The influence of erythrophagocytosis on the interaction of macrophages and salmonella in vitro

Abstract

Phagocytosis and killing of Salmonella typhimurium by mouse peritoneal macrophages was inhibited when the bacteria and antibody-coated homologous erythrocytes or heterologous erythrocytes were simultaneously exposed to macrophages in vitro. No inhibition of phagocytosis or killing was observed in experiments employing uncoated or disrupted antibody-coated homologous erythrocytes. Degradation of S. typhimurium as measured by the loss of fluorescence from intracellular salmonella coated with fluorescein-labeled antibody was inhibited in macrophages which had previously ingested antibody-coated homologous erythrocytes. Anti-mouse-erythrocyte serum was found to have a cytotoxic action on mouse macrophages. However, the viability of macrophages was not altered by phagocytosis of antibody-coated homologous erythrocytes or uncoated heterologous erythrocytes.