A network of phagocytic cells, primarily monocytes and macrophages, located in the connective tissue of the bone marrow, spleen, and liver that are involved in the clearance of bacteria, toxins, exogenous antigens, and immune complexes from the blood and tissues, as well as cytotoxicity against tumor cells.

Mononuclear phagocyte system (monocytes and macrophages) plus the vascular endothelium and the reticular and dendritic cells of lymphoid organs; whether this heterogeneous collection can still be considered a "system" is controversial.

(mononuclear phagocyte system) Mononuclear cells with pronounced phagocytic ability that are distributed extensively in lymphoid and other organs. It includes MACROPHAGES and their precursors; PHAGOCYTES; KUPFFER CELLS; HISTIOCYTES; DENDRITIC CELLS; LANGERHANS CELLS; and MICROGLIA. The term mononuclear phagocyte system has replaced the former reticuloendothelial system, which also included less active phagocytic cells such as fibroblasts and endothelial cells. (From Illustrated Dictionary of Immunology, 2d ed.)

Mononuclear phagocyte system, class of cells that occur in widely separated parts of the human body and that have in common the property of phagocytosis, whereby the cells engulf and destroy bacteria, viruses, and other foreign substances and ingest worn-out or abnormal body cells. German...