Description
Pre-B cell colony enhancing factor (PBEF) was originally identified as a cytokine that potentiated the clonalexpansion and differentiation of pre-B cells, but it is also acknowledged to be the ubiquitous intracellularenzyme nicotinamide phosphoribosyltranferase (NAMPT) and the adipokine “ visfatin ” . PBEF is constitutivelyexpressed in the fetal membranes where its greatest expression is in the amnion. It has intracellular andextracellular forms. Most of the intracellular functions of PBEF are due to its role as a Nampt which can induceangiogenesis through upregulation of VEGF and VEGFR and secretion of MCP-1. Extracellular PBEF has beenshown to increase inflammatory cytokines, such as TNF- α , IL-1 β , IL-16, and TGF- β 1. PBEF also increases theproduction of IL-6, TNF- α , and IL-1 β in CD14+ monocyctes, macrophages, and dendritic cells, enhances theeffectiveness of T cells.