Treg细胞在致弱日本血吸虫尾蚴免疫BALB/c小鼠体内表达研究  

Study on expression of Treg cells in attenuated Schistosoma japonicum cercariae immunized BALB/c mice

作　　者：周霞[1] 邱玉华[2] 龚唯[1] 张静[1] 刘晨晨[1] 骆伟[1] 陈明中[3] 诸葛洪祥[1] 

机构地区：[1]苏州大学医学部病原生物学系,苏州215123 [2]苏州大学医学部免疫学系 [3]苏州大学医学部实验中心

出　　处：《中国血吸虫病防治杂志》2011年第5期541-545,F0003,共6页Chinese Journal of Schistosomiasis Control

基　　金：江苏省自然科学基金(BK2009076)

摘　　要：目的分析致弱日本血吸虫尾蚴免疫小鼠与正常感染小鼠体内CD4+CD25+Foxp3+调节性T细胞(Treg细胞)变化差异,探讨其与致弱尾蚴免疫小鼠诱导免疫保护作用间的关系。方法 40只SPF级BALB/c雌性小鼠随即分3组:一组为辐照致弱尾蚴免疫后攻击感染组(A组),一组为直接攻击感染组(B组),每组各16只小鼠;其余8只小鼠作为空白对照。感染后6、8周剖杀小鼠,取小鼠外周血与肝脾组织,采用流式细胞术(FCM)比较A、B两组小鼠脾细胞和外周血单核细胞(PBMC)中CD4+CD25+Foxp3+/CD4+CD25+T细胞比例,分析Treg细胞免疫活化程度;应用免疫组织化学(IHC)法检测Foxp3在小鼠肝脾组织中表达情况。结果攻击感染后第6周,A组与B组小鼠外周血细胞中CD4+CD25+Foxp3+/CD4+CD25+T细胞比例分别为(14.15±2.62)%和(7.92±2.22)%,差异有统计学意义(P=0);脾细胞中分别为(14.52±2.98)%和(8.18±2.84)%,差异亦有统计学意义(P=0)。攻击感染后第8周,两组小鼠外周血中CD4+CD25+Foxp3+/CD4+CD25+T细胞比例分别为(15.92±2.98)%和(13.26±2.64)%,差异有统计学意义(P=0.02);脾细胞中分别为(16.42±2.46)%和(13.48±2.36)%,差异亦有统计学意义(P=0.001)。小鼠肝脾组织IHC结果显示,攻击感染后第6周,A、B两组小鼠肝组织中Foxp3阳性细胞表达评分分别为"+"、"-",脾组织中为"++"、"+";攻击感染后第8周,肝组织中Foxp3阳性细胞表达评分分别为"++"、"-",脾组织中分别为"++"、"+"。结论 CD4+CD25+Foxp3+Treg细胞在辐照致弱日本血吸虫尾蚴免疫小鼠攻击感染中后期的表达高于直接感染对照组,提示CD4+CD25+Foxp3+Treg在致弱尾蚴免疫小鼠攻击感染后处于较稳定水平,并且未在日本血吸虫攻击感染后明显下调,可能与该免疫小鼠发挥免疫保护作用有关。Objective To study the expression differences of CD4＋CD25＋Foxp3＋Treg cells between the attenuated cercariae immunized mice and the normal infected mice and discuss the immune protection mechanisms of the mice immunized with attenuated cercariae.Methods Forty female BALB/c mice were divided into 2 groups,group A,the attenuated cercariae immunized group（16 mices） and the group B,the normal cercariae infected group（16 mices）,and the last 8 ones served as the blank control.The spleen cells and the ratios of PBMC＇s CD4＋CD25＋Foxp3＋/CD4＋CD25＋T cells were compared between the attenuated cercariae immunized mice and normal mice infected by FCM and the Foxp3 expression levels in spleens and livers were assayed by IHC.The transcription factor Foxp3 in the peripheral blood was detected by RT-PCR.Results In group A and group B,CD4＋CD25＋Foxp3＋/CD4＋CD25＋T ratios in the PBMC 6 weeks post-infection were（14.15±2.62）% and（7.92±2.22）%,respectively（P 0.05）;the ratios in the spleen cells were（14.52±2.98）% and（8.18±2.84）%,respectively（P 0.05）;8 weeks post-infection,the ratios in the PBMC were（15.92±2.98）% and（13.26±2.64）%,respectively,（P 0.05）;the ratios of the spleen cells were（16.42±2.46）% and（13.48±2.36）%,respectively（P 0.05）;6 weeks post-infection,the Foxp3 expression levels in livers were ＂＋＂ and ＂-＂,respectively,and those in the spleens were ＂＋＋＂ and ＂＋＂,respectively;8 weeks post-infection,the Foxp3 expression levels in the livers were ＂＋＋＂ and ＂-＂ respectively,and those in the spleens were ＂＋＋＂ and ＂＋＂,respectively.Conclusions The expression level of attenuated cercariae immunized group＇s CD4＋CD25＋Foxp3＋Treg cells is higher than that in the control group during the late stages,suggesting that CD4＋CD25＋Foxp3＋Treg in the attenuated cercariae immunized mice may play one of the important roles in its immune protection mechanisms.

关 键 词：日本血吸虫 致弱尾蚴 调节性T细胞 转录因子FOXP3 免疫调节 

分 类 号：R383.24[医药卫生—医学寄生虫学]