Abstract:
:Recognition of surface-tethered antigens (Ags) by B-cells leads to the formation of an immune synapse that promotes Ag uptake for presentation onto MHC-II molecules. Extraction of immobilized Ags at the immune synapse of B-cells relies on the local secretion of lysosomes, which are recruited to the Ag contact site by polarization of their microtubule network. Although conserved polarity proteins have been implicated in coordinating cytoskeleton remodeling with lysosome trafficking, the cellular machinery associated with lysosomal vesicles that regulates their docking and secretion at the synaptic interface has not been defined. Here we show that the v-SNARE protein Vamp-7 is associated with Lamp-1+ lysosomal vesicles, which are recruited and docked at the center of the immune synapse of B-cells. A decrease in Vamp-7 expression does not alter lysosome transport to the synaptic interface but impairs their local secretion, a defect that compromises the ability of B-cells to extract, process, and present immobilized Ag. Thus our results reveal that B-cells rely on the SNARE protein Vamp-7 to promote the local exocytosis of lysosomes at the immune synapse, which is required for efficient Ag extraction and presentation.
journal_name
Mol Biol Celljournal_title
Molecular biology of the cellauthors
Obino D,Diaz J,Sáez JJ,Ibañez-Vega J,Sáez PJ,Alamo M,Lankar D,Yuseff MIdoi
10.1091/mbc.E16-10-0722subject
Has Abstractpub_date
2017-04-01 00:00:00pages
890-897issue
7eissn
1059-1524issn
1939-4586pii
mbc.E16-10-0722journal_volume
28pub_type
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