The effect of alpha-fetoprotein on the activation and phagocytosis of granulocytes and monocytes

Abstract

Background/aims: The peripheral blood mononuclear cells constitute the first line of innate immunity.Although restricted to embryonic expression and elevated in liver cancer, alpha-fetoprotein (AFP) has recently been recognized for its role in modulation immunity. The aim of this study is to examine the influence of alpha-fetoprotein on the activation and phagocytosis of granulocytes and monocytes in vitro.

Methodology: The human peripheral blood granulocytes and monocytes were prepared from healthy volunteers. Blood cells were incubated with different levels of AFP and activation by oxidative burst and phagocytosis were measured by flow cytometry.

Results: First- ly, the percentage of monocytes producing reactive oxygen metabolites was higher in groups with exogenous AFP than the group without AFP exposure. Secondly, we assessed the phagocytosis levels of granulocytes and monocytes at different AFP levels. At certain regions of AFP (600-6000ng/mL), the granulocytes and monocytes gained increased capacity of bacteria phagocytosis.

Conclusions: Alpha-fetoprotein level in the plasma is apparently related to monocyte activation. The results also suggested that alpha-fetoprotein can stimulate the phagocytosis of granulocytes and monocytes in vitro.