Summary
A bioRxiv preprint reports that lysosomal acid lipase helps release cholesterol during phagosome maturation. Inhibiting the enzyme changed membrane organisation and had different effects on the survival of two bacterial pathogens.
A bioRxiv preprint posted on 22 September 2026 reports that lysosomal acid lipase (LIPA) helps mobilise cholesterol as phagosomes mature. The authors say inhibiting the enzyme disrupted cholesterol-rich membrane rafts and altered the survival of two bacterial pathogens, with opposite effects for each.
Phagosomes are compartments formed when immune cells engulf microbes. As they mature, changes to their membranes and internal environment help determine how microbes are handled. The study focuses on how cholesterol becomes available during this process.
How LIPA affects phagosomal cholesterol
The researchers combined lipidomics, chemoproteomics and biochemical assays. They report that LIPA has cholesterol-ester hydrolase activity that is enriched on late phagosomes. The enzyme breaks down cholesterol esters, generating free cholesterol; the authors found this cholesterol was needed to form lipid rafts, cholesterol-rich regions of a membrane.
According to the preprint, pharmacologically inhibiting LIPA disrupted raft assembly and impaired phagosomal trafficking. The findings connect cholesterol processing to the physical organisation and movement of maturing phagosomes, rather than treating lipid metabolism as separate from the cell’s handling of engulfed microbes.
Pathogen outcomes differed
LIPA inhibition did not have the same reported effect on both pathogens. The authors say it increased the persistence of Staphylococcus aureus while restricting the survival of Mycobacterium tuberculosis. This difference suggests that changing phagosomal cholesterol can shape pathogen-specific outcomes; it is not a uniformly protective or harmful switch.
The work is presented as a mechanistic study in a bioRxiv preprint. Its abstract describes biochemical assays and pathogen-survival findings, but does not specify the experimental models or provide effect sizes. The results therefore offer a proposed link between cholesterol metabolism and antimicrobial defence, not evidence that manipulating LIPA would treat infection in people.