Endoplasmic reticulum-mediated phagocytosis is a mechanism of entry into macrophages.
Phagocytosis is a key aspect of our innate ability to fight infectious diseases. In this study, we have found that fusion of the endoplasmic reticulum (ER) with the macrophage plasmalemma, underneath phagocytic cups, is a source of membrane for phagosome formation in macrophages. Successive waves of ER become associated with maturing phagosomes during phagolysosome biogenesis. Thus, the ER appears to possess unexpectedly pluripotent fusion properties. ER-mediated phagocytosis is regulated in part by phosphatidylinositol 3-kinase and used for the internalization of inert particles and intracellular pathogens, regardless of their final trafficking in the host. In neutrophils, where pathogens are rapidly killed, the ER is not used as a major source of membrane for phagocytosis. We propose that intracellular pathogens have evolved to adapt and exploit ER-mediated phagocytosis to avoid destruction in host cells.
Gagnon
Etienne
E
Département de Pathologie et Biologie Cellulaire, Université de Montréal, Montréal, Québec, Canada.
Duclos
Sophie
S
Rondeau
Christiane
C
Chevet
Eric
E
Cameron
Pamela H
PH
Steele-Mortimer
Olivia
O
Paiement
Jacques
J
Bergeron
John J M
JJ
Desjardins
Michel
M
D000818:Animals; D002135:Calcium-Binding Proteins / Q000378:metabolism; D037281:Calnexin; D002462:Cell Membrane / Q000502:physiology; D002478:Cells, Cultured; D004285:Dogs; D004721:Endoplasmic Reticulum / Q000378:metabolism / Q000502:physiology* / Q000648:ultrastructure; D007425:Intracellular Membranes / Q000737:chemistry / Q000502:physiology / Q000648:ultrastructure; D008264:Macrophages / Q000166:cytology / Q000502:physiology*; D010587:Phagocytosis / Q000502:physiology*; D010588:Phagosomes / Q000378:metabolism / Q000502:physiology* / Q000648:ultrastructure; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D021381:Protein Transport / Q000502:physiology; D006180:Proton-Translocating ATPases / Q000378:metabolism; D012756:Sheep
D002135:Calcium-Binding Proteins; D037281:Calnexin; D019869:Phosphatidylinositol 3-Kinases; D006180:Proton-Translocating ATPases