Microbicidal capacity and acid hydrolase content of human blood monocytes and peritoneal macrophages.

Peritoneal macrophages and peripheral blood monocytes were collected from healthy women undergoing laparoscopic tubal clipping. Monolayers of adherent cells were examined for protein content, intracellular levels of lysosomal enzymes, and antimicrobial capacity. Compared to blood monocytes, peritoneal macrophages were larger and less glass-adherent and were less capable of intracellular killing of Salmonella typhimurium. Acid hydrolase content, however, was increased in peritoneal macrophages. These data suggest that resting human tissue macrophages may be less active in certain respects than their blood precursors. One should then question whether the enhanced functions observed after long-term in vitro culture of blood monocytes-macrophages accurately reflect the in vivo status of their more differentiated descendants.