Inhibition and augmentation of lymphoma metastasis by adoptively transferred peritoneal macrophages in hamster.

The effect of adoptively transferred peritoneal exudate cells on the metastasis of hamster lymphoma was studied. Metastatic spread occurring after the surgical removal of a primary tumor was considerably inhibited by the adoptive transfer of the peritoneal exudate cells (PEC) stimulated by immunostimulants, using a streptococcal preparation (OK-432) or a purified beta (1-3) glucan (SPG). However, the inhibitory effect on metastasis was abrogated by the in vitro treatment of the peritoneal adherent cells with silica. PEC stimulated with lymphokines in vitro was also effective in inhibiting metastasis. However, the adoptive transfer of peritoneal adherent cells treated in vitro with 12-O-tetradecanoylphorbol acetate (TPA) in vitro, augmented metastatic spread in tumor-bearing hamsters which usually exhibit concomitant immunity. The relation of the state of the functional activity of macrophages to metastasis is discussed.