CTLA-4Ig融合蛋白对病毒性心肌炎小鼠Foxp3+调节性T细胞的影响  

Effect of CTLA-4 immunoglobulin chimera protein on Foxp3+ regulatory T cells in mice with viral myocarditis

作　　者：陈永芬[1] 韩波[1] 伊迎春[1] 张仪 路康[1] 孙士静[1] 

机构地区：[1]山东大学附属省立医院小儿心脏科,山东济南250021 [2]清华大学第一附属医院小儿心内科,北京100016

出　　处：《临床儿科杂志》2011年第7期665-669,共5页Journal of Clinical Pediatrics

基　　金：山东省科学技术发展计划医药卫生项目资助(No.2009GG10002058)

摘　　要：目的探讨细胞毒T淋巴细胞相关抗原4免疫球蛋白(CTLA-4Ig)对柯萨奇B3病毒(CVB3)病毒性心肌炎(VMC)小鼠的病死率、心肌病理改变、病毒复制和心肌组织中Foxp3+调节性T细胞(Tregs)的影响。方法 106只4～6周龄健康雄性Balb/c小鼠,体质量为12～16 g,随机分为CTLA-4Ig组16只、病毒组40只、IgG组40只及正常对照组10只,CTLA-4Ig组、病毒组和IgG组小鼠腹腔注射半数组织细胞感染量(TCID50)为10-3/L的CVB3 0.15 ml,正常对照组小鼠接种0.15 ml不含病毒的Eagle液。CTLA-4Ig组、IgG组小鼠于接种病毒后6、72 h分别注射CTLA-4Ig(0.1 mg/kg)及IgG(0.1 mg/kg)。接种病毒后第7天处死所有小鼠在光镜下观察心肌病理变化并计算心肌组织病理积分;采用实时荧光定量PCR(RQ-PCR)检测心肌组织中CVB3 mRNA的表达;采用免疫组织化学法检测Foxp3分子在心肌组织中的表达,并计算Foxp3+Tregs所占浸润细胞数的百分率。结果与病毒对照组相比较,CTLA-4Ig组小鼠病死率降低(80%比50%,P<0.05),心肌组织病理积分下降(1.78±1.05比1.00±0.72,P<0.05),心肌CVB3 mRNA表达减少(3.48±2.89比0.81±1.06,P<0.05);CTLA-4Ig组小鼠心肌组织中Foxp3+Tregs所占浸润细胞数的百分率较病毒组明显增加(9.22±2.28)%比(5.42±1.59)%,(P<0.05)。结论 CTLA-4Ig可减轻VMC小鼠心肌炎症,降低心肌病毒复制及病死率,其机制可能与上调Foxp3+Tregs比、抑制T细胞活化有关。Objective To investigate the effect of cytotoxic T-lymphocyto-associated protein 4 immunoglobulin（CTLA-4Ig）on the mortality,viral replication,pathologic changes and Foxp3＋ regulatory T cells（Tregs）of myocardium in mice with viral myocarditis induced by Coxsackievirus B3（CVB3）.Methods One hundred and six 4-6 week old healthy male Balb/c mice with body weight of 12-16 g were divided into CTLA-4Ig group（n = 16）,CVB3 group（n = 40）,IgG group（n = 40）,and normal control group（n = 10）randomly.The mice in CTLA-4Ig group,CVB3 group and IgG group were inoculated intraperitoneally with 0.15 ml CVB3 of 50% tissue culture infective dose（TCID50）at 10-3/L.The mice in normal control group were inoculated intraperitoneally with 0.15 ml eagle reagent which has no CVB3.Then the mice in CTLA-4Ig group and IgG group were injected with CTLA-4Ig（0.1 mg/kg）and IgG（0.1 mg/kg）6 and 72 hours after inoculation,respectively.The mice were sacrificed on day 7 after inoculation.The histopatho-logic changes were observed by light microscope and the myocardial histopathology scores were calculated.The expression of CVB3 mRNA of myocardium was detected by real-time quantitative polymerase chain reaction（RQ-PCR）.The expression of Foxp3 protein in myocardium was determined by immunohistochemistry.The percentage of Foxp3＋ Tregs in infiltrating cells was enumerated by counting under light microscopy.Results Compared with CVB3 group,the mortality（80% vs.50%,P 0.05）,myocardial histopathology score（1.78 ± 1.05 vs.1.00 ± 0.72,P 0.05）and the expression of myocardial CVB3 mRNA（3.48 ± 2.89 vs.0.81 ± 1.06,P 0.05）were significantly lower in CTLA-4Ig group while the percentage of Foxp3＋ Tregs in infiltrating cells was significantly higher in CTLA-4Ig group（9.22% ± 2.28% vs.5.42% ± 1.59%,P 0.05）.Conclusion It is suggested that CTLA-4Ig can relieve myocardial inflammation,decrease myocardial virus replication and mortality in mice with CVB3-induced viral myocarditis.CTLA-4Ig might reduce myoca

关 键 词：病毒性心肌炎 细胞毒T淋巴细胞相关抗原4免疫球蛋白 调节性T细胞 FOXP3 小鼠 

分 类 号：R542.21[医药卫生—心血管疾病]