%0 Online Multimedia %A Herranz, Gonzalo %A Aguilera, Pablo %A Dávila, Sergio %A Sánchez, Alicia %A Stancu, Bianca %A Gómez, Jesús %A Fernández-Moreno, David %A de Martín, Raúl %A Quintanilla, Mario %A Fernández, Teresa %A Rodríguez-Silvestre, Pablo %A Márquez-Expósito, Laura %A Bello-Gamboa, Ana %A Fraile-Ramos, Alberto %A Calvo, Víctor %A Izquierdo, Manuel %D 2019 %T Video_7_Protein Kinase C δ Regulates the Depletion of Actin at the Immunological Synapse Required for Polarized Exosome Secretion by T Cells.MOV %U https://frontiersin.figshare.com/articles/media/Video_7_Protein_Kinase_C_Regulates_the_Depletion_of_Actin_at_the_Immunological_Synapse_Required_for_Polarized_Exosome_Secretion_by_T_Cells_MOV/8047775 %R 10.3389/fimmu.2019.00851.s010 %2 https://frontiersin.figshare.com/ndownloader/files/14994962 %K T lymphocytes %K immune synapse %K protein kinase C δ %K multivesicular bodies %K exosomes %K cytotoxic activity %K cell death %X

Multivesicular bodies (MVB) are endocytic compartments that enclose intraluminal vesicles (ILVs) formed by inward budding from the limiting membrane of endosomes. In T lymphocytes, ILVs are secreted as Fas ligand-bearing, pro-apoptotic exosomes following T cell receptor (TCR)-induced fusion of MVB with the plasma membrane at the immune synapse (IS). In this study we show that protein kinase C δ (PKCδ), a novel PKC isotype activated by diacylglycerol (DAG), regulates TCR-controlled MVB polarization toward the IS and exosome secretion. Concomitantly, we demonstrate that PKCδ-interfered T lymphocytes are defective in activation-induced cell death. Using a DAG sensor based on the C1 DAG-binding domain of PKCδ and a GFP-PKCδ chimera, we reveal that T lymphocyte activation enhances DAG levels at the MVB endomembranes which mediates the association of PKCδ to MVB. Spatiotemporal reorganization of F-actin at the IS is inhibited in PKCδ-interfered T lymphocytes. Therefore, we propose PKCδ as a DAG effector that regulates the actin reorganization necessary for MVB traffic and exosome secretion.

%I Frontiers