Differentiation of various mononuclear phagocyte colony-forming cells by hypotonic lysis

Various classes of murine mononuclear phagocyte colony-forming cells (CFU) present in peritoneal exudate, alveolar spaces, and blood are capable of extensive proliferation and form colonies in vitro. In this study, the sensitivity to hypotonic lysis of the proliferative capacity of various classes of mononuclear phagocyte CFC as well as three cell lines was investigated. The results showed that alveolar CFC (AL-CFC) and a macrophage cell line J774 are most resistant to hypotonic conditions, and the committed stem cells for both granulocytes and macrophages (GM-CFC) and blood monocytes (BL-CFC) are most sensitive to hypotonic conditions. Within 7 min all GM-CFC and BL-CFC are killed but less than 5% of AL-CFC are killed. Peritoneal exudate CFC (PE-CFC) displayed intermediate sensitivity since 50% of them were killed within 7 min in the hypotonic conditions. These data suggest that various classes of mononuclear phagocyte CFC can be distinguished from each other by their ability to resist hypotonic lysis.