Lipid droplet proteomics of THP1 macrophages infected with Mycobacterium tuberculosis

ABSTRACT: Growing evidence suggests the importance of lipid metabolism in pathogenesis of tuberculosis. Neutral lipids form the majority of lipids in caseous granulomas characteristic of tuberculosis. Macrophage lipid droplets form the store house of these lipids, yet infection induced changes in the proteome of these dynamic organelles remains elusive. Here we employed quantitative proteomics to identify alterations induced upon infection with live Mycobacterium tuberculosis in comparison with heat killed bacilli and uninfected macrophages. Association of specific proteins coupled with lysosomal function was found to be increased upon infection with live M. tuberculosis. Biochemical and microscopy based evidence validated the enrichment of the small GTPase Arl8b, the guanine nucleotide effector LAMTOR1, and the scavenger receptor SCARB2 on lipid droplets during live Mtb infection. We validated the localization of Arl8b on lipid droplets using super-resolution microscopy. Increased abundance of these lysosomal proteins on lipid droplets upon infection with live Mtb suggests active manipulation of the host lipid droplets by the pathogen. Furthermore, depletion of lipid droplets upon stable knockdown of diacylglycerol O-acyltransferase led to reduction in lysosomal acidification of infected cells, suggesting an active role of lipid droplets in lysosomal function during infection.

INSTRUMENT(S):

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Macrophage

DISEASE(S): Tuberculosis

SUBMITTER: Sheetal Gandotra  

LAB HEAD: Sheetal Gandotra

PROVIDER: PXD008950 | Pride | 2019-11-14

REPOSITORIES: Pride