized by the myeloid-specific antibody, VIM-8. With these techniques and a procedure that combines the resolving power of thin-layer chromatography with the sensitivity of FAB/MS, we propose to obtain structural information on highly complex myeloid-specific (VIM-2) gangliosides. We also propose experiments to measure the activity and specificity of glycosyltransferases which synthesize the leukocyte, lineage- specific and leukemia-associated glycosphingolipid antigens that have previously been identified. A new antibody-based ELISA procedure will be used to determine the level of expression of these glycosyltransferases in normal human leukocytes and leukemia cells. These proposed experiments will (1) provide information on the structures of cell surface markers of normal human leukocytes and leukemia cells, and (2) establish the enzymatic basis for their biosynthesis. This fundamental information is needed to determine the mechanisms which lead to the expression of specific cell surface markers during normal differentiation and leukemogenesis.