Investigation of the effect of posttranslational modification of lipoproteins in TLR2-mediated recognition of <em>Staphylococcus aureus</em>

<em>S. aureus</em> has been postulated to change its lipoprotein acylation patterns under varying environmental conditions. Whether lipoproteins are posttranslationally di- or tri-acylated results in differences in recognition by human Toll-like receptors. In 2012, Kurokawa et al. observed a shift from tri- to di-acylated <em>S. aureus</em> lipoproteins by growth in a decreased pH environment in the stationary phase of growth. The underlying mechanisms, especially the genes involved in tri-acylation of <em>S. aureus</em> lipoproteins, were unknown at that time. Eight years later, Gardiner et al. discovered that two genes lnsA and lnsB encoded enzymes responsible for tri-acylation. LnsA and LnsB activity decreased bacterial recognition by TLR2 and shifted its dimerization partner from TLR6 to TLR1. <br> Based on these findings, the aim of this study was to investigate whether <em>S. aureus</em>-mediated posttranslational lipoprotein modification under stress conditions is conserved across the <em>S. aureus</em> species. In particular, we hypothesized that regulation of lnsA and lnsB expression under stress conditions results in altered TLR2 recognition and immunogenicity, which could account for host adaptation of <em>S. aureus</em> to colonization and infection.