Carcinoembryonic antigen inhibits neutrophil activation by N-formyl-methionyl-leucyl-phenylalanine

Carcinoembryonic antigen(CEA)is a surface glycoprotein expressed in human epithelial cells and is released from their surface,especially during colorectal cancer.Frequently,colorectal cancer is accompa­nied by inflammation,where tumor-infiltrating neutrophils play an important role.CEA was also found to be a strong chemotactic agent for neutrophils.The purpose of this study was to find out if CEA can enhance neu­trophil priming and activation.Primed neutrophils were activated by N-formyl-methionyl-leucyl-phenylalanine(formyl-MLP)and the resulting oxidative burst was measured luminometrically.Unexpectedly,in vitro priming of neutrophils by CEA,alone or preceded by LPS,inhibited subsequent activation of these cells by formyl-MLP.CEA may have anti-inflammatory properties in vivo.