Modulation of macrophage activity in tumor bearing mice by cytogenin

Abstract

Cytogenin recovered the reduced mitogenic response to Con A of spleen cells of tumor bearing mice in vitro. The suppressive factor(s) was detected in adherent cell population in spleen cells. The reduced antitumor effector activity of spleen cells taken from tumor bearing mice was also augmented by the treatment with cytogenin in vitro. The effect of cytogenin was neutralized by the treatment with anti-Mac 1 serum. Administration of cytogenin inhibited the production of nitric oxide by macrophages which is known as one of suppressor factors. Results indicate that one possible action of cytogenin exhibiting antitumor activity in tumor bearing mice may be due to modulation of Mac 1 positive cells.