Macrophage variants in oxygen metabolism

Whereas phagocytic cells from normal individuals have the capacity to kill ingested bacteria and parasites, those from patients with several uncommon genetic deficiency diseases are known to be defective in bactericidal activity. Studies on neutrophils of these patients have revealed fundamental defects in their ability to reduce molecular oxygen and metabolize it to superoxide anion, hydrogen peroxide, and oxygen radicals. In the present experiments, we describe a clone of a continuous murine macrophage-like cell line, J774.16, that, upon appropriate stimulation, activates the hexose monophosphate shunt, and produces superoxide anion and hydrogen peroxide. With nitroblue tetrazolium to select against cells capable of being stimulated by phorbol myristate acetate to reduce the dye to polymer--formazan--which is toxic fot cells, we have selected for variants that are defective in oxygen metabolism. Four of these subclones have been characterized and found to be lacking in the ability (a) to generate superoxide anion, as measured by cytochrome c reduction; (b) to produce hydrogen peroxide, as measured by the ability to form complex I with cytochrome c peroxidase; and (c) to be stimulated to oxidize glucose via the hexose monophosphate shunt. These variants appear to represent a useful model for studying the molecular basis for macrophage cytocidal activity.