title: Ultrastructural evidence for human mast cell-eosinophil interactions in vitro.
abstract: We have hypothesized that mast cells (MC) and eosinophils (Eos), the main effectors of allergy, can form an effector unit. These cells co-exist in the inflamed tissues during the late and chronic stages of allergy and have been shown to be capable of influencing each other's survival and activity via soluble mediators. We have recently described couples of receptor-ligands that are expressed on either/both of these cells and that imply a physical interaction. In this study, we have investigated the existence of short-term (60 min) in vitro interactions between human peripheral blood Eos and cord-blood-derived MC by transmission electron microscopy. We have found that MC and Eos adhere to each other; the lipid body content and the granule morphology of co-cultured MC and Eos, respectively, are altered, and the level of Eos peroxidase (EPO) released by co-cultured Eos is elevated. Moreover, the transfer of EPO from Eos to MC and tryptase from MC to Eos has been observed. Our results thus indicate that, when co-cultured, MC and Eos show signs of physical contact and of reciprocal activation. This is the first in vitro evidence of functional physical interactions between human MC and Eos, interactions that might also occur in vivo during allergic diseases.
authors.affiliation: Pharmacology & Experimental Therapeutics Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Ein Kerem, Jerusalem 91120, Israel.
authors.forename: Yael
authors.initials: Y
authors.lastname: Minai-Fleminger
authors.forename: Moran
authors.initials: M
authors.lastname: Elishmereni
authors.forename: Francesca
authors.initials: F
authors.lastname: Vita
authors.forename: Maria Rosa
authors.initials: MR
authors.lastname: Soranzo
authors.forename: David
authors.initials: D
authors.lastname: Mankuta
authors.forename: Guliano
authors.initials: G
authors.lastname: Zabucchi
authors.forename: Francesca
authors.initials: F
authors.lastname: Levi-Schaffer
mesh_terms: D002450:Cell Communication / Q000502:physiology*; D002478:Cells, Cultured; D018920:Coculture Techniques; D003594:Cytoplasmic Granules / Q000378:metabolism; D047209:Eosinophil Peroxidase / Q000378:metabolism; D004804:Eosinophils / Q000166:cytology / Q000378:metabolism / Q000502:physiology* / Q000648:ultrastructure; D005312:Fetal Blood / Q000166:cytology; D006801:Humans; D006967:Hypersensitivity / Q000503:physiopathology; D050356:Lipid Metabolism / Q000276:immunology; D008407:Mast Cells / Q000166:cytology / Q000378:metabolism / Q000502:physiology* / Q000648:ultrastructure; D008561:Membrane Fusion / Q000276:immunology / Q000502:physiology; D008854:Microscopy, Electron / Q000379:methods
chemical_list: D047209:Eosinophil Peroxidase