1. Mycobacterium tuberculosis releases an antacid that remodels phagosomes.
- Author
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Buter J, Cheng TY, Ghanem M, Grootemaat AE, Raman S, Feng X, Plantijn AR, Ennis T, Wang J, Cotton RN, Layre E, Ramnarine AK, Mayfield JA, Young DC, Jezek Martinot A, Siddiqi N, Wakabayashi S, Botella H, Calderon R, Murray M, Ehrt S, Snider BB, Reed MB, Oldfield E, Tan S, Rubin EJ, Behr MA, van der Wel NN, Minnaard AJ, and Moody DB
- Subjects
- Animals, Gene Expression Regulation, Bacterial, Humans, Hydrogen-Ion Concentration, Lysosomes, Macrophages metabolism, Mice, Molecular Structure, Mycobacterium kansasii genetics, Prevalence, Antacids metabolism, Lipids biosynthesis, Lipids chemistry, Mycobacterium tuberculosis metabolism, Phagosomes metabolism
- Abstract
Mycobacterium tuberculosis (Mtb) is the world's most deadly pathogen. Unlike less virulent mycobacteria, Mtb produces 1-tuberculosinyladenosine (1-TbAd), an unusual terpene nucleoside of unknown function. In the present study 1-TbAd has been shown to be a naturally evolved phagolysosome disruptor. 1-TbAd is highly prevalent among patient-derived Mtb strains, where it is among the most abundant lipids produced. Synthesis of TbAd analogs and their testing in cells demonstrate that their biological action is dependent on lipid linkage to the 1-position of adenosine, which creates a strong conjugate base. Furthermore, C20 lipid moieties confer passage through membranes. 1-TbAd selectively accumulates in acidic compartments, where it neutralizes the pH and swells lysosomes, obliterating their multilamellar structure. During macrophage infection, a 1-TbAd biosynthesis gene (Rv3378c) confers marked phagosomal swelling and intraphagosomal inclusions, demonstrating an essential role in regulating the Mtb cellular microenvironment. Although macrophages kill intracellular bacteria through phagosome acidification, Mtb coats itself abundantly with antacid.
- Published
- 2019
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