Survivin致敏的树突状细胞疫苗激活抗白血病T细胞的实验研究

为研究survivin致敏树突状细胞（DC）疫苗对特异性T细胞的激活影响及对白血病细胞生长抑制作用，采用共聚焦显微镜及免疫沉淀-Western印迹等方法检测急性白血病细胞survivin表达；外周血单个核细胞体外培养，诱导DC细胞的形成；体外进行survivin抗原负载，制备survivin DC疫苗；survivin DC激发同基因型T细胞，用流式细胞术进一步分析T细胞表型；^3H-TdR法测定刺激指数（SI）；并用^51Cr释放法测定特异性的抗白血病CTL细胞毒活性。结果表明，检测19例初治急性白血病患survivin的表达率为84.2％；其荧光分布均在细胞胞浆内；免疫沉淀-Western印迹进一步分析证实其survivin蛋白表达；外周血单个核细胞体外诱导形成的DC细胞具有典型的DC的形态学特征；survivinDC可显刺激T细胞的活化增殖；survivin激活的T细胞中，CD4^ TH比例显较DC组高，DC激发的T细胞则以表达CD8和CD56为主；同时survivinDC显抑制白血病细胞的生长。结论：急性白血病细胞表达survivin抗原，利用survivinDC疫苗可有效地抑制白血病细胞的生长，为DC治疗白血病开辟了一条新途径。

Experimental Study on Activating Antileukemic T Cells by Vaccination with Dendritic Cells Pulsed with Survivin

The objective of this study is to investigate the effect of vaccination with dendritic cells pulsed with survivin antigen on activation of antileukemic T cells, and inhibiting proliferation of leukemic cells. The expression of survivin on acute leukemic cells were detected by cofocal microscopy and immunoprecipitation Western blot. DCs collected from peripheral blood mononuclear cells were pulsed with survivin purified proteins. Stimulation index (SI) and antileukemia CTL induction were analyzed with 3H TdR incorporation and 51 Cr releasing assay, respectively. The phenotype of T cells and DCs were identified by flow cytometry. By immunofluorescence of bone marrow and peripheral blood mononuclear cells, survivin expression was detected in 16 out of 19 AML cases (84.2%). The results showed that survivin fluorescence distribution was in cytoplasm. DCs from peripheral blood mononuclear cells were successfully induced, with typical DC morphologic characteristic. The vaccination with dendritic cells pulsed with survivin antigen dramatically stimulated the proliferation of T cells. The DCs loading survivin activated T cells with higher CD4 + T H ratio as compared with DCs group, T cells activated with DCs expressed CD8 and CD56. Survivin DCs significantly inhibited the growth of leukemic cells in vitro. In conclusion, survivin antigen expressed in the cytoplasm of leukemic cells, leukemic vaccination with DCs pulsed with survivin antigen in vitro inhibited the proliferation of leukemic cells, that may be a pathway for therapy of leukemia.