Bone marrow-derived mouse mast cells (BMMC) and mast cell lines P815 and MC9 have recently been shown to induce antigen-independent B and T lymphocyte activation. It has been demonstrated that a physical contact between mast cells and B and T lymphocytes is not necessary since mast cell supernatants contain full activity. Electron microscopy studies revealed the presence in mast cell supernatants of small vesicles called exosomes with a heterogeneous size from 60 to 100 nm of diameter. When cocultured with spleen cells, purified exosomes induce B and T cell blast formation, proliferation as well as IL-2 and IFN-γ production. In contrast to P815 and MC9 mast cell lines, a pretreatment with IL-4 is required for BMMC to produce active exosomes. Structurally, these exosomes were found to harbor immunologically relevant molecules such as MHC class II, CD86, LFA-1 and ICAM-1. Here we provide for the first time the evidence that mast cells use exosomes as sophisticated messengers to communicate with cells of the immune system.

Keywords:
Mast cells, Exosomes, Lymphocytes, B and T
1.
Mécheri S, David B: Unravelling the mast cell dilemma: Culprit or victim of ist generosity? Immunol Today 1997;18:212–215.
2.
Galli S, Maurer M, Lantz C: Mast cells as sentinels of innate immunity. Curr Opin Immunol 1999;11:53–59.
3.
Frandji P, Oskéritzian C, Cacaraci F, Lapeyre J, Peronet R, David B, Guillet JG, Mécheri S: Antigen-dependent stimulation by bone-marrow-derived mast cells of MHC class II-restricted T cell hybridoma. J Immunol 1993;151:6318–6328.
4.
Fox CC, Jewell SD, Whitacre CC: Rat peritoneal mast cells present antigen to a PPD-specific T cell line. Cell Immunol 1994;158:253–264.
5.
Dimitriadou V, Mécheri S, Koutsilieris M, Fraser W, Al-Dakkak R, Mourad W: Expression of functional major histocompatibility complex class II molecules on HMC-1 human mast cells. J Leukoc Biol 1998;64:791–799.
6.
Gauchat JF, Henchoz S, Mazzei G, Aubry JP, Brunner T, Blasey H, Life P, Talabot D, Flores-Romo L, Thompson J: Induction of human IgE synthesis in B cells by mast cells and basophils. Nature 1993;365:340–343.
7.
Tkaczyk C, Frandji P, Bostros HG, Poncet P, Lapeyre J, Peronet R, David B, Mécheri S: Mouse bone marrow-derived mast cells and mast cell lines constitutively produce B cell growth and differentiation activities. J Immunol 1996;157:1720–1728.
8.
Tkaczyk C, Villa I, Peronet R, David B, Chouaïb S, Mécheri S: In vitro and in vivo immunostimulatory potential of bone marrow-derived mast cells on B and T lymphocyte activation. J Allergy Clin Immunol 1999;105:134–142.
9.
Inamura N, Mekori YA, Bhattacharyya SP, Bianchine PJ, Metcalfe DD: Introduction and enhancement of FcεRI-dependent mast cell degranulation following coculture with activated T cells: Dependency on ICAM-1-and leukocyte function-associated antigen (LFA)-1-mediated heterotypic aggregation. J Immunol 1998;160:4026–4033.
10.
Raposo G, Tenza D, Mécheri S, Peronet R, Bonnerot C, Desaymard C: Accumulation of MHC class II molecules in mast cell secretory granules and their release upon degranulation. Mol Biol Cell 1997;8:2631–2645.
11.
Zitvogel L, Regnault A, Lozier J, Wolfers J, Flament C, Tenza D, Riccardi-Castagnoli P, Raposo G, Amigorena S: Eradication of established murine tumors using a novel cell-free vaccine: Dendritic cell-derived exoxomes. Nat Med 1998;4:594–600.
12.
Mécheri S, David B: Unravelling the mast cell dilemma: Culprit or victim of ist generosity? Immunol Today 1997;18:212–215.
13.
Théry C, Regnault A, Garin J, Wolfers J, Zitvogel L, Ricciardi-Castagnoli P, Raposo G, Amigorena S: Molecular characterization of dendritic cell-derived exosomes: Selective accumulation of the heat shock protein hsp73. J Cell Biol 1999;147:599–610.
© 2001 S. Karger AG, Basel
2001
Copyright / Drug Dosage / Disclaimer
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.
You do not currently have access to this content.