α-干扰素对慢性髓细胞白血病来源的树突状细胞的免疫调节作用(Ⅱ)

Immunoregulatory effects of interferon-α on dendritic cells from patients with chronic myeloid leukemia (Ⅱ)

目的 于慢性髓细胞白血病 (CML)来源的树突状细胞 (DCs)的无血清培养基中 ,加入α 干扰素 (IFN α) ,观察IFN α对CML DCs表达Fas/FasL的影响 ,以及体外IFN α合并DCs瘤苗对CML祖细胞的抑制作用。方法 CML DCs的培养基中除加入SCF、GM CSF、TNF α及IL 4外 ,还加入IFN α。培养 10～ 14d ,鉴定细胞免疫表型、Ph1染色体比例和混合淋巴细胞反应 ,流式细胞仪检测细胞表达Fas/FasL比例 ,碘化丙锭 (PI)染色分析细胞凋亡 ,ELISA法测上清液sFas含量 ,甲基纤维素半固体集落培养法鉴定IFN α加DCs瘤苗对CML的CFU GEMM的体外抑制作用。结果 加入IFN α后 ,CML DC免疫表型及刺激T细胞增殖能力均显著改善 ;CML DCsFas的表达上调 ,sFas含量却下降 ,FasL表达阴性 ;PI染色显示亚二倍体峰的数值升高 ,即凋亡比增加。IFN α合并DCs瘤苗组对CML的CFU GEMM体外抑制作用优于IFN α组或DCs瘤苗组。结论 IFN α在改善CML DCs免疫表型及功能的同时 ,亦可通过Fas途径促进Ph1阳性细胞凋亡。IFN α与DCs瘤苗有协同作用 ,体外二者联合应用对CML祖细胞有明显的抑制作用。

Objective To observe the effect of interferon- α (IFN- α ) on expressions of Fas/Fas ligand (FasL) system in dendritic c ells (DCs) from chronic myeloid leukemia (CML) and the inhibitory effect of IFN - α with DC vaccines on the progenitors of CML in vitro . Methods In addition to adding stem cell factor(SCF), gran ulocyte-macrophage colony-stimulating factor (GM-CSF) , tumor necrosis factor - α (TNF- α ) and interleukin-4 (IL-4), IFN- α was added to seru m-free medium of culturing DCs. After 10～14ds' culture, cell phenotypes, allo genetic mixed lymphocytes reaction and percentages of Ph 1 chromosome were analyzed by using different methods. The expressions of Fas / FasL on CML-DCs a nd cell cycle of DCs labeled with propidium iodine (PI) were measured by flow cy tometry. The concentration of sFas in supernatants was analyzed by enzyme-linke d immunosorbent assay (ELISA). The inhibitory effect of IFN- α with DCs vac cines on colony forming units-granulocyte-erythrocyte-monocyte-macrophage (C FU-GEMM) in vitro was evaluated by using semi-solid medium of methylcellul ose. Results The phenotypes and allogenetic mixed lymphocyt es reaction (MLR) in IFN- α group were improved significantly while the pe rcentage of Ph 1 positive cells decreased. The expression of Fas on CML-DC s was upregulated and the secretory level of sFas decreased when IFN- α was added to the serum-free medium. However, the expression of FasL remained negat ive. The ratio of apoptosis rose gradually with the increase of IFN- α conc entration. The inhibitory effect of IFN- α with DC vaccine group on CFU-GE MM of CML was superior to that of only IFN- α group or DCs vaccine group. Conclusion IFN- α can accelerate the apoptosis of Ph 1 positive cells at least partly through Fas/FasL pathway while the phenotyp es and function of CML-DCs are corrected partly by IFN- α . CML progenitors under semi-solid culture in vitro are inhibited significantly when IFN- α is in combination with DCs vaccines.