Many plasmalogens decrease upon infection.

<p>A- Structure of plasmalogens. Phosphatidylethanolamine (left) and the plasmalogen version of phosphatidylethanolamine (right) are depicted. The plasmalogen variant contains a long chain alcohol in place of a fatty acid and has a double bond between the first two carbons of the alcohol (1-O-alkenyl-2-acyl-<i>sn</i>-glycero-3-phosphoethanolamine; plasmenylethanolamine). B- Example of plasmalogens abundant in the non-infected control fibroblasts. Putative plasmalogens were identified based on their predicted formula as C_xH_2x–2yNO₇P (where y = the number of double bonds in the fatty acid) after ICR-FT/MS analysis (mass error <100 parts/billion, MassTRIX <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0086196#pone.0086196-Suhre1" target="_blank">[46]</a>), and on their sensitivity to acid hydrolysis. Lipid species fulfilling these criteria were either missing or severely reduced in peroxisome-deficient cells (“PEX19”) compared to control fibroblasts (CTL), confirming that they are plasmalogens. Note that, globally, plasmalogen content decreased during infection, most notably at the later time point. Identification of plasmalogens was performed on samples from a single experiment. C- Abundance of control phospholipids. Phospholipids that gave the highest signal intensity in the ICR-FT/MS (corresponding to C42H82NO8P) were arbitrarily chosen as control. D- Total phospholipids detected with ICR-FT/MS. The intensities of all annotated phospholipids (mass error <1 ppm) were summed and normalized to the total sum of intensities in the sample. The data in C and D are representative of two independent experiments.