SORDELLI Daniel Oscar
Shedding of TNFR1 induced by protein A decreases TNF-α availability and inflammation during systemic Staphylococcus aureus infection.
GIAI C; GONZALEZ C; LEDO C; GAROFALO A; DI GENARO MS; SORDELLI DO; GOMEZ MI
INFECTION AND IMMUNITY
AMER SOC MICROBIOLOGY
Lugar: Washington; Año: 2013 vol. 81 p. 4200 - 4207
Staphylococcus aureus infections are an important public health concern due to their increasing incidence and high rates of mortality. The success of S. aureus as a pathogen is highly related to its enormous capacity to evade the host immune response. The critical role of tumor necrosis factor alpha (TNF-α) in the initial host defense against systemic staphylococcal infection has been demonstrated in experimental models and may partially explain the lack of significant benefits observed in clinical trials attempting to neutralize this cytokine in septic patients. S. aureus protein A plays a key role in regulating inflammation through its ability to bind and signal through the TNF-α receptor 1 (TNFR1). In this study, we demonstrate that S. aureus, via protein A-mediated signaling, induces early shedding of TNFR1, which precedes the secretion of TNF-α in vitro and in vivo. The results obtained using a protein A-deficient mutant and tnfr1(-/-) mice strongly suggest that the increased levels of soluble TNFR1 present during experimental S. aureus infection may neutralize circulating TNF-α and impair the host inflammatory response. Early shedding of TNFR1 induced by protein A may constitute a novel mechanism by which S. aureus subverts the host immune response.