Induction of macrophage-mediated tumor lysis by an animal lectin, Sarcophaga peregrina agglutinin.

Several animal lectins, such as Sarcophaga peregrina agglutinin, Limulus polyhemus agglutinin, Helix pomatia agglutinin and Helix aspersa agglutinin, were tested for induction of tumor lysis mediated by macrophages. Among them, only S. peregrina agglutinin purified from the hemolymph of S. peregrina larvae lysed tumor cells in co-operation with macrophages from the peritoneal cavity of mice. S. peregrina agglutinin alone did not kill target tumor cells. Macrophages in the presence of this lectin could kill other syngeneic tumor cells. This lectin-dependent cytolysis by macrophages was inhibited by galactose, a sugar which is specifically recognized by S. peregrina agglutinin. These findings suggest that the animal lectin S. peregrina agglutinin is a ligand in macrophage-mediated cytolysis, inducing binding of effector macrophages to target cells which in turn triggers off lysis of the target cells.