Decreased fibronectin biosynthesis by human cord blood mononuclear phagocytes in vitro.

Cultured cord blood monocytes synthesize significantly less fibronectin than cultured monocyte-macrophages from adult peripheral blood. Biosynthesis of the second component of complement in vitro is similar for both cell systems. The monocyte-macrophages from neonates and adults have similar functional and morphologic properties in long-term cultures. The decreased monocyte-macrophage biosynthesis of fibronectin observed in vitro may be in part related to the reduced plasma fibronectin concentrations and reticuloendothelial system hypofunction which occur in newborn infants.