儿童急性B淋巴细胞白血病CD4＋ CD25high Foxp3＋调节性T淋巴细胞异常机制初探  

Changes and regulation mechanism of CD4＋ CD25high Foxp3＋ regulatory T cells in childhood B-cell acute lymphoblastic leukemia

作　　者：肖海荣[1] 王国兵[2] 文飞球[3] 李长钢[3] 王缨[3] 麦惠容[3] 刘四喜[3] 袁秀丽[3] 

机构地区：[1]暨南大学第二临床医学院,深圳518020 [2]深圳市儿童医院儿科研究所 [3]深圳市儿童医院血液肿瘤科

出　　处：《中华实用儿科临床杂志》2014年第3期177-181,共5页Chinese Journal of Applied Clinical Pediatrics

基　　金：广东省自然科学基金（S2011010003434）;深圳市医学重点学科建设基金

摘　　要：目的 探讨儿童急性B淋巴细胞白血病（B-ALL）调节性T淋巴细胞变化及调节机制.方法 B-ALL患儿18例,健康同年龄对照组15例,分别于化疗前直接取血备检.采用荧光实时定量PCR（real-time PCR）检测CD4＋T淋巴细胞Foxp3、CTLA4、GITR、LAG3、IL-2Rβ/γ、IL-6Rα/β、Smad3/4、RUNXl/3等mRNA表达;流式微球阵列术检测血浆中IL-6、TGF-β的蛋白水平;流式细胞术检测外周血CD4＋ CD25high Foxp3＋调节性T淋巴细胞（Treg）的比例及CD4＋T淋巴细胞IL-2Rα、TGF-βRII、pSTAT3、pSTAT5蛋白表达水平.结果 1.B-ALL患儿外周血CD4＋ CD25high Foxp3＋ Treg细胞比例及转录因子Foxp3表达显著升高（P＜0.05）,其抑制功能相关分子CTLA4、GITR、LAG3表达水平亦明显高于对照组（P ＜0.05）;2.B-ALL患儿CD4＋T淋巴细胞IL-2Rα/β及下游信号分子pSTAT5表达升高（P＜0.05）,且pSTAT5表达与CD4＋ CD25high Foxp3＋细胞比例呈正相关（r=0.17,P＜0.05）,IL-2Rγ表达无统计学差异（P ＞0.05）;3.B-ALL患儿外周血TGF-β水平、CD4＋T淋巴细胞TGF-βRⅠ/Ⅱ及下游信号分子Smad3/4表达显著上调（P＜0.05）,但RUNX1/3表达水平低于对照组（P＜0.05）,其中Smad3、RUNX1表达与CD4＋ CD25high Foxp3＋细胞比例均呈正相关（r=0.87、0.60,P＜0.05）.B-ALL患儿外周血IL-6水平明显增高（P＜0.05）,但IL-6Rα/β表达无统计学差异（P＞0.05）,下游pSTAT3表达显著降低（P＜0.05）,且与CD4＋ CD25high Foxp3＋细胞比例呈负相关（r=-0.39,P＜0.05）.结论 儿童B-ALL调节性T淋巴细胞异常可能与IL-2/pSTAT5、TGF-β/Smad信号过度活化及pSTAT3表达不足有关.Objective To investigate the changes and regulation mechanism of CD4＋ CD25high Foxp3＋ regulatory T cells （Treg） in childhood B-cell acute lymphocytic leukemia（B-ALL）.Methods Eighteen children with B-ALL and 15 age-matched healthy children （control group） were studied.Real-time PCR was used to evaluate the mRNA levels of Foxp3,CTLA4,GITR,LAG3,IL-2Rβ/γ,IL-6Rα/β,Smad3/4,RUNX1/3 in CD4-positive cells.Protein concentrations of cytokines in plasma were measured by cytometric bead array.The proportion of CD4＋ CD25high Foxp3＋ Treg and protein levels of associated molecules were analyzed by flow cytometry.Results 1.The proportion of CD4＋ CD25high Foxp3＋ and expression level of Foxp3 in children with B-ALL were higher than those of control group（P 〈 0.05）,and transcription levels of CTLA-4,GITR and LAG3 were elevated,respectively （P 〈 0.05）.2.Compared with control group,expression levels of IL-2Rα/β and its downstream molecules pSTAT5 in CD4-positive cells increased （P〈 0.05）,though no difference of transcription level of IL-2Rγwas found between the 2 groups（P 〉 0.05）.Correlation analysis showed that there was a significant positive correlation between expression levels pSTAT5 and CD4＋ CD25high Foxp3＋ Treg in children with B-ALL（r =0.17,P 〈 0.05）.3.Plasma concentration of TGF-β,expression levels of its receptor TGF-βRⅠ/Ⅱ and downstream molecules Smad3/4 were up-regulated in children with B-ALL（P 〈 0.05）,while expressions of RUNX1/3 were found to be lower than those of controls group（P 〈 0.05）.Both expression levels of Smad3 and RUNX1 were correlated positively with CD4＋ CD25high Foxp3＋ Treg in children with B-ALL（r =0.87,0.60,P 〈 0.05）.Simultaneously,expression levels of pSTAT3 protein in CD4-positive cells decreased in B-ALL children although plasma concentration of IL-6 was found to be higher than that of control group（P 〈 0.05）.A remarkable negative correlation was found between expression level of pSTAT3 and CD4＋ CD25hi

关 键 词：白血病 B细胞 急性 调节性T淋巴细胞 白细胞介素2 白细胞介素6 转化生长因子-Β 

分 类 号：R733.71[医药卫生—肿瘤]