Protein Kinase C δ Regulates the Depletion of Actin at the Immunological Synapse Required for Polarized Exosome Secretion by T Cells

Autor: Gonzalo Herranz, Pablo Aguilera, Sergio Dávila, Alicia Sánchez, Bianca Stancu, Jesús Gómez, David Fernández-Moreno, Raúl de Martín, Mario Quintanilla, Teresa Fernández, Pablo Rodríguez-Silvestre, Laura Márquez-Expósito, Ana Bello-Gamboa, Alberto Fraile-Ramos, Víctor Calvo, Manuel Izquierdo
Jazyk: angličtina
Rok vydání: 2019
Předmět:
Zdroj: Frontiers in Immunology, Vol 10 (2019)
Druh dokumentu: article
ISSN: 1664-3224
DOI: 10.3389/fimmu.2019.00851
Popis: 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.
Databáze: Directory of Open Access Journals