Review

Exosomes: composition, biogenesis and function

Published online:

Abstract

Exosomes are small membrane vesicles of endocytic origin that are secreted by most cells in culture. Interest in exosomes has intensified after their recent description in antigen-presenting cells and the observation that they can stimulate immune responses in vivo. In the past few years, several groups have reported the secretion of exosomes by various cell types, and have discussed their potential biological functions. Here, we describe the physical properties that define exosomes as a specific population of secreted vesicles, we summarize their biological effects, particularly on the immune system, and we discuss the potential roles that secreted vesicles could have as intercellular messengers.

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Download references

Entrez

  1. EBV

    • A33

      • αM

        • annexin I

          • annexin II

            • annexin IV

              • annexin V

                • annexin VI

                  • APO2L/TRAIL

                    • β2

                      • CBL

                        • CCR5

                          • CD3

                            • CD9

                              • CD13

                                • CD26

                                  • CD28

                                    • CD37

                                      • CD40L

                                        • CD45

                                          • CD53

                                            • CD59

                                              • CD63

                                                • CD74

                                                  • CD81

                                                    • CD82

                                                      • CD86

                                                        • CDC25

                                                          • cofilin

                                                            • enolase-1

                                                              • FASL

                                                                • HLA-DM

                                                                  • HSC70

                                                                    • HSP70

                                                                      • HSP90

                                                                        • ICAM1

                                                                          • IFN-γ

                                                                            • IL-2

                                                                              • LAMP1

                                                                                • LAMP2

                                                                                  • LCK

                                                                                    • MAGE3

                                                                                      • MART1

                                                                                        • MFGE8

                                                                                          • NSF

                                                                                            • P-selectin

                                                                                              • RAB5

                                                                                                • RAB7

                                                                                                  • RAP1B

                                                                                                    • SNAP

                                                                                                      • SNAP23

                                                                                                        • synaptotagmin II

                                                                                                          • synaptotagmin VII

                                                                                                            • syntaxin-3

                                                                                                              • syntaxin-4

                                                                                                                • TSG101

                                                                                                                  • VAMP7

                                                                                                                    • VAMP8

                                                                                                                      Acknowledgements

                                                                                                                      We thank C. Hivroz and P. Benaroch for helpful comments on the manuscript. S.A. and L.Z. were supported by European Community grants.

                                                                                                                      Author information

                                                                                                                      Affiliations

                                                                                                                      1. INSERM U520, Institut Curie, 12 rue Lhomond, 75005 Paris, France.

                                                                                                                        • Clotilde Théry
                                                                                                                        •  & Sebastian Amigorena
                                                                                                                      2. ERIT-M 0208 INSERM, Institut Gustave Roussy, 39 rue Camille Desmoulins, 94805 Villejuif, France.

                                                                                                                        • Laurence Zitvogel

                                                                                                                      Authors

                                                                                                                      1. Search for Clotilde Théry in:

                                                                                                                      2. Search for Laurence Zitvogel in:

                                                                                                                      3. Search for Sebastian Amigorena in:

                                                                                                                      Corresponding author

                                                                                                                      Correspondence to Clotilde Théry.

                                                                                                                      Glossary

                                                                                                                      ANNEXINS

                                                                                                                      A family of cytosolic proteins that have phospholipid-binding domains, the association of which with intracellular membranes is regulated by Ca2+. Several annexins are involved in membrane-fusion events between intracellular compartments.

                                                                                                                      RAB PROTEINS

                                                                                                                      Cytosolic proteins that have GTPase activity, which, in their GTP-bound form, associate with membranes. Different RAB proteins associate with different intracellular compartments — for example, RAB5 associates with early endosomes, RAB7 with late endosomes and RAB11 with recycling endosomes.

                                                                                                                      HEAT-SHOCK PROTEINS

                                                                                                                      (HSPs). A family of proteins that are involved in the binding of other misfolded proteins, and transporting them to the cellular degradation machinery. Several HSPs are synthesized only in conditions of stress, such as heat shock, but a few family members — such as endoplasmic-reticulum-resident gp96, and cytosolic HSC70 and HSP84 — are expressed constitutively.

                                                                                                                      TETRASPANINS

                                                                                                                      A family of transmembrane proteins that have four transmembrane domains and two extracellular domains of different sizes, which are defined by several conserved amino acids in the transmembrane domains. Their function is not known clearly, but they seem to interact with many other transmembrane proteins and to form large multimeric protein networks.

                                                                                                                      DEGRANULATION

                                                                                                                      In mastocytes and cytotoxic T lymphocytes, this term refers to the activation-induced fusion of secretory granules with the plasma membrane, and to the subsequent release of the content of these granules into the extracellular space.

                                                                                                                      FOLLICULAR DENDRITIC CELLS

                                                                                                                      (FDCs). Cells with a dendritic morphology that are present in the lymph nodes, where they present intact antigens held in immune complexes to B cells. FDCs are of non-haematopoietic origin, and are not related to dendritic cells.

                                                                                                                      CROSS-PRESENTATION

                                                                                                                      This term refers to the ability of certain antigen-presenting cells (APCs) to load peptides that are derived from exogenous antigens onto MHC class I molecules. This property is atypical, as most cells present exclusively peptides from their endogenous proteins on MHC class I molecules. Cross-presentation is essential for the initiation of immune responses against viruses that do not infect APCs.