Neutrophils release the serine proteases neutrophil elastase and cathepsin G, which have microbicidal activity and thereby contribute to the innate immune response. Steffen Massberg et al. now show that these neutrophil serine proteases, in association with extracellular nucleosomes, can also promote coagulation and thrombosis within large blood vessels. In a mouse model of systemic bacterial infection, these proteases spurred intravascular coagulation in the microcirculation of the liver, limiting bacterial tissue invasion. These findings point to a role for thrombosis in antimicrobial defense.
- Steffen Massberg
- Lenka Grahl
- Bernd Engelmann