Notch1信号对儿童急性B前体淋巴细胞白血病Foxp3组蛋白乙酰化的影响  

Effects of Notch1 signaling on histone acetylation of Foxp3 gene in children with B-cell precursor acute lymphoblastic leukemia

作　　者：袁秀丽[1] 王国兵[2] 麦惠容[1] 肖海荣[1] 王缨[1] 李长钢[1] 刘四喜[1] Yuan Xiuli;Wang Guobing;Mai Huirong;Xiao Hairong;Wang Ying;Li Changgang;Liu Sixi(Department of Hematology and Oncology,Shenzhen Children′s Hospital,Shenzhen 518038,China)

机构地区：[1]深圳市儿童医院血液肿瘤科,518038 [2]深圳市儿童医院儿科研究所,518038

出　　处：《中华微生物学和免疫学杂志》2021年第11期829-835,共7页Chinese Journal of Microbiology and Immunology

基　　金：广东省医学科学技术研究基金(A2020101);深圳市科技计划项目(JCYJ20170303155916256);深圳市卫生计生系统科研项目(SZLY2018015)。

摘　　要：目的探讨Notch1信号对儿童急性B前体淋巴细胞白血病(BCP-ALL)Foxp3基因组蛋白乙酰化的影响及其在调节性T细胞(Treg)异常机制中的作用。方法初诊治疗前的急性BCP-ALL患儿38例,同年龄健康对照儿童15例,分别取血备检。采用流式细胞术检测外周血CD4+CD25hiFoxp3+Treg细胞比例及Foxp3、细胞毒性T淋巴细胞相关抗原4(cytotoxic T lymphocyte associated antigen 4,CTLA4)、糖皮质激素诱导的肿瘤坏死因子受体(glucocorticoid-induced tumor necrosis factorreceptor,GITR)、CD39、Notch1蛋白表达水平;染色质免疫共沉淀技术检测CD4+T细胞Foxp3基因启动子组蛋白H4乙酰化(H4Ac)及与Notch1受体胞内结合域(Notch1 intracellular domain,NICD1)、p300的结合水平;real-time PCR分析CD4+T细胞Foxp3、早老素1(presenilin 1,PSEN1)、主导控制样蛋白1(mastermind-like transcriptional coactivator 1,MAML1)、SKI交互蛋白(SKI-interacting protein,SKIP)、F-Box和WD40蛋白7(F-box and WD40 domain protein 7,FBXW7)、糖原合成酶3β(glycogen synthase kinase-3 beta,GSK3β)、含锌指结构的转录因子(IKAROS)等mRNA表达水平;ELISA检测血浆中IL-10和TGF-β浓度。结果(1)与对照组比较,BCP-ALL患儿外周血CD4+CD25hiFoxp3+Treg细胞比例、分化及功能相关分子(Foxp3、CTLA4、GITR、CD39)表达水平和血浆IL-10、TGF-β浓度显著增高(P<0.05)。(2)BCP-ALL患者Foxp3基因启动子H4Ac及与NICD1、p300的结合水平明显高于对照组(P<0.05),且与NICD1、p300的结合水平和Foxp3转录呈正相关(r=0.58和0.46,P<0.05)。经竞争性抑制后,BCP-ALL患儿前3项指标均低于未处理组(P<0.05);对照组Foxp3基因启动子与NICD1结合水平显著降低(P<0.05),而另2项指标与未处理对照组比较差异无统计学意义(P>0.05)。(3)与对照组比较,BCP-ALL患儿CD4+T细胞Notch1、PSEN1、MAML1、SKIP表达水平显著升高(P<0.05),负性调节因子FBXW7表达明显降低(P<0.05),GSK3β、IKAROS表达差异无统计学意义(P>0.05)。结论FBXW7表达低下�Objective To investigate the effects of Notch1 signaling on histone acetylation of Foxp3 gene and its roles in regulating regulatory T(Treg)cells in children with acute B-cell precursor lymphoblastic leukemia(BCP-ALL).Methods Blood samples were collected form 38 children with BCP-ALL before treatment and 15 age-matched healthy children(control group).Flow cytometry was performed to detect the proportion of peripheral blood CD4+CD25hiFoxp3+Treg cells and the expression of Foxp3,cytotoxic lymphocyte antigen 4(CTLA4),glucocorticoid-induced tumor necrosis factor receptor(GITR),CD39 and Notch1 at protein level.Histone 4 acetylation(H4Ac)at Foxp3 gene promoter and the binding abilities of Foxp3 gene promoter to NICD1 and p300 in CD4+T cells were measured by chromatin immunoprecipitation.Quantitative real-time PCR was performed to detect the expression of Foxp3,presenilin 1(PSEN1),mastermind-like transcriptional coactivator 1(MAML1),SKI-interacting protein(SKIP),F-box and WD40 domain protein 7(FBXW7),glycogen synthase kinase-3 beta(GSK3β)and IKAROS at mRNA level in CD4+T cells.The concentrations of TGF-βand IL-10 in plasma were evaluated by ELISA.Results(1)The proportion of peripheral blood CD4+CD25hiFoxp3+Treg cells,the expression of differentiation-and function-associated molecules(Foxp3,CTLA4,GITR and CD39)and the concentrations of TGF-βand IL-10 in plasma were higher in the BCP-ALL group than in the control group(P<0.05).(2)In children with acute BCP-ALL,H4Ac at Foxp3 promoter and the binding abilities of Foxp3 gene promoter to NICD1 and p300 were significantly increased as compared with those in control group(P<0.05).The binding abilities of Foxp3 gene promoter to NICD1 and p300 were positively correlated with the expression of Foxp3 at mRNA level(r=0.58 and 0.46,both P<0.05).After competitive inhibition,the three aforementioned indexes in the acute BCP-ALL group were significantly lower than those in untreated group(P<0.05);the binding ability of Foxp3 gene promoter to NICD1 in the control group was also signif

关 键 词：急性B前体淋巴细胞白血病 调节性T细胞 NOTCH1 FOXP3 FBXW7 

分 类 号：R733.71[医药卫生—肿瘤]