Enhancement of antibody-independent phagocytosis by N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7).

A low-molecular weight compound N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7) resulted in strongly enhanced phagocytosis of polystyrene latex beads by peritoneal macrophages of BALB/c mice after intraperitoneal administration. Binding of C3 cleavage product (C3b) to peritoneal macrophages after intraperitoneal injection of W-7 was also enhanced as shown by fluorescent antibody technique. Antibody against W-7 was not detected in the sera of these mice. Therefore, close association of enhanced phagocytosis of polystyrene latex beads with increased binding of C3 cleavage product to macrophages was demonstrated through induction by a low-molecular weight compound in vivo.