Staphylococcus aureus-induced immunosuppressive memory: consequences for bug and for host

The World Health Organization highlights the epidemic of antibiotic resistance in Staphylococcus aureus (SA) (methicillin-resistant SA) as a particular threat to society, strongly advocating for the development of alternatives to antibiotics. Efforts are under way to develop vaccines against SA but progress is curtailed by a lack of sufficient understanding of the mechanisms by which this bacterium interacts with the host immune system. In addition to causing severe invasive disease, SA lives innocuously in the nasal passages of the majority of the population. We understand nothing about how exposure to SA in this context affects our immune system or how this exposure might affect our ability to respond to a vaccine against this organism.

We propose that to colonise the host for long periods, SA must have acquired mechanisms to suppress or avoid detection by the immune system. We believe that by doing this the bacterium has the capacity to train the immune system to be unable to respond to a vaccine administered to boost the immune response to SA upon infection. This research will identify if this is the case and will develop strategies to overcome or neutralise this ‘training’ and improve vaccine effectiveness.