Sub-lethal autolysis. Modification of cell periphery by lysosomal enzymes

Lysosomal activation was induced in dog kidney and HEp-2 cells by treatment with anticellular serum and high concentrations (20 μg/ml) of vitamin A alcohol. The morphological changes accompanying the release of enzymes from activated lysosomes were described. Measurements of cell coat thickness by ellipsometry revealed that lysosomal enzymes released extracellularly were able to digest the coat. The scale of enzyme release was an important factor in determining the amount of coat digested. Complement-sufficient anticellular sera and high concentrations of vitamin A induced marked lysosomal activation and extensive digestion of the coat. Complement-deficient anticellular serum produced significantly less lysosomal labilization and only limited digestion of the coat. The digestion of the cell coat induced by these agents was prevented by pretreatment of the cells with either hydrocortisone or chloroquine.