多表位肽抗原诱导特异性CTL抗慢性髓性白血病细胞的体外实验研究

目的：在应用基因工程技术人工表达获得多表位BCR-ABL融合蛋白的基础上，对该融合抗原在体外诱导对自血病细胞的特异性杀伤效应进行检测，探索慢性髓性自血病（CML）免疫治疗的新途径。方法：从外周血单个核细胞培养树突细胞（DC），以BCR-ABL融合抗原脉冲刺激DC，诱导特异性细胞毒T淋巴细胞（CTL）产生；MTT法检测CTL对白血病靶细胞的特异性杀伤活性。结果：以BCR-ABL融合抗原刺激产生的CTL能特异性抑制b3a2＋的靶细胞生长，包括K562细胞（P〈0．01）和HIJA-A2＋／b3a2＋的CML原代细胞（P〈0．05），而对HIA-A2-或b2a2＋靶细胞无明显抑制作用。结论：设计表达的多表位BCR-ABL融合抗原能在体外诱导特异性抗CML免疫反应，抑制b3a2＋自血病细胞生长，有望为进一步的体内实验奠定基础。

In Vitro Specific Anti-Chronic Myeloid Leukemia Cell Effect of CTL by a Multiple Epitope BCR-ABL Fusion Protein

Objective： To assay the anti-leukemia effect of cytotoxic lymphocytes（CTL） induced by a multiple epitope BCR-ABL fusion protein in vitro acquired by gene engineering technology so as to explore a new method of immunotherapy for chronic myeloid leukemia（CML）. Methods： Dendritic cells（DC） were generated from peripheral mononuclear cells by co-cultivation with granulocyte/macrophage-colony stimulating factor and interleukin-4. Pulsed with the BCR-ABL fusion antigen, harvested DC were transformed into specific CTL. The specific lytic activities of CTL on target cells were detected by standard MTT assay. Results： CTL stimulated with the fusion protein inhibited the growth of b3a2＋ target cells, ineluding K562 cells（P〈0.01） and HLA-A2＋/b3a2＋ CML cells（P〈0.05）, but showed no effect on HLA-A2- or b2a2＋ target cells. Conclusion： The multiple epitope BCR-ABL fusion antigen in our study can induce specific anti-CML immunological reaction and inhibit the growth of b3a2＋ leukemia cells in vitro, which may provide a research basis for further investigation on the strategy of immunotherapy for CML in vivo.