Pentraxin 3 also known as TNF-inducible gene 14 (TSG-14) is a member of the pentraxin superfamily characterized by cyclic multimeric structure. Pentraxin 3 is rapidly produced and released by several cell types, in particular by mononuclear phagocytes, dendritic cells (DCs), fibroblasts and endothelial cells in response to primary inflammatory signals (e.g., toll-like receptor (TLR) engagement, TNFα, IL-1β).
Pentraxin 3 behaves as an acute phase response protein, as the blood levels of Pentraxin 3, low in normal conditions (about 25 ng/ml in the mouse, < 2 ng/ml in humans), increase rapidly (peaking at 6 – 8 h after induction) and dramatically (200 – 800 ng/ml) during endotoxic shock, sepsis and other inflammatory and infectious conditions, correlating with the severity of the disease. Under these conditions, Pentraxin 3 is a rapid marker for primary local activation of innate immunity and inflammation. Studies showed that Pentraxin 3 has a dual role: protection against pathogens and control of autoimmunity.