重组人Flt3配体联合其它细胞因子对免疫细胞的体外抗辐射作用研究

Radioprotective effects of recombinant human Flt3 ligand and other cytokines on immunocytes in vitro

目的 研究重组人Flt3配体 (rhFL)及其他细胞因子在体外对免疫细胞的抗辐射作用及其可能机理。方法 用流式细胞仪分析照射前后外周血单个核细胞 (PBMC)表型及rhFL对受照射PBMC表型的影响。 [3H] TdR测定细胞的增殖能力。PBMC来源贴壁细胞经细胞因子诱导树突状细胞 (DC) ,并观察辐射对诱导DC的影响及rhFL对DC的抗辐射效应 ;用PI AnnexinV、DNALadder分析细胞凋亡。结果 PBMC在体外经 15Gy照射后 ,CD8+ 、CD5 6 + 细胞明显减少 ,照射前细胞培养液中加入 10 0ng mlrhFL ,可促进CD5 6 + 细胞的恢复 ;照射前应用rhFL及照射后联合应用IL 2等细胞因子 ,可促进受照射CD8+ 、CD5 6 + 细胞的恢复 ;rhFL可协同GM CSF、IL 4、TNFα产生DC ,并使DC细胞的数量较常规方法诱导产生的数量增加 6倍 ,而且rhFL对DC分化诱导的辐射抑制作用具有明显的抗性 ;rhFL可抑制照射所致的细胞凋亡。结论 rhFL单独或与其他细胞因子联合应用 ,对人外周血免疫细胞具有明显的抗辐射效应 。

Objective\ To investigate the immunoprotective potential of recombinant human Flt3 ligand (rhFL) and other cytokines on irradiated peripheral blood mononuclear cells (PBMC) in vitro . Methods\ The phenotypes of PBMC were analysed by flow cytometric analysis.The proliferative\|promoting effect of rhFL on irradiated PBMC was measured by 3 H\|thymidine incorporation assay.Dendritic cells (DC) were induced from irradiated PBMC by a cytokine cocktail with or without rhFL.Apoptotic rate of irradiated PBMC was measured with PI\|Annexin V and DNA ladder. Results\ CD8 + and CD56 +cells in PBMC decreased significantly at 24 h and 48 h post\|irradiation.If the PBMC were cultured with rhFL before irradiation and with IL\|2 after irradiation CD8 +,CD56 + cells increased and approached to the non\|irradiated level.The number of DC induced from irradiated PBMC increased by the addition of rhFL.rhFL stimulated the proliferation of the PBMC,but its effect was weaker than that of PHA.Irradiation caused a significant increase of apoptosis in PBMC.Addition of rhFL to the culture reduced apoptosis of PBMC significantly. Conclusion\ rhFL protects the immunocytes in 15 Gy γ\|irradiation treated PBMC from apoposis,so it shows promising irradiation\|protective effects on immune system.\;