Arthritis and sepsis caused by Staphylococcus aureus: can the tissue injury be reduced by modulating the host's immune system?

In recent years, a number of virulence factors that are either expressed, secreted or sequestered by staphylococci have been shown to affect the outcome of the infective process. Secretion of superantigens and exposure of the immune system to sequestered bacterial DNA aggravates the inflammatory response of the infected host to a point that can be life threatening. This exaggerated inflammatory response is mediated by cytokines originating from activated T cells and macrophages. Recent studies show that downregulation of lymphocyte and macrophage responses (e.g. by treatment with corticosteroids) significantly alleviates the outcome of staphylococcal infections when combined with appropriate antibiotics.