Description: CD93 (also known as C1qRp) is a type 1 transmembrane glycoprotein that is required for efficient engulfment of apoptotic cells. Expression of CD93 is confined to myeloid cells with higher expression on monocytes than neutrophils, eosinophils, platelets and endothelial cells. Expression on DC’s is downregulated upon maturation. Additionally, CD93 has been shown to define an early bone marrow stem cell population of hematopoietic and hepatic precursors.
Recently, it was demonstrated that CD93 is proteolytically cleaved from the surface of activated human monocytes and neutrophils in response to inflammatory signals (TNF-alpha, TGF-alpha, TGF-beta, EGF, CD44, and L-Selectin) in vitro and that a soluble form, sCD93, exists in human plasma.
sCD93 induced differentiation of monocytes to macrophage-like cells and plasma CD93 concentration is also potential novel biomarker for coronary artery disease.