Fueling macrophages with metabolic recycling of bacteria

During bacterial infection, macrophages successively encounter and engulf live and killed microbes, and trigger appropriated host responses to eradicate the threat and restore tissue homeostasis. Despite the critical role of phagocytosis during this event, the fate of phagocytosed microbial cargo and its impact on host cell is poorly understood. Our investigation reveals that phagocytosis of bacteria provides bioenergetic and biosynthetic precursors that are differently utilized by macrophages depending on microbial viability. This highlights the capacity of phagocytic cells to adjust their cellular metabolism to the ‘fueling’ capacity of the ingested cargos and how, together with the sensing of microbial viability, it regulates immunometabolic adaptations to adjust host response intensity to the course of microbial infection