Selenium effects on human neutrophilic granulocyte function in vitro.

The effects of an inorganic selenium salt on phagocytic functions of human neutrophilic granulocytes from donors with a low activity of glutathione peroxidase have been investigated. Granulocytes were exposed for 60 min in vitro to sodium selenite in two physiological concentrations (100 and 200 ng Se/ml) and one unphysiologically high concentration (2000 ng/ml). The spontaneous and chemotactic migration, the nitroblue tetrazolium reduction, the phagocytosis of fluorescein-labeled yeast particles and the intracellular killing of staphylococci were then studied in such granulocytes and compared to control cells, which had not been exposed to selenium. The migration and nitroblue tetrazolium reduction abilities of granulocytes were not affected by selenium exposure. The phagocytic and bactericidal activities were significantly increased in granulocytes exposed to selenium in physiological concentrations. However, at 2000 ng Se/ml these activities were found to be equal to or lower than control levels. Thus selenium supplementation might enhance phagocytic and bactericidal functions of human granulocytes, thereby improving the host defense against bacterial infections.