Pentraxin-related protein PTX3 (PTX3) (PTX3)

Pentraxin-related protein PTX3, also known as Pentraxin-3, is the prototype of the long pentraxin family and a central component of the humoral innate immune system. Unlike short pentraxins such as C-reactive protein (CRP), PTX3 is produced locally at sites of inflammation by diverse cell types, including vascular endothelial cells, macrophages, and dendritic cells. It functions as a soluble pattern recognition receptor that binds various pathogens—such as fungi, bacteria, and viruses—and activates the classical complement pathway via C1q to facilitate opsonization and phagocytosis. Beyond its role in host defense, PTX3 is involved in tissue remodeling, female fertility via ovarian cumulus expansion, and the regulation of angiogenesis through its interaction with fibroblast growth factor-2 (FGF2). PTX3 is a sensitive biomarker for cardiovascular disease, sepsis, and COVID-19 severity, and is currently being investigated as a therapeutic target where recombinant forms may enhance host defense and protective immunity, while neutralizing agents may curb chronic inflammation or tumor-promoting pathways in specific cancers.

Other names

Pentraxin 3TNF-inducible gene 14 proteinTSG-14Tumor necrosis factor alpha-induced protein 5TNFAIP5Long pentraxin 3

Modulation of PTX3 levels to either enhance innate immunity and tissue protection via opsonization and complement activation, or to neutralize pro-inflammatory and pro-tumorigenic signaling pathways (e.g., FGF2 sequestration or NF-kB signaling inhibition).