Melo Rossana C N, Spencer Lisa A, Dvorak Ann M, Weller Peter F
Laboratory of Cellular Biology, Department of Biology, Federal University of Juiz de Fora, MG, Brazil.
J Leukoc Biol. 2008 Feb;83(2):229-36. doi: 10.1189/jlb.0707503. Epub 2007 Sep 17.
Eosinophils generate and store a battery of proteins, including classical cationic proteins, cytokines, chemokines, and growth factors. Rapid secretion of these active mediators by eosinophils is central to a range of inflammatory and immunoregulatory responses. Eosinophil products are packaged within a dominant population of cytoplasmic specific granules and generally secreted by piecemeal degranulation, a process mediated by transport vesicles. Large, pleiomorphic vesiculotubular carriers were identified recently as key players for moving eosinophil proteins from granules to the plasma membrane for extracellular release. During secretion, these specialized, morphologically distinct carriers, termed eosinophil sombrero vesicles, are actively formed and direct differential and rapid release of eosinophil proteins. This review highlights recent discoveries concerning the organization of the human eosinophil secretory pathway. These discoveries are defining a broader role for large vesiculotubular carriers in the intracellular trafficking and secretion of proteins, including selective receptor-mediated mobilization and transport of cytokines.
嗜酸性粒细胞产生并储存一系列蛋白质，包括经典阳离子蛋白、细胞因子、趋化因子和生长因子。嗜酸性粒细胞快速分泌这些活性介质是一系列炎症和免疫调节反应的核心。嗜酸性粒细胞产物被包装在细胞质特异性颗粒的主要群体中，通常通过由运输小泡介导的逐片脱颗粒过程分泌。最近，大型、多形性囊泡管状载体被确定为将嗜酸性粒细胞蛋白从颗粒转运到质膜以进行细胞外释放的关键参与者。在分泌过程中，这些特殊的、形态上不同的载体，称为嗜酸性粒细胞宽边帽小泡，会被积极形成，并直接实现嗜酸性粒细胞蛋白的差异和快速释放。本综述重点介绍了有关人类嗜酸性粒细胞分泌途径组织的最新发现。这些发现正在确定大型囊泡管状载体在蛋白质的细胞内运输和分泌中的更广泛作用，包括细胞因子的选择性受体介导的动员和运输。
