Abstract / Summary
Host oxysterols coordinate macrophage cholesterol homeostasis and antimicrobial defense, but whether pathogens directly target oxysterol signaling is unknown. Here, we identify pathogen-mediated enzymatic oxysterol inactivation as a mechanism by which Mycobacterium tuberculosis (Mtb) subverts host cholesterol metabolism. Mtb oxidizes the endogenous oxysterols 27-hydroxycholesterol (27-HC) and 3β-hydroxycholest-5-enoic acid (3β-HCA) into 3-oxo-Δ4 metabolites. Sputum lipidomics across TB cohorts on three continents revealed an active-disease signature characterized by 27-HC depletion and accumulation of 27-hydroxycholest-4-en-3-one (27-HCO) and 3-oxocholest-4-enoic acid (3O-CA), which normalized with treatment. In infected human macrophages, Mtb 3β-hydroxysteroid dehydrogenase (3β-Hsd) generated 27-HCO. Unlike their parent oxysterols, 27-HCO and 3O-CA did not activate liver X receptor (LXR), and 3O-CA failed to suppress sterol regulatory element-binding protein 2 (SREBP2) target genes. Accordingly, 3β-Hsd-deficient Mtb did not induce macrophage cholesterol retention, a phenotype restored by LXR antagonism. Thus, Mtb enzymatically inactivates host oxysterols, disrupting macrophage cholesterol homeostasis and generating treatment-responsive metabolic signatures in human TB.