CHANGES IN THE FUNCTIONAL ACTIVITY OF MACROPHAGES UNDER THE INFLUENCE OF BACTERIAL LECTIN APPLAIED IN DIFFERENT SCHEMES

Abstract

Aim: to investigate the antitumor effect and the influence of B. subtilis IMV B-7724 lectin applied as a single therapy or in combination with cisplatin on various manifestations of macrophages functional activity during the growth of a metastasizing experimental tumor. Materials and methods: the study was performed on C57Bl/6J mice bearing Lewis lung carcinoma (LLC). The effect of the lectin applied as a single therapy or in combination with cisplatin on tumor growth and the functional activity of peritoneal macrophages were evaluated. The functional activity of peritoneal macrophages was studied by the level of NO production, arginase and cytotoxic activity. Results: there was demonstrated an antimetastatic efficacy of B. subtilis IMV B-7724 lectin applied in Lewis lung carcinoma model either as a single therapy or in combination with cisplatin. In all probability, this effect was grounded by the changes in macrophages functional activity. As it is evidenced by a significant (p < 0.05) suppression of macrophages’ cytotoxic activity and characteristic changes in arginase metabolism, M2 macrophages predominated in the control (untreated) tumor-bearing mice. The features of L-arginine metabolism and cytotoxic activity in peritoneal macrophages indicate the preservation of their antitumor activity (polarization toward M1 type) at the terminal stage of experimental tumor growth. Conclusions: in the animals bearing experimental tumor, the most pronounced antitumor effect was observed when the bacterial lectin was applied in combination with cisplatin. The use of B. subtilis IMV B-7724 lectin as a therapeutic agent (either as a single therapy or in combination with cisplatin) preserved the antitumor activity of macrophages and promoted their polarization toward M1 direction at the terminal stage of tumor growth.