糖皮质激素对体外中央记忆性CD8~+ T淋巴细胞的诱导分化作用

目的:以糖皮质激素对人CD8~+ T淋巴细胞的诱导作用为线索,探究其对体外CD8~+ 中央记忆性T淋巴细胞(central memory T cells,T_(CM))的诱导分化作用,以期为CD8~+ T_(CM)过继性免疫疗法提供新的扩增方案。方法:通过密度梯度离心法分离健康人外周血单个核细胞,经磁珠和流式细胞术分选出初始CD8~+ T细胞,将细胞使用细胞因子激活之后分为对照组和实验组,在实验组中加入不同浓度的2种糖皮质激素(醋酸可的松和氢化可的松),进行体外培养,最后通过流式细胞术检测2组细胞中CD8~+ T_(CM)的诱导分化情况,并通过CFSE染色判断细胞增殖情况,通过早期凋亡试剂Annexin V染色判断药物本身对CD8~+ T细胞的毒性作用。结果:浓度梯度实验发现,1μmol/L醋酸可的松对CD8~+ T_(CM)表现出良好的诱导效果,氢化可的松在0.5μmol/L的诱导效果较好。分别在体外培养的第3天和第6天,CFSE染色法检测细胞的增殖情况,经统计学分析发现实验组和对照组之间的差异无统计学显著性,表明糖皮质激素不影响细胞的自然增殖。Annexin V染色法表明,这2种药物无显著的促进凋亡作用,对淋巴细胞毒性小。结论:糖皮质激素在体外对人CD8~+ T_(CM)具有良好的诱导作用。这为改善过继免疫治疗中T_(CM)的体外扩增提供新的参考方法,并且在理论上加深对糖皮质激素生物学功能的理解。

Glucocorticoids enhance differentiation of central memory CD8+ T-lymphocytes in vitro

AIM:To investigate the effect of glucocorticoids, a kind of traditional immunosuppressive drug, on expanding central memory CD8⁺ T cells (CD8⁺ T_CM) and to provide a novel method of generating CD8⁺ T_CM for adoptive immunotherapy.METHODS:Healthy human peripheral blood mononuclear cells were isolated by density gradient centri-fugation. Naïve CD8⁺ T cells were further isolated with MACS microbeads and flow cytometry. After activated by cytokines, the cells were divided into experimental group and control group. Glucocorticoids at different concentrations and an identical volume of PBS were added. The phenotypic characteristics of T_CM in different groups were measured by flow cyto-metry at separate time points. Furthermore, the effect of glucocorticoids on CD8⁺ T cell expansion was further verified using CFSE assay and Annexin V staining.RESULTS:Glucocorticoids significantly increased the proportion of CD8⁺ T_CM in vitro. Glucocorticoids sustained CD8⁺ T cell expansion. Glucocorticoids had low toxicity for CD8⁺ T cells.CONCLUSION:Glucocorticoids effectively increase the number and proportion of CD8⁺ T_CM in vitro, which provides novel insights into the generation of human CD8⁺ T_CM and reveals a novel potential clinical application of glucocorticoids for immunotherapy.