Muramyl dipeptide and anti-CD10 monoclonal antibody immunoconjugate enhances anti-leukemia immunity of T lymphocytes.

ABSTRACT

It is necessary to completely eliminate minimal residual disease (MRD) to cure acute leukemia. Monoclonal antibodies (MAb) have been shown to be effective to eliminate MRD. In this study we aimed to investigate the effect of anti-CD10 MAb conjugated to muramyl dipeptide immunoconjugate (MDP-Ab) on the function of lymphocytes and activated lymphocytes using leukemia xenografts in nude mice as a model. Peripheral blood mononuclear cells were isolated from children with acute lymphoblastic leukemia and induced into dendritic cells (DCs) and lymphocytes. Cytotoxic activity of lymphocytes was detected by LDH release assay. Leukemia xenografts in nude mice were established to assess tumor growth. We found that the killing rate was significantly higher in MDP-Ab group, LPS group and MDP-Ab+LPS group than in control group, and was the highest in MDP-Ab+LPS group. Tumor-bearing mice in MDP-Ab group showed obvious coagulation necrosis. In conclusion, our data suggest that MDP-Ab could effectively prime DCs to improve the anti-tumor immunity of T lymphocytes and inhibit the tumor growth. MDP-Ab may be used as suitable candidate for eliminating residual leukemia cells to prevent relapse.