白细胞介素-37在人外周血CD4^+CD25^+调节性T细胞中的表达

Expression of interleukin-37 in human peripheral blood CD4^+ CD25^+ regulatory T cells

目的:观察白细胞介素-37(IL-37)在健康人外周血CD4^+CD25^+调节性T细胞(Treg)中的表达情况。方法:采用免疫磁性分离法分离人外周血CD4^+CD25^+Treg,流式细胞技术分析其分离纯度,观察刺激剂组(每1×10~5个CD4^+CD25^+Treg细胞加入20μl Dynabeads Human Treg Expander)、非刺激剂组、空白对照组(单纯10%FCS-RPMI 1640培养)CD4^+CD25^+Treg细胞增殖活性及其差异。分别采用Western blot和免疫荧光共聚焦技术检测IL-37的表达水平与定位改变。结果:MACS分离人外周血CD4^+CD25^+Treg细胞纯度为93%,台盼蓝染色细胞活性为98%。与非刺激剂组和空白对照组相比,刺激剂组CD4^+CD25^+Treg增殖活性随时间延长而逐渐增加;非刺激剂组与空白对照组其增殖活性差异无显著性。Western blot结果显示,正常CD4^+CD25^+Treg细胞表达IL-37,在刺激剂作用下随作用时间延长IL-37表达量增加。免疫荧光显微镜和免疫荧光共聚焦图像显示,刺激72 h后IL-37在CD4^+CD25^+Treg细胞内明显表达,并且在细胞质中表达丰富,近胞膜处表达密度较高。结论:IL-37在健康人外周血CD4^+CD25^+Treg细胞中表达,当受到有效刺激后IL-37表达明显上升。

Objective：To investigate the expression of interleukin-37 （IL-37）in healthy human peripheral blood CD4＋CD25＋ regulatory T cells （Tregs）.Methods：Magnetic Activated Cell Sorting （MACS）kit was used to seg-regate CD4＋CD25＋Tregs in human peripheral blood,and the purity of CD4＋CD25＋Tregs was determined by flow cytometry. Proliferation activity of CD4＋CD25＋Tregs was measured in expander group （1×105 CD4＋CD25＋Treg were cultured with 20μl Dynabeads（R） Human Treg expander）,non-expander group,and blank control group（cells were cultured with 10%FCS-RPMI 1640）.Meanwhile,the expression of IL-37 in CD4＋CD25＋Tregs was analyzed by laser scanning confocal microscope and Western blot,respectively. Results：The purity of CD4＋CD25＋Tregs was over 93% after being isolated twice by magnetic beads,and the activity of CD4＋CD25＋Tregs exceeded 98%. In comparison with non-expander and blank control groups,proliferation activity in expander group was signifi-cantly increased along with the prolongation of stimulation. However,the non-expander group and blank control goup showed no significant proliferation. With laser scanning confocal microscope and Western blot,it was identi-fied the expression of IL-37 in human CD4＋CD25＋ Tregs. Under the stimulation by expander,the expression of IL-37 in CD4＋CD25＋Tregs was markedly enhanced. In addition,expression of IL-37 was obvious in the cyto-plasm, and its density was found to be high near the cell membrane under laser scanning confocal microscopy.Conclusions：In healthy human peripheral blood,IL-37 can positively express in CD4＋CD25＋Tregs. With the stimulation by expander,the expression of IL-37 might further be enhanced in CD4＋CD25＋Tregs.