CYTOPLASMIC LIPID BODIES OF INFLAMMATORY CELLS

人体细胞对花生四烯酸的代谢产生了大量的 类二十烷酸衍生物不仅对内源性 细胞的功能，但也作为炎症和免疫的介质。 这项拟议的研究将调查脂质体的作用， 人嗜酸性粒细胞和嗜酸性粒细胞对花生四烯酸的代谢 白细胞 脂质体是非膜结合的，大致呈球形 可通过光和透射识别的细胞质内含物 电子显微镜在各种类型的细胞。 虽然被认为是 由脂质组成，这些细胞内的性质和功能 结构是未知的。 最近的研究表明，这些脂质 体，当细胞参与时，体内的数量增加， 炎症反应，在摄取和掺入 花生四烯酸 为了确定脂质体在细胞凋亡中的作用， 花生四烯酸的代谢，亚细胞分级分离的方法将 开发用于从人嗜中性粒细胞中分离脂质体， 嗜酸性粒细胞 脂质体的脂质和蛋白质含量从纯化的 将确定这两种类型的白细胞。 此外，使用 纯化的，分离的脂质体，参与脂质体的酶的存在， 花生四烯酸的酯化，花生四烯酸从 磷脂和类二十烷酸衍生物的产生，特别是 白三烯C4（嗜酸性粒细胞）和B4（中性粒细胞）， 将评估花生四烯酸。 利用纯化的人嗜酸性粒细胞 和中性粒细胞，这些细胞中脂质体的形成将是 体外诱导，放射性标记的 将评估磷脂前体和脂肪酸进入脂质体的能力 通过电子显微镜放射自显影和中性分析， 分离的脂质体中的脂质和磷脂。 的存在 这些诱导脂质体中的白三烯和其它类二十烷酸将被 评估。 这些研究将确定细胞质脂质的组成 这两个白细胞中的抗体，并将评估以前的 脂质体在花生四烯酸代谢中的作用 这些细胞。 由于脂质体存在于许多不同的细胞中， 研究，除了评估这些细胞质的功能， 粒细胞生成类花生酸介质中的内含物 炎症和免疫，可能阐明了更普遍的作用，这些 花生四烯酸代谢中经常被忽视的细胞器。

The metabolism of arachidonic acid by human cells generates a number of eicosanoid derivatives that may be of importance not only to the endogenous functioning of cells but also as mediators of inflammation and immunity. The proposed research will investigate the role of lipid bodies in the metabolism of arachidonic acid by human neutrophilic and eosinophilic leukocytes. Lipid bodies are non-membrane bound, roughly spherical cytoplasmic inclusions that may be identified by light and transmission electron microscopy in a variety of cell types. Although believed to be composed of lipid, the nature and function of these intracellular structures have been unknown. Recent findings indicate that these lipid bodies, which increase in number in vivo when cells are involved in inflammatory reactions, are active in the uptake and incorporation of arachidonic acid. In order to define the role of lipid bodies in the metabolism of arachidonic acid, methods of subcellular fractionation will be developed to isolate lipid bodies from human neutrophils and eosinophils. The lipid and protein content of lipid bodies purified from these two types of leukocytes will be determined. In addition, using purified, isolated lipid bodies, the presence of enzymes involved in the esterification of arachidonic acid, the release of arachidonic acid from phospholipids and in the generation of eicosanoid derivatives, especially leukotrienes C4 (for eosinophils) and B4 (for neutrophils), from arachidonic acid will be evaluated. Utilizing purified human eosinophils and neutrophils, the formation of lipid bodies in these cells will be induced in vitro, and the temporal incorporation of radiolabeled phospholipid precursors and fatty acids into lipid bodies will be evaluated both by electron microscopic autoradiography and by analyses of neutral lipids and phospholipids in isolated lipid bodies. The presence of leukotrienes and other eicosanoids in these induced lipid bodies will be assessed. These studies will define the composition of cytoplasmic lipid bodies in these two leukocytes and will evaluate the previously unappreciated role of lipid bodies in the metabolism of arachidonic acid by these cells. Because lipid bodies are found in many different cells, these studies, in addition to assessing the function of these cytoplasmic inclusions in granulocyte generation of eicosanoid mediators pertinent to inflammation and immunity, may elucidate a more general role for these often overlooked organelles in cellular arachidonic acid metabolism.