Immune recognition of Staphylococcus aureus wall teichoic acid

The bacterium Staphylococcus aureus can often be found on our skin and in
our nose, but also frequently causes severe infections. Especially infections
with antibiotic-resistant S. aureus (MRSA) are difficult to treat. We investigated
the recognition of a unique structure of the S. aureus cell wall by the human
immune system. New insights into these interactions may be used in the
development of new treatment strategies against S. aureus.
We specifically focused on a sugarcoated structure of the S. aureus cell
wall, known as wall teichoic acid (WTA). We describe how S. aureus WTA is
recognized by langerin, a receptor on skin immune cells and subsequently
induces skin inflammation. Importantly, langerin discriminates S. aureus from
other staphylococcal species. This may provide a possible explanation for the
association between S. aureus, but not other staphylococcal species, and the
allergic skin disorder eczema.
In addition, we developed a new method to analyze antibodies targeting
WTA variants, which differ between group of S. aureus bacteria. To do so,
we produced the WTA variants in the lab, and used these to analyze their
recognition by antibodies present in human blood. Using this method, we
measured the recognition by antibodies on pure WTA, which greatly improved
the sensitivity of the analytic assay. Beyond the use of these WTA compounds
in analytical methods, they can potentially be used in an S. aureus vaccine.
Our work shows that WTA is a promising target for new treatment strategies
against S. aureus.