Figure 1. 1-TbAd produced by M. tuberculosis induces lysosomal lipid storage.

(i) M. tuberculosis (Mtb) produces 1-TbAd, which raises the vacuolar pH and inhibits acidic hydrolases, including lipases, inside the phagolysosome. (ii) Consequently, lipids, including cholesteryl esters and triglycerides, accumulate in the vacuole, mimicking lysosomal storage diseases. (iii) Under conditions of restricted lipid access, M. tuberculosis can use these lipids as a carbon source to promote its intracellular growth.