IMMUNOPOTENTIATING ACTIVITIES OF POLYSACCHARIDE FRACTION FROM PINE SEED SHELL EXTRACT

The function of polysaccharide (PSE) extracted from pine seed shells a s a immunopotentiator was investigated The phagocytosis and chemotaxis of mouse peritoneal macrophages (MP) were augmented by oral administr ation of PSE. The incorporation of H-3-thymidine by Con A-stimulated m ouse splenic cells mas significantly intensified by administration of PSE but the adherent-cells (MP)-eliminated splenic lymphocytes was nor increased. It is shown that the existence of activated MP is needed f or the activation (proliferation) of T lymphocytes. The responsiveness of mouse T cells to alloantigen was also augmented by administration of PSE. The number of anti-SRBC plaque-forming cells in the spleen of mouse and chicken was also significantly increased. The results indica te that MP are first activated by oral administration of PSE and that the activation of T cells is then initiated indirectly by humoral fact ors (cytokines) produced by activated MP.