Lysosomal acid lipase regulates cholesterol metabolism during phagosomal maturation

Phagocytosis, a central process in innate immunity, depends on dynamic lipid remodelling, yet how cholesterol accumulates on late phagosomes remains unresolved. Here, we identify lysosomal acid lipase (LIPA) as a key cholesterol ester (CE) hydrolase driving cholesterol mobilization during phagosomal maturation. Using integrated lipidomics, chemoproteomics, and biochemical assays, we show that LIPA exhibits acidic CE hydrolase activity enriched on late phagosomes, generating free cholesterol essential for lipid raft formation. Pharmacologically inhibiting LIPA disrupts cholesterol-rich lipid raft assembly, impairs phagosomal trafficking, and alters pathogen fate - enhancing Staphylococcus aureus persistence, while restricting Mycobacterium tuberculosis survival. These findings reveal that LIPA couples cholesterol metabolism to phagocytosis, defining a mechanistic link between lipid catabolism and antimicrobial defence. By positioning CE hydrolysis as a critical determinant of phagosomal dynamics, our work uncovers a metabolic checkpoint in innate immunity and identifies LIPA as a potential therapeutic node in infection and inflammation.