title: Vesicular trafficking of immune mediators in human eosinophils revealed by immunoelectron microscopy.
abstract: Electron microscopy (EM)-based techniques are mostly responsible for our current view of cell morphology at the subcellular level and continue to play an essential role in biological research. In cells from the immune system, such as eosinophils, EM has helped to understand how cells package and release mediators involved in immune responses. Ultrastructural investigations of human eosinophils enabled visualization of secretory processes in detail and identification of a robust, vesicular trafficking essential for the secretion of immune mediators via a non-classical secretory pathway associated with secretory (specific) granules. This vesicular system is mainly organized as large tubular-vesicular carriers (Eosinophil Sombrero Vesicles - EoSVs) actively formed in response to cell activation and provides a sophisticated structural mechanism for delivery of granule-stored mediators. In this review, we highlight the application of EM techniques to recognize pools of immune mediators at vesicular compartments and to understand the complex secretory pathway within human eosinophils involved in inflammatory and allergic responses.
authors: Laboratory of Cellular Biology, Department of Biology, ICB, Federal University of Juiz de Fora, UFJF, Rua José Lourenço Kelmer, Juiz de Fora, MG 36036-900, Brazil; Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, CLS 943, Boston, MA 02215, USA. Electronic address: rossana.melo@ufjf.edu.br.
authors: Rossana C N
authors: RC
authors: Melo
authors: Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, CLS 943, Boston, MA 02215, USA.
authors: Peter F
authors: PF
authors: Weller
mesh_terms: D001692:Biological Transport; D004804:Eosinophils / Q000378:metabolism* / Q000648:ultrastructure*; D006801:Humans; D007107:Immune System / Q000378:metabolism*; D016253:Microscopy, Immunoelectron / Q000379:methods*; D022142:Secretory Vesicles / Q000378:metabolism* / Q000648:ultrastructure
keywords: Cell secretion; Eosinophils; Immune mediators, Transmission electron microscopy, Immunogold electron microscopy; Immune response; Inflammation; Leukocytes; Ultrastructure; Vesicular trafficking