Nonspecific B and T cell-stimulatory activity mediated by mast cells is associated with exosomes.
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-gamma 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.
Skokos
D
D
Unité d'Immuno-Allergie, Institut Pasteur, Paris, France.
Le Panse
S
S
Villa
I
I
Rousselle
J C
JC
Peronet
R
R
Namane
A
A
David
B
B
Mécheri
S
S
D000818:Animals; D015703:Antigens, CD / Q000032:analysis; D001402:B-Lymphocytes / Q000276:immunology*; D051940:B7-2 Antigen; D002478:Cells, Cultured; D016207:Cytokines / Q000096:biosynthesis; D000949:Histocompatibility Antigens Class II / Q000032:analysis; D018799:Intercellular Adhesion Molecule-1 / Q000032:analysis; D008213:Lymphocyte Activation; D016169:Lymphocyte Function-Associated Antigen-1 / Q000032:analysis; D008407:Mast Cells / Q000276:immunology*; D008562:Membrane Glycoproteins / Q000032:analysis; D051379:Mice; D008811:Mice, Inbred DBA; D022142:Secretory Vesicles / Q000737:chemistry / Q000502:physiology*; D013601:T-Lymphocytes / Q000276:immunology*
D015703:Antigens, CD; D051940:B7-2 Antigen; C497965:Cd86 protein, mouse; D016207:Cytokines; D000949:Histocompatibility Antigens Class II; D016169:Lymphocyte Function-Associated Antigen-1; D008562:Membrane Glycoproteins; D018799:Intercellular Adhesion Molecule-1