Citation
- Authors: Davis, LC., et al.
- Year: 2020
- Journal: EMBO J. 39 e104058
- Applications: in vitro / DNA / jetPRIME
- Cell types:
- Name: Mouse bone marrow-derived macrophages
Description: Primary mouse bone marrow macrophages
Known as: BMDM - Name: RAW 264.7
Description: Mouse monocytes/macrophages
Known as: RAW
- Name: Mouse bone marrow-derived macrophages
Abstract
Macrophages clear pathogens by phagocytosis and lysosomes that fuse with phagosomes are traditionally regarded as to a source of membranes and luminal degradative enzymes. Here, we reveal that endo-lysosomes act as platforms for a new phagocytic signalling pathway in which FcγR activation recruits the second messenger NAADP and thereby promotes the opening of Ca2+ -permeable two-pore channels (TPCs). Remarkably, phagocytosis is driven by these local endo-lysosomal Ca2+ nanodomains rather than global cytoplasmic or ER Ca2+ signals. Motile endolysosomes contact nascent phagosomes to promote phagocytosis, whereas endo-lysosome immobilization prevents it. We show that TPC-released Ca2+ rapidly activates calcineurin, which in turn dephosphorylates and activates the GTPase dynamin-2. Finally, we find that different endo-lysosomal Ca2+ channels play diverse roles, with TPCs providing a universal phagocytic signal for a wide range of particles and TRPML1 being only required for phagocytosis of large targets.