Inhibition of human neutrophil phagocytosis and intracellular killing of yeast cells by fluoride.

These processes depend upon the catabolism of glucose, which can be inhibited by fluoride (F-). We studied them with a radiolabelling technique using [3H]-uridine, which is incorporated into viable yeast cells, but hardly at all into neutrophils and dead or phagocytosed yeast cells. Lysis of neutrophils and treatment of the lysate with [3H]-uridine allowed estimation of intracellular killing of yeast cells. F- inhibited neutrophil phagocytosis and intracellular killing in a dose-related manner. Intracellular killing was significantly more sensitive to environmental F- than was phagocytosis. This effect on phagocytosis was not because of inhibition of opsonization of yeast, nor was it related to an effect on medium Ca2+.