源于细菌DNA的寡核苷酸对K562/A02细胞来源的树突细胞促成熟作用

目的 研究源于细菌CpG基序的寡核苷酸和含细菌短磷酸二酯骨架的寡核苷酸对K562/A02细胞来源的树突细胞(DC)的促成熟作用.方法 联合应用细胞因子rhGM-CSF和rhIL-4诱导K562/A02细胞成为DC.7 d后以瑞特-姬姆萨染色观察细胞形态的变化,流式细胞术检测细胞免疫表型的变化,用同种混合淋巴细胞反应、细胞毒性T淋巴细胞(CTL)杀伤活性检测、IL-12和IL-6的分泌实验评价DC的成熟程度.然后在DC中分别加入源于细菌CpG基序的寡核苷酸CpG2006以及含细菌短磷酸二酯骨架的寡核苷酸A-ODN和T-ODN,处理3 d后再次检测该DC成熟度.结果 K562/A02细胞可在细胞因子rhGM-CSF和rhIL-4联合作用下分化成为DC,免疫表型检测发现CD83、HLA-DR和CD86分子的表达分别为(65.5±8.4)%、(32.0±4.3)%和(18.6±3.2)%,经CpG2006作用后表达升高到(88.9±3.6)%、(53.9±3.2)%和(39.9±7.3)%;经A-ODN作用后升高到(97.0±5.3)%、(63.9±7.3)%和(40.2±7.4)%;经T-ODN作用后升高到(93.3±4.6)%、(58.3±5.6)%和(36.2±6.8)%,与作用前相比差异均有统计学意义.经CpG2006、A-ODN和T-ODN作用后具有典型DC形态的细胞增多.上述3种寡核苷酸处理的DC均可刺激T细胞产生较强的增殖效应、诱导产生的CTL对靶细胞K562/A02的杀伤率明显增强,IL-6和IL-12分泌明显增高.结论 源于细菌CpG基序的寡核苷酸以及含细菌短磷酸二酯骨架的寡核苷酸对白血病源性DC有促成熟作用.

Improvement effect of bacterium derived oligonucleotides on maturation of K562/A02 cells derived dendritic cells

OBJECTIVE: To study the maturation effect of CpG2006 and phosphodiester oligonucleotides on leukemia-derived dendritic cells. METHODS: Leukemia cells K562/A02 were induced into dendritic cells by rhGM-CSF and rhIL-4. After 7 days induction, the cell-morphology was observed, the immunophenotype of cells was detected by flow cytometry and the cell function was evaluated by allogeneic mixed lymphocyte reactions, CTL responses and secretion of IL-12 and IL-6. Then a CpG oligonucleotide CpG2006, two synthetic bacterial phosphodiester oligonucleotides A-ODN and T-ODN were added to these leukemia-derived DCs. Three days later, the DCs were redetected by the above-mentioned methods. RESULTS: After induced by CpG2006, A-ODN or T-ODN, the leukemia-derived DCs with typical dendritic morphology were increased. The expressions of CD83, HLA-DR and CD86 were (65.5 +/- 8.4)%, (32.0 +/- 4.3)% and (18.6 +/- 3.2)% respectively in day 7 leukemia-derived DCs, raised to (88.9 +/- 3.6)%, (53.9 +/- 3.2)% and (39.9 +/- 7.3)% respectively after exposing CpG2006 for 3 days; increased to (97.0 +/- 5.3)%, (63.9 +/- 7.3)% and (40.2 +/- 7.4)% respectively after treated by A-ODN; and further increased to (93.26 +/- 4.65)%, (58.3 +/- 5.6)% and (36.2 +/- 6.8)% respectively after treated by T-ODN. These results was markedly different than unaffected cells did. These DCs induced by the above-mentioned three oligonucleotides could upregulate significantly the capacity for stimulating allogeneic T cells. They could also induce CTL to generate specific cytotoxic activity against K562/A02 cells. The secretion of IL-6 and IL-12 was increased remarkably. CONCLUSION: CpG2006, as well as two phosphodiester oligonucleotides can induce leukemia-derived DCs maturation.