Abstract
In addition to pathogen-associated molecular patterns (PAMPs) from invasive microorganisms, alarmins, which are major components of host defense mechanisms, are involved in the pathophysiology of sepsis. In fact, the magnitude of the insult is defined according to the damage-associated molecular pattern (DAMP), which is composed of alarmins as well as PAMPs, such as those involving the nucleosome, histones and DNA. Regarding the antimicrobial mechanism of neutrophils, an alternative non-phagocytic mechanism was first recognized as NETosis in 2004. In this mechanism, microorganisms are trapped and eliminated by neutrophil extracellular traps (NETs). NETs are composed of histones and DNA that have been expelled from the nucleus as well as antimicrobial proteases, including elastase and myeloperoxidase. NETosis, a cell-death pathway reported to be distinct from apoptosis, is an active area of recent research. Since NETs are composed of deleterious substances, they are extremely harmful to the host cells once they released into the circulating blood. Therefore, the meanings and putative roles of these components in sepsis has attracted much attention.
