Enrichment of macrophages in cell suspensions of human intestinal mucosa by elutriation centrifugation.

To obtain macrophage-rich cell suspensions from human intestinal mucosa, lamina propria specimens were dissociated by incubating in EDTA-collagenase-DNAase solutions and further purified by counter-current centrifugation. During enzymatic incubation macrophage dissociation was linear over the first 8-10 h, reaching a maximum concentration of 10% of total cells and then it plateaued. Counter-current centrifugation resulted in a 5-fold enrichment of macrophages to a mean of 50% with an average recovery rate of 84%. Yields exceeded 0.69 X 10(5) macrophages/g mucosa. Greater than 90% of these cells phagocytosed Staphylococcus aureus, and could be maintained in culture for up to 8 days. Electron microscopy showed satisfactory preservation of the ultrastructure of the macrophages, which also seemed functionally intact.