Surface Glycopolymers Are Crucial for <i>In Vitro</i> Anti-Wall Teichoic Acid IgG-Mediated Complement Activation and Opsonophagocytosis of <i>Staphylococcus aureus</i>

다국어 초록 (Multilingual Abstract)

<P>The cell envelopes of many Gram-positive bacteria contain wall teichoic acids (WTAs). <I>Staphylococcus aureus</I> WTAs are composed of ribitol phosphate (RboP) or glycerol phosphate (GroP) backbones substituted with <SMALL>d</SMALL>-alanine and <I>N</I>-acetyl-<SMALL>d</SMALL>-glucosamine (GlcNAc) or <I>N</I>-acetyl-<SMALL>d</SMALL>-galactosamine (GalNAc). Two WTA glycosyltransferases, TarM and TarS, are responsible for modifying the RboP WTA with α-GlcNAc and β-GlcNAc, respectively. We recently reported that purified human serum anti-WTA IgG specifically recognizes β-GlcNAc of the staphylococcal RboP WTA and then facilitates complement C3 deposition and opsonophagocytosis of <I>S. aureus</I> laboratory strains. This prompted us to examine whether anti-WTA IgG can induce C3 deposition on a diverse set of clinical <I>S. aureus</I> isolates. To this end, we compared anti-WTA IgG-mediated C3 deposition and opsonophagocytosis abilities using 13 different staphylococcal strains. Of note, the majority of <I>S. aureus</I> strains tested was recognized by anti-WTA IgG, resulting in C3 deposition and opsonophagocytosis. A minority of strains was not recognized by anti-WTA IgG, which correlated with either extensive capsule production or an alteration in the WTA glycosylation pattern. Our results demonstrate that the presence of WTAs with TarS-mediated glycosylation with β-GlcNAc in clinically isolated <I>S. aureus</I> strains is an important factor for induction of anti-WTA IgG-mediated C3 deposition and opsonophagocytosis.</P>