转GM-CSF基因瘤苗治疗白血病的实验研究

Experimental study on the treatment of leukemia using GM-CSF gene-modified cancer vaccines

目的由于白血病细胞的不局限性,其治疗方法受到很大的限制。本研究旨在探讨转粒细胞巨噬细胞集落刺激因子(GMCSF)基因瘤苗在白血病免疫治疗中的有效性和可行性。方法通过细胞生长曲线和动物致瘤性实验检测GMCSF基因对红白血病细胞系FBL3细胞生物学特性的影响;用丝裂霉素灭活FBL3GMCSF细胞制备转GMCSF基因瘤苗,通过转基因瘤苗免疫预防和免疫治疗动物实验探讨其预防和治疗白血病的可行性。结果FBL3GMCSF细胞体外生物学特性与FBL3vect和FBL3细胞相比没有明显差异。细胞形态和生长速度均无差别。动物致病等实验显示,分别接种FBL3GMCSF、FBL3vect和FBL3细胞,各组肿瘤均持续生长,但同一接种数量间相比,FBL3GMCSF平均出瘤时间比FBL3vect和FBL3晚,肿块平均体积也相应较小。丝裂霉素灭活FBL3GMCSF细胞后作为瘤苗,免疫小鼠产生的免疫保护力明显强于灭活的FBL3vect和FBL3。FBL3GMCSF组与FBL3vect、亲本FBL3细胞和PBS对照组相比出瘤时间晚、肿瘤生长速度慢、小鼠生存期延长,其中有4/10的小鼠长期存活(超过60天)。另外,转基因瘤苗免疫治疗动物实验结果也显示:与FBL3vect、亲本FBL3细胞和PBS对照组相比FBL3GMCSF组肿瘤生长速度受到明显抑制,其中2/10只小鼠肿瘤完全消失;小鼠生存期延长,其中有2/10的小鼠长期存活(超过60天)。结论丝裂霉素灭活FBL3GMCSF后作为瘤苗可有效对白血病进行免疫治疗,有良好的临床研究和应用前景。

Objective The treatment of leukemia is limited by diffusion of leukemia cells. The aim of this study was to investigate the effectiveness and feasibility of immune therapy for leukemia by vaccination with granulocyte-macrophage colony-stimulating factor（GM-CSF）. Methods The biological characteristics of FBL-3-GM-CSF cells were studied by the growth curve and tumorigenicity experiment in vivo. The GM-CSF gene-modified tumor vaccines were prepared with mitomycin-C inactivated FBL-3-GM-CSF cells. The effects of vaccination with mitomycin-C inactivated FBL-3-GM-CSF on immune prophylaxis and immune therapy of leukemia were investigated in animal experiments. Results There was no significant difference in the biological characteristics （cellular morphology and growth rate） between FBL-3-GM-CSF, FBL- 3-vect and FBL-3 cells. In mice vaccinated with the FBL-3-GM-CSF cells, tumor formation was later and the tumor volume was smaller than those vacinated with FBL-3-vect or FBL-3 cells. Vaccination with mitomycin-C inactivated FBL-3-GM- CSF in mice could significantly induce potent anti-tumor immune reaction compared with that with FBL-3- vect cells, FBL- 3 cells or PBS. The growth rate of tumor in mice vaccinated with FBL-3-GM-CSF was markedly slower and the survival time was dramatically longer compared with in those vaccinated with the FBL-3-vect cells, FBL-3 cells or PBS. Conclusions The vaccination with mitomycin-C inactivated FBL-3-GM-CSF for the treatment of leukemia is effective and feasible. The study provided experimental and theoretical data for further clinical study and application of GM-CSF gene-modified cancer vaccines.