Comparative lipidomic profiling of the human commensal bacterium<i>Propionibacterium acnes</i>and its extracellular vesicles

Abstract

<i>Propionibacterium acnes</i> is a lipophilic commensal bacterium mainly found on the skin and in the gastrointestinal tract. Pathophysiological effects of <i>P. acnes</i> have recently been reported not only in acne progression but in various diseases. As an emerging mode of bacterial communication, extracellular vesicles (EVs) have been demonstrated to conduct critical pathophysiological functions. To provide information on <i>P. acnes</i> lipid composition for the first time, we conducted a comparative lipidomic analysis of <i>P. acnes</i> and <i>P. acnes</i> EVs and identified 214 lipids with high confidence using triplicated liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) analyses. <i>P. acnes</i> EVs contained substantially more PCs, DGs, PAs, PEs, LPAs, LPCs, and MGs than <i>P. acnes</i>, and contained fewer PSs, SO1Ps, SA1Ps, LPGs, LPIs, and LPSs. Distinctively, <i>P. acnes</i> EVs possessed a markedly reduced amount of TG. These findings will provide useful clues for understanding the biological and pathophysiological mechanisms of <i>P. acnes</i> and for clinical applications such as vaccine development, diagnostics and therapeutics.