VAMP8-mediated NOX2 recruitment to endosomes is necessary for antigen release

Contains fulltext : 178043.pdf (publisher's version ) (Open Access)Cross-presentation of foreign antigen in major histocompatibility complex (MHC) class I by dendritic cells (DCs) requires activation of the NADPH-oxidase NOX2 complex. We recently showed that NOX2 is recruited to phagosomes by the SNARE protein VAMP8 where NOX2-produced reactive oxygen species (ROS) cause lipid oxidation and membrane disruption, promoting antigen translocation into the cytosol for cross-presentation. In this study, we extend these findings by showing that VAMP8 is also involved in NOX2 trafficking to endosomes. Moreover, we demonstrate in both human and mouse DCs that absence of VAMP8 leads to decreased ROS production, lipid peroxidation and antigen translocation, and that this impairs cross-presentation. In contrast, knockdown of VAMP8 did not affect recruitment of MHC class I and the transporter associated with antigen processing 1 (TAP1) to phagosomes, although surface levels of MHC class I were reduced. Thus, in addition to a secretory role, VAMP8-mediates trafficking of NOX2 to endosomes and phagosomes and this promotes induction of cytolytic T cell immune responses

Interleukin-6 secretion is limited by self-signaling in endosomes

Contains fulltext : 202589.pdf (publisher's version ) (Open Access

Le droit international privé européen confronté aux objectifs de l'Union européenne : analyse de la question à l'aune de l'article 6 du règlement Rome I sur la loi applicable aux obligations contractuelles

Master [120] en droit, Université catholique de Louvain, 201

Molecular mechanisms of interleukin 6 release in dendritic cells

Contains fulltext : 194284.pdf (publisher's version ) (Open Access)Radboud University, 12 september 2018Promotor : Figdor, C.G. Co-promotores : Bogaart, G. van den, Beest, M.B.A. ter187 p

Secretory vesicles of immune cells contain only a limited number of interleukin 6 molecules

Contains fulltext : 191566.pdf (publisher's version ) (Open Access

Visualizing Intracellular SNARE Trafficking by Fluorescence Lifetime Imaging Microscopy

Contains fulltext : 189977.pdf (publisher's version ) (Open Access

Fluorescence Lifetime Imaging Microscopy reveals rerouting of SNARE trafficking driving dendritic cell activation

Contains fulltext : 177737.pdf (publisher's version ) (Open Access)SNARE proteins play a crucial role in intracellular trafficking by catalyzing membrane fusion, but assigning SNAREs to specific intracellular transport routes is challenging with current techniques. We developed a novel Forster resonance energy transfer-fluorescence lifetime imaging microscopy (FRET-FLIM)-based technique allowing visualization of real-time local interactions of fluorescently tagged SNARE proteins in live cells. We used FRET-FLIM to delineate the trafficking steps underlying the release of the inflammatory cytokine interleukin-6 (IL-6) from human blood-derived dendritic cells. We found that activation of dendritic cells by bacterial lipopolysaccharide leads to increased FRET of fluorescently labeled syntaxin 4 with VAMP3 specifically at the plasma membrane, indicating increased SNARE complex formation, whereas FRET with other tested SNAREs was unaltered. Our results revealed that SNARE complexing is a key regulatory step for cytokine production by immune cells and prove the applicability of FRET-FLIM for visualizing SNARE complexes in live cells with subcellular spatial resolution