MORPHOLOGICAL ANALYSIS OF SPECIFIC ULTRASTRUCTURES OF THE CELL MEMBRANE FORMED IN CELL-TO-CELL CONTACT ASSOCIATED WITH IMMUNOLOGICAL REACTION

1992 ~ 1994年开展的“免疫反应中血管内皮细胞与白细胞相互作用的超微结构分析”项目，取得了如下结果：在原位肝移植和淋巴结移植中，白细胞与内皮细胞相互作用活跃;结果表明，两种细胞均形成了特异的超微结构，如细胞膜的高密度和丝状桥。与这些现象相关的内皮细胞具有发达的高尔基体，这导致了糖蛋白在这种相互作用中起重要作用的想法。该方法的特点之一是电镜制备的免疫反应在固定前在器官保存液UW中完成。结果表明，细胞间粘附分子（ICAM-1）仅表达于高内皮微静脉（HEV）细胞的突起和皱褶中。这些结构与ICAM-1结合后，可以捕获淋巴细胞，因为淋巴细胞经常落入褶皱之间的沟道中并粘附在褶皱上。最后，作为本项目的一个结论，虽然体内免疫反应中的细胞与细胞的相互作用是通过粘附分子的相互作用来完成的，但细胞膜的超微结构变化促进了这种相互作用。为了理解细胞间相互作用的动力学，不仅需要知道分子是否表达，而且需要知道它们在一个细胞中三维表达的位置。

The project as to ultrastructural analysis of the interaction between vascular endothelial cells and leukocytes in immunological reaction, which had been carried out from 1992 to 1994, has produced the following results.In orthotopic liver transplantation and lymph node transplantation, leukocytes interacted with endothelial cells actively. It was folloewed by formation of specific ultrastructures in both cells, e.g.filamentous bridges and high density of the cell membrane. Endothelial cells, which were associated with these phenomena, are characterized by well developed Golgi apparatus, which leads to the idea that glycoproteins play an important role in this interacion.To detect glycoproteins, e.g.adhesion molecules immunohistochemically and three-dimensionally, a new method is developed here. One feature of this method was that immunoreaction for EM (electron microscopy) preparation is finished in UW solution, organ preserving solution, before fixation. After the reaction, usual treatment for EM is possible and has guaranteed simultanous comparison between transmission EM and scanning EM and good preservation of ultrastrucure as well.The method disclosed that intercellular adhesion molecule (ICAM-1) expressed exclusively in processes and folds of high endothelial venule (HEV) cells. These structures combined with ICAM-1 functioned to trap lymphocytes, because lymphocytes often dropped into the furrows between folds and adhered to them.Finally as one conclusion from this project, though cell-to-cell interaction in in vivo immunological reaction is accomplished through interaction of adhesion molecules, ultarastructural changes of the cell membrane promate this interaction. To understand dynamism of cell-to-cell interaction, it is necessary to know not only whether molecules express or not, but also where they express in one cell three-dimensionally.