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Control of interleukin‐18 secretion by dendritic cells: role of calcium influxes
Author(s) -
Gardella Stefania,
Andrei Cristina,
Poggi Alessandro,
Zocchi M.Raffaella,
Rubartelli Anna
Publication year - 2000
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(00)02015-9
Subject(s) - secretion , exocytosis , microbiology and biotechnology , calcium , chemistry , cytosol , cytokine , interleukin , organelle , biology , biochemistry , immunology , organic chemistry , enzyme
Here we show that dendritic cells accumulate the precursor form of the leaderless secretory protein interleukin‐18 (pro‐interleukin‐18) in the cell cytosol and in organelles co‐fractionating with endolysosomes. Upon antigen specific contact with T lymphocytes, particulated pro‐interleukin‐18 decreases rapidly, and the cytokine appears extracellularly, suggesting that exocytosis of pro‐interleukin‐18‐containing organelles is induced. Exocytosis of secretory lysosomes is modulated by calcium: in agreement with this, calcium influx results in secretion of pro‐interleukin‐18. In turn, pro‐interleukin‐18 secretion induced by T cells is prevented by the calcium channel blocker nifedipine. Our results demonstrate a novel, calcium‐mediated mechanism of post‐translational regulation of secretion for interleukin‐18, that allows a fast release of the cytokine.