Mycobacterium tuberculosis WhiB3 Maintains Redox Homeostasis by Regulating Virulence Lipid Anabolism to Modulate Macrophage Response
Figure 2
Mtb WhiB3 regulates biosynthesis of complex virulence lipids.
Wt Mtb, MtbΔwhiB3, and MtbΔwhiB3tetRO:whiB3 (Comp.) were cultured in 7H9 liquid media containing 0.1% Tween 80, and total lipids labeled using [14C] propionate. In each lane, silica TLC plates were loaded with 100,000 cpm of [14C] propionate-derived total lipids and various lipid fractions were analysed. (A) Polar lipid fraction was resolved using 10% methanol in chloroform as the solvent. (B) PAT lipids were analyzed by developing TLC plates in petroleum ether∶acetone (92∶8). (C) PDIM and TAG were analyzed by developing TLC plates in petroleum ether∶acetone (98∶2). (D) SL-1 and DAT were analyzed by developing TLC plates in chloroform∶ethanol∶water (90∶10∶1). (E) TMM and TDM were analyzed by loading 100,000 cpm of [1, 2-14C] acetate-derived total lipids on a silica TLC plate and developed using chloroform∶methanol∶acetone∶acetic acid (80∶20∶6∶1). Lanes (1) wt Mtb, (2) MtbΔwhiB3 and (3) complemented MtbΔwhiB3tetRO:whiB3 strain (Comp). Phosphorimaging (imageQuant software; GE Healthcare) were used to examine the relative distribution of 14C among the lipid fractions.