再生障碍性贫血外周血Th17和CD4+CD25+Treg细胞表达情况研究

摘要

本研究旨在探讨成人再生障碍性贫血(aplastic anemia,AA)外周血Th17和CD4+ CD25+调节性T细胞(Treg)表达情况.45例初发AA患者分为轻型AA(n=25)和重型AA(n =25)两组,15例正常人作为对照.应用流式细胞术检测AA患者外周血中Th17和CD4+ CD25+ Treg的比例,ELISA检测血清及刺激后外周血单个核细胞(PBMNC)上清液中的白介素(IL-17)、γ干扰素(IFN-γ)及肿瘤坏死因子-α(TNF-α)水平,并与正常对照组比较.结果表明:重型AA (SAA)组外周血Th17细胞比例,血清中IL-17及IFN-γ表达高于轻型AA(MAA)和正常人组,而重型AA组外周血CD4+ CD25+ Foxp3+ Treg细胞比例降低.与轻型AA和正常对照相比,重型AA患者单个核细胞培养后上清液中IL-17及IFN-γ表达水平显著增加.AA患者血红蛋白计数与Th17细胞及血清IL-17表达呈负相关,与CD4+ CD25+Treg表达成正相关.结论:重型AA患者外周血Th17细胞应答增强,而CD4+ CD25+ Treg细胞缺乏,贫血的严重程度与外周血Th17/Treg免疫应答失衡密切相关.%This study was aimed to investigate the expression of blood Thl7 and CD4 + CD25 + regulatory T cells (Treg) in the patients with aplastic anemia(AA).Forty-five patients with AA were enrolled into this study,and were divided into mild aplastic anemia(MAA) group (n =25) and severe aplastic anemia group(SAA) (n =20),blood cell count was recorded.15 healthy donors were enrolled as control.Proportions of blood Thl7 and CD4 + CD25 + Treg cells were determined by flow cytometry.The serum levels of IL-17,IFN-γ and TNF-o,as well as their concentrations in culture supematant of phytohemagglutinin (PHA)-stimulated peripheral blood mononuelear cells,were measured by ELISA.The results showed that the proportions of blood Thl7 cells and concentration of blood serum IL-17 and IFN-γ increased in patients with SAA,compared with MAA and normal controls,but CD4 + CD25 + Foxp3 + Treg cells obviously decreased in patients with SAA.The concentrations of IL-17 and IFN-γsignificantly increased in culture supematant of SAA group.Hemoglobin level in the patients with AA negatively correlated with the population of Th17 cells and serum IL-17 level,whereas positively correlated with the expression of CD4 + CD25 + Treg cells.It is concluded that the increased response of Th17 cells and deficiency of CD4 + CD25 + Treg cells present in severe aplastic anemia.The severitv of anemia may be related with the imbalance between Th17 and CD4 + CD25 + Treg cell response.