Efficacy of leukemia vaccine combined 1-MT immune treatment of tumor-bearing mice / 白血病·淋巴瘤

ABSTRACT

Objective To explore the active immunotherapeutic effects of whole-cell leukemia vaccine combined with 1-methyl-tryptophan (1-MT, inhibitor of idoleamine 2,3-dioxygenase, IDO) treatment on leukemia. Methods The tumor-bearing mice model was made by hypodermic injection of FBL-3 cells. Then these mice were divided into 5 groups, normal group, PBS control group, CTX chemotherapy group, vaccine treated group and vaccine combined with 1-MT treated group (1-MT group), respectively. The main outcome measures including general condition, response rate, tumor size, metastasis and survival time were investigated. Results The mice of PBS control group were slow to move and much heavier (including tumor nodules) than the other groups. No obvious difference was observed in activity, eating behavior and weight between normal group, vaccine treated group and 1-MT treated group. The mice of CTX chemotherapy group were observed epilation, arched body and worn, and those weights decreased significantly compared with other group. The treatment-related mortality of vaccine-treated group and 1-MT group was lower than that of CTX chemotherapy group significantly (0, 0 vs 40 %). There were no significant difference in complete remission rates between vaccine treated group and 1-MT group (61.1 % vs 70.0 %, χ2 = 0.221, P >0.05). But the recurrence rate of 1-MT group was lower than vaccine treated group (0 vs 36.36 %). The tumor nodules growth of recurrent mice could be inhibited by 1-MT. The mean survival time of vaccine treated group and 1-MT group were longer than that in CTX chemotherapy group and PBS control group (χ2 = 52.13, P <0.01). Conclusion Whole-cell leukemia vaccine can inhibit tumor growth and prolong tumor-bearing mice survival time with remarkable curative effects and few side effects. Vaccine combined with 1-MT treatment can significantly reduce tumor recurrence rate, and 1-MT was still effective in inhibiting recurrence of tumor nodules growth after vaccine treatment.