How Do Phagocytes Eat?

Abstract

Phagocytosis is a cellular function relevant for host defense against infection, tissue turnover and other aspects of human physiology. It is representative of functions where external stimuli activate motile events in the cell. Recognition of suitable objects by the plasma membrane of the phagocyte initiates phagocytosis. Knowledge of serum proteins that coat objects rendering them recognizable is considerable, but understanding the chemical basis of recognition is meager. The signals activated by recognition are not known. Phagocytosis causes pseudopodia to enclose objects in vacuoles, this is ascribable to metabolic energy-dependent interactions between actin filaments and other contractile proteins in the peripheral cytoplasm. These interactions may regulate the fusion of lysosomes with phagocytic vacuoles, important for the processing of ingested objects after phagocytosis.