The different autophagic roads by which phagosomes travel to lysosomes

Autophagy delivers cytoplasmic constituents, like damaged mitochondria, to lysosomes. Recently, it was noted that the same molecular machinery also regulates phagosome delivery for degradation. In this issue of The EMBO Journal, Brooks and colleagues demonstrate that KIM-1/TIM-1 receptor-mediated phagocytosis in epithelial cells does not seem to cause modification of the phagosomal membrane itself by the autophagic machinery, but engulfment of phagosomes by autophagosomes for delivery to lysosomes and MHC restricted antigen presentation. This study suggests that the autophagic machinery can regulate phagocytosis via two pathways, modification of phagosomes during LC3-associated phagocytosis (LAP) and macroautophagy of phagosomes. The engulfment of phagosomes by autophagosomes is required for delivery to lysosomes and for MHC restricted antigen presentation.