Dezocine promotes T lymphocyte activation and inhibits tumor metastasis after surgery in a mouse model

Dezocine is an opioid analgesic with both μ-receptor agonist and antagonist activities. Administration of opioids influences the immune system through immune cells. Dendritic cells (DC) play crucial functions in inducing T cell response and mediating immune functions. DC surface displays several different opioid receptors whose expression is induced during DC maturation. We aimed to explore the effects of dezocine on DCs and T cells, as well as on tumor treatment. Mice were intraperitoneally administrated with increasing doses of dezocine (0.75, 1.25 and 2.0 mg/kg). Mouse bone marrow-derived dendritic cells (BMDCs) were then isolated from the bone marrow. The BMDC surface markers were evaluated by flow cytometry. T cell proliferation was assessed by the carboxyfluorescein succinimidyl ester assay. The number of mature DCs were increased by dezocine treatment in both human umbilical cord blood and mouse peripheral blood, suggesting that dezocine enhanced BMDC maturation. Dezocine-treated BMDCs promoted CD8+ T cell proliferation and cytotoxicity, while dezocine treatment inhibited tumor metastasis in mice. We therefore conclude that the administration of dezocine promotes BMDC maturation and inhibits tumor metastasis through elevating CD8+ T cell proliferation and cytotoxicity.