MEROCYANINE DYES AS LEUKEMIA-SPECIFIC PROBES

该提案的长期目标是了解 生理和分子基础的特异性， 荧光染料Mercury 540（MC 540）显示白血病 细胞 染色的生理学基础似乎涉及 白血病细胞病理性滞留， 正常细胞的活化表型。 的分子基础 染色似乎存在于血浆的脂质双层中 膜的 本研究旨在探讨这一机制 控制双层是否被染色。 MC 540优先嵌入膜，其脂质 松散包装的 在红细胞中，脂质堆积依赖于 磷脂的跨双层分布， 依赖于脂质-细胞骨架的相互作用。 鬼 从正常红细胞制备的红细胞将被用作模型来检查 蛋白质修饰在控制这些相互作用中的作用。 将开发一种可光活化的脂质类似物，以确定 这些相互作用是否是通过调节 血影蛋白的细胞骨架网络的物理接近， 膜双层 质膜脂质的重要性 改变跨双层脂质分布的转运将是 评估。 这些研究的结果将与 用红细胞进行的类似实验的结果， 慢性粒细胞白血病患者，以确定 这些简单白血病染色的分子基础 细胞 最后，这些机制在控制 将对活化和非活化的正常白细胞进行染色， 作为建立白血病病变的第一步， 白细胞负责其染色。

The long-term objectives of the proposal are to understand both the physiological and molecular basis of the specificity which the fluorescent dye merocyanine 540 (MC540) displays for leukemia cells. The physiological basis of staining appears to involve the pathological retention by leukemia cells of an immature or activated phenotype of normal cells. The molecular basis of staining appears to reside in the lipid bilayer of the plasma membrane. This proposal is designed to investigate the mechanism controlling whether the bilayer is stained or not. MC540 preferentially intercalates into membranes whose lipids are loosely-packed. In erythrocytes, lipid packing is dependent on the transbilayer distribution of phospholipids, which in turn appears to be dependent on lipid-cytoskeletal interactions. Ghosts prepared from normal erythrocytes will be used as models to examine the role of protein modification in controlling these interactions. A photoactivable lipid analogue will be developed to determine whether these interactions are controlled by regulating the physical proximity of the spectrin cytoskeletal network to the membrane bilayer. The importance of plasma membrane lipid transport in altering transbilayer lipid distribution will be assessed. The results from these studies will be compared with results from similar experiments carried out with erythrocytes from patients with chronic myelogenous leukemia in order to determine the molecular basis for the staining of these simple leukemia cells. Finally, the role of these mechanisms in controlling the staining of activated and non-activated normal leukocytes will be evaluated as a first step in establishing the lesion in leukemic leukocytes responsible for their staining.