IRAP Endosomes Control Phagosomal Maturation in Dendritic Cells.

Autor:	Weimershaus M; Institut National de la Santé et de la Recherche Médicale, Unité 1151, Université de Paris, Centre National de la Recherche Scientifique, UMR 8253, Paris, France., Mauvais FX; Institut National de la Santé et de la Recherche Médicale, Unité 1151, Université de Paris, Centre National de la Recherche Scientifique, UMR 8253, Paris, France., Evnouchidou I; Institut National de la Santé et de la Recherche Médicale, Unité 1151, Université de Paris, Centre National de la Recherche Scientifique, UMR 8253, Paris, France.; Inovarion, Paris, France., Lawand M; Institut National de la Santé et de la Recherche Médicale, Unité 1151, Université de Paris, Centre National de la Recherche Scientifique, UMR 8253, Paris, France., Saveanu L; Institut National de la Santé et de la Recherche Médicale, Unité 1151, Université de Paris, Centre National de la Recherche Scientifique, UMR 8253, Paris, France., van Endert P; Institut National de la Santé et de la Recherche Médicale, Unité 1151, Université de Paris, Centre National de la Recherche Scientifique, UMR 8253, Paris, France.
Jazyk:	angličtina
Zdroj:	Frontiers in cell and developmental biology [Front Cell Dev Biol] 2020 Dec 11; Vol. 8, pp. 585713. Date of Electronic Publication: 2020 Dec 11 (Print Publication: 2020).
DOI:	10.3389/fcell.2020.585713
Abstrakt:	Dendritic cells (DCs) contribute to the immune surveillance by sampling their environment through phagocytosis and endocytosis. We have previously reported that, rapidly following uptake of extracellular antigen into phagosomes or endosomes in DCs, a specialized population of storage endosomes marked by Rab14 and insulin-regulated aminopeptidase (IRAP) is recruited to the nascent antigen-containing compartment, thereby regulating its maturation and ultimately antigen cross-presentation to CD8 + T lymphocytes. Here, using IRAP -/- DCs, we explored how IRAP modulates phagosome maturation dynamics and cross-presentation. We find that in the absence of IRAP, phagosomes acquire more rapidly late endosomal markers, are more degradative, and show increased microbicidal activity. We also report evidence for a role of vesicle trafficking from the endoplasmic reticulum (ER)-Golgi intermediate compartment to endosomes for the formation or stability of the IRAP compartment. Moreover, we dissect the dual role of IRAP as a trimming peptidase and a critical constituent of endosome stability. Experiments using a protease-dead IRAP mutant and pharmacological IRAP inhibition suggest that IRAP expression but not proteolytic activity is required for the formation of storage endosomes and for DC-typical phagosome maturation, whereas proteolysis is required for fully efficient cross-presentation. These findings identify IRAP as a key factor in cross-presentation, trimming peptides to fit the major histocompatibility complex class-I binding site while preventing their destruction through premature phagosome maturation. Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. (Copyright © 2020 Weimershaus, Mauvais, Evnouchidou, Lawand, Saveanu and van Endert.)
Databáze:	MEDLINE
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