How to clear a pathogen during inflammation: Switching from phagocytosis to macropinocytosis through coronin 1 phosphorylation

The processes that allow phagocytes to eliminate pathogenic microbes under inflammatory conditions remain incompletely understood. Recent work has implicated coronin 1 in the modulation of endocytic traffic upon macrophage activation. While in resting macrophages, uptake occurs largely through receptor-mediated phagocytosis, inflammatory stimuli such as interferon-and tumor necrosis factor-were found to activate macropinocytic uptake of cargo through phosphatidyl-3 kinase activation in a coronin 1-dependent manner. In this commentary we will briefly describe these recently published results , and discuss how this inducible pathway may serve to clear the inflammatory site from large amounts of infectious material and couple pathogen clearance to a proper activation of immune responses.