Description
Previous reports have shown low vitamin D serum levels and polymorphisms in the vitamin D receptor (VDR) to be associated with increased risk for TB. Given that 1,25-dihydroxyvitamin D3 has a role in lipid metabolism control, we tested whether the link between 1,25-dihydroxyvitamin D3 and tuberculosis involves macrophage lipid metabolism. Since formation of lipid droplets (LD) is a hallmark of lipid dysregulation in M. tuberculosis-infected macrophages, we measured LD content as a readout of altered lipid metabolism in infected THP-1 cells. Induction of LD, which peaked by 24 hours post-infection was prevented by addition of 1,25-dihydroxyvitamin D3 at the time of infection. To investigate the mechanism of 1,25-dihydroxyvitamin D3 modulation of LD formation, we analyzed the transcriptome of M. tuberculosis-infected THP-1 cells with and without 1,25-dihydroxyvitamin D3 treatment.