Toxicity of staphylococcal alpha toxin for rabbit alveolar macrophages

Highly purified staphylococcal alpha toxin was toxic in vitro for rabbit alveolar macrophages. Cytotoxicity, manifested by loss of the ability to exclude trypan blue dye and by morphological evidence of cell necrosis and lysis, was observed after exposure for 4 h to 1 microgram of toxin preparation per ml and after exposure for 8 h to 0.1 microgram of toxin per ml. In addition, exposure to toxin under conditions which did not kill more than 10% of the cells (1 microgram/ml for 1.5 to 2 h) significantly reduced the phagocytic activity of the cells and their ability to respond to an activator of hexose monophosphate shunt activity.