Abstract
Mediator release from mast cells (MC) is a crucial step in allergic and non-allergic inflammatory disorders. However, the final events in response to activation leading to membrane fusion and thereby facilitating degranulation have hitherto not been analyzed in human MC. Soluble N-ethyl-maleimide-sensitive factor attachment protein receptors (SNARE) represent a highly conserved family of proteins that have been shown to mediate intracellular membrane fusion events. Here, we show that mature MC isolated from human intestinal tissue express soluble N-ethylmaleide sensitive factor attachment protein (SNAP)-23, Syntaxin (STX)-1B, STX-2, STX-3, STX-4, and STX-6 but not SNAP-25. Furthermore, we found that primary human MC express substantial amounts of vesicle associated membrane protein (VAMP)-3, VAMP-7 and VAMP-8 and, in contrast to previous reports about rodent MC, only low levels of VAMP-2. Furthermore, VAMP-7 and VAMP-8 were found to translocate to the plasma membrane and interact with SNAP-23 and STX-4 upon activation. Inhibition of SNAP-23, STX-4, VAMP-7 or VAMP-8, but not VAMP-2 or VAMP-3, resulted in a markedly reduced high-affinity IgE receptor-mediated histamine release. In summary, our data show that mature human MC express a specific pattern of SNARE and that VAMP-7 and VAMP-8, but not VAMP-2, are required for rapid degranulation.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Antibodies / pharmacology
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Blotting, Western
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Cell Degranulation / drug effects
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Cell Degranulation / physiology*
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Cell Membrane / metabolism
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Cytoplasm / metabolism
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Fluorescent Antibody Technique
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Gene Expression / drug effects
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Histamine Release / drug effects
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Histamine Release / physiology
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Humans
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Mast Cells / drug effects
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Mast Cells / metabolism
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Mast Cells / physiology*
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Metalloendopeptidases / pharmacology
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Qa-SNARE Proteins / genetics
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Qa-SNARE Proteins / immunology
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Qa-SNARE Proteins / metabolism
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Qb-SNARE Proteins / genetics
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Qb-SNARE Proteins / immunology
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Qb-SNARE Proteins / metabolism
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Qc-SNARE Proteins / genetics
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Qc-SNARE Proteins / immunology
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Qc-SNARE Proteins / metabolism
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R-SNARE Proteins / genetics
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R-SNARE Proteins / metabolism
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R-SNARE Proteins / physiology*
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Reverse Transcriptase Polymerase Chain Reaction
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SNARE Proteins / genetics
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SNARE Proteins / metabolism
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Tetanus Toxin / pharmacology
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Vesicle-Associated Membrane Protein 2 / genetics
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Vesicle-Associated Membrane Protein 2 / metabolism
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Vesicle-Associated Membrane Protein 2 / physiology
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Vesicle-Associated Membrane Protein 3 / genetics
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Vesicle-Associated Membrane Protein 3 / metabolism
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Vesicle-Associated Membrane Protein 3 / physiology
Substances
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Antibodies
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Qa-SNARE Proteins
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Qb-SNARE Proteins
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Qc-SNARE Proteins
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R-SNARE Proteins
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SNAP23 protein, human
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SNARE Proteins
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Tetanus Toxin
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VAMP2 protein, human
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VAMP3 protein, human
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VAMP7 protein, human
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VAMP8 protein, human
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Vesicle-Associated Membrane Protein 2
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Vesicle-Associated Membrane Protein 3
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Metalloendopeptidases
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zinc-endopeptidase, tetanus neurotoxin