Phagocytic and lysosomal activity in Langerhans cells from sensitized guinea pigs

Guinea pig skins were sensitized and challenged with horseradish peroxidase. Langerhans cell granules contained the horseradish peroxidase. The cytoplasmic locations of horseradish peroxidase in Langerhans cells changed with the passage of time: The antigen was found initially in peripheral Langerhans cell granules and subsequently in those located near the nucleus. The number of lysosome-like dense bodies, or multivesicular bodies increased with time. After 24 hr the antigen was absent from the Langerhans cell granules and seen only in lysosome-like dense bodies, or multivesicular bodies. When acid phosphatase activity was examined, the Langerhans cell granules attached to plasma membranes and rod-shaped granules were negative. It was positive in lysosome-like dense bodies, multivesicular bodies, and the bulb part of the Langerhans cell granules. A similar sequence of observations was made when guinea pig skins were sensitized and challenged with ferritin and 2,4-dinitro-1-chlorobenzene. It is concluded that Langerhans cell granules can take up antigens and assume an aspect of the lysosome.